

 
Residential Energy Tax Credits: 
Overview and Analysis 
Margot L. Crandall-Hollick 
Analyst in Public Finance 
Molly F. Sherlock 
Specialist in Public Finance 
March 18, 2014 
Congressional Research Service 
7-5700 
www.crs.gov 
R42089 
 
Residential Energy Tax Credits: Overview and Analysis 
 
Summary 
Currently, on their 2013 federal income tax return, taxpayers may be able to claim two tax credits 
for residential energy efficiency: one expired at the end of 2013 and under current law cannot be 
claimed beginning with 2014 tax returns; the other is scheduled to expire at the end of 2016. The 
nonbusiness energy property tax credit (Internal Revenue Code [IRC] §25C) provides 
homeowners with a tax credit for investments in certain high-efficiency heating, cooling, and 
water-heating appliances, as well as tax credits for energy-efficient windows and doors. For 
installations made during 2011, 2012, or 2013, the credit rate is 10% of eligible expenses, with a 
maximum credit amount of $500. The credit available for 2011, 2012, and 2013 was less than 
what had been available during 2009 and 2010, when taxpayers were allowed a 30% tax credit of 
up to $1,500 for making energy-efficiency improvements to their homes. The residential energy 
efficient property credit (IRC §25D), which provides a 30% tax credit for investments in 
properties that generate renewable energy, such as solar panels, is scheduled to remain available 
through 2016. 
Advances in energy efficiency have allowed per-capita residential energy use to remain relatively 
constant since the 1970s, even as demand for energy-using technologies has increased. Experts 
believe, however, that there is unrealized potential for further residential energy efficiency. One 
reason investment in these technologies might not be at optimal levels is that certain market 
failures result in energy prices that are too low. If energy is relatively inexpensive, consumers will 
not have a strong incentive to purchase a technology that will lower their energy costs. Tax credits 
are one policy option to potentially encourage consumers to invest in energy-efficiency 
technologies.  
Residential energy-efficiency tax credits were first introduced in the late 1970s, but were allowed 
to expire in 1985. Tax credits for residential energy efficiency were again enacted as part of the 
Energy Policy Act of 2005 (P.L. 109-58). These credits were expanded and extended as part of the 
American Recovery and Reinvestment Act of 2009 (ARRA; P.L. 111-5). The Section 25C credit 
was extended, at a reduced rate, and with a reduced cap, through 2011, as part of the Tax Relief, 
Unemployment Insurance Reauthorization, and Job Creation Act of 2010 (P.L. 111-312). At the 
end of 2012, the 25C credit was extended for 2012 and 2013 by the American Taxpayer Relief 
Act (ATRA; P.L. 112-240). 
Although the purpose of residential energy-efficiency tax credits is to motivate additional energy-
efficiency investment, the amount of the investment resulting from these credits is unclear. 
Purchasers investing in energy-efficient property for other reasons—for example, concern about 
the environment—would have invested in such property absent tax incentives, and hence stand to 
receive a windfall gain from the tax benefit. Further, the fact that the incentive is delivered as a 
nonrefundable credit limits the provision’s ability to motivate investment for low- and middle- 
income taxpayers with limited tax liability. The administration of residential energy-efficiency tax 
credits has also had compliance issues, as identified in a recent Treasury Department Inspector 
General for Tax Administration (TIGTA) report.  
There are various policy options available for Congress to consider regarding incentives for 
residential energy efficiency. One option is to let the existing tax incentives expire as scheduled. 
Another option would be to repeal these tax credits (as proposed in Chairman Camp’s tax reform 
proposal). A third option would be to extend or modify the current tax incentives. Finally, 
policymakers could replace the current tax credits with a grant or rebate program—the Home Star 
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Residential Energy Tax Credits: Overview and Analysis 
 
Energy Retrofit Act of 2010 (H.R. 5019/S. 3177 in the 111th Congress), for example. Grants or 
rebates could be made more widely available, and not be limited to taxpayers with tax liability. 
Enacting a grant or rebate program, however, would have additional budgetary cost. 
 
Congressional Research Service 
Residential Energy Tax Credits: Overview and Analysis 
 
Contents 
Introduction ...................................................................................................................................... 1 
Current Law ..................................................................................................................................... 3 
The Economic Rationale for Residential Energy-Efficiency Tax Credits ....................................... 4 
Market Failures and Market Barriers ......................................................................................... 4 
How Tax Credits May Address Market Failures and Market Barriers ...................................... 6 
Analysis of Residential Energy Tax Credits .................................................................................... 7 
Efficiency: Do Tax Credits Motivate Residential Energy-Efficiency Investments?.................. 8 
Equity: Who Benefits from Residential Energy Tax Credits? ................................................... 9 
Administration: Are Energy-Efficiency Tax Credits Administratively Simple and 
Transparent? ......................................................................................................................... 11 
Policy Options ............................................................................................................................... 12 
Allow Tax Credits to Expire as Scheduled .............................................................................. 13 
Extend or Modify Current Tax Incentives ............................................................................... 13 
Replace Tax Credits with Grants or Rebates ........................................................................... 14 
 
Figures 
Figure 1. U.S. Energy Consumption by Sector ................................................................................ 1 
Figure 2. Residential Energy Use Trends ........................................................................................ 2 
Figure 3. Distribution of the Residential Energy Tax Credits by Claimants and Credit 
Amount, 2011 ............................................................................................................................. 11 
 
Tables 
Table 1. Residential Energy-Efficiency Tax Credits in 2014 ........................................................... 3 
Table 2. Distribution and Average Amount of Residential Energy Tax Credits, 
by Adjusted Gross Income, 2011 ................................................................................................ 10 
Table A-1. Nonbusiness Energy Property Tax Credit (§25C) ........................................................ 15 
Table A-2. Residential Energy Efficient Property Tax Credit (§25D) ........................................... 16 
Table B-1. Residential Energy Credits Claimed and Average Amount, 2006-2010 ...................... 19 
Table B-2. Overview of Legislative Changes to the Nonbusiness Energy Property Tax 
Credit (§25C), 2005-2012 ........................................................................................................... 21 
Table B-3. Overview of Legislative Changes to Residential Energy-Efficient Property Tax 
Credit (§25D), 2005-2010 .......................................................................................................... 22 
Table C-1. Revenue Losses Associated with Residential Energy-Efficiency Tax 
Incentives, 2008-2017 ................................................................................................................ 23 
 
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Residential Energy Tax Credits: Overview and Analysis 
 
Appendixes 
Appendix A. Specifications for Property Eligible for Residential Energy-Efficiency Tax 
Credits ......................................................................................................................................... 15 
Appendix B. Legislative History ................................................................................................... 17 
Appendix C. Budgetary Impact of Residential Energy Tax Incentives ......................................... 23 
 
Contacts 
Author Contact Information........................................................................................................... 24 
 
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Residential Energy Tax Credits: Overview and Analysis 
 
Introduction 
Residential energy efficiency can benefit consumers through reduced utility bills, and support 
national environmental policy objectives by reducing the demand for electricity generated using 
fossil-fuels and reducing current strains on the electric power grid. Various policies to increase 
conservation and energy efficiency have been adopted since the 1970s, including tax incentives.1 
Developing and deploying technologies that are consistent with the most efficient use of our 
nation’s energy resources is broadly appealing. What remains unclear, however, is what set of 
policy tools the federal government should employ to meet energy-efficiency objectives.  
In 2011, 22% of total energy consumed in the United States was consumed by the residential 
sector (see Figure 1). Residential-sector energy use has been increasing over time, with the 
residential sector today consuming roughly 8% more energy in 2011 than in 2000. Residential 
energy use per capita, however, has remained relatively constant since the 1970s (see Figure 2). 
Thus, while overall demand for energy in the residential sector has increased with population 
growth, efficiency gains have allowed residential energy use per capita to remain relatively flat 
even as consumers increasingly use energy-demanding technologies.  
Figure 1. U.S. Energy Consumption by Sector 
(2011) 
 
Source: U.S. Energy Information Administration, Annual Energy Review, September 2012.  
Notes: Total energy consumption in each end-use sector includes primary energy consumption, electricity retail 
sales, and electrical system energy losses.  
                                                 
1 Policies that have been adopted to support energy efficiency and conservation, that are beyond the scope of this 
report, include research and development (R&D) funding, pilot programs, and efficiency standards and mandates. 
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Residential Energy Tax Credits: Overview and Analysis 
 
Figure 2. Residential Energy Use Trends 
(1949–2011) 
 
Source: U.S. Energy Information Administration, Annual Energy Review, September 2012. 
Although energy-efficiency gains have been made in recent decades, experts suggest that a large 
potential for increased energy efficiency in the residential sector remains.2 Despite this potential, 
concerns remain that consumers may not invest in the optimal level of energy efficiency. If this 
potential for enhanced energy efficiency is realized in the coming decades, residential energy use 
trends could change, perhaps leading to reduced residential energy use per capita over time. 
However, population growth may still result in continued increases in total residential energy use. 
This report explores one policy option for promoting residential energy efficiency: tax credits. It 
begins by providing an overview of the current residential energy-efficiency tax credits3 
(appendices to this report provide a more detailed legislative history). The report then goes on to 
provide an economic rationale for residential energy-efficiency tax incentives, introducing the 
concept of “market failures” and “market barriers” which may lead to suboptimal or 
“economically inefficient” investment in energy-efficiency technologies. That section 
summarizes various market failures and market barriers in the residential energy sector and 
outlines ways tax incentives correct them. The final sections of this report provide an economic 
                                                 
2 For example, see Hannah Choi Granade, John Creyts, and Anton Derkach et al., Unlocking Energy Efficiency in the 
U.S. Economy, McKinsey & Company, July 2009, http://www.mckinsey.com/Client_Service/
Electric_Power_and_Natural_Gas/Latest_thinking/Unlocking_energy_efficiency_in_the_US_economy.aspx. 
3 The terms “residential energy-efficiency credits” and “residential energy credits” are used interchangeably in this 
report. The Internal Revenue Service refers to these credits as “residential energy credits.” 
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analysis of the primary tax incentives for residential energy efficiency and briefly review various 
policy options.  
Current Law 
In 2013, taxpayers are eligible to claim tax credits for expenditures related to residential energy-
efficiency and residential renewable-energy generation technologies. The first credit, the 
nonbusiness energy property tax credit (IRC §25C), allows taxpayers to claim a tax credit for 
energy-efficiency improvements they make to the building envelope (insulation, windows, doors) 
of their primary residence and for the purchase of high-efficiency heating, cooling, and water-
heating appliances they purchase for their primary residence.4 The amount of the credit is 
calculated as 10% of expenditures on building envelope improvements plus the cost of each 
energy-efficient property capped at a specific amount (ranging from $50 to $300), excluding 
labor and installation costs. Given the price of high-efficiency heating, cooling, and water-heating 
appliances, taxpayers generally claim the maximum amount of the credit for energy-efficient 
property. The maximum value of the credit is capped at $500. This cap applies to claims for the 
Section 25C credit made in the current year, as well as those made in the prior tax year. In other 
words, if a taxpayer claimed $500 or more of the Section 25C credit prior to 2013, they cannot 
claim it in 2013. Table 1 summarizes eligibility requirements for residential energy-efficiency tax 
credits in 2013. 
Table 1. Residential Energy-Efficiency Tax Credits in 2014 
 
Section 25C Credit 
 Section 25D Credit 
Calculation of credit 
10% of Qualifying Energy-Efficiency 
30% of Energy Efficient Property  
Improvements + Qualifying Energy 
Property  
Types of Qualifying 
Qualifying Energy-efficiency 
Energy Efficient Property 
Property 
Improvements  
(1) Solar Electric 
(1) Insulation 
(2) Solar Water Heating 
(2) Windows (Including Skylights) 
(3) Fuel Cell: $500 per 0.5kW of Capacity 
(3) Doors 
(4) Smal  Wind Energy 
(4) Qualifying Metal Roof 
(5) Geothermal Heat Pumps 
(5) Asphalt Roof with Cooling Granules 
 
Energy Property and Associated Caps
(1) Electric Heat Pump; Central Air 
Conditioner; Natural Gas, Propane, or Oil 
Water Heater; Biomass Stove: $300 
(3) Natural Gas, Propane or Oil Furnace or 
Hot Water Boiler: $150 
(4) Advanced Main Air Circulating Fan: $50 
Credit Cap 
$200 for windows (lifetime cap) 
None 
$500 (lifetime cap) 
Scheduled Expiration 
Expired on December 31, 2013 
December 31, 2016 
Source: CRS analysis of P.L. 109-58, P.L. 109-432, P.L. 110-343, P.L. 111-5 P.L. 111-312, and P.L. 112-240. 
                                                 
4 This residence must be an existing home, not a new home.  
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The second credit, the residential energy efficient property tax credit (IRC §25D), allows 
taxpayers to claim a tax credit for properties that generate renewable energy (e.g., solar panels, 
geothermal heat pumps, small wind energy, fuel cells) that they install on their residence.5 The 
amount of the credit is calculated as 30% of expenditures on technologies that generate renewable 
energy, including labor and installation costs. The maximum value of the Section 25D credit for 
renewable-energy-generating technologies other than fuel cells is not capped.6 The Section 25C 
credit is scheduled to expire at the end of 2013, whereas the Section 25D credit is scheduled to 
expire at the end of 2016.7 For more detailed information on the Section 25C and Section 25D 
credits, including eligible energy-efficiency property specifications, see Appendix A. A 
comprehensive legislative history of these credits can be found in Appendix B. 
The Economic Rationale for Residential 
Energy-Efficiency Tax Credits 
A rational consumer would be expected to invest in an energy-efficiency technology if the 
savings that resulted from using the property were greater than the cost of the property. For 
example, if insulation was expected to lower home-heating costs to such an extent that the 
homeowner fully recovered the costs of the insulation through lower heating bills, the homeowner 
would be expected to make this purchase. However, some consumers appear to forgo making 
these investments, which is known as the “energy-efficiency paradox.”  
Various economic theories may help explain why consumers do not invest in the optimal amount 
of residential energy efficiency. Certain “market failures” related to both the production and 
consumption of energy may help explain why consumers do not make more investments in 
energy-efficiency technologies, such that the optimal or “economically efficient” number of 
consumers use these technologies. In addition to these market failures, other market barriers to 
investment in residential energy efficiency have been identified.8 The Section 25C and Section 
25D credits do not directly correct for some of the market failures and market barriers discussed 
below, which may limit their impact on increasing energy efficiency.  
Market Failures and Market Barriers 
There are a variety of reasons why consumers may not make optimal investments in residential 
energy efficiency. Market failures, including both externalities and principal-agent problems, 
provide one possible explanation. Other market barriers, including capital market imperfections 
                                                 
5 For all technologies, except fuel cells, the credit can be claimed for installations of renewable-energy-generating 
technologies made to any of the taxpayers’ residences, not just a principal residence. Eligible fuel cell installation must 
be made on a taxpayer’s primary residence. 
6 The credit for fuel cells is called at $500 per 0.5W of power capacity. 
7 The renewable-energy-generating technology must be placed in service before December 31, 2016. 
8 As part of the Energy Policy Act of 2005 (P.L. 109-58), Congress established an advisory committee to study this 
issue. In 2007, the advisory committee released a report, Carbon Lock-In: Barriers to Deploying Climate Change 
Mitigation Technologies. An analysis of this report can be found in CRS Report R40670, Energy Efficiency in 
Buildings: Critical Barriers and Congressional Policy, by Paul W. Parfomak, Fred Sissine, and Eric A. Fischer. This 
report presents market barriers likely to prevent efficient adoption of energy-efficient technologies, drawing on both the 
Carbon Lock-In report and the economics literature on energy-efficient technology adoption.  
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and informational issues, may also help explain suboptimal investment in residential energy 
efficiency.  
Energy consumption externalities are a potential reason why markets may underallocate resources 
for residential energy-efficiency investment. Broadly, an externality is a cost or benefit associated 
with a transaction that is not reflected in market prices. Specifically, residential electricity 
consumption may be associated with negative environmental externalities, such as pollution 
costs. If electricity prices do not reflect any potential negative environmental consequences of 
electricity production, consumers do not pay the full cost associated with consuming electricity. 
These lower prices lead consumers to consume more electricity than is optimal, and to 
underinvest in energy efficiency.9 
Conversely, the adoption of newly developed energy-efficient technologies may result in positive 
externalities via “knowledge spillover” effects. For example, if one homeowner pays for and 
installs a new type of solar panel on his home, his neighbors may see this technology, learn about 
it, and be more likely to adopt it themselves.10 These knowledge spillover effects mean that, in 
addition to the benefits to each individual consumer, the adoption of emerging technologies has a 
greater benefit to society as a whole. Since markets fail to consider the benefits associated with 
knowledge spillover effects, more of the technology should be adopted than is adopted under the 
market forces of supply and demand.11 
Another type of market failure, the principal-agent problem, can occur when there is a disconnect 
between the incentives for those making energy-efficient property purchasing decisions (the 
agent) and the ultimate energy consumer (the principal). For example, in non-owner-occupied 
housing, landlords (agents) may underinvest in energy efficiency when tenants (principals) pay 
the utility bills.12 Builders of new homes may also install lower-cost, less efficient technologies if 
they do not believe the cost of installing high-efficiency products can be recovered when the 
property is sold. Since the landlord and the builder make decisions regarding the level of energy-
efficiency investment, without knowing the energy use patterns of the end user (the tenant or 
homebuyer), landlords and builders may not invest in the optimal amount of energy efficiency.  
Capital market imperfections may also lead households to underinvest in energy-efficiency 
property. Oftentimes, investments in energy efficiency involve high initial costs, followed by a 
flow of savings. Purchasers unable to obtain funds up front may purchase less expensive, less 
efficient alternatives. Low-income households tend to be more credit constrained, and therefore 
more likely to settle for less energy-efficient alternatives when unable to borrow cash up front.13  
                                                 
9 As an example, consider an individual running an energy-using appliance, such as an air conditioner. While the 
individual may consider the impact of the air conditioner on their electricity bill, they are unlikely to think about the 
CO2 emissions associated with generating the electricity necessary to power the air conditioner. If carbon emissions are 
not priced, and parties involved in transactions involving carbon emissions do not pay for the environmental cost of 
such emissions, the market outcome will result in a higher level of emissions than is socially optimal. 
10 Knowledge spillover benefits are most likely to result when consumers are considering adoption of new 
technologies. Many of the products currently eligible for energy-efficiency tax incentives incorporate technologies that 
have been available for a number of years, and are thus not new to the market. 
11 Adam B. Jaffe, Richard G. Newell, and Robert N. Stavins, “Technology Policy for Energy and the Environment,” in 
Innovation Policy and the Economy, ed. Adam B. Jaffe, Josh Lerner, and Scott Stern, 4th ed. (Cambridge, MA: The 
MIT Press, 2004), pp. 35-68. 
12 This assumes that landlords are not able to capture the benefits of greater energy efficiency through higher rents.  
13 Low income borrowers that are given loans are likely to face higher interest rates. Since low income individuals face 
(continued...) 
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Finally, when consumers lack information about energy-saving technologies, they may be 
unaware of the opportunity to make such investments. If consumers have some, but not all the 
information relevant to make investments in energy-efficiency technologies, they may still be less 
willing to make these purchases. For example, uncertainty about future energy prices may make 
consumers reluctant to make irreversible energy-property investments.  
How Tax Credits May Address Market Failures and 
Market Barriers 
Various government policies can be used to enhance the functioning of markets in the face of 
market failures or market barriers. Tax incentives are one option. Other policy options, which are 
beyond the scope of this report, might include non-tax incentives, such as grants, rebates, or 
credit enhancements. (Although one particular grant program, Energy Star, is briefly discussed as 
a policy option at the end of this report, a comprehensive analysis of this policy option is not 
provided in this report.) The government may also choose to address energy market failures using 
regulations or mandates. Governments can also support investments in energy efficiency through 
informational programs (e.g., the Energy Star labeling program). 
Policymakers can attempt to correct negative externalities associated with residential energy 
consumption by using tax credits like the Section 25C and Section 25D credits to lower the cost 
of energy-efficiency investments, thereby motivating additional investment in these technologies. 
Other tax incentives not discussed in this report, like the energy-efficient appliance manufacturer 
credit (IRC §45M), which lowers the cost of producing energy-efficient appliances (known as a 
“supply-side” incentive), may also bring down the cost of certain technologies. (For a list of 
residential energy-efficiency tax incentives, see Appendix C, Table C-1.) By encouraging 
additional investment, the availability of tax credits may also address the positive externalities 
that result from energy-efficiency technologies in terms of increased awareness about these 
technologies. Governments can also increase knowledge about technologies with information 
programs like the Energy Star labeling program.  
However, if markets underinvest in energy efficiency because electricity prices are artificially 
low, tax credits are not the most economically efficient policy option for increasing energy-
efficiency investment. Tax credits result in federal revenue losses and can provide windfall gains 
to taxpayers. The most efficient way to increase investment in energy efficiency under these 
circumstances would be to allow electricity prices to fully reflect electricity costs. This could be 
done by removing existing federal financial support for electricity (e.g., energy-related tax 
subsidies) or by taxing electricity production that generates external costs not currently reflected 
in market prices. Increasing the price of electricity such that consumers face the full costs 
associated with electricity consumption would encourage increased investment in energy-
efficiency technologies. 
Most currently available tax incentives for residential energy efficiency do not directly address 
the principal-agent problem discussed earlier. The Section 25C and Section 25D credits are not 
available to renters, and thus do not directly encourage renters to invest in residential energy 
                                                                  
(...continued) 
higher interest rates, they are likely to use a higher discount rate when evaluating energy-saving investments. When 
evaluated using a higher discount rate, fewer projects will appear to have long-run cost savings.  
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efficiency. Further, since the Section 25C and Section 25D credits cannot be claimed for 
investments made to rental property, landlords do not benefit from incentives designed to 
encourage residential energy-efficiency investments. Other tax incentives not discussed in this 
report, like the tax credit for energy-efficient new homes (IRC §45L), more directly address 
potential principal-agent problems in the market for new homes.  
Tax credits, which may be claimed several months after eligible purchases are made, will have 
limited effect in overcoming capital market imperfections for homeowners who may be unable to 
secure credit to pay for the upfront costs associated with energy-efficient technologies. Although 
tax incentives for residential energy efficiency do reduce the cost of investment, tax credits may 
not be the most effective policy option for providing immediate savings to consumers that are 
credit constrained.14  
Finally, in cases where consumers lack information about energy efficient technologies, and 
additional information is not fully effective at alleviating this market failure, policies that 
subsidize efficiency, like tax credits, may be beneficial and increase the adoption of these 
technologies, thereby increasing societal welfare. However, recent research suggests that such 
policies might decrease total welfare if adopted by those who are well-informed about energy 
efficiency. For such consumers, tax credits will not be necessary to encourage them to make 
energy efficient investment, and will instead provide a windfall gain to the recipients.15 Hence, 
according to this research, tax credits will be of the greatest benefit when they target consumers 
subject to the largest energy inefficiencies.  
Although the two tax credits analyzed in this report are designed to encourage additional 
investment in residential energy-efficient property in existing homes, they may not rectify other 
existing market failures, limiting their ability to increase usage of energy-efficient technologies to 
their optimal or economically efficient levels.  
Analysis of Residential Energy Tax Credits 
The following sections provide a brief economic analysis of the Section 25C and Section 25D tax 
credits, evaluating their behavioral effects on increasing investment, their fairness or equity, and 
potential administrative issues. From an economic standpoint, tax incentives are effective if they 
succeed in causing taxpayers to engage in the desired behavior. In the case of residential energy-
efficiency tax benefits, it is not clear how effective such tax credits are at causing additional 
investment, as opposed to rewarding consumers that would have made investments absent tax 
incentives. Residential energy tax credits also tend to benefit higher-income taxpayers, an issue 
which is explored in detail below. Finally, the Treasury Inspector General for Tax Administration 
(TIGTA) has identified administrative issues with the current tax benefits for residential energy 
efficiency. The results of their report are also summarized below.  
                                                 
14 As an alternative, grants or rebates that reduce the cost of energy-efficient property at the time of purchase are a more 
direct mechanism for reducing upfront costs. If capital market imperfections are preventing investment in energy-
efficient technologies, a consumer loan program would be a more direct option for addressing this market barrier. 
15 For more information, see Hunt Allcott and Michael Greenstone, “Is There An Energy Efficiency Gap?,” NBER 
Working Paper Series , January 2012, Working Paper 17766, http://www.nber.org/papers/w17766.pdf?new_window=
1.  
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Efficiency: Do Tax Credits Motivate Residential 
Energy-Efficiency Investments? 
The goal of residential energy-efficiency tax credits is to encourage individuals to increase 
residential energy-efficiency investments. From the government’s perspective, these tax policies 
are successful if tax credits cause additional residential energy-efficiency investment. If, however, 
tax credits simply reward consumers for investments that would have been made absent such tax 
incentives, then the tax incentives are not achieving the policy goal. Tax credits that reward 
consumers for residential energy-efficiency investments, rather than lead consumers to make 
additional residential energy-efficiency investments, provide a windfall gain to credit recipients 
without resulting in additional economy-wide energy-efficiency investment or reduced energy 
consumption.  
Concerns that tax credits for residential energy efficiency may not generate additional investment 
were raised when such credits were first introduced in the 1970s. In 1979, one year after 
residential energy tax credits were first introduced, several Members of Congress voiced their 
reservations about these tax credits in a series of House Ways and Means hearings on President 
Carter’s proposals to expand residential energy tax benefits. During one of these hearings, 
Representative Bill Frenzel remarked, 
I am nervous about tax credits. The principal tax credit bill we passed last year does not seem 
to have given great incentive in the marketplace. The drain on Treasury has been less than 
we expected because people did not flock to take advantage of it. The tax credit tends to be a 
reward for economic action that was forced by other factors. The tax credit does not 
motivate, but rather simply occurs at the end of the year when the fellow finds out there was 
a tax credit available. And I do not think that is a very efficient and effective stimulus.16 
Empirical evidence evaluating whether the residential energy tax credits available in the late 
1970s and early 1980s caused additional investment in energy-efficiency property is mixed. 
Although some researchers found that tax incentives that reduced the price of energy-efficiency 
property would lead to additional investment,17 others found that the tax credits were instead 
more likely associated with windfall gains to credit recipients as opposed to additional energy-
efficiency investment.18 Whether tax credits can result in additional energy-efficiency investment 
remains an issue to be considered by policymakers evaluating options for encouraging enhanced 
residential energy-efficiency investment.  
There are several reasons why residential energy tax credits may not have a significant impact on 
purchasing decisions for many consumers. First, consumers investing in residential energy-
efficiency improvements may be responding to other market incentives, such as the high price of 
energy. For the consumer that would have invested in residential energy-efficiency property 
without the tax incentive, federal revenue losses associated with the tax credit are windfall gains 
                                                 
16 U.S. Congress, House Committee on Ways and Means, The President’s Energy Program, Phase III, committee print, 
96th Cong., 1st sess., July 1979, p. 317. 
17 See Kevin A. Hassett and Gilbert E. Metcalf, “Energy Tax Credits and Residential Conservation Investment: 
Evidence from Panel Data,” Journal of Public Economics, vol. 57, no. 2 (June 1995), pp. 201-217. 
18 See Michael J. Walsh, “Energy Tax Credits and Housing Improvement,” Energy Economics, vol. 11, no. 4 (October 
1989), pp. 275-284 and Jeffery A. Dubin and Steven E. Henson, “The Distributional Effects of the Federal Energy Tax 
Act,” Resources and Energy, vol. 10, no. 3 (1988), pp. 191-212. 
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to the consumer. Second, savings associated with tax credits are not realized until tax returns are 
filed, often months after energy-efficiency property is purchased. This reduces the incentive 
power of the credit. Third, tax credits only reduce the price of investment in residential energy-
efficiency property for taxpayers having income tax liability to offset with credits. Estimates 
suggest that in 2011, 46% of U.S. households will have no federal income tax liability, meaning 
that tax credits for energy-efficiency investment do not provide a current financial incentive for 
such investments for these taxpayers.19  
Tax incentives for residential energy efficiency are most likely to motivate energy-efficiency 
investments for certain types of taxpayers. As noted above, tax incentives only create a financial 
incentive for investment for taxpayers with tax liability. Thus, higher-income taxpayers are more 
likely to benefit from residential energy-efficiency tax incentives. Higher-income taxpayers are 
also more likely to be motivated to invest in residential energy efficiency through tax incentives. 
Tax credits may also motivate those already in the market for energy property to make more 
efficient choices. If consumers choose to invest in certain residential energy-efficiency 
equipment, such as heating and cooling property, only when existing units are no longer 
operational, tax credits might motivate the purchase of high-efficiency units amongst taxpayers 
with tax liability.  
Equity: Who Benefits from Residential Energy Tax Credits? 
The purpose of residential energy-efficiency tax incentives is to increase investment in energy 
efficiency and properties that generate renewable energy. For these tax credits to be effective, 
they must be targeted at individuals and households that make choices regarding energy property 
investments. For residential credits, the target population is homeowners. Taxpayers that are 
homeowners tend to be higher income than taxpayers living in renter-occupied housing.20 Hence, 
it would be expected that energy tax incentives targeted at homeowners would tend to benefit 
higher-income taxpayers.  
This is borne out in tax data, as residential energy-efficiency tax credits are predominantly 
claimed by middle-and upper-income taxpayers (see Table 2 and Figure 3). In 2011, roughly 
three-quarters (73.2%) of residential energy tax credits claims were made on tax returns with 
adjusted gross income (AGI) above $50,000.21 In addition, these tax units claimed 81.7% of the 
total value of residential credits in 2011. Although tax units with incomes below $50,000 
compose nearly two-thirds (65.4%) of all tax units, approximately one-quarter (26.8%) of tax 
units in this income class claim residential energy tax credits, claiming less than 19% of the total 
value of these credits. In addition, as a tax unit’s income rises, the average amount of its 
residential credit also rises, such that tax units with the highest income level receive on average a 
credit that is more than eight times the average credit value for the lowest income tax unit. 
                                                 
19 See Rachel Johnson, James Nunns, and Jeffrey Rohaly et al., Why Some Tax Units Pay No Income Tax, Tax Policy 
Center: Urban Institute: Brookings Institution, July 2011, http://www.taxpolicycenter.org/UploadedPDF/1001547-
Why-No-Income-Tax.pdf; and CRS Report R41362, Who Doesn’t Pay Income Taxes?, by Thomas L. Hungerford. 
20 According to the American Housing Survey, in 2009 the median income of homeowners was $60,000 compared to 
$28,400 for renters.20 
21 In this section, tax returns and tax units are used interchangeably and include returns with no taxable income. A tax 
unit is not necessarily an individual, but represents all the individuals included on an income tax return including 
spouses and dependents. 
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Residential Energy Tax Credits: Overview and Analysis 
 
Table 2. Distribution and Average Amount of Residential Energy Tax Credits, 
by Adjusted Gross Income, 2011 
Percentage of Tax 
Percentage of 
Returns Claiming 
Total Amount of 
Adjusted Gross 
Percentage of All 
Residential 
Credit (Revenue 
Average Amount 
Income 
Tax Returns 
Credits 
Loss) 
of Credit 
$0-$15K 26.5% 
1.0% 
0.4%  $193.85 
$15K-$30K 21.4% 
7.8% 
4.3%%  $255.82 
$30K-$50K 
17.5% 17.9% 13.5% $345.37 
$50K-$75K 
13.0% 22.2% 14.5% $299.55 
$75K-$100K 8.2% 
18.1% 
15.8% 
$400.99 
$100K-$200K 
10.2% 25.8% 29.3% $521.77 
$200K and above 
3.2% 
7.0% 
22.2% 
$1,454.01 
TOTAL 
100.0% 100.0% 100.0% $460.06 
Source: CRS calculations based on the 2011 IRS Statistics of Income (SOI) data, Table 3.3, http://www.irs.gov/
taxstats/indtaxstats/article/0,,id=96981,00.html. 
Note: Items may not sum to 100% due to rounding.  
The non-refundability feature of the Section 25C and Section 25D tax credits may limit who can 
claim these tax benefits. By definition, the value of a nonrefundable credit cannot exceed a 
taxpayer’s tax liability. Although the Section 25D tax credit can be carried forward to offset tax 
liability in future years, the Section 25C credit cannot be carried forward. Thus, taxpayers without 
sufficient tax liability in the current year cannot benefit from the Section 25C credit. Taxpayers 
that eliminate their tax liability through claims of other tax incentives, such as those for the 
working poor, child-related tax incentives, and education tax benefits, are not able to benefit from 
certain tax-related residential energy-efficiency incentives. 
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Residential Energy Tax Credits: Overview and Analysis 
 
Figure 3. Distribution of the Residential Energy Tax Credits 
by Claimants and Credit Amount, 2011 
 
Source: CRS calculations based on the 2011 IRS Statistics of Income (SOI) data, Table 3.3, http://www.irs.gov/
taxstats/indtaxstats/article/0,,id=96981,00.html. 
Residential energy-efficiency tax incentives tend to be limited to higher-income taxpayers which 
may undermine one of the policy rationales behind using tax credits to motivate energy-efficiency 
investments. If households are not investing in energy-efficiency property because of the high up-
front costs, and because these households are credit constrained, then tax credits that reduce this 
cost might encourage additional investment. However, if the tax credits are available only to 
higher-income households, households that are less likely to be credit constrained, then tax 
incentives may not be the most effective policy option for addressing this market barrier.  
Administration: Are Energy-Efficiency Tax Credits 
Administratively Simple and Transparent?  
An ideal tax code would be simple for taxpayers to comply with while also being simple for the 
government to administer. Taxpayers are more likely to claim tax benefits where compliance 
costs are low. If filing for certain tax benefits becomes too burdensome, eligible taxpayers might 
elect not to claim certain tax benefits, and therefore not respond to certain incentives delivered 
through the tax code.  
There may be a trade-off, however, between allowing for tax credits with little reporting 
requirements and overall taxpayer compliance. In April 2011, the Treasury Department’s 
Inspector General for Tax Administration (TIGTA) released a report on the residential energy tax 
credits which found that the processing of these credits provided numerous opportunities for 
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fraud.22 Specifically, TIGTA found that the IRS could not verify whether individuals that claim 
either the Section 25C or Section 25D residential credit actually made qualifying energy 
modifications to their homes and whether the modifications they made were for their residence.  
The IRS was unable to confirm that claimants of these credits are eligible for them when income 
tax returns were processed because they do not require taxpayers to provide information about the 
residences where they are installed, nor do they require third-party verification (i.e., receipts) that 
qualifying expenses were incurred. Prior to the issuance of the 2011 tax form (filed in 2012), the 
form that taxpayers used to claim both of these credits, IRS Form 5695, did not ask taxpayers for 
any information that would confirm their eligibility for these credits. As a result, TIGTA was 
unable to confirm that 30% of taxpayers in their sample23 who claimed the credits were even 
homeowners. The TIGTA report also noted that analysis of 2009 tax returns indicated that 5% of 
tax returns claiming these credits did not show any indication of homeownership.  
The IRS updated Form 5695 beginning with the 2011 tax year to request additional information 
about the taxpayer’s home where the energy efficiency improvements take place. For example, 
for the 25C credit, the form now asks taxpayers if the residential energy costs are for the 
taxpayer’s main home in the United States. The form also requests the address of the home where 
the residential energy efficiency improvements were made, as well as confirmation that the home 
is an existing (not newly constructed) home. While taxpayers still commit fraud and lie on these 
forms, this information can be used to determine if taxpayers have mistakenly claimed these 
credits. TIGTA also found that 362 prisoners or underage individuals were allowed to claim 
$404,578 worth of these credits erroneously. Generally, prisoners and underage children will be 
ineligible for these credits because if they are prisoners for an entire year, they will tend to be 
unable to purchase the energy-saving improvements, and underage individuals are unlikely to 
have purchased a residence. TIGTA made several recommendations to the IRS, including (1) 
revise Form 5695 to require the address of the applicable residence and whether that residence 
was a principal or secondary residence and (2) use available data on prisoners and underage 
individuals to ensure they are eligible for the residential energy tax credits. Notably, TIGTA did 
not recommend that the IRS also require third-party validation of qualifying expenditures. 
Although this information could be valuable in determining eligibility for these credits, it might 
also increase processing times and costs which would increase complexity for taxpayers and the 
IRS. 
Policy Options24  
The Section 25C and Section 25D tax credits are temporary provisions, and one policy option 
available to Congress is to allow these tax credits to expire as scheduled. Absent congressional 
action, the Section 25C credit for nonbusiness energy property will not be available after 2013. 
                                                 
22 Treasury Inspector General For Tax Administration, Processes Were Not Established to Verify Eligibility for 
Residential Energy Credits, Reference Number: 2011-41-038, April 19, 2011, http://www.treasury.gov/tigta/
auditreports/2011reports/201141038fr.pdf. 
23 TIGTA examined a statistically representative sample of 150 tax returns. 
24 The policy options discussed here include incentive-oriented options. Alternative policy options could be to impose 
regulations or standards mandating certain levels of energy efficiency. While standards and mandates may work to 
increase energy efficiency in newly installed property, imposing standards and mandates provide limited incentives for 
increasing efficiency in existing residential property.  
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Residential Energy Tax Credits: Overview and Analysis 
 
The Section 25D program is not scheduled to expire until the end of 2016. There may be other 
policy options Congress might want to consider regarding future incentives for residential energy 
efficiency, including modifying the credits or replacing them with a grant program.  
Allow Tax Credits to Expire as Scheduled 
One option regarding these 
credits is to let them expire as 
Proposed Changes to Residential Energy Tax 
scheduled. For taxpayers who 
Credits Under Chairman Camp’s Tax Reform Plan 
base their purchasing decisions 
On February 26, 2014, Chairman Camp introduced a draft tax reform 
on the availability of credits, 
bill, which among other tax changes, would repeal both the 25C and 
25D tax credits, effective beginning in 2015. 
this may result in taxpayers 
choosing not to make eligible 
The Joint Committee on Taxation (JCT) estimates that these changes 
purchases after their 
would increase revenues by $2.3 billion between 2014 and 2023, 
entirely attributable to repealing 25D. Since 25C expired at the end of 
expiration.25 However, in so far 
2013, repealing it in 2014 would have no budgetary effect.  
as the credits are claimed by 
people who would make 
qualifying purchases absent these incentives, the expiration of these provisions would eliminate a 
windfall tax benefit while reducing revenue losses. Under current law, the Section 25D tax credit 
results in an estimated $0.2 billion in revenue loss annually. The two-year extension of the 
Section 25C tax credits enacted at the end of 2012 was estimated to result in $2.4 billion in 
revenue loss between 2013 and 2014.  
Extend or Modify Current Tax Incentives 
Policymakers may choose to extend, expand, or otherwise modify residential energy-efficiency 
tax incentives. As detailed in the legislative history in Appendix B, the current tax credits for 
residential energy efficiency have undergone a number of changes since being added to the code 
in 2005. Extending the credit in its current form, with the $500-per-taxpayer cap in place, would 
provide limited incentives for additional investment for homeowners that have already claimed 
tax credits under Section 25C. These credits can be expanded in a variety of ways, including by 
calculating the credit using a more generous formula, expanding the types of technologies eligible 
for the credit, and by removing caps (both technology-specific and aggregate caps). Expansions 
may provide additional incentives that could encourage taxpayers to make more purchases. As 
illustrated in Table B-1, the value of these credits grew nearly five times between 2007 (when 
both Section 25C and Section 25D were in effect) and 2009 (when ARRA expanded these tax 
credits). Further, expansion of these credits may also provide additional windfalls to taxpayers 
who were going to make these purchases anyway.  
Policymakers could also scale back these provisions in a variety of ways, including by reinstating 
technology-specific caps for the Section 25D credit, introducing an overall cap for the Section 
25D credit (currently uncapped), reducing the technology-specific caps of Section 25C, or 
reducing the overall cap on Section 25C. Given that these would be changes from current policy, 
they may increase confusion among taxpayers when trying to estimate the size of their credits. 
Policymakers could also phase-out these credits for upper-income taxpayers who would be more 
                                                 
25 Alternatively, before the expiration of these provisions, taxpayers may increase their purchases of energy-efficient or 
renewable-energy-generating technologies to take advantage of these provisions before they expire. 
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Residential Energy Tax Credits: Overview and Analysis 
 
likely to make eligible purchases without the credits. Extension of current policy, whether in 
current form, expanded, or scaled back, will have a greater budgetary cost than expiration of these 
benefits. 
Replace Tax Credits with Grants or Rebates 
Finally, policymakers may seek to replace these tax credits with a rebate program, or some 
alternative mechanism to provide direct cash payments to consumers for eligible purchases. This 
may be a more beneficial way to provide incentives to consumers purchasing energy-efficiency or 
renewable-energy-generating technologies, especially for consumers who do not have sufficient 
funds to make eligible expenditures and cannot wait until they file their taxes to receive a 
financial benefit from their purchases. Such a program could also benefit those with little or no 
tax liability who cannot benefit from nonrefundable tax credits. In 2010, both the House and 
Senate introduced legislation intended to create a rebate program, with rebates payable to 
contractors installing qualified energy-efficiency property.  
The Home Star Energy Retrofit Act of 2010 (H.R. 5019 and S. 3177 and included in S. 3663) 
would have created a temporary two-tiered rebate program called Home Star. Its Silver Star 
program tier would have provided up to $3,000 per home in rebates for straightforward home 
upgrades, including insulation; efficient heating, ventilation, and air conditioning units; new 
windows; and other measures. The Gold Star program tier would have offered $3,000 rebates for 
more comprehensive energy retrofits achieving at least 20% energy savings, with rebates 
increasing up to $8,000 per home for retrofits achieving 45% energy savings.26 Although some 
experts believed the Home Star program would result in an increased purchases of energy-
efficiency improvements to homes, there were concerns that it could be more costly than 
expected (the legislation authorized $6 billion in appropriations), that there might be difficulties 
with its administration, and that it would not provide sufficient benefit to do-it-yourself repairs or 
improvements.27 The legislation, which passed the House in 2010, was not considered by the 
Senate in the 111th Congress. To date, similar legislation has not been introduced in the 113th 
Congress.  
                                                 
26 For more information, see http://homestarcoalition.org/HOME_STAR_Overview.pdf. 
27 For more information on the Home Star program, including operational issues, see CRS Report R41273, The Home 
Star Energy Retrofit Act of 2010: Operational and Market Considerations, by Paul W. Parfomak. 
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Appendix A. Specifications for Property Eligible for 
Residential Energy-Efficiency Tax Credits 
This appendix provides additional details on the technical standards for property to qualify for the 
tax credits in IRC Section 25C and Section 25D.  
Table A-1. Nonbusiness Energy Property Tax Credit (§25C) 
(2012 and 2013) 
Property Qualifying 
Standard 
Energy-efficiency Improvements to Building Envelope 
Insulation materials or systems 
Meets 2009 International Energy Conservation Code (IECC) 
and Amendments 
Windows, doors, and skylights 
Must be Energy Star Qualified 
Roofs 
Metal roofs with appropriate pigmented coatings and asphalt 
roofs with appropriate cooling granules that also meet 
Energy Star requirements 
Energy Efficient Property 
Electric Heat Pump (air source) 
For split systems: Heat Seasonal Performance Factor (HSPF) 
≥ 8.5, Energy Efficiency Ratio (EER) ≥ 12.5, Seasonal Energy 
Efficiency Ratio (SEER) ≥ 15. For package systems: HSPF ≥ 
8, EER≥12, SEER ≥ 14 
Central Air Conditioner 
For split systems: SEER ≥ 16, EER ≥ 13. For package 
systems: SEER ≥ 14 and EER ≥ 12. 
Natural Gas, propane or oil water heater  
Energy Factor ≥ 0.82 or a thermal efficiency or at least 90% 
Electric Heat Pump Water Heater  
Energy Factor ≥ 2.0 
Natural gas, propane, or oil furnace 
Annual Fuel Utilization Efficiency (AFUE) ≥95 
Natural gas, propane or oil water boiler 
AFUE ≥ 95 
Advanced main air circulating fan: $50 
Must use no more than 2% of the furnace’s total energy 
Biomass Fuel Stoves 
Thermal efficiency rating of at least 75% 
Source: U.S. Department of Energy, Energy Star Program, http://www.energystar.gov/, 2012 and 2013 Federal 
Tax Credits for Consumer Energy Efficiency Updated January 30, 2013. 
Notes: In 2012 and 2013, the aggregate amount of credit is limited to $500 per taxpayer. A taxpayer is ineligible 
for this tax credit if this credit has already been claimed by the taxpayer in an amount of $500 in any previous 
year, including 2009 and 2010 when the aggregate credit limits were higher. The credit is only available for 
expenditures for an existing home that is the taxpayer’s principal residence. New construction and rentals do 
not qualify.  
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Table A-2. Residential Energy Efficient Property Tax Credit (§25D) 
(2013) 
Property Qualifying 
Standard 
Solar electric and solar water heating property 
Qualifying property must be used exclusively for purposes 
other than heating swimming pools and hot tubs and must 
meet applicable fire and electrical code requirement. At 
least half of the energy generated by a solar water heating 
property must come from the sun and the system must be 
certified by the Solar Rating and Certification Corporation 
(SRCC) or a comparable entity endorsed by the 
government or the state in which the property is installed.  
Fuel cell 
Efficiency of at least 30% and must have a capacity of at least 
0.5 kW 
Smal  wind 
Nameplate capacity of not more than 100 kW 
Geothermal heat pumps 
Water to Air: For closed loop: EER ≥ 17.1 and Coefficient 
of Performance (COP) ≥ 3.6. For open loop: EER ≥ 21.1 and 
COP ≥ 4.1.  
Water to Water: For closed loop: EER ≥ 16.1 and 
Coefficient of Performance (COP) ≥ 3.1. For open loop: 
EER ≥ 20.1 and COP ≥ 3.5. 
For direct expansion: EER ≥ 16 and COP ≥ 3.6 
Source: U.S. Department of Energy, Energy Star Program, http://www.energystar.gov/, 2012 and 2013 Federal 
Tax Credits for Consumer Energy Efficiency Accessed March 18, 2014. 
Notes: Excluding fuel cel  properties, the credit is available for expenditures for principal residences and second 
homes. Both existing homes and new construction qualifies. Rental units do not qualify. For fuel cel  instal ations, 
the credit is restricted to principal residences (existing homes and new construction). Rentals and second homes 
do not qualify. 
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Appendix B. Legislative History 
Tax credits for residential energy efficiency were first introduced in the late 1970s. These 
incentives were allowed to expire in the mid-1980s. The present-day residential energy tax 
incentives, introduced in 2005, are similar to the earlier incentives of the late 1970s and early 
1980s.  
Residential Energy Credits in the 1970s and 1980s 
The Energy Tax Act of 1978 (P.L. 95-618) introduced the first tax credit for conservation and 
renewable-energy generation. Specifically this credit had two components. The first component 
was calculated as 15% of the first $2,000 of energy-conservation expenditures (a maximum credit 
value of $300). The second component was calculated as 30% of the first $2,000 in qualified 
expenditures for solar, wind, and geothermal energy plus 20% of the next $8,000 in qualified 
expenditures (a maximum credit value of $2,200). The final value of the credit was the sum of 
these two components, with the maximum value equaling $2,500. In 1980, Congress passed the 
Crude Oil Windfall Profit Tax Act of 1980 (P.L. 96-223), which increased the amount of the 
credit.28 Specifically, this law increased the amount of the second component of the credit 
attributable to renewable energy generation to 40% of the first $10,000 of expenditures (yielding 
a maximum value of $4,000 for this component of the credit). This credit was allowed to expire at 
the end of 1985. Not until 2005, 20 years later, would Congress again enact federal tax credits for 
residential energy efficiency and renewable-energy property. 
The Energy Policy Act of 2005   
The Energy Policy Act of 2005 (EPACT05; P.L. 109-58) created two new temporary tax credits 
for homeowners who made energy-efficiency improvements to their homes. Under EPACT05, 
both credits were in effect for 2006 and 2007. The first credit was the nonbusiness energy 
property credit (IRC §25C). Under Section 25C, taxpayers were eligible for a nonrefundable tax 
credit equal to 10% of qualified expenditures, subject to certain limitations for specific types of 
property. Specifically, property-specific credit limits were $50 per year for any advanced main air 
circulating fan; $250 per year for any qualified natural gas, propane, or oil furnace or hot water 
boiler; and $300 for electric heat pumps, geothermal heat pumps, central air conditioners, and 
boilers and water heaters that met certain efficiency standards. The maximum amount of Section 
25C credit that could be taken for windows over 2006 and 2007 was capped at $200. The lifetime 
cap for the Section 25C credit was $500 for 2006 and 2007.29 The credit could only be applied to 
improvements made to the taxpayer’s principal residence.  
The second credit temporary established by EPACT05 for 2006 and 2007 was the residential 
energy-efficient property credit (IRC §25D). This nonrefundable credit was calculated as 30% of 
expenditures on qualified photovoltaic properties (where the sun’s energy is used to generate 
                                                 
28 For more information on the history of the credit in the late 1970s and early 1980s, see Robert McIntyre, “Lessons 
for Tax Reformers from the History of the Energy Tax Incentives in the Windfall Profit Tax Act of 1980 ,” The Boston 
College Law Review, vol. 22, no. 705 (1981). 
29 In other words, if a taxpayer used $500 worth of §25C credit in 2006 for her home, she would be ineligible for the 
credit in 2007, irrespective of whether she had qualifying expenses in 2007.  
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electricity), solar water-heating properties (excluding those used for heating swimming pools and 
hot tubs), and fuel-cell generators, subject to annual limits. Specifically, the credit for 
photovoltaic and solar water-heating properties could not exceed $2,000 per year, whereas the 
credit for fuel cells could not exceed $500 per year. Qualifying photovoltaic and solar water-
heating property expenditures included those made on any of the taxpayer’s residences, whereas 
qualifying fuel-cell expenditures were limited to those made to the taxpayer’s principal residence.  
At the end of 2007, Section 25C expired. By contrast Section 25D was extended for the 2008 tax 
year by the Tax Relief and Health Care Act of 2006 (P.L. 109-432). Further, this act clarified that 
all property which used solar energy to generate electricity, not just photovoltaic property, could 
qualify for the Section 25D credit. 
The Emergency Economic Stabilization Act (EESA) 
In 2008, the Emergency Economic Stabilization Act of 2008 (EESA; P.L. 110-343) reinstated and 
modified the Section 25C credit for the 2009 tax year. EESA also expanded the list of qualified 
energy property to include biomass fuel stoves, which were eligible for a $300 credit. Geothermal 
heat pumps were removed from the list of eligible property under Section 25C but were added to 
the list of eligible property under Section 25D.  
EESA extended the Section 25D tax credit for eight years, through 2016, modified it for existing 
technologies, and expanded it to new technologies. Specifically, the act eliminated the $2,000 
maximum annual credit limit for qualified solar-electric property expenditures beginning in 2009. 
In addition, it expanded the credit to include expenditures for qualified small wind-energy 
property and (as previously mentioned) qualified geothermal heat pump property. The credit for 
qualified small wind energy was equal to 30% of expenditures made by taxpayers on a small 
wind-energy property up to a cap. The cap was set at $500 for each half kilowatt of electric 
capacity generated by a wind turbine, not to exceed $4,000 annually. The credit for qualifying 
geothermal heat pumps was calculated as 30% of expenditures up to a $2,000 annual cap for this 
technology. Taxpayers were eligible for the credits for both small wind-energy and geothermal 
properties installed on any of their residential properties.  
The American Recovery and Reinvestment Act (ARRA) 
The American Recovery and Reinvestment Act of 2009 (ARRA; P.L. 111-5) further extended and 
modified the Section 25C and Section 25D tax credits. With respect to the Section 25C credit, 
ARRA extended the credit for two years (2009 and 2010) and modified the calculation of the 
credit to be equal to 30% of qualified expenditures for energy-efficiency improvements and 
energy property, eliminating the technology-specific credit amounts.30 In addition, the aggregate 
credit cap was lifted from $500 to $1,500 for 2009 and 2010 and the $200 aggregate cap for 
windows was eliminated for 2009 and 2010. Hence, if taxpayers used $1,000 of credit in 2009, 
their credit would be limited to $500 in 2010, irrespective if they had used this credit in 2006 and 
2007. The removal of the aggregate cap for windows meant that in 2009 and 2010, taxpayers 
could claim up to $1,500 in tax credits for qualified windows. Finally, ARRA generally reduced 
                                                 
30 The changes that ARRA made to the §25C credit in 2009 superseded the 2009 changes that had been made to the 
credit by EESA. 
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the efficiency standards for both energy-efficiency improvements and energy property, expanding 
the availability of the credit to additional products. 
ARRA also changed the Section 25D tax credit for 2009 and 2010, primarily by removing the 
maximum credit caps for every type of technology except fuel cells. These changes were effective 
from 2009 through 2016.  
Following the changes made to the Section 25C and Section 25D tax credits under ARRA, the 
number of credits being claimed and the total dollar amount of credits being claimed increased 
(see Table B-1). Further, under ARRA, average credit amounts were higher than they had been 
during 2006 and 2007, reflecting the higher credit rate. When the ARRA expansions expired, the 
number of taxpayers claiming the residential energy credit fell, along with the total amount and 
average amount of these credits. 
Table B-1. Residential Energy Credits Claimed and Average Amount, 2006-2010 
Number of Tax Returns 
Total Amount of 
Which Include Claims for 
Residential Credits 
 
Residential Credits 
Claimed (Millions) 
Average Credit Amount 
2006 4,344,189 
$1,000.15 
$230 
2007 4,326,398 
$1,007.58 
$233 
2008 225,733 
$216.69 
$960 
2009 6,711,682 
$5,822.88 
$868 
2010 7,155,889 
$6,173.49 
$863 
2011 3,642,988 
$1,676.00 
$460.06 
Source: Internal Revenue Service, Statistics of Income (SOI), Individual Statistical Tables by Size of Adjusted 
Gross Income, Table 3.3, 2006-2011.  
Notes: The Section 25C tax credit expired at the end of 2007 and was unavailable in 2008, hence the 2008 
numbers represent claims for the Section 25D tax credit. In 2011, the maximum value of the 25C credit was 
lowered from $1,500 to $500. 
The 2010 Tax Act (P.L. 111-312) 
Tax Relief, Unemployment Insurance Reauthorization, and Job Creation Act of 2010 (The 2010 
Tax Act; P.L. 111-312) extended the Section 25C credit for one year, through the end of 2011. 
However, the credit structure returned to the structure that existed prior to the enactment of 
ARRA.31 Importantly, the general lifetime limit ($500) and window lifetime limit ($200) were 
reinstated. Hence, if a taxpayer had claimed a total of $500 in Section 25C credits over 2006, 
2007, 2009, and 2010 combined, they would be ineligible for the credit in 2011. Similarly if they 
had claimed $200 in credits for windows in 2006, 2007, 2009, and 2010 combined, they would be 
ineligible to claim the credit for windows in 2011. Additionally, certain efficiency standards that 
were relaxed under ARRA were restored to their prior levels. Finally, the technology-specific 
credit limits for energy-efficiency property were reinstated at pre-ARRA levels.  
                                                 
31 The Section 25C credit in 2011 applies to asphalt roofs with cooling granules and biomass stoves, changes that were 
made by EESA.  
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The American Taxpayer Relief Act (ATRA) 
The American Taxpayer Relief Act (P.L. 112-240, ATRA) extended the 2011 parameters of the 
25C credit for two additional years—2012 and 2013. 
 
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Table B-2. Overview of Legislative Changes to the Nonbusiness Energy Property Tax Credit (§25C), 2005-2012 
 
2005 
2008 
2009 
2010 
2012 
 
P.L. 109-58 (EPACT05) 
P.L. 110-343 (EESA) 
P.L. 111-5 (ARRA) 
P.L. 111-312 
P.L. 112-240 
Calculation of Credit 
10% of Qualifying Energy-
* 
30% of Qualifying Energy-
10% of Qualifying Energy-
* 
efficiency Improvements + 
efficiency Improvements + 
efficiency Improvements + 
Qualifying Energy Property 
30% of Qualifying Energy 
Qualifying Energy Property 
(fixed by type. see below) 
Property  
(capped by type) 
(fixed amounts by property 
type eliminated) 
Types of Qualifying 
(1) Insulation 
Added- 
* *  * 
Energy-efficiency 
(2) Windows (Including 
(1) Asphalt Roof with 
Improvements to 
skylights) 
cooling granules 
Building Envelope 
(3) Doors 
(4) Qualifying Metal Roof 
 
Types of Qualifying 
(1) Energy Efficient Building 
Added- 
Properties are unchanged, 
(1) Energy Efficient Building 
* 
Energy Property and 
Property: $300 
(1) Biomass fuel stoves: 
but fixed dol ar amounts per 
Property: $300 
Credit Amount 
  Electric Heat Pump (air 
$300 
property type are 
  Electric Heat Pump (air 
 
 
source) 
eliminated. 
source) 
  Geothermal Heat Pump 
Removed- 
  Biomass fuel stoves: $300 
  Central Air Conditioner 
(2) Geothermal heat 
  Central Air Conditioner 
  Natural Gas, Oil or 
pumps 
  Natural Gas, Oil or Propane  
Propane Water heater 
Water heater 
  Electric Heat Pump 
  Electric Heat Pump Water 
Water Heater 
Heater 
(2) Natural gas, propane, or 
(2) Natural gas, propane, or 
oil furnace: $150 
oil furnace: $150 
(3) Natural gas, propane or 
(3) Natural gas, propane or oil 
oil water boiler: $150 
water boiler: $150 
(4) Advanced main air 
(4) Advanced main air 
circulating fan: $50 
circulating fan: $50 
Aggregate Cap for 
$200 over all prior tax 
* 
$200 aggregate cap for 
$200 (for all prior tax years 
* 
Windows 
years 
windows removed for 2009 
beginning in 2006 including 
and 2010 
2009 and 2010) 
Aggregate Cap for 
$500 over all prior tax 
* 
$1,500 over 2009 and 2010 
$500 (for all prior tax years 
* 
Credit 
years 
(excludes expenditures in 
beginning in 2006 including 
2006, 2007) 
2009 and 2010) 
Applicable Tax Years 
2006 and 2007 
2009 
2009 and 2010 
2011 
2012 and 2013 
CRS-21 
 
Source: CRS analysis of P.L. 109-58, P.L. 110-343, P.L. 111-5, P.L. 111-312, and P.L. 112-240. 
Note: * Unchanged from prior law. 
Table B-3. Overview of Legislative Changes to Residential Energy-Efficient Property Tax Credit (§25D), 2005-2010 
 
2005 
2006 
2008 
2009 
 
P.L. 109-58 (EPACT05) 
P.L. 109-432 
P.L. 110-343 (EESA) 
P.L. 111-5 (ARRA) 
Calculation of Credit 
30% of energy efficient property 
* * * 
(subject to maximum credit amount by 
type of property , see below) 
Qualifying Renewable 
(1) Solar electric (photovoltaic): $2,000
Clarified that all solar electric, 
Added- 
Modified- 
Energy Generating Property  (2) Solar water heating: $2,000 
not just photovoltaic property, 
(1) Small wind energy: $500 per 
(1) Small wind energy: max 
and Max Credit Amount by 
(3) Fuel Cell: $500 per 0.5kW of 
qualified for the credit, 
0.5kW power capacity up to 
credit value eliminated 
Type of Property 
power capacity 
$4,000 
(2) Geothermal heat pumps: 
(includes labor costs) 
(2) Geothermal heat pumps: 
max credit value eliminated 
$2,000 
(3) Solar water heating: max 
(applicable from 2008-2016) 
credit value eliminated 
Modified- 
(1) Solar electric (photovoltaic): 
max credit amount eliminated 
Aggregate Cap for Credit 
None 
* 
* 
* 
Applicable Tax Years 
2006 and 2007 
2008 
2009-2016 
2009-2016 
Source: CRS analysis of P.L. 109-58, P.L. 109-432, P.L. 110-343, P.L. 111-5, P.L. 111-312 and P.L. 112-240. 
Note: * Unchanged from prior law. 
CRS-22 
 
Appendix C. Budgetary Impact of Residential Energy Tax Incentives 
Table C-1. Revenue Losses Associated with Residential Energy-Efficiency Tax Incentives, 2008-2017 
(billions of dollars) 
Provision 
2008 2009 2010 2011 2012 2013 2014 2015 2016 
2017 
Credit for Energy Efficiency Improvements to Existing 
0.8 0.3 1.7 1.5 2.9 3.0 2.5  -  -  - 
Homes (IRC §25C) 
Residential Energy Efficient Property Credit (IRC 
-i-  0.1 0.2 0.2 0.8 0.9 1.0 1.0 1.1 0.9 
§25D) 
New Energy Efficient Home Credit (IRC §45L) 
-i- -i- -i- -i- -i- -i- -i- -i- -i- -i- 
Credit for the Production of Energy Efficient 
0.1 0.1 0.2 0.2 0.2 0.2 0.1 0.1  -i-  -i- 
Appliances (IRC §45M) 
Exclusion of Energy Conservation Subsidies Provided 
-i- -i- -i- -i- -i- -i- -i- -i- -i- -i- 
by Public Utilities (IRC §136) 
Source: Joint Committee on Taxation, JCS-13-1, JCS-1-12, JCS-3-10, JCS-1-10, JCS-2-08 
Note: An “-i-“ indicates an estimated revenue loss of less than $50 million. 
 
 
CRS-23 
Residential Energy Tax Credits: Overview and Analysis 
 
 
Author Contact Information 
 
Margot L. Crandall-Hollick 
  Molly F. Sherlock 
Analyst in Public Finance 
Specialist in Public Finance 
mcrandallhollick@crs.loc.gov, 7-7582 
msherlock@crs.loc.gov, 7-7797 
 
 
Congressional Research Service 
24