`(a) ALLOWANCE OF CREDIT- In the case of an individual, there shall be allowed as a credit against the tax imposed by this chapter for the taxable year an amount equal to the sum of--
`(1) 15 percent of the qualified photovoltaic property expenditures made by the taxpayer during such year,
`(2) 15 percent of the qualified solar water heating property expenditures made by the taxpayer during such year,
`(3) 30 percent of the qualified fuel cell property expenditures made by the taxpayer during such year,
`(4) 30 percent of the qualified wind energy property expenditures made by the taxpayer during such year, and
`(5) the sum of the qualified Tier 2 energy efficient building property expenditures made by the taxpayer during such year.
`(b) LIMITATIONS-
`(1) MAXIMUM CREDIT- The credit allowed under subsection (a) shall not exceed--
`(A) $2,000 for property described in subsection (d)(1),
`(B) $2,000 for property described in subsection (d)(2),
`(C) $1,000 for each kilowatt of capacity of property described in subsection (d)(4),
`(D) $2,000 for property described in subsection (d)(5), and
`(E) for property described in subsection (d)(6)--
`(i) $75 for each electric heat pump water heater,
`(ii) $250 for each electric heat pump,
`(iii) $250 for each advanced natural gas furnace,
`(iv) $250 for each central air conditioner,
`(v) $75 for each natural gas water heater, and
`(vi) $250 for each geothermal heat pump.
`(2) SAFETY CERTIFICATIONS- No credit shall be allowed under this section for an item of property unless--
`(A) in the case of solar water heating property, such property is certified for performance and safety by the non-profit Solar Rating Certification Corporation or a comparable entity endorsed by the government of the State in which such property is installed,
`(B) in the case of a photovoltaic property, a fuel cell property, or a wind energy property, such property meets appropriate fire and electric code requirements, and
`(C) in the case of property described in subsection (d)(6), such property meets the performance and quality standards, and the certification requirements (if any), which--
`(i) have been prescribed by the Secretary by regulations (after consultation with the Secretary of Energy or the Administrator of the Environmental Protection Agency, as appropriate),
`(ii) in the case of the energy efficiency ratio (EER)--
`(I) require measurements to be based on published data which is tested by manufacturers at 95 degrees Fahrenheit, and
`(II) do not require ratings to be based on certified data of the Air Conditioning and Refrigeration Institute, and
`(iii) are in effect at the time of the acquisition of the property.
`(c) CARRYFORWARD OF UNUSED CREDIT- If the credit allowable under subsection (a) exceeds the limitation imposed by section 26(a) for such taxable year reduced by the sum of the credits allowable under this subpart (other than this section and section 25D), such excess shall be carried to the succeeding taxable year and added to the credit allowable under subsection (a) for such succeeding taxable year.
`(d) DEFINITIONS- For purposes of this section--
`(1) QUALIFIED SOLAR WATER HEATING PROPERTY EXPENDITURE- The term `qualified solar water heating property expenditure' means an expenditure for property to heat water for use in a dwelling unit located in the United States and used as a residence by the taxpayer if at least half of the energy used by such property for such purpose is derived from the sun.
`(2) QUALIFIED PHOTOVOLTAIC PROPERTY EXPENDITURE- The term `qualified photovoltaic property expenditure' means an expenditure for property that uses solar energy to generate electricity for use in such a dwelling unit.
`(3) SOLAR PANELS- No expenditure relating to a solar panel or other property installed as a roof (or portion thereof) shall fail to be treated as property described in paragraph (1) or (2) solely because it constitutes a structural component of the structure on which it is installed.
`(4) QUALIFIED FUEL CELL PROPERTY EXPENDITURE- The term `qualified fuel cell property expenditure' means an expenditure for qualified fuel cell property (as defined in section 48(a)(4)) installed on or in connection with such a dwelling unit.
`(5) QUALIFIED WIND ENERGY PROPERTY EXPENDITURE- The term `qualified wind energy property expenditure' means an expenditure for property which uses wind energy to generate electricity for use in such a dwelling unit.
`(6) QUALIFIED TIER 2 ENERGY EFFICIENT BUILDING PROPERTY EXPENDITURE-
`(A) IN GENERAL- The term `qualified Tier 2 energy efficient building property expenditure' means an expenditure for any Tier 2 energy efficient building property.
`(B) TIER 2 ENERGY EFFICIENT BUILDING PROPERTY- The term `Tier 2 energy efficient building property' means--
`(i) an electric heat pump water heater which yields an energy factor of at least 1.7 in the standard Department of Energy test procedure,
`(ii) an electric heat pump which has a heating seasonal performance factor (HSPF) of at least 9, a seasonal energy efficiency ratio (SEER) of at least 15, and an energy efficiency ratio (EER) of at least 12.5,
`(iii) an advanced natural gas furnace which achieves at least 95 percent annual fuel utilization efficiency (AFUE),
`(iv) a central air conditioner which has a seasonal energy efficiency ratio (SEER) of at least 15 and an energy efficiency ratio (EER) of at least 12.5,
`(v) a natural gas water heater which has an energy factor of at least 0.80 in the standard Department of Energy test procedure, and
`(vi) a geothermal heat pump which has an energy efficiency ratio (EER) of at least 21.
`(7) LABOR COSTS- Expenditures for labor costs properly allocable to the onsite preparation, assembly, or original installation of the property described in paragraph (1), (2), (4), (5), or (6) and for piping or wiring to interconnect such property to the dwelling unit shall be taken into account for purposes of this section.
`(8) SWIMMING POOLS, ETC., USED AS STORAGE MEDIUM- Expenditures which are properly allocable to a swimming pool, hot tub, or any other energy storage medium which has a function other than the function of such storage shall not be taken into account for purposes of this section.
`(e) SPECIAL RULES- For purposes of this section--
`(1) DOLLAR AMOUNTS IN CASE OF JOINT OCCUPANCY- In the case of any dwelling unit which is jointly occupied and used during any calendar year as a residence by 2 or more individuals the following shall apply:
`(A) The amount of the credit allowable, under subsection (a) by reason of expenditures (as the case may be) made during such calendar year by any of such individuals with respect to such dwelling unit shall be determined by treating all of such individuals as 1 taxpayer whose taxable year is such calendar year.
`(B) There shall be allowable, with respect to such expenditures to each of such individuals, a credit under subsection (a) for the taxable year in which such calendar year ends in an amount which bears the same ratio to the amount determined under subparagraph (A) as the amount of such expenditures made by such individual during such calendar year bears to the aggregate of such expenditures made by all of such individuals during such calendar year.
`(2) TENANT-STOCKHOLDER IN COOPERATIVE HOUSING CORPORATION- In the case of an individual who is a tenant-stockholder (as defined in section 216) in a cooperative housing corporation (as defined in such section), such individual shall be treated as having made his tenant-stockholder's proportionate share (as defined in section 216(b)(3)) of any expenditures of such corporation.
`(3) CONDOMINIUMS-
`(A) IN GENERAL- In the case of an individual who is a member of a condominium management association with respect to a condominium which the individual owns, such individual shall be treated as having made the individual's proportionate share of any expenditures of such association.
`(B) CONDOMINIUM MANAGEMENT ASSOCIATION- For purposes of this paragraph, the term `condominium management association' means an organization which meets the requirements of paragraph (1) of section 528(c) (other than subparagraph (E) thereof) with respect to a condominium project substantially all of the units of which are used as residences.
`(4) ALLOCATION IN CERTAIN CASES- Except in the case of qualified wind energy property expenditures, if less than 80 percent of the use of an item is for nonbusiness purposes, only that portion of the expenditures for such item which is properly allocable to use for nonbusiness purposes shall be taken into account.
`(5) WHEN EXPENDITURE MADE; AMOUNT OF EXPENDITURE-
`(A) IN GENERAL- Except as provided in subparagraph (B), an expenditure with respect to an item shall be treated as made when the original installation of the item is completed.
`(B) EXPENDITURES PART OF BUILDING CONSTRUCTION- In the case of an expenditure in connection with the construction or reconstruction of a structure, such expenditure shall be treated as made when the original use of the constructed or reconstructed structure by the taxpayer begins.
`(C) AMOUNT- The amount of any expenditure shall be the cost thereof.
`(6) PROPERTY FINANCED BY SUBSIDIZED ENERGY FINANCING- For purposes of determining the amount of expenditures made by any individual with respect to any dwelling unit, there shall not be taken in to account expenditures which are made from subsidized energy financing (as defined in section 48(a)(5)(C)).
`(f) BASIS ADJUSTMENTS- For purposes of this subtitle, if a credit is allowed under this section for any expenditure with respect to any property, the increase in the basis of such property which would (but for this subsection) result from such expenditure shall be reduced by the amount of the credit so allowed.
`(g) TERMINATION- The credit allowed under this section shall not apply to expenditures after December 31, 2007.'.
(b) CREDIT ALLOWED AGAINST REGULAR TAX AND ALTERNATIVE MINIMUM TAX-
(1) IN GENERAL- Section 25C(b), as added by subsection (a), is amended by adding at the end the following new paragraph:
`(3) LIMITATION BASED ON AMOUNT OF TAX- The credit allowed under subsection (a) for the taxable year shall not exceed the excess of--
`(A) the sum of the regular tax liability (as defined in section 26(b)) plus the tax imposed by section 55, over
`(B) the sum of the credits allowable under this subpart (other than this section and section 25D) and section 27 for the taxable year.'.
(2) CONFORMING AMENDMENTS-
(A) Section 25C(c), as added by subsection (a), is amended by striking `section 26(a) for such taxable year reduced by the sum of the credits allowable under this subpart (other than this section and section 25D)' and inserting `subsection (b)(3)'.
(B) Section 23(b)(4)(B) is amended by inserting `and section 25C' after `this section'.
(C) Section 24(b)(3)(B) is amended by striking `23 and 25B' and inserting `23, 25B, and 25C'.
(D) Section 25(e)(1)(C) is amended by inserting `25C,' after `25B,'.
(E) Section 25B(g)(2) is amended by striking `section 23' and inserting `sections 23 and 25C'.
(F) Section 26(a)(1) is amended by striking `and 25B' and inserting `25B, and 25C'.
(G) Section 904(h) is amended by striking `and 25B' and inserting `25B, and 25C'.
(H) Section 1400C(d) is amended by striking `and 25B' and inserting `25B, and 25C'.
(c) ADDITIONAL CONFORMING AMENDMENTS-
(1) Section 23(c), as in effect for taxable years beginning before January 1, 2004, is amended by striking `section 1400C' and inserting `sections 25C and 1400C'.
(2) Section 25(e)(1)(C), as in effect for taxable years beginning before January 1, 2004, is amended by inserting `, 25Cs,' after `sections 23'.
(3) Subsection (a) of section 1016, as amended by this Act, is amended by striking `and' at the end of paragraph (29), by striking the period at the end of paragraph (30) and inserting `, and', and by adding at the end the following new paragraph:
`(31) to the extent provided in section 25C(f), in the case of amounts with respect to which a credit has been allowed under section 25C.'.
(4) Section 1400C(d), as in effect for taxable years beginning before January 1, 2004, is amended by inserting `and section 25C' after `this section'.
(5) The table of sections for subpart A of part IV of subchapter A of chapter 1 is amended by inserting after the item relating to section 25B the following new item:
`Sec. 25C. Residential energy efficient property.'.