$Missed Deductions

Can I carry forward unused energy tax credits?

Tax Creditsintermediate3 answers · 6 min readUpdated February 28, 2026

Quick Answer

Yes, unused energy tax credits can be carried forward for up to 5 years total (the original year plus 4 additional years). If you have a $12,000 solar credit but only owe $8,000 in taxes, the unused $4,000 carries forward to offset next year's taxes.

Best Answer

DF

Diana Flores, Tax Credits & Amendments Specialist

Taxpayers who installed energy improvements but couldn't use the full credit due to low tax liability

Top Answer

How energy tax credit carryforwards work


Yes, you can carry forward unused portions of residential energy credits for up to 5 years total (the installation year plus 4 additional years). This applies to solar, geothermal, wind, fuel cells, and battery storage credits.


Unlike some credits that are "use it or lose it," energy credits are designed to provide full value even if you don't owe enough taxes in the installation year.


Example: Solar credit carryforward


Mike's Situation:

  • Installed $30,000 solar system in 2025
  • Federal solar credit: $9,000 (30%)
  • 2025 tax liability: $5,500
  • Used in 2025: $5,500 (reduces tax to $0)
  • Carries forward to 2026: $3,500

  • In 2026, Mike can use the remaining $3,500 to offset his tax liability. If he still can't use it all, it continues carrying forward until 2029 (the 5-year limit).


    Credit carryforward timeline



    Which energy credits can carry forward?


    All residential energy credits on Form 5695 can be carried forward:


  • Solar electric systems: 30% through 2032
  • Solar water heating: 30% through 2032
  • Geothermal heat pumps: 30% through 2032
  • Small wind turbines: 30% through 2032
  • Fuel cells: 30% through 2032, capped at $500 per 0.5kW
  • Battery storage: 30% if charged by renewable energy

  • How carryforwards appear on your tax return


    When you file your taxes:


    1. Current year Form 5695: Shows new energy improvements and credits

    2. Prior year carryforward: Added to Line 6 of Form 5695

    3. Total available credit: Current year + carryforward

    4. Credit used: Limited to your tax liability

    5. Remaining carryforward: Moves to next year


    Real-world carryforward scenarios


    Scenario 1 - Retiree with low income:

  • $25,000 solar system = $7,500 credit
  • Annual tax liability: $2,000
  • Uses $2,000 per year for 4 years (2025-2028)
  • Loses final $500 in 2029 (5-year limit expires)

  • Scenario 2 - Working professional:

  • $40,000 solar + battery system = $12,000 credit
  • 2025 tax liability: $8,000 (uses $8,000)
  • 2026 promotion increases tax liability to $15,000 (uses remaining $4,000)
  • Full credit utilized in 2 years

  • What you should do


    Don't let concerns about "wasting" energy credits prevent you from installing renewable energy systems. The 5-year carryforward period gives you flexibility to use credits as your income and tax situation changes.


    Keep detailed records of your energy improvements and track unused credits year-to-year. Use our refund estimator to see how carried-forward credits might affect your upcoming tax refund.


    Key takeaway: Energy tax credits carry forward for 5 years total, so a $10,000 solar credit can be used over multiple years until fully utilized or the carryforward period expires.

    *Sources: [IRS Form 5695 Instructions](https://www.irs.gov/pub/irs-pdf/i5695.pdf), [IRS Publication 17](https://www.irs.gov/pub/irs-pdf/p17.pdf)*

    Key Takeaway: Energy tax credits carry forward for 5 years total, so a $10,000 solar credit can be used over multiple years until fully utilized or the carryforward period expires.

    Energy credit carryforward limits and timeline

    Credit TypeCarryforward PeriodExample: $10,000 CreditMaximum Benefit Years
    Solar (residential)5 years totalUse $2,000/year for 5 yearsInstallation year + 4
    Geothermal5 years totalUse $2,000/year for 5 yearsInstallation year + 4
    Wind (small)5 years totalUse $2,000/year for 5 yearsInstallation year + 4
    Battery storage5 years totalUse $2,000/year for 5 yearsInstallation year + 4
    Fuel cells5 years totalUse $2,000/year for 5 yearsInstallation year + 4

    More Perspectives

    RK

    Robert Kim, Tax Return Analyst

    Homeowners who made multiple energy improvements and need to understand how carryforwards stack

    Managing multiple energy credit carryforwards


    Homeowners often make several energy improvements over multiple years, creating layers of carryforward credits that need careful tracking.


    Example: Stacked improvements and carryforwards


    The Johnson Family Timeline:


    2024: Installed geothermal system

  • Cost: $22,000
  • Credit: $6,600
  • Tax liability: $4,000
  • Used: $4,000, Carryforward: $2,600

  • 2025: Added solar panels

  • Cost: $28,000
  • Credit: $8,400
  • Prior carryforward: $2,600
  • Total available: $11,000
  • Tax liability: $7,500
  • Used: $7,500, Carryforward: $3,500

  • 2026: Added battery storage

  • Cost: $15,000
  • Credit: $4,500
  • Prior carryforward: $3,500
  • Total available: $8,000
  • Tax liability: $9,200
  • Used: $8,000, Carryforward: $0

  • Order of credit usage


    Credits are used on a first-in, first-out basis:

    1. Oldest carryforward credits first (to prevent expiration)

    2. Current year credits second

    3. Remaining amounts carry forward


    Maximizing your carryforward strategy


    Timing considerations:

  • Bunch improvements in low-income years when you can't use credits immediately
  • Spread improvements across years if you have consistent high tax liability
  • Consider Roth conversions in years with large carryforwards to increase tax liability

  • Record-keeping for multiple carryforwards


    Track each improvement separately:

  • Installation date and cost
  • Credit amount claimed
  • Amount used each year
  • Remaining carryforward
  • Expiration year

  • This helps you prioritize which credits to use first and avoid losing valuable credits to expiration.


    Key takeaway: Multiple energy improvements create stacked carryforwards that can provide tax benefits for several years — proper planning ensures you maximize every dollar of available credits.

    Key Takeaway: Multiple energy improvements create stacked carryforwards that can provide tax benefits for several years — proper planning ensures you maximize every dollar of available credits.

    DF

    Diana Flores, Tax Credits & Amendments Specialist

    Families planning energy improvements while managing other tax credits and changing financial situations

    Energy credit carryforwards for growing families


    Families face unique challenges with energy credit carryforwards due to changing incomes, growing expenses, and competing tax credits like the child tax credit.


    Balancing energy credits with family credits


    Family credits are generally more valuable because they're partially refundable:


    Priority order:

    1. Child tax credit: Up to $1,700 per child is refundable

    2. Earned income tax credit: Fully refundable

    3. Energy credits: Non-refundable, but carry forward

    4. Other non-refundable credits


    Family scenario: Managing career growth and credits


    The Chen Family:

  • 2025: New parents, lower income, installed $35,000 solar system
  • Solar credit: $10,500
  • Tax liability after child credit: $3,000
  • Used solar credit: $3,000, Carryforward: $7,500

  • 2026-2028: Career advancement, higher income
  • Can use remaining $7,500 over 2-3 years as income grows

  • Strategic planning for families


    Consider future income changes:

  • Early career: Install energy systems knowing credits will carry forward as income grows
  • Peak earning years: Use accumulated carryforwards
  • Pre-retirement: Time improvements for when you'll have lower income but higher tax liability

  • Coordinate with life events:

  • Home purchase: Bundle energy improvements with mortgage for better financing
  • New baby: Install improvements in years with lower earned income
  • Job changes: Use carryforwards during higher-income periods

  • What families should do


    Don't delay beneficial energy improvements because you can't use the full credit immediately. The 5-year carryforward gives you flexibility as your family's financial situation evolves. Focus on the long-term energy savings and environmental benefits — the tax credits are a bonus that will eventually be fully realized.


    Key takeaway: Families can install energy systems during lower-income periods and use the carried-forward credits as their careers advance and tax liability increases over the 5-year window.

    Key Takeaway: Families can install energy systems during lower-income periods and use the carried-forward credits as their careers advance and tax liability increases over the 5-year window.

    Sources

    energy tax creditscarryforward creditssolar tax credit

    Reviewed by Diana Flores, Tax Credits & Amendments Specialist on February 28, 2026

    This content is for educational purposes only and is not a substitute for professional tax advice. Consult a qualified tax professional for advice specific to your situation.