Carbon Middle Management: Research Report
March 2025
U.S. Energy
Public Funding
Fifty-year retrospective comparison of public funding, tax expenditures, and state policy support across nuclear, solar, wind, CCS, battery storage, and geothermal (1975–2025). Includes net metering cross-funding transfers and state incentive coverage. Forward-looking projections are excluded; all values reflect enacted legislation, actual expenditures, or estimates anchored to government data.
Coverage Period
1975–2025
50 fiscal years
Real 2024 USD
Technologies
Nuclear · Solar
Wind · CCS
Battery · Geothermal
Cumulative Public Funding by Technology, 1975–2025
Real 2024 USD · Toggle scenarios to see how rankings change
NEM: Price-Anderson:
NEM = net metering ratepayer cost transfer ($20–50B CMM estimate). P-A = Price-Anderson liability cap ($25–75B implicit value, highly uncertain). OBBBA (2025) imposed a 12/31/2027 placed-in-service deadline for new solar and wind federal credits; nuclear, battery, CCS, geothermal preserved. OBBBA also raised §45Q utilization/EOR credit to $85/tonne (from $60), creating parity with permanent storage.
!Nuclear and solar rankings reverse depending on NEM and Price-Anderson assumptions. Neither answer is wrong: they reflect genuine disputes about what counts as public support. Use the toggles above to see each scenario.
iOBBBA (2025) preserves nuclear, battery, CCS, and geothermal incentives past 2027. Solar and wind face a hard placed-in-service cliff of 12/31/2027. OBBBA also raised the §45Q utilization/EOR credit from $60 to $85/tonne, creating parity with geological storage — a major change that JCT estimates will cost an additional ~$14B over FY2025–2034. See the Timeline tab for details on each technology.
IRA §45U creates the first nuclear deployment credit at parity with solar and wind: up to ~$11.6B/yr if all U.S. nuclear capacity qualifies at $15/MWh.
Public Funding by Type Over Time: by Technology CRS · EIA · JCT · LBNL · CMM

Each chart shows estimated annual public funding flows in real 2024 USD, stacked by type. Values represent mid-range estimates from CRS R&D data, EIA public funding reports, JCT tax expenditures, LBNL RPS compliance data, and CMM synthesis. Hover for year-by-year breakdown.

Hover over chart stream labels in the legend to see the primary source document. Shared y-axis enables cross-technology comparison; individual y-axis reveals internal composition of each technology's funding mix.

Nuclear
Annual flow · Real 2024 USD
50-yr total (mid)~$178B
Solar
Annual flow · Real 2024 USD
50-yr total (mid, incl. NEM)~$238B
Wind
Annual flow · Real 2024 USD
50-yr total (mid)~$132B
CCS
Annual flow · Real 2024 USD
50-yr total (mid)~$29B
Battery Storage
Annual flow · Real 2024 USD
50-yr total (mid)~$32B
Geothermal
Annual flow · Real 2024 USD
50-yr total (mid)~$20B
Chart Methodology Note

Annual flows estimated from: (1) CRS RS22858 decade-by-decade DOE R&D allocation; (2) EIA Federal Public Funding Reports FY2016/2019/2022; (3) JCT tax expenditure estimates for ITC, PTC, §45U, §45Q; (4) LBNL RPS Status Report compliance cost series; (5) CPUC/LBNL net metering cross-funding data. Pre-1990 values for solar, wind, and geothermal carry higher uncertainty. All values are approximate annual mid-estimates, illustrative of order-of-magnitude and trend.

This report is retrospective: chart data ends at the last year with actual or enacted data for each stream. Tax credit streams generally end at 2022 (last year with JCT/EIA actuals); R&D appropriations extend through enacted FY2024–2025 budgets and include IIJA supplemental appropriations where applicable (wind, solar, geothermal FY2022+). CCS R&D values represent estimated CCS-specific subset of the broader FECM budget. CCS State/RGGI and Battery NEM+Storage streams removed from prior versions (insufficient sourcing).

Data Confidence Key
Solid = Government source data (DOE appropriations, JCT tax expenditure reports, Treasury disbursements)
Dashed = Anchored estimate (identified sources with interpolation between anchor points; e.g., RPS compliance, ZECs, CCS R&D subset)
Dotted = Modeled / thin sourcing (net metering national extrapolation, state ITCs, offshore mandates, geothermal tax credits/grants)
Master Scorecard: All Public Funding Vectors Cumulative real 2024 USD

Net metering is a ratepayer cost transfer: not a government expenditure: excluded from EIA federal inventories. Included here as a state policy instrument with measurable distributional effects.

iSpent vs. designated. This scorecard combines economically distinct categories: direct expenditures (R&D appropriations actually disbursed), foregone tax revenue (credits claimed against tax liability — based on JCT tax expenditure estimates and EIA data), ratepayer cost transfers (RPS compliance, NEM, ZECs — paid through electricity bills, not government budgets), and contingent liabilities (loan guarantees — federal exposure that may never result in actual cost). Face values are used for loan guarantees for comparability, though the true federal cost is the credit subsidy cost (typically 5–15% of face value). See Methodology tab for definitions of each funding type.
All Technologies · All Vectors
Ranges reflect methodological uncertainty
TechnologyR&DTax CreditsGrants/DOELoan Guar.RPS/StateNet Metering †ZECs/MandatesTotal
Nuclear$85–95B$2–3B$10–15B$8–12B$15–25BN/A$10–18B~$158–205B
Solar$12–18B$85–110B$15–25B$3–6B$45–70B$30–65B$5–10B~$195–310B
Wind$8–14B$50–70B$5–10B$2–4B$35–55B$1–3B$2–4B~$103–160B
CCS$10–18B$3–8B$3–6B$1–3BNot quantified ‡N/A$1–3B~$18–38B
Battery$3–6B$8–15B$4–8B$0.5–2B$2–5BN/A$2–5B~$19–41B
Geothermal$4–6B$4–8B$1–2B<$0.5B$3–6BN/A$1–3B~$13–26B

† Net metering: retail-rate cost transfer from non-solar to solar ratepayers. Not a government expenditure. CMM estimate: $30–65B national cumulative 1995–2025. CA CPUC data ($3.4B/yr in 2021, $8.5B/yr in 2024) provides the largest state anchor; CA represents roughly 40–50% of U.S. distributed solar capacity. National extrapolation carries high uncertainty. See Net Metering tab.

‡ CCS state support: WY, IL, ND, TX, LA have enacted CCS-adjacent grants, severance tax exemptions for CO₂-EOR, and storage liability frameworks. RGGI and CA Cap-and-Trade create indirect carbon pricing adjacency. No defensible aggregate annual series exists; prior versions of this dashboard included a modeled $0.5–2B estimate that has been removed pending better sourcing.

Complete State Incentives: All Six Technologies LBNL · CPUC · State Agencies

RPS compliance costs alone total an estimated $80–130B over 2001–2025, yet most federal public funding inventories stop at the state border.

Nuclear $25–45B state total
TypePrograms & StatesEst. CumulativeStatus
Zero Emission CreditsNY ($462M/yr, ~$5.5B since 2017), IL ($235M/yr), NJ (~$300M/yr), CT (~$200M/yr), OH ($150M/yr 2019–22, rescinded). Palisades restart: ~$300M MI state + federal DOE loan guarantee support (~$1.5B).$10–18BActive
Clean Energy StandardsNY CES through 2030, IL CEJA, NJ ZEC extended. Above-market zero-carbon electricity procurement.Incl. in ZECActive
State R&D / NYPANYPA operating support, NY Green Bank adjacency, state university nuclear engineering programs$2–4BOngoing
Solar $70–130B state total (incl. NEM)
TypePrograms & StatesEst. CumulativeStatus
RPS Compliance CostsSolar SREC carve-outs in MA, NJ, DC, MD, CT at $200–450/MWh peak. LBNL: $4.7B/yr national RPS compliance by 2018.$45–70BOngoing
Net Metering †CA: $3.4B/yr (2021) → $8.5B/yr (2024). NEM 3.0 cut CA compensation 75% (April 2023). LBNL/Brattle: +1.1¢/kWh per 5pp NEM penetration.$30–65BContested
State ITCs & RebatesNC 35% ITC (2007–15, $800M–1.2B). MA SMART ~$200M/yr. NY-Sun $1B+. CA CSI ~$2B total.$5–10BMostly sunset
Community SolarIL, NY, MA, MN, NJ, CO above-wholesale compensation. NY NYSERDA $400M+ committed.$2–5BExpanding
Wind $38–63B state total
TypePrograms & StatesEst. CumulativeStatus
RPS ComplianceWind captured ~60–70% of early RPS procurement 2000–2015. TX CREZ transmission build-out: ~$7B ratepayer-funded for wind.$35–55BOngoing
Offshore MandatesNY 9 GW, NJ 7.5 GW, MA 3.2 GW. OREC premiums $30–80/MWh over market. Early stage, accelerating.$3–8BGrowing

Note: State and local property tax abatements (TX Ch. 312, IA exemptions, MN/KS/OK wind exemptions) are not included in these totals. See Methodology tab for discussion of the abatement data gap.

CCS · ~$2–6B state total (not charted)
Carbon Capture State Incentives
WY, IL, ND, TX, LA grants (~$1.5B total). Severance tax exemptions for CO₂-EOR. State carbon storage legislation (liability frameworks) lowers project costs. RGGI/CA Cap-and-Trade: CCS-eligible but no defensible annual series exists. These values are not included in the CCS chart due to thin sourcing.
Battery Storage · ~$5–13B state total
Storage State Incentives
CA AB 2514+ procurement mandates. CA SGIP: $1.5B+ since 2001, peak $300M/yr. NY (6 GW by 2030), MA, NJ mandates. NEM 3.0 specifically designed to incentivize battery adoption.
Geothermal · ~$4–10B state total
Geothermal State Incentives
MD post-2022 RPS carve-out at $94.47/MWh. NV, AZ, UT, CA RPS provisions. NV property tax exemption. UT, AZ, ID tax credits. NV Office of Energy exploration grants.
Net Metering: Evidence & Methodology LBNL · CPUC · Brattle · CMM
"

Net metering and Price-Anderson are structurally similar: both shift costs from technology adopters to third parties, both are excluded from standard federal public funding inventories, and both can flip technology rankings when included.

CMM Research Note · 2025
What Is Net Metering as a Public Funding Mechanism?

NEM allows solar owners to receive credits for excess electricity at or near the full retail rate (~$0.25–0.35/kWh). The public funding value is the gap between that credit and the actual wholesale avoided cost (~$0.05–0.08/kWh), recovered from non-solar ratepayers through utility rate design. This transfer does not appear in government budgets: which is why EIA excludes it from its federal public funding inventories.

Contested: Solar advocates argue value-of-solar analyses (grid deferral, avoided T&D, carbon avoidance) often equal or exceed the retail rate credit. Critics note the cost shift is regressive: it benefits wealthier solar adopters at the expense of renters and lower-income ratepayers.

Study-by-Study Evidence Comparison
Seven sources · 2013–2025
Source Finding Magnitude Notes
LBNL (2017)
At <5% solar penetration, effects negligible. At 10%, NEM produces ±5% price impact under volumetric rates.
±5% at 10% penetration
Most widely cited; industry-neutral
LBNL / Brattle (2025)
5pp increase in net-metered solar → +1.1¢/kWh nationally. CA NEM contributed up to 2¢/kWh.
+1.1¢/kWh per 5pp NEM
Econometric; most recent
CPUC Public Advocates (2024)
CA cost shift grew from $3.4B/yr (2021) to $8.5B/yr (2024). ~21–27% of non-solar CA bill supports NEM.
$8.5B/yr (CA, 2024)
Utility-side; excludes grid benefits
Verdant (2021)
CA NEM 2.0 unreformed → $13B increase over 20 years. Drove NEM 3.0 reform proceeding.
$650M/yr avg (CA)
Pre-NEM 3.0
NREL (2025)
Rooftop solar causes <$1/month impact per non-solar ratepayer nationally at current penetration.
<$1/month per HH
Per-household metric; low penetration
CMM Estimate 1995–2025
LBNL/Brattle penetration-price relationship applied to historical NEM deployment. CA ~40–50% of total.
$20–50B national
CMM synthesis
Policy History by Technology, 1975–2025 Six technologies
Nuclear
1954–1979: The Dominant Decade
Federal monopoly on atomic energy
Atomic Energy Act (1954) created the framework for commercial nuclear. Price-Anderson Act (1957) capped liability, transferring risk to the public. Nuclear absorbed 50–60% of all federal energy R&D. DOE nuclear R&D peaked at $8.6B/yr in FY1979. Pfund-Healey (2011): nuclear averaged $3.3B/yr in its first 15 years of public funding vs. $0.4B/yr for all renewables combined.
1979–2000: Freeze and Retrenchment
Three Mile Island ends the expansion era
TMI accident (1979) froze new construction. No new reactor orders placed after 1978 were completed. DOE nuclear R&D budgets fell sharply through the 1980s. Price-Anderson renewed 1988. The Nuclear Waste Policy Act (1982) created the repository framework, with costs borne by ratepayers via the Nuclear Waste Fund ($0.001/kWh). Near-zero state support throughout this period.
2000–2015: Nuclear Renaissance (Aborted)
EPAct loan guarantees and new licensing
EPAct 2005 created $18.5B in DOE loan guarantees for new nuclear, a new production tax credit ($0.018/kWh for 8 years, first 6,000 MW), and streamlined NRC licensing. NRC issued new combined licenses. Vogtle and Summer projects broke ground post-2008. Summer abandoned 2017. Vogtle Units 3&4 completed 2023/2024 at roughly 4x original budget.
2016–2022: State Zero-Emission Credits
States rescue operating reactors
ZEC programs emerged as economically stressed reactors faced premature closure. NY (2016, ~$462M/yr), IL (2017, ~$235M/yr), NJ (2019, ~$300M/yr), CT (2019, ~$200M/yr), OH (2019, rescinded 2023 post-scandal). Palisades (MI): restart supported by ~$300M in Michigan state funding plus a ~$1.5B DOE loan guarantee under Title XVII, the first federal loan guarantee for a nuclear restart. Cumulative ZEC and restart payments: $10–18B. These represented the first material state public funding for nuclear since the Atomic Energy Commission era.
2022–2025: IRA and OBBBA
First federal deployment parity with solar and wind
IRA (2022) §45U created a production credit of up to $15/MWh for existing nuclear (JCT: $13.1B over 2024–2028). First federal nuclear deployment credit comparable in structure to the solar ITC and wind PTC. OBBBA (2025) preserved nuclear incentives past the 2027 cliff that applies to solar and wind. Advanced nuclear also eligible for §48E investment credit and DOE loan guarantees under Title XVII.
Solar
1975–1985: Early R&D and the First Credit
Solar in the shadow of nuclear
DOE solar R&D peaked at ~$0.5B/yr in FY1979 before Reagan-era cuts reduced it to under $0.1B/yr by 1988. Energy Tax Act (1978) created a 10% residential solar credit (expired 1985). Solar remained a rounding error in federal energy support. Cumulative federal solar support 1975–1985: under $3B.
1986–2005: Policy Vacuum
Near-zero federal support; states fill partial gap
PURPA (1978) provided some market access for solar. Iowa (1983) and Minnesota (1994) created the first state standards with renewable preferences. Net metering laws began appearing in the mid-1990s but penetration remained tiny. EPAct 2005 restored the solar ITC at 30% for commercial and 30% residential (capped at $2,000).
2006–2013: ITC Activation and ARRA Surge
The structural turning point
8-year ITC extension (2008) and removal of the residential cap triggered the first major deployment surge. ARRA (2009) added cash grants in lieu of ITC ($1602 grants), DOE loan guarantees (Solyndra, SunPower, First Solar), and $1.5B+ in additional solar support. NC's 35% state ITC (2007–2015) deployed ~$800M–1.2B. State RPS SREC markets in NJ, MA, DC emerged with solar carve-outs at $200–450/MWh.
2014–2021: Scale and NEM Emergence
Cost crossover and the cost-shift question
Solar ITC extended repeatedly (2015, 2020). Module costs fell 90%+ since 2009. Annual ITC value grew from ~$2B (2012) to $7.5B (2022). NEM cross-funding transfers became material: CA cost shift grew to $3.4B/yr by 2021. CPUC Verdant (2021) projected $13B over 20 years if unreformed. NY-Sun, MA SMART, and community solar programs added $1–2B in state support.
2022–2025: IRA Peak and NEM Reform
Maximum federal support; state retrenchment begins
IRA (2022) reset ITC to 30%+ with adders (domestic content, energy community, low-income) potentially reaching 70%. JCT solar ITC: $27.5B in FY2024 alone. Treasury OTA (March 2024) projects $424.6B in ITC+PTC 2024–2033. CA NEM 3.0 (April 2023) cut solar export compensation 75%, materially reducing the cost shift going forward. OBBBA (2025) created a hard 12/31/2027 placed-in-service cliff for new solar.
Wind
1975–1991: R&D and California Demonstration
Wind as an energy security experiment
DOE wind R&D at ~$0.25B/yr in the late 1970s. PURPA (1978) created the first market for wind via "qualifying facility" status. California tax credits (25% state + 25% federal) sparked the first commercial wind farms in the Altamont, Tehachapi, and San Gorgonio passes in the early 1980s. Cumulative federal wind R&D 1975–1991: ~$2B. Most CA wind projects were uneconomic without incentives.
1992–2003: PTC and Boom-Bust Cycles
The intermittent credit problem
Energy Policy Act (1992) created the Production Tax Credit at 1.5¢/kWh (indexed to inflation). PTC expired and revived five times between 1992 and 2012, creating boom-bust installation cycles. Iowa (1983) and Minnesota (1994) enacted early renewable portfolio standards. The PTC stop-start pattern imposed significant investment uncertainty; installations fell sharply in PTC-lapse years (1999, 2001, 2003).
2004–2015: RPS Drives Scale
State mandates as the primary driver
29 states had mandatory RPS by 2009. Wind captured 60–70% of early RPS procurement due to lowest cost among eligible resources. TX CREZ transmission build-out (~$7B, ratepayer-funded) unlocked West Texas wind resources. ARRA (2009) allowed cash grants in lieu of PTC. Annual PTC value grew to ~$3–4B/yr by 2012–2015. LBNL: RPS compliance reached $4.1B/yr nationally by 2017 with wind as primary beneficiary.
2016–2021: PTC Phase-down and Offshore Emergence
Onshore matures; offshore begins
Tax Cuts and Jobs Act (2017) began PTC phase-down to 60% of full value by 2019. State offshore wind mandates began: NY (9 GW by 2035), NJ (7.5 GW by 2035), MA (3.2 GW). OREC premiums of $30–80/MWh over market price. Block Island Wind Farm (2016): first U.S. offshore wind project. Vineyard Wind I approved 2021.
2022–2025: IRA Reset and OBBBA Cliff
IRA restores full PTC; OBBBA creates 2027 deadline
IRA (2022) restored the PTC to full value and extended through 2032 with potential for further extension via clean electricity standards. Offshore Wind Development Act provisions, BOEM lease auctions, and port infrastructure investments. OBBBA (2025) imposed a hard 12/31/2027 placed-in-service deadline for new wind, threatening the offshore project pipeline where projects often take 5–7 years from contract to operation.
Carbon Capture and Storage (CCS)
1975–2000: R&D Only
Carbon capture as an R&D concept
DOE carbon capture R&D began in the mid-1970s as an outgrowth of enhanced oil recovery (EOR) research. The Office of Fossil Energy funded research into post-combustion capture, pre-combustion capture, and oxyfuel combustion. CO₂-EOR projects (Rangely, Weyburn) demonstrated geological storage viability. Sleipner project (Norway, 1996) became the first commercial CO₂ geological storage. Cumulative U.S. federal CCS R&D 1975–2000: roughly $3–5B.
2001–2010: FutureGen and Demonstration Era
Ambitious federal demonstration programs
FutureGen (2003) was a $1B+ DOE-industry partnership for integrated gasification combined cycle (IGCC) with CCS; it was restructured and ultimately cancelled in 2015. ARRA (2009) provided $3.4B for CCS demonstration projects. The Carbon Sequestration Regional Partnerships (7 partnerships) spent roughly $500M mapping geological storage capacity. Section 45Q credit created 2008 at $20/tonne for geological storage and $10/tonne for EOR: too low to drive commercial deployment.
2011–2021: Demonstration Failures and §45Q Reform
Kemper and the road to IRA
Kemper County Energy Facility (Mississippi) failed at $7.5B total cost, abandoned CCS in 2017. Boundary Dam (Saskatchewan, Canada) demonstrated post-combustion capture at commercial scale. Bipartisan Budget Act (2018) reformed §45Q with a ramp schedule reaching $50/tonne for geological storage and $35/tonne for utilization by 2026 — the first commercially meaningful federal CCS credit. The IRA subsequently superseded these BBA amounts before they fully matured. Several projects announced under reformed §45Q, including Petra Nova (operational then suspended). A 2020 TIGTA audit found that 10 claimants accounted for ~$1B in total §45Q credits claimed (2010–2019), with ~87% ($894M) claimed without compliant EPA monitoring and verification plans; the IRS subsequently disallowed ~$531M in noncompliant credits.
2022–2025: IRA Expansion and OBBBA Preservation
§45Q reaches $85/tonne; OBBBA creates EOR parity
IRA (2022) raised §45Q to $85/tonne for geological storage, $60/tonne for utilization, and $180/tonne for direct air capture (DAC) geological storage. DOE committed $3.5B to four regional DAC hubs. Multiple industrial CCS projects announced. OBBBA (July 2025) preserved §45Q beyond 2027 and — critically — raised the utilization/EOR credit from $60 to $85/tonne, creating full parity between permanent storage and enhanced oil recovery for the first time. JCT estimated the OBBBA §45Q expansion will cost an additional ~$14B over FY2025–2034, on top of ~$36B in pre-OBBBA Treasury estimates. FEOC restrictions added for foreign entities.
Battery Storage
1975–2008: Defense Origins and Early R&D
Battery technology as a DOD and DOE research problem
Battery storage R&D originated in DOD and NASA programs. DOE Advanced Battery Research funded lead-acid, nickel-cadmium, and early lithium-ion research. EPRI (Electric Power Research Institute) funded early grid-scale storage demonstrations. The USABC (U.S. Advanced Battery Consortium, 1991) coordinated DOE-automaker battery R&D for EVs. Cumulative federal battery storage R&D through 2008: roughly $1–2B, primarily through vehicle programs.
2009–2014: ARRA and the First Deployment Incentives
Federal investment in grid-scale storage
ARRA (2009) provided $620M for smart grid demonstrations, including early grid storage projects. DOE ARPA-E (created 2009) funded next-generation battery chemistries (flow batteries, sodium-sulfur, advanced Li-ion). California AB 2514 (2010) directed utilities to procure 1.3 GW of storage by 2020. CA SGIP (Self-Generation Incentive Program, established 2001) expanded to cover battery storage. The §48C manufacturing credit supported battery factory investments.
2015–2021: ITC Eligibility and State Mandates
Storage becomes policy infrastructure
IRS Notice 2015-70 clarified ITC eligibility for co-located solar+storage. FERC Order 841 (2018) required grid operators to allow storage participation in wholesale markets. NY, MA, NJ, and OR enacted storage mandates. CA SGIP reached $300M/yr in peak disbursements. NEM 1.0 and 2.0 incentivized solar+storage pairing. Treasury guidance (2020) extended ITC to standalone storage paired with solar. Lithium-ion battery costs fell 90%+ from 2010 to 2021.
2022–2025: IRA Standalone Credit and OBBBA Preservation
The most structurally advantaged technology post-2027
IRA (2022) §48E created the first standalone storage ITC (30%+ with adders), independent of solar co-location. §48C advanced manufacturing credit supported domestic battery production. CA NEM 3.0 (2023) was specifically designed to incentivize solar+storage over solar-only by restructuring export compensation. OBBBA (2025) preserved battery storage credits past 2027. Battery storage is the only major clean energy technology with a clear federal incentive runway through 2030 and rapidly growing state mandate stack.
Geothermal
1975–1985: Post-OPEC R&D Peak
Geothermal as a domestic energy security asset
DOE geothermal R&D peaked at ~$0.35B/yr in FY1979 as part of the post-OPEC energy security response. The Geothermal Energy Research, Development, and Demonstration Act (1974) and the National Geothermal Energy Research, Development, and Demonstration Act (1980) formalized federal support. The Geysers complex (CA) provided the bulk of U.S. geothermal capacity. PURPA (1978) gave geothermal qualifying facility status. Energy Tax Act (1978) created the first federal ITC for geothermal equipment (10–15%), making geothermal one of the earliest renewable technologies to receive a federal investment tax credit.
1986–2004: Budget Cuts and Policy Limbo
Neglected after the oil price collapse
Reagan administration cuts reduced DOE geothermal R&D to under $0.1B/yr by the mid-1980s. Geothermal remained in a policy holding pattern through the 1990s. No new utility-scale geothermal projects of significance came online. The §48 ITC for geothermal power persisted at a reduced 10% rate. EPAct 1992 made geothermal electricity eligible for the new §45 PTC alongside wind and closed-loop biomass — the first production-based credit for geothermal. DOE R&D focused on reducing well drilling costs, which represent 50–60% of geothermal project capital expenditure. Cumulative federal geothermal support 1986–2004: roughly $2B.
2005–2015: EPAct and Enhanced Geothermal
EGS as the long-term prize
EPAct 2005 reauthorized and expanded DOE geothermal programs, including the first federal support for Enhanced Geothermal Systems (EGS). ARRA (2009) provided ~$400M for geothermal demonstration projects. Several state RPS programs added geothermal provisions; NV property tax exemption created. DOE's EGS research at the Newberry Volcano (OR) and Brady Hot Springs (NV). The Geothermal Rising advocacy coalition grew the state RPS carve-out framework.
2022–2025: IRA and the Next-Generation Moment
EGS and OBBBA preservation create a long runway
IRA (2022) extended and expanded both the §48 ITC (up to 30% with prevailing wage/domestic content bonuses) and §45 PTC (up to 2.75¢/kWh) for geothermal, plus specific DOE loan guarantee authority for geothermal exploration. Residential geothermal heat pumps qualified for 30% under §25D. The Geothermal Energy from Oil and Gas Experienced Workforce Act directed DOE to support workforce transitions. OBBBA (2025) gave geothermal uniquely favorable treatment: the construction start deadline for the clean electricity ITC/PTC was extended to January 1, 2035 for geothermal — a full eight years beyond the 12/31/2027 cliff imposed on solar and wind, and the longest runway of any energy technology. MD enacted a specific geothermal RPS carve-out at $94.47/MWh (2022). Fervo Energy and other next-generation EGS developers raised significant private capital against this policy backdrop.
Key Analytical Findings Seven conclusions
01
Net metering materially changes solar's total: and the technology ranking
Incorporating NEM ($20–50B est.) raises solar's cumulative estimate to $185–290B, potentially surpassing nuclear ($155–200B + Price-Anderson). This crossover depends on NEM methodology and Price-Anderson valuation. Neither answer is obviously wrong: they reflect genuine disputes about what counts. Use the scenario toggle on the Overview tab to see each case.
02
Solar and wind state incentives are larger than commonly recognized
Solar's state stack: RPS ($45–70B) + NEM ($20–50B) + state ITCs ($5–10B) = $70–130B. Wind's: RPS ($35–55B) + offshore mandates ($3–8B). These dwarf what shows up in federal public funding inventories alone.
03
Nuclear state incentives are concentrated, recent, and politically fragile
Nuclear had near-zero state support from 1975–2015. Post-2016 ZECs ($8–15B cumulative) are significant but compressed into nine years and remain vulnerable to reversal: as Ohio demonstrated in 2023.
04
RPS compliance costs are the largest undercounted state public funding category
LBNL: national RPS compliance reached $4.7B/yr by 2018. Cumulative 2001–2025: $80–130B shared primarily between solar and wind. Absent from most public funding comparisons that focus on federal tax expenditures. The table below shows directly what the EIA FY2022 report counted versus what this report adds.
EIA FY2022 vs. CMM: What Gets Counted
Why the totals differ so dramatically
CategoryEIA FY2022 Report EIAThis Report CMMDifference and Reason
Nuclear (total FY2022) $390M — tax provisions + limited direct R&D to non-federal recipients ~$1.7B — full DOE-NE appropriation + ZEC ratepayer transfers EIA excludes R&D to federal labs and state ZECs (not federal programs). CMM includes full DOE-NE budget authority and state ZEC programs.
Solar (total FY2022) $7.5B — ITC tax expenditure + direct expenditures ~$12–14B — ITC + SETO R&D + RPS share + NEM EIA excludes state RPS compliance costs (state programs) and NEM (no federal budget impact). CMM adds both.
Wind (total FY2022) $3.6B — PTC tax expenditure + limited direct ~$6–7B — PTC + WTO R&D + RPS compliance share EIA excludes state RPS compliance costs. CMM adds the wind share of national RPS compliance (~$2–2.5B/yr by 2022).
RPS Compliance (all) $0 — explicitly excluded as state program ~$4.7B/yr by 2018; $80–130B cumulative 2001–2025 This single omission accounts for the largest gap between EIA and CMM totals. RPS compliance is funded by ratepayers under state mandate — real public cost, no federal budget impact.
Net Metering $0 — excluded (no federal budget impact) $20–50B cumulative (CMM est.) Ratepayer cost transfer. EIA excludes by definition. CMM includes as structurally analogous to other ratepayer-funded state programs.
Total FY2022 (all energy) ~$18B (EIA FY2022 total, in-scope) Estimated ~$35–45B/yr using CMM definition The ~2x gap is almost entirely explained by RPS compliance costs and NEM transfers, both of which are real ratepayer costs excluded from EIA's federal-budget-only definition.
05
Battery storage is the structural OBBBA winner: federal and state
CA SGIP ($1.5B+), NY/MA/NJ mandates, NEM+storage cross-funding, and preserved post-2027 federal credits position battery storage for an accelerating incentive stack through 2030. Unique state-federal stacking effect shared only with geothermal.
06
IRA §45U creates nuclear deployment credit parity for the first time
§45U provides up to $15/MWh for existing nuclear. JCT: $13.1B over 2024–2028. Theoretical max $11.6B/yr. First time nuclear has received a deployment credit comparable in structure to the solar ITC and wind PTC.
07
CCS and geothermal remain state-incentive thin and federally dependent
Both rely disproportionately on federal programs, making them more exposed to federal policy shifts than solar or wind: which have diversified state support stacks that partially insulate them from federal reversals.

iForward-looking projections excluded. This report covers 1975–2025 retrospective public funding only. The IRA (2022) and OBBBA (2025) created large, uncapped, demand-driven credits whose future cost depends on deployment rates, Treasury rulemaking, and FEOC enforcement. JCT, Treasury, Goldman Sachs, and Princeton REPEAT have published divergent projections ranging from $180B to $900B over 2023–2032. These are not included because actual claims data is not yet available for most post-2022 credits. As actuals become available through IRS statistics and JCT tax expenditure updates, they will be incorporated into future editions.

Key Data Sources
Primary & secondary
SourceCoverageKey Contribution
CRS RS22858 (Clark, 2018)DOE R&D 1948–2018 by technologyNuclear = 48% of all DOE energy R&D over 70 years
EIA Federal Public Funding FY2022All federal energy public fundingFY2022 total ~$18B; solar $7.5B; wind $3.6B; nuclear $390M (pre-§45U)
JCT Tax Expenditure EstimatesAnnual ITC/PTC/§45U/§45Q§45U: $13.1B over 2024–2028; solar ITC: $27.5B in FY2024 alone
LBNL RPS Status ReportsState RPS compliance costs, 2001–2024$4.7B/yr by 2018; roughly half of all U.S. RE growth linked to RPS
LBNL / Brattle (Oct 2025)Factors in U.S. electricity price increases5pp NEM penetration → +1.1¢/kWh nationally; CA NEM → 2¢/kWh
CPUC Public Advocates (2024)CA NEM 1.0/2.0 cost shiftCA cost shift: $3.4B/yr (2021) → $8.5B/yr (2024)
Pfund-Healey DBL (2011)First 15 years of public funding by technologyNuclear: $3.3B/yr; renewables: $0.4B/yr: 10× disparity in early years
Methodology and Sources Full transparency
Purpose and Scope

This report estimates cumulative U.S. federal and state public financial support for six energy technologies over 1975–2025 in real 2024 dollars. It draws on multiple government sources and independent analyses. All values are order-of-magnitude estimates. Annual figures in the charts are constructed from discrete anchor points and interpolated between them — they are not year-by-year audit-quality data.

The report uses a broad definition of public funding that includes: direct federal appropriations (R&D), tax expenditures (credits, deductions), direct grants and loan guarantees, state regulatory compliance costs, and ratepayer cost transfers. This is broader than the EIA subsidy definition, which limits scope to programs with an identifiable federal budget impact and excludes most state programs and ratepayer transfers.

Research and Development
R&D Sources by Technology
Full DOE budget authority
TechnologyDOE OfficePrimary SourceKey Anchor PointsUncertainty
Nuclear Office of Nuclear Energy (NE) DOE NE Budget page (energy.gov/ne/our-budget); CRS RS22858; GAO EMD-79-52 (1979) FY1979 peak ~$5.8B; FY2021=$1,508M; FY2022=$1,655M; FY2023=$1,773M; FY2024=$1,685M (all enacted, real 2024$) Low FY2016+; Medium pre-2000
Solar Solar Energy Technologies Office (SETO) DOE SETO FOA announcements; DOE FY2025 Budget in Brief; CRS RS22858 FY2019=$130M; FY2020=$125M; FY2021~$128M; FY2023~$280–360M; FY2025 req=$318M Medium: SETO budget not always publicly broken out separately from EERE total
Wind Wind Energy Technologies Office CRS R40913 enacted figures (annual series); CRS RS22858 for pre-2010 FY2016=$95.5M; FY2017=$90M; FY2018=$92M; FY2019=$92M; FY2020=$104M; FY2021=$110M; FY2022=$114M Low FY2013+; Medium pre-2009
CCS Fossil Energy and Carbon Management (FECM) EIA FY2016-2022 subsidy report (Table A7); CBO 2012 federal fuel support brief ARRA 2009 ~$3.4B for CCS (multi-year, ~$700M/yr); FECM total ~$750–890M/yr FY2021–2022; CCS-specific subset estimated at ~$450–550M/yr (60–75% of FECM total, excluding methane, critical minerals, hydrogen, NETL operations) Medium-High: FECM budget mixes CCS with other fossil/carbon programs; CCS-specific subset is a CMM estimate. Pre-2010 values interpolated from CRS RS22858.
Battery Storage Vehicle Technologies Office (VTO) + Energy Storage DOE FY2025 Budget in Brief (VTO=$502M req); DOE FY2023 CBJ (VTO=$602M req) VTO enacted FY2016~$280M, rising to ~$450M by FY2022; storage-specific ~25–35% of VTO High pre-2015: VTO includes EVs broadly; grid storage subset is an estimate
Geothermal Geothermal Technologies Office (GTO) CRS R40913 enacted figures (annual series); CRS RS22858 for pre-2010 FY2016=$70M; FY2017=$84M; FY2018=$105M; FY2019=$105M; FY2020=$148M; FY2021=$150M; FY2022=$162M; FY2025=$488M (IIJA-inflated) Low FY2013+; Note: FY2025 figure unusually high due to IIJA supplemental appropriations
!All R&D figures represent full DOE program budget authority — the total appropriation for the relevant technology office. This is broader than the EIA subsidy report definition, which counts only R&D disbursed to non-federal recipients. The two definitions can differ by 2–3x for the same year. This report uses the broader definition because government funding of national laboratory and federally-operated R&D is a real public expenditure that shaped technology development, regardless of whether it flowed to a private entity.
iPre-1990 R&D values for solar, wind, geothermal, and battery storage carry higher uncertainty. Historical program-level data is less granular; values are estimated from CRS RS22858 aggregate totals and DOE budget history tables. The nuclear pre-1990 series is better anchored due to the GAO (1979) review covering FY1950–1978 and the CRS RS22858 nuclear share data.
Tax Credits and Tax Expenditures
Tax Credit Sources by Technology
JCT · EIA · Treasury OTA
Credit / TechnologySourceKey ValuesWhat Is IncludedWhat Is Excluded
Solar ITC (§48/§48E) JCT annual tax expenditure estimates; EIA FY2016–2022 subsidy report (Table A2); Treasury OTA March 2024 FY2016~$2.2B; FY2022=$7.5B (EIA); FY2024 est.~$18–27B (post-IRA); Treasury OTA: $424.6B ITC+PTC over 2024–2033 Residential and commercial ITC; Section 1603 cash grants in lieu of ITC (2009–2011); IRA adders (domestic content, energy community, low-income) State solar ITCs (counted separately under state incentives); MACRS accelerated depreciation (not technology-specific)
Wind PTC (§45) JCT tax expenditure estimates; EIA FY2016–2022 report; CRS wind energy policy reports FY2013 peak ~$5.8B (with ARRA grants); FY2016=$1.3B (EIA); FY2019~$4.0B; FY2022~$3.5B Federal PTC at 2.6–2.75¢/kWh; phase-down periods 2017–2019; IRA extension and restoration to full value Offshore wind ORECs (counted under state mandates); state wind tax exemptions (counted under state incentives)
Nuclear §45U JCT; IRA §45U enacted 2022 (effective tax year 2023) JCT: $13.1B estimated FY2024–2028; theoretical max ~$11.6B/yr (all U.S. nuclear capacity at $15/MWh) §45U production credit for existing nuclear ($15/MWh maximum, phases out as electricity price rises above $25/MWh) Pre-2023 nuclear tax provisions (accelerated depreciation, decommissioning fund deductions) excluded as not technology-specific. EPAct 2005 nuclear PTC (§45J) never triggered — no reactors built under that provision.
CCS §45Q JCT; EIA FY2016–2022 report; IRA expansion analysis Pre-2018: $20/tonne storage, $10/tonne EOR. BBA ramp to $50/$35 (superseded by IRA). IRA: $85/tonne storage, $60/tonne utilization, $180/tonne DAC. OBBBA: $85 for all uses (parity). JCT scored IRA §45Q at ~$3.2B/decade; Treasury estimated ~$30B/decade — order-of-magnitude divergence reflects uncertainty about deployment pace. §45Q as enacted through OBBBA (July 2025); includes EOR parity at $85/tonne. Credit subsidy cost of DOE loan guarantees for CCS counted separately under grants. RGGI and cap-and-trade revenues (indirect; not a direct credit); state carbon pricing adjacency effects. State CCS grants (WY, ND, IL, LA, TX) not included in federal series — see State Incentives tab.
Battery §48C/§48E JCT; IRA §48E standalone storage ITC; §48C advanced manufacturing Pre-IRA: ITC available only for solar-paired storage; §48C manufacturing: $10B IRA allocation. Post-IRA §48E: 30%+ standalone ITC §48E standalone storage ITC (2023+); §48C advanced manufacturing credit for domestic battery production; co-located solar+storage ITC (pre-2023) §45X production credits for battery components (manufacturing, not deployment); EV credits (§30D) excluded as transportation policy
Geothermal ITC/PTC JCT; EIA FY2016–2022 report; IRA/OBBBA provisions §48 ITC for geothermal power since 1978 (10–15%, later 10%, IRA raised to 30% with bonuses). §45 PTC eligibility since EPAct 1992 (up to 2.75¢/kWh). §25D residential GHP credit: 30%. Values small due to limited installed base: ~$250–350M/yr post-IRA. OBBBA extends construction deadline to Jan 1, 2035. §48 ITC for geothermal power; §45 PTC eligibility (choose one); §25D residential geothermal heat pump credit; §48E/§45Y clean electricity credits (post-2024) State geothermal incentives (counted separately); exploration risk sharing (DOE loan guarantees for EGS excluded — no such guarantees yet issued)
iTax expenditure estimates measure foregone federal revenue, not cash outlays. The JCT and Treasury produce annual estimates; these are the primary source for all credit values in this report. Post-IRA values (2023+) carry greater uncertainty because the IRA created uncapped, demand-driven credits — actual utilization depends on deployment rates and Treasury rulemaking on adder qualifications.
Grants and Direct Expenditures

This category covers non-R&D direct federal expenditures: demonstration project grants, ARRA cash grants in lieu of tax credits (Section 1603), DOE loan program disbursements, and other direct support. The primary sources are EIA FY2016–2022 (Table A6), DOE USASpending.gov data, and CBO analyses.

ProgramTechnologiesAmountPeriodSource
Section 1603 Cash Grants (ARRA)Wind (~$14.7B, 56%), Solar (~$8.4B, 32%), Geothermal, Other~$26.2B total disbursed2009–2011Treasury data; EIA subsidy reports
DOE Loan Guarantees (Title XVII)Nuclear (Vogtle ~$8.3B; Palisades ~$1.5B); Solar (SunPower, First Solar, Solyndra); Wind (offshore)~$16B+ committed2008–2025DOE Loan Programs Office; EIA 2023 report; CRS R47293
ARRA Clean Energy DemonstrationCCS (FutureGen, regional partnerships), Smart Grid, Solar, Wind~$30B total EERE+FEFY2009–2014CBO 2012; EIA 2013 subsidy report
IIJA Clean Energy DemonstrationsCCS (4 DAC hubs $3.5B), Battery, Geothermal, Nuclear (advanced)~$16B for EEREFY2022–2031CRS E&W Appropriations reports; DOE program pages
FutureGen (CCS demo)CCS only~$1B+2003–2015DOE; CBO
!Loan guarantees are not the same as grants. The federal cost of a loan guarantee is the credit subsidy cost — the present value of expected losses, not the face value of the loan. For Vogtle, DOE's estimated credit subsidy cost was roughly $460M on the $8.3B guarantee. However, the guarantee enabled a project that could not obtain conventional private financing, so the full face value is reported in some analyses as the public exposure. This report notes the distinction but uses face values for comparability.
iChart methodology note: The nuclear loan guarantee chart stream apportions the Vogtle $8.3B commitment across construction years (2010–2022, ~$0.4–0.6B/yr) and the Palisades $1.5B guarantee across 2023–2025. These are annualized approximations of multi-year commitments, not official annual DOE LPO disbursement figures. Pre-2010 nuclear loan guarantee values are zero — no meaningful federal loan guarantees for nuclear existed before EPAct 2005 / Title XVII.
RPS and State Compliance Costs

Renewable Portfolio Standard (RPS) compliance costs are the above-market payments made by utilities (and ultimately ratepayers) to procure renewable electricity in compliance with state mandates. These are the largest single state-level public support mechanism and are largely absent from federal subsidy inventories.

How RPS Compliance Costs Are Estimated

Primary source: Lawrence Berkeley National Laboratory (LBNL) Renewable Portfolio Standards Annual Status Report (published annually). LBNL calculates total above-market cost as the difference between the contract price paid for renewable energy and the applicable avoided-cost or wholesale market benchmark. For SREC (solar renewable energy credit) markets, the compliance cost includes SREC prices paid at auction or bilaterally.

Key LBNL findings used in this report: Total national RPS compliance cost reached $4.7B/yr by FY2018. Solar SREC carve-outs (NJ, MA, DC, MD, CT) have carried prices of $200–450/MWh, generating the majority of SREC market value. Roughly half of all U.S. renewable energy growth 2000–2020 is attributable to RPS policies.

Wind vs. solar allocation: LBNL reports total RPS compliance costs, not wind-vs.-solar splits for every year. The solar and wind RPS shares in the charts are CMM estimates based on renewable procurement shares by year from LBNL deployment data. This introduces meaningful uncertainty particularly before 2015.

TypeTechnologiesEst. CumulativeKey SourceIncluded/Excluded
RPS Compliance CostsSolar (SREC carve-outs); Wind (general RPS procurement)$80–130B total, 2001–2025LBNL RPS Status Reports (annual); LBNL Barbose et al. 2019Included. Above-market cost only, not total contract value
TX CREZ TransmissionWind~$7BPUCT; EIA grid investment dataPartially included in wind grants/infrastructure; note this was ratepayer-funded, not state appropriation
Nuclear ZECsNuclear (NY, IL, NJ, CT, OH)$10–18B, 2016–2025State utility commissions; individual ZEC proceedings; CMM calculation from program $/yr ratesIncluded. Above-market payment to nuclear operators; funded through electricity rates
Offshore Wind ORECsWind$3–8B cumulative to dateState PUC OREC proceedings (NY, NJ, MA, CT); BOEM dataIncluded; though most payments are still prospective. Values reflect contracts executed, not yet fully disbursed
Geothermal RPS Carve-outsGeothermal$1–3B cumulativeMD PSC (MD RPS carve-out $94.47/MWh enacted 2022); NV, AZ state utility filingsIncluded; thin sourcing. Cumulative total modest given small installed base
Net Metering
What Net Metering Is and Is Not

Net metering (NEM) is a utility billing mechanism that credits distributed solar owners for excess electricity at or near the full retail rate (typically $0.25–0.35/kWh). The cost transfer arises because the retail rate includes fixed infrastructure costs (poles, wires, transformers) that solar owners avoid paying when they export power at the retail price but still use the grid for backup. Non-solar ratepayers pay more to cover those fixed costs.

This is not a government expenditure. It does not appear in federal budgets, state budgets, or EIA subsidy inventories. It is a regulatory design choice that redistributes costs among ratepayers. CMM includes it because: (1) it is a material public policy intervention that benefits a specific technology; (2) the scale is comparable to or larger than many programs that are counted; and (3) structural analogues (Price-Anderson for nuclear, RPS for wind) are included.

SourceMethodFindingCMM Use
LBNL / Brattle (Oct 2025)Econometric analysis of state electricity price changes; controlled for fuel mix, demand, infrastructure5pp increase in net-metered solar penetration associated with +1.1¢/kWh nationallyPrimary quantitative anchor for national cost transfer estimate
CPUC Public Advocates Office (2024)California-specific rate analysis: fixed cost shortfall from NEM 1.0/2.0 participantsCA cost shift grew from $3.4B/yr (2021) to $8.5B/yr (2024); ~21–27% of non-solar CA billsCalifornia anchor point; CA = ~40–50% of national NEM total
Verdant Associates (2021)CA NEM 2.0 unreformed 20-year cost projection for CPUC NEM 3.0 proceedingCumulative CA cost shift ~$13B if unreformed over 20 years (~$650M/yr avg)Pre-NEM 3.0 baseline; confirms CPUC methodology
NREL (2025)National household-level analysis at current (2024) penetration rates<$1/month per non-solar ratepayer nationally at current penetrationLower bound; per-household metric understates total when scaled across millions of non-solar households
CMM National Estimate: $20–50B Cumulative 1995–2025

Method: Apply the LBNL/Brattle penetration-price elasticity (+1.1¢/kWh per 5pp NEM penetration) to historical annual NEM deployment data. Multiply implied price premium by non-solar electricity consumption. CA is modeled separately using the CPUC anchor points ($0–0.5B/yr 1995–2010, rising to $3.4B/yr by 2021, $8.5B/yr by 2024, then declining post-NEM 3.0). National = CA estimate + 2–3x multiplier for other states (CA has ~40–50% of national NEM capacity).

Why the range is wide: (1) Disputed causation — studies disagree on whether NEM penetration is the cause of price increases vs. correlated factors; (2) Value-of-solar offset — solar advocates argue distributed solar provides grid services (peak reduction, T&D deferral, avoided emissions) worth $0.06–0.14/kWh, potentially exceeding the retail rate credit; (3) Pre-2015 data is thin; most NEM growth occurred after 2010.

What is excluded: NEM+storage cost transfers are counted in the battery storage state stream, not here. Commercial NEM (non-residential) is included in the estimate. Community solar cost transfers are not separately quantified.

ZECs, State Mandates, and Other State Programs

This category covers state-level programs outside of RPS compliance that provide direct financial benefit to specific technologies. Like RPS compliance costs, most of these are ratepayer-funded rather than government-appropriated.

Program / TypeTechnologyCalculation MethodCumulative EstimateSource Quality
Zero Emission Credits (ZECs)NuclearAnnual $/yr program rate × years active: NY ~$462M/yr (2016+); IL ~$235M/yr (2017+); NJ ~$300M/yr (2019+); CT ~$200M/yr (2019+); OH $150M/yr (2019–2022)$10–18B (2016–2025)High: program rates from state PUC orders; date ranges from enacted legislation
Palisades Restart (MI)NuclearMI state appropriation ~$300M (enacted); DOE Title XVII loan guarantee ~$1.5B (announced 2024)~$1.8BHigh: specific program with published amounts. Note: DOE loan guarantee = credit subsidy cost ~$460M, not $1.5B face value
CA SGIP (Battery)Battery StorageCPUC annual SGIP program disbursements; program total through 2025. Morgan Lewis (2026) confirms $280M most recent allocation~$1.5B+ (2001–2025)High: CPUC public program data
State Battery Procurement MandatesBattery StorageMorgan Lewis (2026) documents 13 states with procurement targets. Cost transfer estimated from ratepayer-funded contracts above market. Morgan Lewis: ~40 GW by end-2026 U.S. installed; ~80–85% in CA and TX$3–8B est. (2020–2025)Medium: mandate GW targets are well-sourced; dollar cost of above-market contracts requires per-state rate case analysis not fully available
State Solar ITCs / RebatesSolarKey programs: NC 35% ITC (2007–2015, ~$800M–1.2B total); CA CSI (2006–2013, ~$2B); MA SMART (~$200M/yr); NY-Sun ($1B+ committed). State budget documents + program reports$5–10B est.Medium: major programs well-sourced; smaller state programs not fully catalogued
MD Geothermal RPS Carve-outGeothermalMD PSC enacted $94.47/MWh geothermal tier (2022). Small installed base limits total cost transfer. Estimate based on contracted capacity × $/MWh premium above market<$0.5B to dateHigh for program terms; low for utilization (minimal capacity deployed)
What Is Not Included and Why
Excluded ItemRelevanceReason for Exclusion
Price-Anderson Act (Nuclear)Caps nuclear operator liability at ~$13.5B; estimated full liability could be $100B+. GAO, CBO, and independent analysts treat this as a substantial implicit subsidy.No identifiable federal budget impact. EIA explicitly excludes it. The cost transfer is contingent on an accident occurring — in expectation, the value depends on probability assumptions that are highly disputed. Including it could add $5–50B to the nuclear cumulative total depending on assumptions. Users should be aware this is excluded.
Nuclear Waste Fund (DOE)~$43B in the fund (ratepayer-funded at 0.1¢/kWh since 1983); permanent repository never built despite decades of collections.Ratepayer-funded; not a public expenditure. The unresolved repository situation represents a federal obligation not fully discharged — arguably a future public cost. Not quantified here.
Federal Power Marketing Administrations (Hydro)BPA, WAPA, SWPA provide below-market federal hydropower. EIA 2008 estimated ~$2B/yr in interest rate support.Hydropower is not one of the six technologies covered by this report.
Military / DOD nuclear programsNaval nuclear propulsion R&D (DOD/Navy) and weapons programs (NNSA) drove significant nuclear technology development that benefited civilian nuclear.Defense programs have no civilian market application as a primary purpose; attribution to commercial nuclear R&D would require non-standard assumptions. NNSA weapons budget exceeds $20B/yr — including any fraction would dramatically skew the nuclear R&D estimate.
General tax provisions (MACRS, bonus depreciation)Accelerated depreciation benefits all capital-intensive industries including energy.Not technology-specific; benefits all capital investments. EIA explicitly excludes these from its energy subsidy definition. Including them on a pro-rata basis would add substantially to all technologies.
EV tax credits (§30D, §45W)Indirectly benefits battery storage through manufacturing scale and cost reduction.Transportation policy, not energy storage policy. Attribution to grid storage would require cost-allocation assumptions.
State and local property tax abatements and exemptions Wind: TX Chapter 312/313 abatements (largest program nationally; enabled most West Texas wind development); IA full property tax exemption on wind turbines; MN, KS, OK, SD, ND exemptions. AWEA estimated TX Chapter 313 alone provided ~$1.5B in abatements to wind projects through its 2022 expiration.

Solar: ~36 states exempt solar installations from property tax assessment. Major states include CA, NY, NJ, MA, CO, AZ. Lawrence Berkeley (2021) found state solar property tax exemptions saved solar owners $0.5–1.5¢/kWh in many states, implying meaningful cumulative value at current installed base.

Nuclear: Treatment varies dramatically by state. Some states tax at full assessed value; others use production-value assessment (far lower given capital intensity); others have negotiated payment-in-lieu-of-taxes (PILOT) agreements. Large nuclear plants can represent 30–50% of a county's assessed value, making the abatement terms consequential.

Battery/CCS/Geothermal: Property tax exemptions exist in some states for storage and geothermal; not systematically catalogued at dollar scale.
Why excluded from all technology totals: No single national database tracks actual abatement dollar values by technology at the project or state level. DSIRE (Database of State Incentives for Renewables and Efficiency) catalogs program existence and terms but does not report aggregate expenditure values. Individual state analyses exist — AWEA/ACP for wind, LBNL for solar — but use different methodologies and coverage periods that cannot be directly summed into a cross-technology comparable series.

The asymmetry this creates: Wind and solar likely benefit most in absolute dollar terms from property tax exemptions given their large installed bases and broad state coverage. Nuclear may benefit most on a per-plant basis given asset values. CCS, battery storage, and geothermal have limited coverage. Excluding abatements therefore creates a mild undercount that is not uniform across technologies — it disproportionately understates wind and solar state support relative to CCS and geothermal.

Future inclusion: A rigorous abatement analysis would require compiling county assessor records, PILOT agreements, and state tax expenditure reports for each major project in each state. This is a tractable research project but beyond the scope of the current report. It will be incorporated in a future edition.
Community solar cost transfersCommunity solar subscribers typically receive credits at above-wholesale rates.Methodology for estimating cross-subsidy value not established; programs vary significantly by state. Not included in NEM estimate.
Known Exclusions and Data Gaps

This report does not capture all forms of public support for energy technologies. The following material categories are excluded or only partially captured, with approximate magnitudes where estimable. Transparency about what is not included is as important as what is.

ExclusionTechnologies AffectedEst. MagnitudeReason for Exclusion
MACRS 5-Year Accelerated Depreciation Solar, Wind, Battery, Geothermal, CCS (5-yr recovery vs. 20-30 yr economic life) $5-15B/yr (all energy); cumulative $50-150B+ MACRS (est. 1986) is a general business tax provision, not energy-specific. Treasury classifies it as part of the reference tax law baseline, meaning it is not a "tax expenditure" under that definition. The 5-yr recovery period for renewables (vs. 20-30 yr economic life) provides material benefit. CBO includes MACRS in wind/solar analyses. Excluded because no technology-specific annual series exists; benefit is entangled with bonus depreciation (100% under TCJA through 2022, phasing to 40% in 2025). If included, would increase solar and wind cumulative totals by roughly 15-25%.
Section 1603 Cash Grants (allocation gap) Wind (~$14.7B, 56%), Solar (~$8.4B, 32%), Geothermal and other (~$3.1B, 12%) $26.2B total (Treasury) Treasury disbursed $26.2B to 109,766 clean energy projects (2009-2018). This amount is partially reflected in the solar and wind grant streams in the charts, but may be understated. Wind received 56% of dollars despite only 1% of project count. The technology-level annual disbursement breakdown is not fully reconciled against chart grant data; a gap of $5-15B may exist.
State Property Tax Exemptions Solar (36 states), Wind (IA, TX, KS, MN, OK, others), Geothermal (select) $5-20B cumulative (all technologies) No aggregate annual series exists. 36 states exempt solar from property tax; IA exempts wind for 5-10 years; TX Ch. 312 wind abatements est. $200-500M cumulative. This is the single largest identified data gap in the analysis.
State Sales Tax Exemptions Solar (25 states), Wind (IA, MN, CO, others), Geothermal (select) $2-8B cumulative 25 states exempt solar equipment; several exempt wind. On a $20K residential system at ~6% sales tax, the exemption is ~$1,200. At ~5M cumulative U.S. residential installations, residential solar alone may represent $3-6B. No aggregate annual series exists.
DOE LPO Portfolio (non-nuclear) Solar mfg., Battery mfg. (Ultium, BlueOval SK), Clean vehicles, Grid $40B+ committed post-IRA Only nuclear (Vogtle, Palisades) is tracked in this report. The broader LPO portfolio for battery/solar manufacturing is $40B+ in face value and growing. Excluded because credit subsidy costs are not publicly disaggregated by technology.
Section 45X Mfg. PTC Solar components, Wind components, Battery cells, Inverters $30-60B over 2023-2032 (JCT) Manufacturing credit, not deployment. Excluded to maintain deployment-focused framing, but magnitude rivals several included categories. OBBBA FEOC restrictions may reduce utilization.
EV Credits (section 30D/45W) Battery (indirectly: EV demand drives battery cost reduction) $50-100B+ over 2023-2032 Transportation policy, not energy generation. OBBBA terminated consumer EV credits after Sept. 30, 2025. However, EV credits are the largest single driver of battery technology cost reduction.
CCS State Grants and EOR Exemptions CCS $0.5-2B (indirect) Previously included as a chart stream; removed for insufficient sourcing. See State Incentives tab.
Nuclear Decommissioning Fund Tax Benefits Nuclear $1-3B cumulative Tax-deductible contributions to qualified decommissioning funds (section 468A). Modest magnitude; reflects deferred tax liability rather than direct public funding.
iIf MACRS, state property/sales tax exemptions, the full LPO portfolio, and Section 1603 allocation gaps were included, cumulative totals for solar and wind would increase by roughly 20-40%. Battery storage totals would increase significantly due to LPO manufacturing loans. Nuclear totals would increase modestly. CCS totals would be largely unchanged. The relative ranking of technologies is unlikely to change, but the absolute magnitudes would be materially larger.
abel" style="font-size:11px">08 Inflation Adjustment and Currency
Real 2024 USD

All values are expressed in real 2024 U.S. dollars. Nominal historical values are converted using the GDP implicit price deflator from OMB Historical Tables (Table 10.1), consistent with the deflator used in CRS RS22858. The GDP deflator is preferred over CPI for government spending comparisons because it better reflects the prices of goods and services government programs actually purchase.

Important caveats: (1) Energy equipment prices have fallen dramatically — solar module costs declined 99%+ since 1977 in real terms. Expressing early solar R&D in 2024 dollars gives it apparent parity with modern dollar amounts, but the purchasing power for actual hardware was very different. (2) For tax credits, the nominal value of foregone revenue is reported as stated by JCT/Treasury; inflation-adjusting these is less meaningful because they represent current-year revenue impacts.