Cleantech startups have among the broadest federal funding options of any sector. DOE, NSF, EPA, USDA, and multiple DOD components all fund clean energy R&D through SBIR. ARPA-E funds breakthrough energy concepts at $500K-$10M+. And until recently, the Inflation Reduction Act added billions more in tax credits and demonstration funding.
But 2026 is a different landscape. SBIR just restarted after a 5-month authorization lapse. The IRA has been partially rolled back. DOE's Office of Clean Energy Demonstrations was dissolved. Some programs are open, some are paused, and some are gone entirely.
This guide maps every major program, tells you what's actually available right now, and helps you figure out where your startup fits.
The landscape in 2026: what changed
Three things shifted the cleantech funding landscape since 2024:
1. SBIR reauthorization (March 2026). After a 5-month lapse, SBIR/STTR was reauthorized through September 2031. Agencies are now restarting solicitations on staggered timelines. DOE and DOD are first (April-May 2026). EPA and USDA will follow later in summer 2026. The new law also created Strategic Breakthrough Awards -- up to $30M for post-Phase II companies with matching private capital.
2. IRA rollbacks (July 2025). The One Big Beautiful Bill Act cut several IRA clean energy provisions. The 48C Advanced Energy Project Credit ($10B) is fully allocated with no new rounds. Technology-neutral clean electricity credits (45Y/48E) were largely repealed. DOE's Loan Programs Office had its IRA authority stripped. Some credits survive (45X manufacturing, 45V hydrogen) but with accelerated sunsets.
3. DOE restructuring. The Office of Clean Energy Demonstrations (OCED) was dissolved, terminating 223 projects and $7.5B in funding. This primarily affected large-scale demonstration projects, not SBIR. DOE SBIR is fully intact and restarting.
The bottom line for startups: SBIR is back and fully funded. ARPA-E is active but constrained. The IRA supplemental programs are mostly gone or winding down. For seed-to-Series A cleantech companies, the core SBIR pathway remains the most reliable source of non-dilutive capital.
Federal SBIR programs for cleantech
DOE SBIR/STTR -- the anchor program
DOE runs the largest cleantech-focused SBIR program by far: $300M+ annually across 60+ technical topics covering virtually every clean energy technology area.
| Details | |
|---|---|
| Phase I | Up to $200,000 over 9 months |
| Phase II | Up to $1,100,000 over 2 years |
| Cycle | Two solicitation releases per fiscal year (Release 1, Release 2) |
| Key requirement | Mandatory Letter of Intent (LOI) before full proposal |
| 2026 status | Restarting; first post-reauthorization solicitation expected late April -- May 2026 |
Technology areas by DOE office:
- Office of Energy Efficiency and Renewable Energy (EERE): Solar, wind, geothermal, bioenergy, hydrogen, energy storage, building efficiency, advanced manufacturing, vehicle technologies
- Office of Fossil Energy and Carbon Management (FECM): Carbon capture and storage, direct air capture, methane reduction, critical minerals
- Office of Nuclear Energy (NE): Advanced reactors, nuclear fuels, small modular reactors
- Office of Electricity (OE): Grid modernization, energy storage, transmission technologies
- Office of Science: Fusion energy, advanced computing for energy, basic energy sciences
The LOI trap: DOE is one of the few SBIR agencies that requires a Letter of Intent before accepting full proposals. The LOI is a brief (1-2 page) overview of your proposed work. Miss the LOI deadline and you cannot submit a full proposal for that cycle -- no exceptions. LOI deadlines are typically 4-6 weeks before full proposal deadlines. When DOE publishes its first FY2026 solicitation, track both deadlines carefully.
Where to look: science.osti.gov/sbir for topic listings. DOE publishes topic descriptions months before proposal deadlines, giving you time to identify matches.
NSF SBIR -- the fastest path
NSF doesn't publish cleantech-specific topics. Instead, it defines broad technology areas and evaluates any technology that fits. The Energy Technologies track covers solar, wind, grid storage, energy efficiency, hydrogen, nuclear, geothermal, carbon capture, and advanced materials for energy.
| Details | |
|---|---|
| Phase I | Up to $305,000 over 6-18 months |
| Phase II | Up to $1,250,000 |
| Entry point | Rolling Project Pitches (reviewed within 3 weeks) |
| 2026 status | Active; Project Pitches accepted now, next full proposal deadline May 5, 2026 |
Why start here: NSF's Project Pitch system lets you test whether your technology is a fit before investing weeks in a full proposal. Submit a brief pitch, get a response in ~3 weeks, and if invited, submit the full proposal. No other SBIR agency offers this kind of low-friction entry point. See our NSF SBIR Project Pitch guide for how to write one.
EPA SBIR -- environmental technology
EPA's SBIR program is smaller but highly relevant for water, air quality, and remediation technologies.
| Details | |
|---|---|
| Phase I | Up to $100,000 over 6 months |
| Phase II | Up to $400,000 over 2 years |
| Commercialization Option | Additional $100,000 supplement to match third-party investment |
| Cycle | Single annual solicitation |
| 2026 status | Paused; expected compressed cycle in spring/summer 2026 |
Topics: PFAS remediation, clean water technologies, air quality monitoring, waste reduction and circular economy, safer chemicals, environmental justice solutions, and climate adaptation.
Key detail: EPA has no STTR program. If you need a university partnership, you'll use SBIR with a university subcontract (capped at one-third of Phase I). EPA also doesn't participate in the new Strategic Breakthrough Awards.
USDA SBIR -- ag-tech and bioenergy
Relevant if your cleantech intersects with agriculture, food systems, or rural energy.
| Details | |
|---|---|
| Phase I | Up to $175,000 (most topics) |
| Phase II | Up to $600,000 over 24 months |
| Extras | Up to $6,500 in Technical and Business Assistance (TABA) funds |
| 2026 status | FY2026 solicitation not yet released; expected summer 2026 |
Topics: Precision agriculture, bioenergy and biofuels, soil health monitoring, sustainable forestry, agricultural AI and robotics, food safety technology.
DOD cleantech tracks
Several DOD components fund energy technologies, particularly around military energy resilience and field-deployable clean power.
Army xTechSBIR CleanTech is the most direct path. It's a dedicated cleantech competition with topics including energy storage, clean microgrids, electric transportation, and clean industrial technology. Winners receive an opportunity to submit Phase I or Direct-to-Phase II SBIR proposals.
Other DOD cleantech entry points:
- Army energy demand reduction and resiliency topics
- Navy shipboard energy and power systems
- Air Force (AFWERX) operational energy topics
- DARPA energy-related BAAs (less frequent, larger scope)
DOD Phase I awards range from $50K-$250K depending on the component. Phase II awards range from $750K-$1.75M. DOD was among the first agencies to restart solicitations after the reauthorization (March-April 2026).
NASA SBIR -- space-adjacent clean energy
NASA funds power generation and storage technologies relevant to space applications, but with terrestrial spillover: solar arrays, fuel cells, batteries, thermal management, advanced materials, and sustainable aviation fuels.
| Details | |
|---|---|
| Phase I | Up to $150,000 over 6 months |
| Phase II | Up to $850,000 over 24 months |
| 2026 status | Transitioning to BAA model; release TBD, expected April-May 2026 |
NASA awards are smaller than DOE or NSF, but the dual-use angle (space + terrestrial) can strengthen your commercial narrative.
The complete SBIR comparison for cleantech
| Agency | Phase I | Phase II | Best for | 2026 Status |
|---|---|---|---|---|
| DOE | $200K | $1.1M | Core clean energy (storage, grid, nuclear, hydrogen, solar, wind) | Restarting April-May |
| NSF | $305K | $1.25M | Any energy tech (broadest scope, fastest entry) | Active now |
| EPA | $100K | $400K | Water, air, PFAS, remediation, circular economy | Summer 2026 |
| USDA | $175K | $600K | Ag-tech, bioenergy, rural energy, soil | Summer 2026 |
| DOD | $50-250K | $750K-1.75M | Energy resilience, field power, microgrids | Restarting now |
| NASA | $150K | $850K | Space power, batteries, fuel cells, aviation | April-May 2026 |
Beyond SBIR: larger programs
ARPA-E
ARPA-E funds transformative energy research at a scale SBIR can't match: $500K to $10M+ per project. It's not an entitlement program -- ARPA-E issues focused Funding Opportunity Announcements for specific technology challenges, plus periodic OPEN solicitations for breakthrough concepts across all areas.
The bar is high. ARPA-E funds technologies that could fundamentally change how we produce, store, or use energy. Incremental improvements to existing technology don't qualify. The agency wants "if this works, it changes the economics of the entire sector" proposals.
2026 reality: ARPA-E faces significant budget pressure (the administration proposed a 57% cut). The agency is still issuing FOAs and posting teaming partner lists, but fewer new programs are launching compared to 2023-2024. If you have genuinely breakthrough energy technology, monitor arpa-e-foa.energy.gov for opportunities. If your technology is evolutionary rather than revolutionary, SBIR is a better fit.
Key details:
- For-profit entities incorporated in the US can apply as lead or team member
- Cost share above 20% is strongly encouraged (not formally required for all programs)
- Typical project duration: 2-3 years
- Current opportunities: teaming partner lists for Advanced Stimulation & Enhanced Recovery Technologies (ASER) and Advanced Reactor Fuels
DOE non-SBIR funding opportunities
DOE issues Funding Opportunity Announcements (FOAs) through its technology offices (EERE, FECM, NE) that aren't part of SBIR. These sit between SBIR and ARPA-E in scale, typically $500K to $2M+ per project, and are open to small businesses as prime or sub-applicants.
How they differ from SBIR: DOE FOAs are topic-specific (e.g., "next-generation solar cell manufacturing" or "carbon mineralization pilots"), often require cost share (20-50%), and follow different review processes. They're worth monitoring if your technology fits a current DOE priority area.
DOE Technology Commercialization Fund (TCF) is another path worth knowing. TCF funds partnerships between national labs and private companies to move lab technologies toward market. If your technology builds on or complements national lab research, TCF can fund the bridge work. Awards vary by project.
Where to look: energy.gov/eere/funding for EERE FOAs. infrastructure-exchange.energy.gov for the broader DOE funding exchange.
Selected state programs
State clean energy programs are hit-or-miss, but a few consistently fund startups:
| Program | State | Amount | Best for |
|---|---|---|---|
| NYSERDA | New York | $50K-$1M+ | Clean energy technology demonstration |
| MassCEC | Massachusetts | Varies | Clean energy R&D and pilots |
| MassVentures START | Massachusetts | $100K-$500K | Companies with existing SBIR Phase II (supplements federal) |
| California Energy Commission | California | $50K-$500K+ | Grid innovation, building efficiency, transportation |
| DCEO SBIR Match | Illinois | Up to $100K | Matches federal SBIR Phase I awards |
State programs work best when stacked with federal grants. MassVentures START, for example, specifically targets companies that have won SBIR Phase II -- it funds the commercialization activities that federal grants don't cover.
IRA tax credits: what's left for startups
The Inflation Reduction Act originally added billions in clean energy tax credits. After the July 2025 reconciliation bill, here's what's still relevant to startups:
45X -- Advanced Manufacturing Production Credit (still available)
Per-unit credit for domestic production of solar components, wind components, inverters, battery cells, and critical minerals. If you're manufacturing clean energy components in the US, this credit applies to your production output.
- Wind component credits end after December 31, 2027
- Full phaseout begins 2030, terminated after 2032
- Foreign Entity of Concern (FEOC) restrictions apply starting 2026
- Startup angle: Pre-revenue companies can sell credits to profitable entities for cash using IRA's credit transferability provision (preserved under the reconciliation bill)
45V -- Clean Hydrogen Production Credit (available, accelerated sunset)
Up to $3/kg for the cleanest hydrogen production (well-to-gate emissions below 0.45 kg CO2e/kg). Available for facilities where construction begins by December 31, 2027 (moved up 5 years from the original IRA sunset).
What's gone or fully allocated
| Program | Status | Detail |
|---|---|---|
| 48C Advanced Energy Project Credit | Fully allocated | All $10B distributed across two rounds (2024-2025). No new rounds. |
| 45Y/48E Technology-Neutral Clean Electricity | Largely repealed | Not available for projects starting construction after ~September 2025 |
| DOE Loan Programs Office (IRA authority) | Repealed | Existing commitments honored; no new IRA-funded loans |
| OCED demonstration projects | Dissolved | 223 projects terminated, $7.5B reclaimed |
Stacking grants across agencies
You can apply to multiple SBIR agencies simultaneously, and you should. Each agency evaluates proposals independently. A battery startup could submit to DOE SBIR (energy storage topic), NSF SBIR (energy technologies track), and DOD (Army energy resilience) in the same cycle without conflict.
Rules to know:
- You cannot use the same SBIR funds to pay for the same work twice. Each grant must fund a distinct scope of work, even if the underlying technology is the same.
- You can hold multiple active SBIR awards from different agencies concurrently. A DOE Phase I and an NSF Phase II at the same time is fine as long as the scopes don't overlap.
- State grants and IRA tax credits can stack with federal SBIR, but some state programs (like DCEO SBIR Match) are explicitly designed to supplement a federal award.
- The new Strategic Breakthrough Awards require prior Phase II completion and 100% matching from private capital or qualifying government sources, making them relevant for Series A companies with existing SBIR track records.
The stacking strategy: Use NSF Phase I to validate feasibility, DOE Phase I for a deeper technology-specific dive, and state programs to cover commercialization activities that federal grants don't fund. Many of Cada's cleantech clients build multi-agency portfolios that total $1M+ in non-dilutive funding within 18-24 months.
Where to start
If you're a first-time applicant: Start with NSF. The Project Pitch system lets you test fit in 3 weeks with minimal time investment. If NSF isn't the right agency match, the exercise still forces you to articulate your innovation clearly -- useful for any SBIR application.
If you know your technology area:
- Grid, storage, nuclear, hydrogen, carbon capture → DOE SBIR (watch for the first FY2026 solicitation)
- Water, air, PFAS, remediation → EPA SBIR (coming summer 2026)
- Ag-tech, bioenergy, soil → USDA SBIR (coming summer 2026)
- Dual-use energy/defense → DOD cleantech tracks (restarting now)
- Breakthrough energy concept → ARPA-E (if the bar fits)
If you're manufacturing components: Look at 45X tax credit eligibility. Even pre-revenue companies can monetize these credits through transferability.
If you want a personalized assessment: We map cleantech startups to the best-fit programs across all agencies. Book a strategy review and we'll tell you which programs match your technology, where you're most competitive, and what order to apply in.
For a broader view of how SBIR works across all sectors, see our complete SBIR guide. For how agencies score applications, see how SBIR applications are scored.