Solar Topics in Small Business Innovation Research and Small Business Technology Transfer (SBIR/STTR) | Department of Energy

If you’re a small business developing innovative solar energy technology, the Department of Energy’s Solar SBIR (Small Business Innovation Research) and STTR (Small Business Technology Transfer) programs can provide up to $1.3 million in non-dilutive funding to help you commercialize your innovation. This is grant funding specifically for small businesses working on solar hardware, software, or systems that can advance the deployment and performance of solar energy in the United States.

The program operates in phases: Phase I provides up to $200,000 for 6-12 months to prove technical feasibility and commercial potential. If you succeed in Phase I, you can apply for Phase II funding of up to $1.1 million for 24 months to develop a prototype and demonstrate commercial viability. Some companies also access Phase IIB funding (commercialization support) and Phase III (non-SBIR funding for production and sales).

What makes SBIR/STTR particularly valuable is that it’s non-dilutive—you don’t give up equity. The government funds your R&D, you retain ownership of your technology and company, and you’re free to commercialize your innovation. For early-stage solar companies, this can be the difference between getting your technology to market and running out of runway before you find product-market fit.

The Solar Energy Technologies Office (SETO) within DOE releases specific topic areas each year focusing on priorities like advanced photovoltaics, grid integration, power electronics, manufacturing innovations, and solar recycling. Your proposal must address one of these topic areas and demonstrate both technical innovation and commercial potential.

Key Details at a Glance

What SBIR and STTR Actually Fund

The programs fund research and development activities that move solar innovations from concept toward commercialization. Here’s what you can use the funding for:

Phase I (Feasibility Study) - Up to $200,000 for 6-12 months:

• Technical feasibility studies and proof-of-concept work
• Prototype development and initial testing
• Market research and commercial feasibility assessment
• Intellectual property development and protection
• Personnel costs for your team working on the project
• Materials, supplies, and equipment needed for R&D
• Consultant or contractor services
• Travel related to the project

Phase I is about answering the question: “Does this technology work, and is there a market for it?” You’re not building a commercial product yet—you’re proving the concept and demonstrating that it’s worth further investment.

Phase II (Development and Demonstration) - Up to $1,100,000 for up to 24 months:

• Prototype development and refinement
• Performance testing and validation
• Manufacturing process development
• Field demonstrations and pilot deployments
• Market development and customer engagement
• Business model development
• Regulatory and certification work
• Intellectual property protection and licensing strategies
• Personnel, equipment, materials, and services needed for development

Phase II is about developing a working prototype, demonstrating it in relevant environments, and preparing for commercialization. By the end of Phase II, you should have a product or technology ready for market entry.

What you can’t fund:

• Basic research with no clear path to commercialization
• Activities that occurred before the award start date
• Marketing and sales (except market research)
• General business operations unrelated to the specific project
• Equipment or facilities that aren’t essential to the R&D project

The funding is specifically for R&D that advances your solar innovation toward commercial deployment, not for running your business generally.

SBIR vs STTR: Which Program to Apply For

DOE offers both SBIR and STTR funding for solar innovations. The key difference is partnership requirements:

SBIR (Small Business Innovation Research):

• Your small business leads the project
• Principal Investigator must be primarily employed by your company
• You can work with research institutions, but it’s not required
• At least 2/3 of Phase I work and 1/2 of Phase II work must be performed by your small business

STTR (Small Business Technology Transfer):

• Your small business partners with a research institution (university, national lab, nonprofit research org)
• Formal research agreement required between business and institution
• At least 40% of Phase I work and 30% of Phase II work must be performed by your small business
• At least 30% of Phase I work and 40% of Phase II work must be performed by the research institution
• Principal Investigator can be from either the business or the institution

Choose SBIR if:

• You have the technical expertise in-house to do the R&D
• You don’t need a research institution partner
• You want maximum flexibility in how you conduct the work

Choose STTR if:

• You’re commercializing technology developed at a university or national lab
• You need access to specialized equipment, facilities, or expertise at a research institution
• You have a strong existing relationship with a research partner
• Your PI is at the research institution and you want them to lead the technical work

You can apply to both programs if you have projects that fit each structure, but each application must be for a distinct project.

2025 Solar Topic Areas

DOE releases specific topic areas each year. While the exact topics for 2025 will be in the official solicitation, recent years have focused on:

Advanced Photovoltaic Technologies:

• Next-generation PV materials and devices (perovskites, tandems, etc.)
• Improved silicon PV performance and durability
• Building-integrated photovoltaics (BIPV)
• Floating solar and agrivoltaics innovations

Grid Integration and Energy Storage:

• Advanced inverters and power electronics
• Solar forecasting and grid services
• Hybrid solar + storage systems
• Microgrid and distributed energy resource management

Manufacturing and Supply Chain:

• Domestic PV manufacturing innovations
• Automated production processes
• Quality control and testing equipment
• Supply chain resilience and domestic sourcing

Operations, Maintenance, and Recycling:

• O&M cost reduction technologies
• Performance monitoring and diagnostics
• End-of-life PV recycling and circular economy
• Repowering and life extension technologies

Soft Costs and Enabling Technologies:

• Permitting and interconnection software
• Financing and business model innovations
• Community solar platforms
• Workforce training technologies

Review the official solicitation when released to see the specific topic areas for 2025 and choose the one that best fits your innovation.

Application Process and Timeline

The SBIR/STTR application process is rigorous but well-defined:

Step 1: Review the Solicitation (When Released) - DOE releases a detailed solicitation document outlining topic areas, requirements, evaluation criteria, and instructions. Read this carefully—it’s your roadmap.

Step 2: Register in Required Systems (2-4 weeks before deadline) - You need to be registered in:

• SAM.gov (System for Award Management)
• Grants.gov
• DOE’s eXCHANGE system

Registration can take weeks, so start early. Don’t wait until the week before the deadline.

Step 3: Develop Your Proposal (6-8 weeks) - Write your technical proposal (typically 15-20 pages for Phase I) including:

• Technical innovation and approach
• Commercial potential and market analysis
• Team qualifications and capabilities
• Work plan with milestones
• Budget and budget justification

Also prepare required forms, company qualifications, letters of support, and other documentation.

Step 4: Submit Through eXCHANGE (Before Deadline) - Submit your complete application through DOE’s eXCHANGE system. Late submissions are not accepted, and technical issues are not excuses. Submit at least 24 hours before the deadline.

Step 5: Evaluation (3-6 months) - DOE conducts thorough review including:

• Technical merit evaluation by expert reviewers
• Commercial potential assessment
• Team and company capability review
• Budget reasonableness review
• Programmatic fit assessment

Step 6: Award Notifications - DOE notifies applicants of selection decisions. Typically 10-15% of Phase I applications are funded.

Step 7: Negotiation and Award (1-3 months) - If selected, you’ll negotiate final budget, work plan, and terms with DOE before receiving the award.

The entire process from application deadline to award typically takes 6-9 months.

Insider Tips for Competitive Proposals

Address a specific topic area directly. Don’t try to shoehorn your technology into a topic it doesn’t fit. Choose the topic that genuinely aligns with your innovation and address it explicitly in your proposal.

Balance technical innovation with commercial potential. DOE wants both. A brilliant technical innovation with no market won’t get funded. Neither will a great market opportunity with incremental technology. You need both.

Show you understand the solar industry. Demonstrate knowledge of current solar technology, market dynamics, key players, and challenges. Reviewers are solar experts—they’ll spot if you don’t understand the industry.

Be specific about your innovation. Don’t just say “we’re developing better solar panels.” Explain exactly what’s innovative: “We’re developing perovskite-silicon tandem cells with 30% efficiency using a novel interface layer that solves the stability problem that has limited commercial deployment.”

Quantify commercial potential. Provide specific market size data, customer segments, pricing analysis, and go-to-market strategy. “The US residential solar market is $15 billion annually” is better than “solar is a big market.”

Demonstrate team capability. Show that your team has the technical expertise and business experience to execute. Highlight relevant experience, publications, patents, or previous commercialization success.

Have a realistic work plan. Break your project into clear phases with specific milestones and deliverables. Reviewers can tell if your timeline is unrealistic or your milestones are vague.

Budget appropriately. Your budget should match your work plan. If you’re proposing complex prototype development, a $50,000 budget isn’t credible. Justify major expenses and show you understand what things cost.

Get letters of support from potential customers or partners. Letters from companies that would use your technology or partners who will collaborate strengthen your commercial potential story.

Follow the instructions exactly. Use the required format, page limits, font sizes, and structure. Proposals that don’t follow instructions get rejected without review.

Have someone outside your company review your proposal. You’re deep in your technology, but reviewers aren’t. Make sure your proposal is clear to someone who isn’t an expert in your specific area.

Common Mistakes That Sink Applications

Applying with technology that’s too early or too mature. SBIR/STTR is for proof-of-concept and prototype development, not basic research or commercial production. If you’re still figuring out fundamental science, it’s too early. If you’re already selling products, it’s too late.

Weak commercial potential story. Many technical teams focus entirely on the technology and treat the market analysis as an afterthought. Commercial potential is 50% of the evaluation—take it seriously.

Vague or unrealistic work plans. “Month 1-6: Develop prototype. Month 7-12: Test prototype” isn’t a work plan. Break down exactly what you’ll do each quarter with specific technical milestones.

Ignoring the topic area. Your proposal must address one of the specific topic areas in the solicitation. Don’t submit a generic solar proposal and hope it fits somewhere.

Poor writing. If reviewers can’t understand your proposal, they can’t fund it. Write clearly, define technical terms, and organize logically.

Missing required elements. Every year, proposals get rejected because they’re missing required forms, exceed page limits, or don’t include mandatory sections. Follow the instructions.

Unrealistic budgets. Either too low (suggesting you don’t understand what the work costs) or too high (suggesting inefficiency). Budget should match industry norms for similar R&D work.

No clear path to Phase II. Phase I proposals should explain how Phase I results will lead to Phase II work. If Phase I is a dead end, why fund it?

What Happens If You Win

If you’re selected for a Phase I award, here’s what to expect:

Award Negotiation (1-2 months): Work with DOE to finalize your work plan, budget, and terms. Be prepared to adjust based on DOE feedback.

Project Execution (6-12 months): Conduct your Phase I R&D according to your work plan. You’ll have a DOE project officer who monitors progress and provides guidance.

Reporting: Submit quarterly progress reports and a final report. These should document technical progress, commercial developments, and how you’re meeting milestones.

Phase II Application: If your Phase I is successful, you can apply for Phase II funding. Phase II applications are only open to Phase I awardees and have a separate deadline and process.

Commercialization: Even during Phase I, start thinking about commercialization. Who are your customers? What’s your business model? How will you scale?

Success in Phase I significantly increases your chances of Phase II funding, but it’s not automatic. You need to demonstrate that Phase I proved feasibility and that Phase II will move you substantially closer to market.

Frequently Asked Questions

Can startups apply, or only established companies? Startups are eligible and frequently win awards. You need to be a for-profit company, but you don’t need years of operating history.

Do I need to have revenue to apply? No. Pre-revenue companies can and do win SBIR/STTR awards.

Can I apply if I’ve received SBIR/STTR funding before? Yes. There’s no limit on how many SBIR/STTR awards a company can receive, though there are limits on total Phase II awards across all agencies.

What if my technology addresses multiple topic areas? Choose the best fit and explain in your proposal how it addresses that topic. Don’t try to address multiple topics in one proposal.

Can I submit the same proposal to multiple agencies? No. You can’t submit identical proposals to different agencies’ SBIR/STTR programs simultaneously.

What happens to intellectual property? You retain ownership of IP developed under SBIR/STTR awards. The government gets a non-exclusive license for government purposes.

Can foreign nationals work on the project? Yes, but the PI must be primarily employed by the US small business, and the work must be performed in the US.

What if I don’t have all the expertise in-house? You can hire consultants, subcontract work, or (for STTR) partner with a research institution.

How to Apply

Step 1: Monitor the DOE EERE SBIR/STTR website for the 2025 solicitation release. Sign up for email notifications.

Step 2: When the solicitation is released, download and read it thoroughly. Pay special attention to topic areas, eligibility requirements, and evaluation criteria.

Step 3: Register in SAM.gov, Grants.gov, and DOE eXCHANGE immediately. Don’t wait.

Step 4: Develop your proposal following the solicitation instructions exactly.

Step 5: Submit through eXCHANGE before the February 21, 2025 deadline (or updated deadline if announced).

For current information, visit the DOE Solar Energy Technologies Office SBIR/STTR page or contact the SBIR/STTR program office with questions.

The DOE Solar SBIR/STTR program has funded hundreds of solar innovations that have gone on to commercial success. If you have innovative solar technology and the capability to commercialize it, this non-dilutive funding can help you prove your concept and build a viable business.