Duration Addition to Electricity Storage (DAYS) | DE FOA 0001906

Opportunity Information: Apply for DE FOA 0001906

The Duration Addition to Electricity Storage (DAYS) opportunity is a Department of Energy ARPA-E funding program aimed at pushing new long-duration electricity storage technologies that are still too early-stage for most private investment. ARPA-E was created under the America COMPETES legislation to strengthen US economic and energy security by advancing technologies that can cut reliance on imported energy, reduce energy-related emissions (including greenhouse gases), and improve efficiency across the economy, while keeping the United States in a technology leadership position. In practice, that means ARPA-E uses time-limited, milestone-driven R&D funding to move promising concepts from scientific ideas toward early prototypes and credible commercialization pathways.

DAYS specifically targets long-duration electricity storage (LDES) systems that can discharge at rated power for roughly 10 to about 100 hours. This is an important middle ground: it goes beyond the shorter, intra-day shifting that dominates much of today’s grid storage (often 1 to 4 hours, sometimes up to 8), but it is not meant for seasonal storage that would cover weeks or months. ARPA-E frames 10 to 100 hours as a duration window that could address grid needs like multi-day renewable shortfalls, improved reliability during extended outages or weather events, and capacity support without having to overbuild generation or transmission. Because these systems may cycle less frequently than daily batteries and can often tolerate slower ramp rates, the program highlights that developers might be able to make different design tradeoffs than conventional high-power, high-cycle storage, potentially lowering total cost.

The core technical and economic goal of DAYS is aggressive: develop LDES systems that can deliver electricity at a levelized cost of storage (LCOS) of 5 cents per kWh-cycle across the entire 10 to ~100 hour duration range. In other words, the program is not just looking for a single-duration solution that looks good at one operating point; it is pushing for technologies whose economics remain compelling as duration increases. ARPA-E notes that this implies a lifetime cost target that effectively becomes more stringent as storage duration gets longer, which is different from many common storage targets that assume a fixed duration and therefore a single cost benchmark. They also indicate that reaching the 5 cents/kWh-cycle level likely requires round-trip efficiency above 50 percent, signaling that very low-cost systems with poor efficiency are unlikely to meet the intent of the program.

On the technology side, DAYS is open to multiple pathways and explicitly expects proposals across chemical, electrochemical, thermal, and mechanical storage approaches. What is not flexible is the energy interface requirement: proposed systems must be charged by electricity only and must output electricity only. That condition rules out concepts whose primary output is heat, fuels, or other non-electric products, and it emphasizes grid-relevant storage that can be directly integrated as an electricity asset. If successful, ARPA-E expects DAYS-funded projects to yield new stationary storage options that improve grid resilience, provide low-cost capacity, reduce stress on transmission and distribution infrastructure, and make it easier to integrate a higher share of low-cost but intermittent renewables such as wind and solar.

From an administrative standpoint, this is a discretionary research and development funding opportunity issued as a cooperative agreement (meaning DOE/ARPA-E expects substantial involvement during the project, typically through active project management and milestone oversight). The opportunity number is DE-FOA-0001906 under CFDA 81.135. Eligibility is broadly open (unrestricted) subject to any specific clarifications in the full FOA. The award ceiling listed is $10,000,000 per award, with an expectation of around 15 awards. The FOA was posted May 1, 2018, with a mandatory Notice of Intent due June 15, 2018 (5:00 p.m. ET) and full applications due July 2, 2018 (5:00 p.m. ET). Applications had to be submitted through ARPA-E’s eXCHANGE system, and submissions through other channels would not be reviewed.

• The Department of Energy, Advanced Research Projects Agency Energy in the science and technology and other research and development sector is offering a public funding opportunity titled "Duration Addition to Electricity Storage (DAYS)" and is now available to receive applicants.
• Interested and eligible applicants and submit their applications by referencing the CFDA number(s): 81.135.
• This funding opportunity was created on May 01, 2018.
• Applicants must submit their applications by Jul 02, 2018 Applicants must submit a mandatory Notice of Intent by June 15, 2018 at 500 p.m. ET. Full Applications must be submitted by July 2, 2018 at 500 p.m. ET.. (Agency may still review applications by suitable applicants for the remaining/unused allocated funding in 2026.)
• Each selected applicant is eligible to receive up to $10,000,000.00 in funding.
• The number of recipients for this funding is limited to 15 candidate(s).
• Eligible applicants include: Unrestricted (i.e., open to any type of entity above), subject to any clarification in text field entitled Additional Information on Eligibility.

Apply for DE FOA 0001906

[Watch] Creating a grant proposal using the step-by-step wizard inside the applicant portal: