FOCUS-ing on hybridisation, storage and dispachability

In July 2013, the Advanced Research Projects Agency-Energy (ARPA-E) announced $30 million for research into solar projects aimed at advancing the technology.

Entitled Full-Spectrum Optimized Conversion and Utilization of Sunlight (FOCUS), the new program, which will bring together some of the brightest minds in the solar industry, aims to develop two technology options that will ultimately deliver low-cost, high-efficiency solar energy on demand. This includes a new hybrid solar energy converters and new hybrid energy storage systems.

Alex Ghenis and Janice Lee of Strategen and Members of the California Energy Storage Alliance (CESA ) speak to CSP Today’s Andrew Williams about the implications of FOCUS initiative on CSP hyrbidisation, storage and dispachability.

AW: Do you welcome the recent establishment of the ARPA-E FOCUS program? If so, why?
We are very excited about the new ARPA-E FOCUS program. ARPA-E has been at the forefront of investing in promising energy storage technology that will lead to a cleaner, more efficient, and more stable nationwide electricity system. Already, four of ARPA-E's eight program's focus on energy storage, and others could potentially include energy storage technologies. This shows that the Department of Energy believes in the promise of energy storage for improving the grid, and is aggressively committing to making that transformative improvement a reality.

The FOCUS program builds off this commendable investment to expand the capabilities of another powerful technology, concentrated solar thermal power. By integrating CSP with both electric and thermal energy storage, we can create controllable, dispatchable renewable energy sources that reduce carbon emissions while meeting grid needs. ARPA-E's investment in this is an investment in a crucial component of the grid of the future, and will pay off for years to come."



AW: In what way (or ways) do you think that the CSP solar industry can best get involved in the FOCUS program? In particular, how best do you think the CSP industry might assist in the development of i) new hybrid solar energy converters? and, ii) new hybrid energy storage systems?
"With evolving technology classes like CSP hybrid solar energy converters and energy storage systems, collaboration and collective learning are key. The CSP industry can help development of hybrid converters and energy storage systems by facilitating this collaboration and learning through building networks between developers and strengthening those connections. The CSP industry should also work with hybrid energy converter and energy storage developers to establish a multitude of pilot projects, including a diverse set of technologies and combinations thereof, to accelerate RD&D of technologies and applications. Finally, the CSP industry can help with funding for hybrid solar energy converters and energy storage systems: as a more mature industry group, CSP developers have access to funding and can use their capital and credit to help expand converter & energy storage installations and technological evolution."


AW: Are there any specific technology areas that you think hold particular promise? If so, which areas?
"The FOCUS program will cover electric and thermal energy storage, which collectively represent multiple energy storage technologies. For example, molten salt energy storage is a key technology to be paired with CSP: the heat from concentrated solar power can melt salt, and that salt's stored heat can be used for power generation later on. Electrical energy storage can range anywhere from flywheels to conventional batteries to flow batteries to bulk energy storage systems, such as compressed air energy storage (CAES). Given the goals of the FOCUS program, medium- to long-duration technologies are the most promising. So, co-located batteries (i.e. sodium sulfur or lithium-ion) and flow batteries will be key for shifting energy from day to night and making up for intermittency. We may also be able to explore CSP generation being placed next to large compressed air energy storage or pumped hydro plants, and efficiently transferring large amounts of energy over hours, days, or even months.

Because FOCUS is based on hybrid energy storage installations, we are likely to see lot of molten salt resources paired with conventional or flow batteries. This will serve the best of both worlds between thermal and electrical energy storage."


AW: Looking ahead, how would you like to see the FOCUS initiative and subsequent projects develop? Would you like to see any changes in the specific themes and/or approach of the competition - if so, what?
"As with any technology development grant, we hope to see an open and fair competition between technology and project developers. The FOCUS program should thus have clear goals and criteria that fit in with national grid development initiatives and give technology developers direction in their work. It should also pursue a variety of promising technologies and applications - both to find the best options available and to support a diverse array of transformative technologies. Hybrid solar energy converters and energy storage systems can change the grid in a multitude of ways, and we should develop projects in the way that helps realize their full potential.

From what we've seen so far, the FOCUS program seems well organized with strong direction and admirable goals. We will keep an eye on its progress and work with government and developers to ensure that it is successful going forward."