In the roughly 15 years that I have been active as a concentrating solar technologies (CST—power and fuels) researcher, I have seen the field develop substantially. When I started my career in CST working at Sandia National Labs in 2004, our group of researchers was very small, the Central Receiver Test Facility was being used mostly for astronomy and re-entry vehicle testing, and utility-scale solar thermal power was essentially limited to the SEGS plants. A lot has changed since then, and today there is roughly 5 GW of global CSP capacity including molten salt power towers producing electricity at a price that is competitive with conventional generation while demonstrating the feasibility of utility scale thermal energy storage. In a sense, the successes of the CSP industry over the past decade or so have fulfilled many of the technical and economic goals of the industry. In that same time period other renewable energy technologies have enjoyed similar success; wind power capacity has grown from less than 50 GW to more than 500 GW, and the cost of utility scale solar photovoltaic power will soon drop below $0.04/kWh, if it has not already. There have also been advances in the area of electrochemical energy storage, electric vehicles are becoming mainstream, and power transmission and utilization strategies that look fundamentally different than the utility grid of the past are being proposed and pursued. One could easily argue that we are now seeing the beginning of a rapid transformation in the way that energy is produced and consumed globally. What is less easy to see clearly is specifically where CST can best contribute to this transformation. Where should researchers in our field focus their efforts to have the greatest impact on a rapidly changing energy landscape?
That is a tough question to answer, and one that many of us struggle with routinely. Instead of tackling it head on, I offer my perspective from years of experience working in the field, beginning with a comment on how the research portfolio for the CST community is developed. Currently, we undertake road mapping efforts in the USA and in Europe on a somewhat frequent basis, typically facilitated by funding agencies, such as the Department of Energy. These efforts often involve direct collaboration with industrial partners and favor a more incremental approach to development because of the emphasis placed on demonstrating near-term economic gains (e.g., LCOE reduction), and a general aversion to risk on the part of the funding agency. This is not a bad thing for some projects, but it is also not particularly forward-thinking. Perhaps our relatively small research community would be well-served by taking some of these road mapping efforts “in house,” and meeting at our technical conferences in working sessions aimed specifically at identifying R&D opportunities that could lead to major breakthroughs in CST. An emphasis on breakthroughs is important, in part, because some of the greatest barriers to wider adoption of CST will likely not be overcome without major and rapid advances; timeliness matters a lot in energy R&D because of the increasingly competitive environment.
In my experience as a research engineer, I have found that projects can be grouped in two general categories, those that can be successfully completed through the application of solid engineering to address well-understood challenges, and those that require a breakthrough in the area of materials science in order to attain their performance goals. Occasionally, these elements are combined in a single, large R&D effort. Often this combination is made in response to political or strategic pressures, and can lead to a project that requires multiple miracles to succeed, but lacks the focus of resources to address even one. My point here is that we should be careful with how projects are scoped and be intentional in directing resources toward the most significant barriers to success. If the greatest barrier to demonstrating really compelling and impactful results is specific to materials, then the project should focus only on materials, with the development of the other elements to follow. In this way, we can best utilize limited resources to make large gains, rather than incremental improvements with only the promise of future success.
I continue to be optimistic that CST can play a significant role in our energy future. I believe that we have an opportunity at present to be bold in our research aspirations and leverage the competitive attributes of CST in a way that clearly demonstrates the value of solar thermal power and fuels. Our community has done great work getting us to where we are today, and the good news is that there are still plenty of tough challenges ahead as we work to build a truly sustainable, global energy and fuels infrastructure.