The U.S. Department of Energy (DOE) recently released On the Path to SunShot, a series of eight reports that takes stock of progress made halfway into the ten-year SunShot Initiative and highlights remaining opportunities for and barriers to achieving cost reductions by 2020. DOE originally launched the SunShot Initiative in 2011 to drive down the cost of solar energy with aggressive research and development. Sandia Labs contributed significantly to two of these new reports:
Emerging Issues and Challenges with Integrating High Levels of Solar into the Distribution System

From 2010 through the first half of 2015, the installed capacity of solar photovoltaics (PV) connected to the U.S. distribution system increased six fold, from approximately 1.8 GW to more than 11 GW. The rapid deployment of high penetrations of PV into the distribution system has both highlighted challenges and demonstrated many successful examples of integrating higher penetration levels than previously thought possible.  For example, one analysis suggests that widespread use of advanced inverters and voltage management solutions could double the electricity-distribution system’s hosting capacity for distributed PV at low costs. Researchers analyzed challenges and identified solutions and research needs to achieve much higher levels of solar integration to achieve DOE’s SunShot targets.

Advancing Concentrating Solar Power Technology, Performance, and Dispatchability

The ability of concentrating solar power (CSP) to generate and store thermal energy when net demand is low and release that energy when demand is high—even when the sun is not shining—increases the electricity system’s ability to balance supply and demand over multiple time scales.  Such flexibility becomes increasingly important as more variable-generation renewable energy is added to the system. For example, one analysis suggests that, under a 40% renewable portfolio standard in California, CSP with storage could provide more than twice as much value to the electricity system as variable-generation PV.  Sandia researchers contributed analyses and defined technology improvement opportunities in the CSP report that can increase the performance and efficiency of components that will reduce the levelized costs of CSP.