New Study Shows How Solar Can Enhance Grid Reliability

January 11, 2017
Dennis Schroeder/NREL
Laura Wisland
Former contributor

President Obama’s publication in Science is just the most recent reiteration of how far we have come with clean energy development in the last decade. The question now is not whether we should transition to cleaner sources of energy, but rather how do we do so in the most reliable and cost-effective way?

In California, where we are planning to satisfy at least 50% of our electricity needs with renewables by 2030, we are working on accelerating the solutions that will enable us to integrate large quantities of clean energy onto the grid. One of the most exciting strategies—using renewables to provide the grid reliability services traditionally provided by natural gas—just got a little closer to reality.

A new study released by the California Independent System Operator (CAISO) (aka the grid operator for most of the state) finds that large-scale solar plants, with the right type of inverter technology, can provide many of the essential grid reliability services the grid needs. The study concludes that “It may in this way mitigate the impact of its variability on the grid, and contribute to important system requirements more like traditional generators.”

In a nutshell, the CAISO is saying it has found a strategy for operating renewables in a way that supports further integration of renewables onto the system. Renewables can now be part of the integration solution.

The test was conducted in August on one of First Solar’s 300 MW PV plants. According to the CAISO, the data demonstrates the capability of PV plants to provide various grid services. From the report: “This data showed how the development of advanced power controls can leverage PV’s value from being simply an intermittent energy resource to providing services that range from spinning reserves, load following, voltage support, ramping, frequency response, variability smoothing and frequency regulation to power quality.”

This finding is a real-world validation of research we completed last year which found that enabling renewables to provide grid reserves, especially in the downward direction, could be a particularly useful and cost-effective way to reduce grid management issues and greenhouse gas emissions. After all, gas plants have to be running to provide these services, which means they are emitting carbon, and potentially crowding out renewable generation.

At the time we published this report, the CAISO was skeptical. This pilot project has been very helpful to help them seriously consider renewables as part of the integration solution. I am beyond thrilled with the results and will be working with my clean energy colleagues to identify the economic and contractual incentives that will encourage large-scale solar plants to provide more of these grid services in the future. If we are serious about dramatically ramping up renewables and ramping down natural gas, we will need these grid services to come from carbon-free technologies, including large-scale solar plants.