New Standards to Connect Renewables to the Grid

Executive Column: Michael Kormos, executive vice president – Operations

PJM prepares for the grid of the future by adopting new standards and technologies that accommodate growth and have new capabilities. Recently, the Federal Energy Regulatory Commission approved standards for enhanced inverters–a technology that enables intermittent generation projects, such as wind and solar, to provide voltage and frequency support to the grid.  PJM proposed the standards, and FERC approved them depending on PJM addressing some minor issues.

Inverters convert direct current to alternating current, which is the current transmitted through local distribution lines. However, typically the inverters for intermittent energy sources have not been required to provide voltage and frequency support. Enhanced inverters enable intermittent generators to provide some of the same essential grid support functions as the conventional generators.  The new standards require generators to have inverters that can provide voltage support and ride-through voltage and frequency disturbances.  The standards apply to new variable energy resources requesting an interconnection to the PJM grid as of May 1, 2015. The standards do not affect existing generators, nor do they apply to projects with a capacity less than 10 kilowatts.

To date, there are about 2,250 megawatts of solar photovoltaic registered through the Generation Attribute Tracking System, the renewable energy certificate program administered through PJM’s subsidiary, PJM-EIS. Of that amount, 352.6 MWs participate in PJM markets. There is also 6,676 MW of wind capacity in PJM.

PJM is trying to prepare the grid for the rapid growth of renewable energy. We, along with the industry, are learning important lessons from others like Germany, for example, which set aggressive targets for renewable energy. In its push to replace nuclear and fossil-fueled generation with renewable energy, Germany now must build or retrofit expensive infrastructure to support it. It is less costly and more efficient to require those infrastructure improvements on the front end.

We recognize that system changes are needed to accommodate the growth of renewable energy while maintaining reliability. The key to the grid of the future is timing: being just ahead of the growth curve to accommodate it but not too far ahead if conditions change.