Distributed Generation

The Challenge: Incorporating renewables and storage while maintaining grid safety and reliability

California’s electrical distribution grid, originally designed for a unidirectional power flow from large centralized power plants, must now adapt to large-scale deployment of distributed renewable generation such as photovoltaics (PV) and co-located battery storage. Power delivery from many intermittent sources distributed along the grid can result in issues such as critical voltage variability, if not properly handled, and can adversely modify load profiles. Customers are interested in accessing clean renewable power for their homes and businesses, optimizing energy use, and lowering their operating costs. For California to achieve successful integration of distributed generation (DG) technologies, grid design and operation must include new predictive, diagnostic, and control capabilities that reduce customer energy consumption and cost while improving electrical distribution grid reliability.

The Solution:

In this California Energy Commission EPIC funded project, Lawrence Berkeley National Laboratory (Berkeley Lab) researchers turned to the U.S Department of Energy’s FLEXLAB® facility to address grid impacts while optimizing the customer benefits. Berkeley Lab investigated solutions to enable high levels of DG in the electricity system. The research team designed and built a central testing facility to evaluate DG technology in California, and used it to study its impact on the grid. Novel control systems were designed and field-tested in the controlled and flexible environment of the FLEXGRID facility. The team also developed and validated simulation models based on the facility’s hardware, to rapidly evaluate many different scenarios before testing with the hardware. The researchers developed a controller for combined PV and storage systems to mitigate the steep ramping known as the “duck curve,” provide benefits to building owners by maximizing their revenue, and provide grid operators with voltage stabilizing functionality

The Bottom Line: Available technologies facilitate renewable integration and cost savings

Use of controllers and innovative inverters can increase predictability and control of power flows from distributed renewable resources, providing improved operations and cost savings for customers, and grid reliability and financial benefits to utilities and ratepayers alike. Simulations showed that an annual electricity bill could be reduced by as much as 35 percent, with about a six-year payback period of the investment in battery storage—significantly shorter than the manufacturer’s 10-year warranty.

Download the full case study here: Safe, Reliable Management of Distributed Generation on the Grid