Here’s the basic problem with wind and solar energy: it is sometimes not windy, and the sun doesn’t shine at night*. Solar energy supply, for instance, peaks in the middle of the day, while household energy demand peaks in the mornings and evenings.
This is why a grid with 100% renewable energy is tricky to think about with the absence of affordable batteries (or other forms of energy storage), and without either natural gas, coal or nuclear energy providing the “base load” of electricity on the grid.
One US company is changing that with innovative technology and grid management techniques, as reported by Greentech Media.
Last summer, First Solar and California grid operator CAISO ran a set of tests to show that utility-scale solar PV, instead of being a disruptive influence on the power grid, could actually help stabilize it.
Over a series of days in August, First Solar slightly curtailed power output at a 300-megawatt solar farm in California, enabled its array of inverters, and plugged into CAISO’s system. It then orchestrated the plant’s output to follow CAISO’s automatic generation control (AGC) signals, respond to its frequency regulation commands, and use inverters for voltage regulation, power factor regulation and reactive power control.
The results, according to a report released last week, showed that First Solar was able to meet, and sometimes exceed, the frequency regulation response usually provided by natural-gas-fired peaker plants. First Solar was also able to provide inverter-based services throughout the day — and possibly even at night.
If this technology is proven to be successful in various conditions, it could reduce potential reliance on energy storage, and hasten the transition away from coal.
*Let’s not get pedantic about this.