Electricity from natural gas still needed to cool California

Last week was a scorcher across California. It didn’t matter where you were — Sacramento, Fresno, Palm Springs, San Francisco and Oakland all set new daily high temperature records. San Diego County even broke its all-time high temperature at 124 degrees.

The oppressive heat grounded airplanes, stoked wildfires, buckled some roads and even led to deaths — a reminder that our Mediterranean climate sometimes turns hostile. Climate change will only make this worse.

As you might expect, Californians’ demand for electricity increased dramatically as we relied on air conditioning to combat the heat. According to the California Independent System Operator, the primary agency responsible for managing the grid, energy demand was projected to peak at roughly 47,000 megawatts — the fourth highest in the past 20 years.

In the face of this tremendous demand, California’s electrical grid performed amazingly well. This is somewhat of a marvel, given the complexity of the grid and our dynamic demand for power.

The grid’s performance was also a reminder of the continued importance of natural gas in meeting California’s needs, even as the state transitions to more renewable sources.

For example, despite the growth of solar power, available solar energy on the grid peaked at roughly 10,000 megawatts last week — roughly 22 percent of the needed peak supply — while natural gas provided roughly 50 percent.

Solar power will likely be able to meet a greater percentage of demand as incentives boost its development, but even then there is an issue of matching supply and demand. For example, as the heat lasted well into the night, so did Californians’ demand for electricity. However, electricity generated from solar had dropped to 60 percent of its peak by 6 p.m. and was completely offline by 8:30 p.m. Solar was meeting only 7 percent of California’s demand at 7 p.m. and zero percent by 8:30 p.m. each day.

In the future, storage may play a role in saving solar and wind power for later use. However, power storage technology is still very expensive. We still need natural gas power and will for some time.

If we had not had access to natural gas last week, grid power would have been purchased to keep things cool. Grid power is frequently generated from coal — a far dirtier fuel that increases greenhouse emissions and human health problems.

None of this should dampen California’s enthusiasm for renewable energy. California’s transition to renewable energy is important to fighting climate change, curbing pollution and helping to develop green jobs.

However, we need to recognize the practical limitations of renewable energy in our planning. As policymakers contemplate our energy future, they need to make sure that we don’t let our aspirations interfere or disrupt the reliability of the grid. As last week showed, people’s lives depend on it.