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How electrifying can help keep California powered during heat waves

For ten days straight this month, communities across California sweltered in extreme heat as temperatures soared to 116ºF in Sacramento and 109ºF in San Jose. The September heat wave that Californians are emerging from is extraordinary by today’s standards. It broke records in some regions for the most consecutive days recorded at 100ºF or higher, pushing the electricity grid to the brink.

When the California Independent System Operator (ISO) issued a statewide Flex Alert on September 9 asking for electricity conservation to avoid power outages, Californians took immediate action, shedding thousands of megawatts (MWs) in less than an hour to avoid widespread blackouts. California’s grid operator also proved that it can keep the lights on by using a number of flexible resources to match demand and supply. But while these efforts helped avoid rolling outages, more is needed.

California must stop depending on fossil fuels, which exacerbate extreme heat, and take action to electrify homes and buildings, the producer of a quarter of the state’s carbon emissions. To keep communities safe as temperatures rise, the state also needs to ensure that households have access to highly efficient cooling. California has the opportunity to lead by not only procuring more renewables, but by utilizing smarter appliances and more fully integrating the grid so that it becomes more reliable.

But how can electrification create a more reliable and flexible grid?

During the September heat wave, peak demand hit an all-time high of over 52,000 MWs. This is where heat pump technology can help make the grid more reliable and flexible. Heat pump water heaters can maximize use of the grid by heating water when solar is abundant, and storing the hot water for use later to avoid contributing to the peak and worsening grid strain. This also helps households save money on their utility bills while eliminating greenhouse gas (GHGs) and nitrogen oxide (NOx) emissions created by gas water heaters. Additionally, connecting a household’s efficient electric appliances to smart thermostats – which can respond in real time to grid conditions through demand response – can help make the grid more reliable.

Heat pumps, which provide highly efficient heating and cooling, can also reduce grid stress and eliminate the climate pollution driving hotter and longer heat waves. Almost 40% of California households have A.C. units that are more than 14 years old and nearing the end of life. If California replaced these aging units with modern heat pumps, this could save at least 500 MWs by ramping up incentive programs, and conservatively up to 2 gigawatts (GWs) of electricity load with policy leadership – the equivalent of the power generated at the Diablo Canyon Power Plant, or the energy needed to provide power to 3 million Californians. The potential savings could reach up to 5 GWs, depending on the model of the heat pumps used in combination with smart thermostats and other features that are readily available. Failing to replace old A.C. units with heat pumps would lock in an additional 15 to 25 years of pollution and miss a critical opportunity to reduce the emissions contributing to extreme heat. To accelerate the transition to heat pumps, California must scale up incentive programs and remove barriers to installation.

For the roughly 25% of California homes that lack access to cooling – many of which are low-income households and communities of color – investing in heat pumps will ensure their health and comfort without overloading the grid with inefficient window A.C. units as the need for cooling increases with more intense heat waves. The state’s $1.4 billion budget funding to decarbonize and invest in heat pumps will serve as a downpayment on providing energy-efficient cooling, weatherization, and other upgrades to protect California households from extreme heat events.

Beyond replacing water and space heaters, there are more opportunities that can boost grid reliability through electrification. For instance, during the recent heat wave, Californians utilized resources like rooftop solar and electric vehicle (EV) batteries, which prevented an additional 8,000 MW of stress to the grid. By leveraging bi-directional charging from EVs – which feed electricity from EV batteries back onto the grid during periods of peak grid stress – California can free up extra electricity to ease the strain on the grid and keep the lights on in homes.

Though the state is making great steps to cut pollution and fight climate change, the impacts of extreme heat will continue to challenge the grid in real and pressing ways. To create a flexible and reliable grid and ensure that Californians are protected from climate-fueled weather events, the state should continue to decarbonize buildings and homes, and make it easier and more affordable for households to upgrade to clean and efficient electric appliances.