AmericaAs negative electricity prices due to rooftop solar generation skyrocket, the California state government is struggling to find ways to deal with excess electricity.
In sunny California, solar cells are everywhere. They are located amid the arid desert landscape of the Central Valley and dotted across the rooftops of urban Los Angeles. According to the latest calculations, California has nearly 47 gigawatts of installed solar power capacity, enough to supply 13.9 million households and meet more than a quarter of the state’s electricity. But now, the state government and the grid operator are grappling with a strange situation. Too much solar power on sunny days when demand is not too high leads to negative electricity prices, according to Washington Post.
To handle this, California stopped encouraging solar panels on rooftops and reduced the rate of installation. But narrowing economic interests could slow the growth of solar power in a state looking to transition to renewable energy. As other states build more solar power plants, they may soon face similar problems.
“This is an insurmountable challenge,” said Michelle Davis, global director of solar power at energy research and consulting firm Wood Mackenzie Power and Renewables. “But it’s a challenge that many grid operators have never addressed.”
Solar power has many great benefits: there are almost no operating costs after construction, it does not create air pollution, and it produces energy without burning fossil fuels. But its one main disadvantage is that the Sun does not shine all the time.
More than 15 years ago, a research team at the National Renewable Energy Laboratory modeled the future popularity of solar power and noticed something strange. When there is a lot of solar power on the grid, the gap between demand for electricity and renewable energy is U-shaped. The spike in demand in the morning will be replaced by almost zero demand at noon, when Solar power can produce all the electricity people need. Then, as the Sun sets, demand spikes again.
California’s grid operator, CAISO, calls this effect the “duck curve.” The effect is most pronounced during the spring months, when solar cells receive lots of sunlight but have little need for heating and cooling. In the last few years in California, the duck curve became a giant canyon and solar power went unused. In 2022, the state wasted 2.4 million megawatt hours of electricity, 95% of which was solar power. Last year, the state experienced that level of waste in just the first eight months of the year.
Clyde Loutan, director of renewable energy integration at CAISO, said California has long been preparing for more solar power on the grid, but it underestimated the pace of solar PV growth in the region. home.
Cutting solar power is not technically difficult, according to Paul Denholm, a graduate student at the National Renewable Energy Laboratory. But reducing self-produced electricity increases electricity prices, while reducing the benefits of installing solar panels on the roof. Since the 1990s, California has paid owners of rooftop solar panels when they supply energy to the grid. That means they earn $0.2 – $0.3 for every kilowatt hour of electricity they produce.
But a year ago, the state government changed the system and now only compensates new solar panel owners for the value of their electricity to the grid. In the spring, when the duck curve is deepest, the amount can fall close to zero. Customers can get more money if they install batteries and supply power to the grid in the morning or early evening. This change faced fierce opposition from Californians and rooftop solar power companies. Electric company Wood Mackenzie predicts solar installations by Californians will drop about 40% in 2024.
Other states that have been slower to adopt solar panels than California are also starting to experience a similar situation. Nevada, a state that produces 23% of its electricity from solar energy, also recorded a deepening duck curve. Hawaii, where thousands of homes have rooftop solar panels, has reduced payments to those households.
California grid operators hope their experience will provide lessons for other states. CAISO is selling excess electricity to several neighboring states. California also plans to install more batteries and other solar power storage systems for use in the evening. Transmission lines can also help distribute electricity more evenly. Some power outages come from areas that don’t have enough power lines to respond to sudden increases in solar power.