Solar energy is punching above its weight in driving the U.S. energy transition, ET EnergyWorld

LITTLETON: Solar farms generated less than 6 percent of the electricity produced by U.S. utilities in 2023, but that annual share largely underestimates the critical role solar plays in enabling utilities to accelerate their energy transformation efforts .

On a daily basis, solar power plants can have such a disruptive impact on the system’s electricity flows that utilities are forced to develop options to quickly reduce production from other sources and store excess energy for later use.

In turn, the resulting agility and emerging ingenuity across the energy sector are helping to accelerate global energy transition efforts by forcing power systems to more effectively adapt to wide swings in clean energy production.

As the supply of all forms of renewable energy continues to grow rapidly, utilities that learn to maximize the volume of solar energy in today’s generation systems will be best positioned to support the continued evolution of energy systems in the decades to come.

CLEANER BUT MORE VOLATILE

No other clean energy source can create both the opportunities and challenges presented by the rapidly growing supply of solar energy.

According to the U.S. Energy Information Administration (EIA), solar’s overall share of U.S. electricity production may be small today, but it is growing rapidly, with production expected to increase by 155 percent between 2018 and 2023.

This growth rate compares with a 56 percent increase in wind power generation and a 22.4 percent increase in natural gas power generation over the same period.

To meet the growing supply of renewable energy and meet emissions reduction commitments in the energy sector, U.S. utilities reduced coal-fired power generation by 41% between 2018 and 2023, reducing the share of coal in the energy mix from approximately 30% to 16%. . .

But by replacing so much of coal’s baseload power with increasing amounts of intermittent renewable energy from solar farms, the U.S. power system has become more volatile and cleaner over the past five years.

MAKE THE WAY!

California’s power system best illustrates the variability resulting from the rapid increase in solar generation.

Ember, California, the largest producer of solar power in the U.S., increased solar production by 72% from 2018 to 2023 and relies on solar for about 28% of its electricity supply, according to energy advisory team Ember, California.

The state also accounts for about 25 percent of the nation’s solar-generated electricity supply.

But an enduring challenge is converting the state’s abundant sunlight into usable electricity without disrupting energy markets.

As more solar power plants were connected to California’s grid over the past decade, power prices in the state came under increasing pressure during the middle of the day, when solar production peaked.

Compounding the problem is that the peak period of solar production coincides with the traditionally lowest period of system demand, so energy companies are forced to lower energy prices to balance system needs until solar production declines later in the day.

The resulting “duck curve” shape in energy prices has become a well-known phenomenon over the past few years, with the unintended distortion of market dynamics caused by the solar glut widely ridiculed in 2023 by opponents of the energy transition.

Solar energy production in California has increased even more in 2024, and solar electricity production through May 23 will be 27% higher than during the same period in 2023, according to LSEG data.

The uneven distribution of this production creates daily disruptions in the state’s power generation mix, with solar energy accounting for 0 percent of the energy generated before sunrise and more than 70 percent during the sunniest times of the day.

Power prices in California continue to come under intense pressure during peak solar production times, routinely turning negative for periods as the market pricing mechanism tries to attract demand and discourage production from other sources.

BATTERY POWERED

To mitigate the impact of system imbalance caused by uncontrolled solar production, California utilities have deployed utility-scale battery grids that can absorb excess energy during periods of peak solar production and discharge after sunset.

The battery network is still under construction, but already covers about 20 percent of California’s system’s demand during peak demand, just after solar production shuts down and when people returning from work increase household demand for electricity.

The batteries also reduce California’s need to import energy during periods of peak demand, which reduces regional energy burdens and helps California become less dependent on energy supplies from neighboring states.

California’s battery system also acts as an educational tool for other power grids that are also grappling too early with the effects of too much solar power.

With the broader use of smart energy meters, which encourage consumers to use more energy during peak periods, all U.S. utilities are learning key ways to cope with the rapid growth of solar energy production and preparing for continued progress in the energy transition.

Gavin Maguire