Seven months after the workers installed the solar panels on the Garcia family’s home near Stanford University, the system is little more than a roof ornament. The problem: The devices of the local energy supplier are so overloaded that there is no more space for the electricity from the panels.

“We wasted $ 30,000 on a system we can’t use,” said Theresa Garcia. “It was just really frustrating.”

President Biden urges lawmakers and regulators to wean the United States off fossil fuels and counter the effects of climate change. However, its ambitious goals could be undermined by aging transformers and obsolete power lines that have made it difficult for homeowners, local governments, and businesses to use solar panels, batteries, electric cars, heat pumps, and other devices that can help reduce greenhouse gas emissions.

Much of the equipment in the power grid was built decades ago and needs to be modernized. It was developed for a world where electricity flows in one direction – from the grid to people. Now households and companies are increasingly supplying energy to the grid via their roof solar cells.

These issues have become more pressing because the fastest way to reduce greenhouse gas emissions is to convert machines, cars, and heating appliances that currently run on oil and natural gas to electricity generated from the sun, wind, nuclear and other zero-emission energy sources. But the electricity grid is nowhere near enough capacity to power all of the things that can help combat the effects of climate change, energy experts said.

“It’s a perfect violent storm when it comes to meeting the requirements we’re going to have,” said Michael Johnston, executive director of codes and standards for the National Electrical Contractors Association. “That’s not a small problem.”

Ms. Garcia and her husband Quin bought their home in the Portola Valley a little over a year ago. They invested in solar energy because Ms. Garcia, a 37-year-old biotech lawyer, and her husband, a venture capitalist, wanted to do their part in the fight against climate change.

The Garcias are not pioneers. About one in ten utilities in the state has solar power, according to the California Solar and Storage Association.

Hence, the Garcias were surprised when their utility Pacific Gas & Electric did not allow them to take full advantage of the panels.

The problem is that rooftop solar panels can produce much more electricity on sunny days than is used in the neighborhoods where they are installed. This can overload electrical transformers that regulate and direct the flow of electricity in a neighborhood, forcing them to shut down or explode. Such problems can be avoided by installing newer transformers with larger capacity.

Barry Cinnamon, the managing director of Cinnamon Energy Systems, the company that installed the panels in Garcia’s home, said such problems are far too common. “My experience and understanding of the way utilities do things is that they just wait until the neighborhood is overloaded and then the transformer explodes,” said Mr Cinnamon.

PG&E apologized for the delay in upgrading the transformer outside of the Garcia house, noting that this can take workers up to six months if they are overcrowded with projects.

During a heat wave in August 2020, an aging transformer exploded at a substation in downtown San Jose, about 25 miles from the Garcias home. That darkened the homes of tens of thousands of people, some for days.

City Mayor Sam Liccardo expressed frustration with PG&E, saying that the company’s outdated equipment is hindering San Jose’s plan to increase the use of solar panels, electric cars and other new devices. To meet its climate goals, the city has already banned the use of natural gas in new buildings, the country’s largest local government.

“It’s an infrastructure that fails,” said Mr. Liccardo, a Democrat. “We are very ambitious. The question is whether a network will be ready there. “

Mark Esguerra, senior director of electric asset strategy at PG&E, said the company plans to upgrade many more of its devices. Since the San Jose outage last year, the company has replaced 400 transformers in and around that city, out of a total of 62,000 in the Santa Clara district. The company added that it supports the use of solar panels by nearly 600,000 of its residential customers and electric cars by 360,000 customers.

“We know our network will be different in a few years,” said Esguerra.

How much and how fast?

The big challenge for policy makers and utilities is figuring out how quickly they can invest in the grid while keeping energy affordable.

It would cost hundreds of billions of dollars to modernize distribution grids across the country to meet the country’s clean energy goals, said Ben Hertz-Shargel, global head of Grid Edge, a division of Wood Mackenzie, a research and consultancy firm . This does not include expenses for transmission lines and power generation facilities such as solar and wind parks.

Mr. Hertz-Shargel has personal experience with the shortcomings of the power grid. Recently, when he was about to charge his Tesla at his Long Island home, the electrical equipment connecting the utility’s power line to his home got so hot it melted.

“I’m the only electric car on my block and even this modest use was enough to overwhelm the secondary side of the grid in my house,” he said. “It just shows how many weak links there are in the supply system.”

How much money utilities spend on their equipment is determined through a complicated process that involves government regulators approving increases in the electricity tariffs paid for upgrades.

State officials don’t want to hike tariffs too much because it harms consumers and could undermine public support for clean energy, said Abigail Anthony, a utility regulatory agency in Rhode Island who also chairs a committee that looks at these issues at the National Association of Regulatory Utility investigates commissioners.

“Not only the cars and the heating systems have to be affordable,” said Ms. Anthony, “but also the fuel, the electricity, has to be cheap, especially compared to oil, gasoline and natural gas.”

People pushing for bigger investments say the spending will pay off by saving money on monthly bills and preventing the worst effects of climate change.

Consider the following example: If all 330,000 households in San Jose stopped running on gasoline and natural gas and switched to electric cars, heat pumps, and electric water heaters and stoves, the city would use three times as much electricity as it does today, Rewiring America, a nonprofit group that campaigns for network upgrades and guidelines to combat climate change.

But the money that San Jose residents and businesses spend on electricity won’t necessarily triple or even double, the group claims. That’s because people could generate some electricity from solar panels on the roof and store that energy in house batteries. You could install smart thermostats and devices to use electricity when it costs less, like at night, said Sam Calisch, research director at Rewiring America.

Emily Fisher, senior vice president of clean energy at the Edison Electric Institute, a utility trade group, gave another example. Mr Biden wants electric cars to account for half of all new cars sold in the country by 2030. If all of these cars were plugged in with high energy consumption during the day, utility companies would have to spend a lot on upgrades. But if regulators allowed more utilities to offer lower electricity tariffs at night, people would charge cars when there was enough spare capacity.

Some companies are already finding ways to make themselves less dependent on the power grid when there is high demand. Electrify America, a subsidiary of Volkswagen that operates an electric vehicle charging network, has installed large batteries at some charging stations to avoid paying fees that utility companies collect from companies that use too much electricity.

Robert Barrosa, senior director of sales and marketing at Electrify America, said the company could eventually help utilities by taking the power when there was too much and delivering it when it wasn’t enough.

Ultimately, electrifying cars, heaters, stoves, and other appliances currently running on fossil fuels could save the average family $ 1,050 to $ 2,585 a year, according to Rewiring America. These products are more energy efficient and electricity tends to cost less than comparable amounts of gasoline, heating oil and natural gas. Electric cars and electrical appliances are also cheaper to run.

“Done correctly, the money can continue to flow into a more reliable network,” said Calisch, “especially in view of the increasing stress caused by climate change.”