Over the last ten years millions of homes across America have gotten solar panels installed. These panels let homeowners cut their power bills get electricity right from their roofs and sometimes store it for later use. But are these home setups the best way to lower fossil fuel use?
The answer isnt simple. Some researchers think home solar makes electricity more expensive and reduces the need for cheaper big solar farms — making the whole switch to clean power costlier. As more homeowners get solar (partly due to better government help) it could actually make it harder for the U.S. to reach its climate goals.
Jesse Jenkins‚ who teaches engineering at Princeton University says home solar is an example of “crises and mismatches“ that happen when we bill for electricity wrong. “Some people are going to pay more than they should‚ and some people are going to pay less than they should‚“ he said. “Its going to cause unnecessary costs“
The problem is solar only makes power when the suns out. It can give lots of power from 9 am to 5 pm; in places like California during spring solar can almost power the whole state then.
This means home solar is kind of competing with big solar farms run by power companies. “I call it a ʼsolar-shaped holeʼ in the electricity grid‚“ Jenkins said. “The more rooftop solar you have‚ the less valuable utility-scale solar is“
At some level it doesnt matter if the solar power comes from a big desert farm or someones roof — as long as its making power. But home solar costs way more than big farms. Putting panels on a house costs about $4.20 per watt before tax breaks while big farms cost about $1.16 per watt.
“Pooling together private and federal money its just going to be a lower cost way to get kilowatt-hours of solar‚ if its utility-scale‚“ said Duncan Callaway‚ who teaches about energy at UC Berkeley.
Home solar groups say the cost of big solar doesnt include all the other costs of building big farms.
“They are not adding in the cost of what it takes to deliver that electron to your home‚“ said Bernadette del Chiaro‚ who leads the California Solar and Storage Association.
Right now about 28% of all U.S. solar is on homes and businesses roofs. By 10/16/2035‚ we need about 1‚000 gigawatts of solar to hit climate goals — if more of that is home solar than big farms‚ we could spend billions extra on clean energy.
Some of that cost is paid by people putting solar on their homes; but part is covered by government tax credits and lower power bills for those customers. Now homeowners can get a federal tax credit for 30% of the cost of installing solar; they can save hundreds on power bills each year.
Home solar has other good points. Supporters say it can lower other costs — home panels dont need long power lines to bring energy from far-away desert farms to cities. (The slow building of power lines is holding back clean energy; it can also take a long time to connect big solar farms to the power grid.)
Panels on stores or homes also save space; they wont hurt prairie ecosystems or endangered animals. Big wind and solar farms can take 10 times the space of coal and gas plants — though some developers have tried mixing solar farms with cattle grazing or growing crops.
“These installations benefit everyone by taking strain off the grid‚“ Abigail Ross Hopper‚ who leads the Solar Energy Industries Association‚ said in an email. “We need massive increases in solar deployment at all scales in order to decarbonize the grid“
Amy Heart‚ a leader at Sunrun (a home solar company)‚ says half of their new systems have battery storage‚ which helps with the problem of all solar being made at the same time.
Callaway says it depends on what people value: cleaning up the grid cheaply or saving land. “Some people prefer to leave open space open‚“ he said. “If that is the value‚ then rooftop solar makes sense“
Home solar in the U.S. also costs more than in other countries. In some places‚ home and big solar cost about the same per watt. In America‚ high costs for ads and the variety of American homes make it pricier.
“We have local counties and cities that have their own building codes‚“ said Joachim Seel‚ who studies policy at Lawrence Berkeley National Laboratory. “There are local permitting procedures and inspections.“ Even the types of American homes — ranches‚ townhouses‚ multi-story colonials — can increase costs compared to other countries. “I dont think theres an easy way around it‚“ he added.
Heart says the U.S. has 40‚000 jurisdictions and red tape that solar providers must deal with — much more than other countries. “We make it so complicated‚“ she said.
Researchers say part of the issue is that many states and power companies give very good deals to home solar users — often paying them more than their solar is worth to the grid. In states like California and Arizona‚ Jenkins said‚ midday homeowners might get 20 cents back for each kilowatt-hour they send to the grid. But for a grid already full of solar‚ that extra energy is worth almost nothing.
The result is that richer homeowners who can afford solar get cheap power bills — while poorer residents see higher bills to make up for it. In California alone‚ researchers think home solar will add $4 billion to $6.5 billion to customers bills in 2024. One fix is to match the tax breaks and benefits of home solar more closely to the value it actually adds to the power grid.
Some groups disagree that this cost-shift is happening. The California Solar and Storage Association says solar has helped avoid peak midday demand in the state — and that most of the growth in power bills has come from high utility spending. Power companies say they need higher rates to protect their equipment from wildfire and other climate extremes.
“The utilities view rooftop solar as competition — it directly conflicts with their business model‚“ del Chiaro said. “We see it as very convenient scapegoating“
Few scientists or researchers want to get rid of home solar panels completely. Research has shown that solar panels are contagious — the best way to predict if a household will install them is if their neighbors already have them. Taking steps to change your lifestyle can also encourage people to take other steps: installing climate-friendly heat pumps‚ buying electric cars and eating less meat.
“Having your own solar system on your own rooftop — I think for many people it helps them think about energy consumption and energy efficiency in general‚ and take ownership of that‚“ Seel said. “From that perspective‚ its important“