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With net metering out of favor, the options for homeowners have gotten more complicated.
The early adopters of DIY solar had to pay a premium to put panels on their rooftops, sure — but at least they had a simple way to recoup that investment. Every kilowatt of self-generated sun power was one they didn’t have to buy from the power company. And for houses with big solar setups, so big they could satisfy their own needs and then some, selling their excess electricity back onto the grid could even be lucrative.
This strategy, called net metering, turned lots of homeowners and businesses into little power plants. These days, though, utilities are pushing back. New rules and laws in states such as Indiana, North Carolina, and even sun-drenched Arizona and California have throttled back on how much they’ll pay individual solar generators. Some mandated a lower price be paid to homeowners, making it less worthwhile to get a large home solar setup in the first place.
That presents a dilemma for homeowners generating more solar power than they can use: Where does it all go? The answer, it turns out, is more complicated than simply selling excess kilowatts back to the power company.
Arguments against the old-school way of net metering, where people essentially earn back the full price of energy they sell, lean on economic fairness. People who don’t pay for electricity or even make money back via their solar panels don’t pay for the grid maintenance that’s built into the price of electricity, and therefore pass it on to everyone else (although the size of this effect is in dispute). There’s also a design question: Grid systems were built to direct electricity from the power company to homeowners. When energy starts to flow in both directions, things can get unstable.
Whether rooftop solar is even good for the climate, actually, remains a confounding question. The counter-argument, as expounded by Jesse Jenkins on a recent episode of Heatmap’s Shift Key podcast, is that rooftop solar replaces utility-scale solar capacity that could’ve been built at lower cost, thus slowing down the clean energy transition.
Nevertheless, homes are installing solar, and their excess energy has to go somewhere, lest those kilowatt-hours be wasted. But if not onto the grid, then where? That’s the question I asked Steven Low, a professor and clean energy expert at the California Institute of Technology. (Disclosure: My full time job is as a communications editor at Caltech.)
“If you have significant feedback from [photovoltaic solar panels] to the grid then you may trigger protections, and that will screw up the operation of the grid,” he said. If only a few homes have solar, “that is probably not a big issue. But if you have more and more such PVs generating power that will affect the grid, then this will be a problem.”
For now at least, the best solution can be summed up in a single word: batteries. Low and his colleagues are collaborating with the power department in Pasadena, California to test batteries that can store and release excess power automatically to stop voltage from becoming unstable. In Hawaii, which has a high percentage of households with solar, Hawaiian Electric has a program to pay customers who put in a home battery system alongside their solar setup. The logic is twofold: First, a stash of backup power makes homes more resilient in case of a blackout, and storing solar power in a big battery is climate-friendlier than firing up a diesel generator. Second, from the utilities’ point of view, more storage means less uncertainty on the grid.
A problem, of course, is that batteries aren’t cheap — and they’re in high demand. “The battery at this point, especially since EV is taking off, is still usually much more valuable for transportation than for electricity service,” Low told me. Home batteries don’t need to be as big because appliances don’t use as much energy as a car flying down the freeway. Tesla’s powerwall has a capacity of 13.5 kWh, for example, less than a quarter as much as the battery in a standard-range Tesla Model Y. Multiple batteries can be stacked in a group, but the cost adds up quickly. Low speculated that perhaps used EV batteries will find a second life as home backup batteries once their capacity falls so far that they’re no longer useful for road trips.
Helpfully, a grid-connected home battery can move energy in multiple ways. A solar home could stash extra clean energy during the day to use in the dark of night. People who live under a virtual power plant can engage in “energy arbitrage” — the buy low, sell high practice of storing energy when it’s cheap and selling it back onto the grid when it’s expensive. (Technically, you don’t even need the solar panels to do this, although the emissions reduction would be far smaller.)
The idea of electricity moving in every direction — not just from the electric company to you — leads to the promise of the microgrid, the energy-sharing gold standard where neighbors can share power. The school district in Santa Barbara, California, for example, is developing a solar-powered microgrid to reinforce the resilience of an area that’s particularly vulnerable to earthquakes and other grid disruptions. If the grid goes down, a neighborhood, company, or organization with a microgrid that can “island” itself is able to keep the lights, on as homes and businesses that can make or store extra energy sell it to their neighbors.
Before any of that can happen, though, “there needs to be some incentive structure for me to provide power to my neighbor, also using the grid that belongs to the utility,” Low said. That last part is the trickiest. It’s not just the technical and financial infrastructure needed to share electricity across the cul-de-sac. The utility must agree to let energy flows in this way over infrastructure that it owns. And somebody has to oversee such a complex energy web.
“Let's say you have a lot of households and businesses install PV,” Low said. “They have their storage, and they want arbitrage because they can be profitable selling waste.” But you also want to make sure people are maximizing their own storage for stability’s sake. “Who's going to do that coordination? A natural way is for utilities to do that, but then that will require the utility to either control or at least communicate with each household,” which would in turn require complex data-sharing infrastructure.
As Tim Hale of Scaled Microgrids told me, it’s not easy for people to decide whether all that trouble is worthwhile because there’s no simple way to put a price tag on making a company or a community more resilient against power disruptions.
“It's a very complex thought exercise for people to go through,” he said “Generally speaking, there are companies and entities and people that value resilience and there are people that don't. Right? And the people who value resilience are the people that build microgrids.”
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The Loan Programs Office is good for more than just nuclear funding.
That China has a whip hand over the rare earths mining and refining industry is one of the few things Washington can agree on.
That’s why Alex Jacquez, who worked on industrial policy for Joe Biden’s National Economic Council, found it “astounding”when he read in the Washington Post this week that the White House was trying to figure out on the fly what to do about China restricting exports of rare earth metals in response to President Trump’s massive tariffs on the country’s imports.
Rare earth metals have a wide variety of applications, including for magnets in medical technology, defense, and energy productssuch as wind turbines and electric motors.
Jacquez told me there has been “years of work, including by the first Trump administration, that has pointed to this exact case as the worst-case scenario that could happen in an escalation with China.” It stands to reason, then, that experienced policymakers in the Trump administration might have been mindful of forestalling this when developing their tariff plan. But apparently not.
“The lines of attack here are numerous,” Jacquez said. “The fact that the National Economic Council and others are apparently just thinking about this for the first time is pretty shocking.”
And that’s not the only thing the Trump administration is doing that could hamper American access to rare earths and critical minerals.
Though China still effectively controls the global pipeline for most critical minerals (a broader category that includes rare earths as well as more commonly known metals and minerals such as lithium and cobalt), the U.S. has been at work for at least the past five years developing its own domestic supply chain. Much of that work has fallen to the Department of Energy, whose Loan Programs Office has funded mining and processing facilities, and whose Office of Manufacturing and Energy Supply Chains hasfunded and overseen demonstration projects for rare earths and critical minerals mining and refining.
The LPO is in line for dramatic cuts, as Heatmap has reported. So, too, are other departments working on rare earths, including the Office of Manufacturing and Energy Supply Chains. In its zeal to slash the federal government, the Trump administration may have to start from scratch in its efforts to build up a rare earths supply chain.
The Department of Energy did not reply to a request for comment.
This vulnerability to China has been well known in Washington for years, including by the first Trump administration.
“Our dependence on one country, the People's Republic of China (China), for multiple critical minerals is particularly concerning,” then-President Trump said in a 2020 executive order declaring a “national emergency” to deal with “our Nation's undue reliance on critical minerals.” At around the same time, the Loan Programs Office issued guidance “stating a preference for projects related to critical mineral” for applicants for the office’s funding, noting that “80 percent of its rare earth elements directly from China.” Using the Defense Production Act, the Trump administration also issued a grant to the company operating America's sole rare earth mine, MP Materials, to help fund a processing facility at the site of its California mine.
The Biden administration’s work on rare earths and critical minerals was almost entirely consistent with its predecessor’s, just at a greater scale and more focused on energy. About a month after taking office, President Bidenissued an executive order calling for, among other things, a Defense Department report “identifying risks in the supply chain for critical minerals and other identified strategic materials, including rare earth elements.”
Then as part of the Inflation Reduction Act in 2022, the Biden administration increased funding for LPO, which supported a number of critical minerals projects. It also funneled more money into MP Materials — including a $35 million contract from the Department of Defense in 2022 for the California project. In 2024, it awarded the company a competitive tax credit worth $58.5 million to help finance construction of its neodymium-iron-boron magnet factory in Texas. That facilitybegan commercial operation earlier this year.
The finished magnets will be bought by General Motors for its electric vehicles. But even operating at full capacity, it won’t be able to do much to replace China’s production. The MP Metals facility is projected to produce 1,000 tons of the magnets per year.China produced 138,000 tons of NdFeB magnets in 2018.
The Trump administration is not averse to direct financial support for mining and minerals projects, but they seem to want to do it a different way. Secretary of the Interior Doug Burgum has proposed using a sovereign wealth fund to invest in critical mineral mines. There is one big problem with that plan, however: the U.S. doesn’t have one (for the moment, at least).
“LPO can invest in mining projects now,” Jacquez told me. “Cutting 60% of their staff and the experts who work on this is not going to give certainty to the business community if they’re looking to invest in a mine that needs some government backstop.”
And while the fate of the Inflation Reduction Act remains very much in doubt, the subsidies it provided for electric vehicles, solar, and wind, along with domestic content requirements have been a major source of demand for critical minerals mining and refining projects in the United States.
“It’s not something we’re going to solve overnight,” Jacquez said. “But in the midst of a maximalist trade with China, it is something we will have to deal with on an overnight basis, unless and until there’s some kind of de-escalation or agreement.”
A conversation with VDE Americas CEO Brian Grenko.
This week’s Q&A is about hail. Last week, we explained how and why hail storm damage in Texas may have helped galvanize opposition to renewable energy there. So I decided to reach out to Brian Grenko, CEO of renewables engineering advisory firm VDE Americas, to talk about how developers can make sure their projects are not only resistant to hail but also prevent that sort of pushback.
The following conversation has been lightly edited for clarity.
Hiya Brian. So why’d you get into the hail issue?
Obviously solar panels are made with glass that can allow the sunlight to come through. People have to remember that when you install a project, you’re financing it for 35 to 40 years. While the odds of you getting significant hail in California or Arizona are low, it happens a lot throughout the country. And if you think about some of these large projects, they may be in the middle of nowhere, but they are taking hundreds if not thousands of acres of land in some cases. So the chances of them encountering large hail over that lifespan is pretty significant.
We partnered with one of the country’s foremost experts on hail and developed a really interesting technology that can digest radar data and tell folks if they’re developing a project what the [likelihood] will be if there’s significant hail.
Solar panels can withstand one-inch hail – a golfball size – but once you get over two inches, that’s when hail starts breaking solar panels. So it’s important to understand, first and foremost, if you’re developing a project, you need to know the frequency of those events. Once you know that, you need to start thinking about how to design a system to mitigate that risk.
The government agencies that look over land use, how do they handle this particular issue? Are there regulations in place to deal with hail risk?
The regulatory aspects still to consider are about land use. There are authorities with jurisdiction at the federal, state, and local level. Usually, it starts with the local level and with a use permit – a conditional use permit. The developer goes in front of the township or the city or the county, whoever has jurisdiction of wherever the property is going to go. That’s where it gets political.
To answer your question about hail, I don’t know if any of the [authority having jurisdictions] really care about hail. There are folks out there that don’t like solar because it’s an eyesore. I respect that – I don’t agree with that, per se, but I understand and appreciate it. There’s folks with an agenda that just don’t want solar.
So okay, how can developers approach hail risk in a way that makes communities more comfortable?
The bad news is that solar panels use a lot of glass. They take up a lot of land. If you have hail dropping from the sky, that’s a risk.
The good news is that you can design a system to be resilient to that. Even in places like Texas, where you get large hail, preparing can mean the difference between a project that is destroyed and a project that isn’t. We did a case study about a project in the East Texas area called Fighting Jays that had catastrophic damage. We’re very familiar with the area, we work with a lot of clients, and we found three other projects within a five-mile radius that all had minimal damage. That simple decision [to be ready for when storms hit] can make the complete difference.
And more of the week’s big fights around renewable energy.
1. Long Island, New York – We saw the face of the resistance to the war on renewable energy in the Big Apple this week, as protestors rallied in support of offshore wind for a change.
2. Elsewhere on Long Island – The city of Glen Cove is on the verge of being the next New York City-area community with a battery storage ban, discussing this week whether to ban BESS for at least one year amid fire fears.
3. Garrett County, Maryland – Fight readers tell me they’d like to hear a piece of good news for once, so here’s this: A 300-megawatt solar project proposed by REV Solar in rural Maryland appears to be moving forward without a hitch.
4. Stark County, Ohio – The Ohio Public Siting Board rejected Samsung C&T’s Stark Solar project, citing “consistent opposition to the project from each of the local government entities and their impacted constituents.”
5. Ingham County, Michigan – GOP lawmakers in the Michigan State Capitol are advancing legislation to undo the state’s permitting primacy law, which allows developers to evade municipalities that deny projects on unreasonable grounds. It’s unlikely the legislation will become law.
6. Churchill County, Nevada – Commissioners have upheld the special use permit for the Redwood Materials battery storage project we told you about last week.