solar

us-grid-adds-batteries-at-10x-the-rate-of-natural-gas-in-first-half-of-2024

US grid adds batteries at 10x the rate of natural gas in first half of 2024

batteries, Energy, green, natural gas, nuclear, renewable energy, Science, solar, Sustainability, Wind / /

In transition —

By year’s end, 96 percent of the US’s grid additions won’t add carbon to the atmosphere.

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US grid adds batteries at 10x the rate of natural gas in first half of 2024

While solar power is growing at an extremely rapid clip, in absolute terms, the use of natural gas for electricity production has continued to outpace renewables. But that looks set to change in 2024, as the US Energy Information Agency (EIA) has run the numbers on the first half of the year and found that wind, solar, and batteries were each installed at a pace that dwarfs new natural gas generators. And the gap is expected to get dramatically larger before the year is over.

Solar, batteries booming

According to the EIA’s numbers, about 20 GW of new capacity was added in the first half of this year, and solar accounts for 60 percent of it. Over a third of the solar additions occurred in just two states, Texas and Florida. There were two projects that went live that were rated at over 600 MW of capacity, one in Texas, the other in Nevada.

Next up is batteries: The US saw 4.2 additional gigawatts of battery capacity during this period, meaning over 20 percent of the total new capacity. (Batteries are treated as the equivalent of a generating source by the EIA since they can dispatch electricity to the grid on demand, even if they can’t do so continuously.) Texas and California alone accounted for over 60 percent of these additions; throw in Arizona and Nevada, and you’re at 93 percent of the installed capacity.

The clear pattern here is that batteries are going where the solar is, allowing the power generated during the peak of the day to be used to meet demand after the sun sets. This will help existing solar plants avoid curtailing power production during the lower-demand periods in the spring and fall. In turn, this will improve the economic case for installing additional solar in states where its production can already regularly exceed demand.

Wind power, by contrast, is running at a more sedate pace, with only 2.5 GW of new capacity during the first six months of 2024. And for likely the last time this decade, additional nuclear power was placed on the grid, at the fourth 1.1 GW reactor (and second recent build) at the Vogtle site in Georgia. The only other additions came from natural gas-powered facilities, but these totaled just 400 MW, or just 2 percent of the total of new capacity.

Wind, solar, and batteries are the key contributors to new capacity in 2024.

Enlarge / Wind, solar, and batteries are the key contributors to new capacity in 2024.

The EIA has also projected capacity additions out to the end of 2024 based on what’s in the works, and the overall shape of things doesn’t change much. However, the pace of installation goes up as developers rush to get their project operational within the current tax year. The EIA expects a bit over 60 GW of new capacity to be installed by the end of the year, with 37 GW of that coming in the form of solar power. Battery growth continues at a torrid pace, with 15 GW expected, or roughly a quarter of the total capacity additions for the year.

Wind will account for 7.1 GW of new capacity, and natural gas 2.6 GW. Throw in the contribution from nuclear, and 96 percent of the capacity additions of 2024 are expected to operate without any carbon emissions. Even if you choose to ignore the battery additions, the fraction of carbon-emitting capacity added remains extremely small, at only 6 percent.

Gradual shifts on the grid

Obviously, these numbers represent the peak production of these sources. Over a year, solar produces at about 25 percent of its rated capacity in the US, and wind at about 35 percent. The former number will likely decrease over time as solar becomes inexpensive enough to make economic sense in places that don’t receive as much sunshine. By contrast, wind’s capacity factor may increase as more offshore wind farms get completed. For natural gas, many of the newer plants are being designed to operate erratically so that they can provide power when renewables are under-producing.

A clearer sense of what’s happening comes from looking at the generating sources that are being retired. The US saw 5.1 GW of capacity drop off the grid in the first half of 2024, and aside from a 0.2 GW of “other,” all of it was fossil fuel-powered, including 2.1 GW of coal capacity and 2.7 GW of natural gas. The latter includes a large 1.4 GW natural gas plant in Massachusetts.

But total retirements are expected to be just 7.5 GWO this year—less than was retired in the first half of 2023. That’s likely because the US saw electricity use rise by 5 percent in the first half of 2025, based on numbers the EIA released on Friday (note that this link will take you to more recent data a month from now). It’s unclear how much of that was due to weather—a lot of the country saw heat that likely boosted demand for air conditioning—and how much could be accounted for by rising use in data centers and for the electrification of transit and appliances.

That data release includes details on where the US got its electricity during the first half of 2024. The changes aren’t dramatic compared to where they were when we looked at things last month. Still, what has changed over the past month is good news for renewables. In May, wind and solar production were up 8.4 percent compared to the same period the year before. By June, they were up by over 12 percent.

Given the EIA’s expectations for the rest of the year, the key question is likely to be whether the pace of new solar installations is going to be enough to offset the drop in production that will occur as the US shifts to the winter months.

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512-bit RSA key in home energy system gives control of “virtual power plant”

Biz & IT, Encryption, hacking, power management, RSA, Security, solar, Uncategorized / /
512-bit RSA key in home energy system gives control of “virtual power plant”

When Ryan Castellucci recently acquired solar panels and a battery storage system for their home just outside of London, they were drawn to the ability to use an open source dashboard to monitor and control the flow of electricity being generated. Instead, they gained much, much more—some 200 megawatts of programmable capacity to charge or discharge to the grid at will. That’s enough energy to power roughly 40,000 homes.

Castellucci, whose pronouns are they/them, acquired this remarkable control after gaining access to the administrative account for GivEnergy, the UK-based energy management provider who supplied the systems. In addition to the control over an estimated 60,000 installed systems, the admin account—which amounts to root control of the company’s cloud-connected products—also made it possible for them to enumerate names, email addresses, usernames, phone numbers, and addresses of all other GivEnergy customers (something the researcher didn’t actually do).

“My plan is to set up Home Assistant and integrate it with that, but in the meantime, I decided to let it talk to the cloud,” Castellucci wrote Thursday, referring to the recently installed gear. “I set up some scheduled charging, then started experimenting with the API. The next evening, I had control over a virtual power plant comprised of tens of thousands of grid connected batteries.”

Still broken after all these years

The cause of the authentication bypass Castellucci discovered was a programming interface that was protected by an RSA cryptographic key of just 512 bits. The key signs authentication tokens and is the rough equivalent of a master-key. The bit sizes allowed Castellucci to factor the private key underpinning the entire API. The factoring required $70 in cloud computing costs and less than 24 hours. GivEnergy introduced a fix within 24 hours of Castellucci privately disclosing the weakness.

The first publicly known instance of 512-bit RSA being factored came in 1999 by an international team of more than a dozen researchers. The feat took a supercomputer and hundreds of other computers seven months to carry out. By 2009 hobbyists spent about three weeks to factor 13 512-bit keys protecting firmware in Texas Instruments calculators from being copied. In 2015, researchers demonstrated factoring as a service, a method that used Amazon cloud computing, cost $75, and took about four hours. As processing power has increased, the resources required to factor keys has become ever less.

It’s tempting to fault GivEnergy engineers for pinning the security of its infrastructure on a key that’s trivial to break. Castellucci, however, said the responsibility is better assigned to the makers of code libraries developers rely on to implement complex cryptographic processes.

“Expecting developers to know that 512 bit RSA is insecure clearly doesn’t work,” the security researcher wrote. “They’re not cryptographers. This is not their job. The failure wasn’t that someone used 512 bit RSA. It was that a library they were relying on let them.”

Castellucci noted that OpenSSL, the most widely used cryptographic code library, still offers the option of using 512-bit keys. So does the Go crypto library. Coincidentally, the Python cryptography library removed the option only a few weeks ago (the commit for the change was made in January).

In an email, a GivEnergy representative reinforced Castellucci’s assessment, writing:

In this case, the problematic encryption approach was picked up via a 3rd party library many years ago, when we were a tiny startup company with only 2, fairly junior software developers & limited experience. Their assumption at the time was that because this encryption was available within the library, it was safe to use. This approach was passed through the intervening years and this part of the codebase was not changed significantly since implementation (so hadn’t passed through the review of the more experienced team we now have in place).

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US’s power grid continues to lower emissions—everything else, not so much

carbon emissions, coal, electric grid, Energy, natural gas, Science, solar, Sustainability, Wind / /

Down, but not down enough —

Excluding one pandemic year, emissions are lower than they’ve been since the 1980s.

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Graph showing total US carbon emissions, along with individual sources. Most trends are largely flat or show slight declines.

On Thursday, the US Department of Energy released its preliminary estimate for the nation’s carbon emissions in the previous year. Any drop in emissions puts us on a path that would avoid some of the catastrophic warming scenarios that were still on the table at the turn of the century. But if we’re to have a chance of meeting the Paris Agreement goal of keeping the planet from warming beyond 2° C, we’ll need to see emissions drop dramatically in the near future.

So, how is the US doing? Emissions continue to trend downward, but there’s no sign the drop has accelerated. And most of the drop has come from a single sector: changes in the power grid.

Off the grid, on the road

US carbon emissions have been trending downward since roughly 2007, when they peaked at about six gigatonnes. In recent years, the pandemic produced a dramatic drop in emissions in 2020, lowering them to under five gigatonnes for the first time since before 1990, when the EIA’s data started. Carbon dioxide release went up a bit afterward, with 2023 marking the first post-pandemic decline, with emissions again clearly below five gigatonnes.

The DOE’s Energy Information Agency (EIA) divides the sources of carbon dioxide into five different sectors: electricity generation, transportation, and residential, commercial, and industrial uses. The EIA assigns 80 percent of the 2023 reduction in US emissions to changes in the electric power grid, which is not a shock given that it’s the only sector that’s seen significant change in the entire 30-year period the EIA is tracking.

With hydro in the rearview mirror, wind and solar are coming after coal and nuclear.

With hydro in the rearview mirror, wind and solar are coming after coal and nuclear.

What’s happening with the power grid? Several things. At the turn of the century, coal accounted for over half of the US’s electricity generation; it’s now down to 16 percent. Within the next two years, it’s likely to be passed by wind and solar, which were indistinguishable from zero percent of generation as recently as 2004. Things would be even better for them if not for generally low wind speeds leading to a decline in wind generation in 2023. The biggest change, however, has been the rise of natural gas, which went from 10 percent of generation in 1990 to over 40 percent in 2023.

A small contributor to the lower emissions came from lower demand—it dropped by a percentage point compared to 2022. Electrification of transport and appliances, along with the growth of AI processing, are expected to send demand soaring in the near future, but there’s no indication of that on the grid yet.

Currently, generating electricity accounts for 30 percent of the US’s carbon emissions. That places it as the second most significant contributor, behind transportation, which is responsible for 39 percent of emissions. The EIA rates transportation emissions as unchanged relative to 2022, despite seeing air travel return to pre-pandemic levels and a slight increase in gasoline consumption. Later in this decade, tighter fuel efficiency rules are expected to drive a decline in transportation emissions, which are only down about 10 percent compared to their 2006 peak.

Buildings and industry

The remaining sectors—commercial, residential, and industrial—have a more complicated relationship with fossil fuels. Some of their energy comes via the grid, so its emissions are already accounted for. Thanks to the grid decarbonizing, these would be going down, but for business and residential use, grid-dependent emissions are dropping even faster than that would imply. This suggests that things like more efficient lighting and appliances are having an impact.

Separately, direct use of fossil fuels for things like furnaces, water heaters, etc., has been largely flat for the entire 30 years the EIA is looking at, although milder weather led to a slight decline in 2023 (8 percent for residential properties, 4 percent for commercial).

In contrast, the EIA only tracks the direct use of fossil fuels for industrial processes. These are down slightly over the 30-year period but have been fairly stable since the 2008 economic crisis, with no change in emissions between 2022 and 2023. As with the electric grid, the primary difference in this sector has been due to the growth of natural gas and the decline of coal.

Overall, there are two ways to look at this data. The first is that progress at limiting carbon emissions has been extremely limited and that there has been no progress at all in several sectors. The more optimistic view is that the technologies for decarbonizing the electric grid and improving building electrical usage are currently the most advanced, and the US has focused its decarbonization efforts where they’ll make the most difference.

From either perspective, it’s clear that the harder challenges are still coming, both in terms of accelerating decarbonization, and in terms of tackling sectors where decarbonization will be harder. The Biden administration has been working to put policies in place that should drive progress in this regard, but we probably won’t see much of their impact until early in the following decade.

Listing image by Yaorusheng

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40% of US electricity is now emissions-free

coal, Energy, hydroelectric, natural gas, nuclear power, renewable energy, Science, solar, Sustainability, Wind / /

Decarbonizing, but slowly —

Good news as natural gas, coal, and solar see the biggest changes.

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Image of electric power lines with a power plant cooling tower in the background.

Just before the holiday break, the US Energy Information Agency released data on the country’s electrical generation. Because of delays in reporting, the monthly data runs through October, so it doesn’t provide a complete picture of the changes we’ve seen in 2023. But some of the trends now seem locked in for the year: wind and solar are likely to be in a dead heat with coal, and all carbon-emissions-free sources combined will account for roughly 40 percent of US electricity production.

Tracking trends

Having data through October necessarily provides an incomplete picture of 2023. There are several factors that can cause the later months of the year to differ from the earlier ones. Some forms of generation are seasonal—notably solar, which has its highest production over the summer months. Weather can also play a role, as unusually high demand for heating in the winter months could potentially require that older fossil fuel plants be brought online. It also influences production from hydroelectric plants, creating lots of year-to-year variation.

Finally, everything’s taking place against a backdrop of booming construction of solar and natural gas. So, it’s entirely possible that we will have built enough new solar over the course of the year to offset the seasonal decline at the end of the year.

Let’s look at the year-to-date data to get a sense of the trends and where things stand. We’ll then check the monthly data for October to see if any of those trends show indications of reversing.

The most important takeaway is that energy use is largely flat. Overall electricity production year-to-date is down by just over one percent from 2022, though demand was higher this October compared to last year. This is in keeping with a general trend of flat-to-declining electricity use as greater efficiency is offsetting factors like population growth and expanding electrification.

That’s important because it means that any newly added capacity will displace the use of existing facilities. And, at the moment, that displacement is happening to coal.

Can’t hide the decline

At this point last year, coal had produced nearly 20 percent of the electricity in the US. This year, it’s down to 16.2 percent, and only accounts for 15.5 percent of October’s production. Wind and solar combined are presently at 16 percent of year-to-date production, meaning they’re likely to be in a dead heat with coal this year and easily surpass it next year.

Year-to-date, wind is largely unchanged since 2022, accounting for about 10 percent of total generation, and it’s up to over 11 percent in the October data, so that’s unlikely to change much by the end of the year. Solar has seen a significant change, going from five to six percent of the total electricity production (this figure includes both utility-scale generation and the EIA’s estimate of residential production). And it’s largely unchanged in October alone, suggesting that new construction is offsetting some of the seasonal decline.

Coal is being squeezed out by natural gas, with an assist from renewables.

Enlarge / Coal is being squeezed out by natural gas, with an assist from renewables.

Eric Bangeman/Ars Technica

Hydroelectric production has dropped by about six percent since last year, causing it to slip from 6.1 percent to 5.8 percent of the total production. Depending on the next couple of months, that may allow solar to pass hydro on the list of renewables.

Combined, the three major renewables account for about 22 percent of year-to-date electricity generation, up about 0.5 percent since last year. They’re up by even more in the October data, placing them well ahead of both nuclear and coal.

Nuclear itself is largely unchanged, allowing it to pass coal thanks to the latter’s decline. Its output has been boosted by a new, 1.1 Gigawatt reactor that come online this year (a second at the same site, Vogtle in Georgia, is set to start commercial production at any moment). But that’s likely to be the end of new nuclear capacity for this decade; the challenge will be keeping existing plants open despite their age and high costs.

If we combine nuclear and renewables under the umbrella of carbon-free generation, then that’s up by nearly 1 percent since 2022 and is likely to surpass 40 percent for the first time.

The only thing that’s keeping carbon-free power from growing faster is natural gas, which is the fastest-growing source of generation at the moment, going from 40 percent of the year-to-date total in 2022 to 43.3 percent this year. (It’s actually slightly below that level in the October data.) The explosive growth of natural gas in the US has been a big environmental win, since it creates the least particulate pollution of all the fossil fuels, as well as the lowest carbon emissions per unit of electricity. But its use is going to need to start dropping soon if the US is to meet its climate goals, so it will be critical to see whether its growth flat lines over the next few years.

Outside of natural gas, however, all the trends in US generation are good, especially considering that the rise of renewable production would have seemed like an impossibility a decade ago. Unfortunately, the pace is currently too slow for the US to have a net-zero electric grid by the end of the decade.

40% of US electricity is now emissions-free Read More »

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Government makes an app to cut down government’s role in solar permitting

Energy, green, green energy, NREL, photovoltaics, renewable energy, Science, solar, Sustainability / /
Aerial view of houses with roof-top solar panels.

Enlarge / NREL has taken some of the hassle out of getting permits for projects like these.

Can government agencies develop software to help cut bureaucratic red tape through automation? The answer is “yes,” according to the promising results achieved by the National Renewable Energy Laboratory (NREL), which has saved thousands of hours of labor for local governments by creating a tool called SolarAPP+ (Solar Automated Permit Processing Plus) for residential solar permits.

“We estimate that automatic SolarAPP+ permitting saved around 9,900 hours of… staff time in 2022,” NREL staff wrote in the report, “SolarAPP+ Performance Review (2022 Data). “Based on median timelines, a typical SolarAPP+ project is permitted and inspected 13 business days sooner than traditional projects… SolarAPP+ has eliminated over 134,000 days in permitting-related delays.”

SolarAPP+ automates over 100 compliance checks in the permitting process that are usually the responsibility of city, county, or town employees, according to Jeff Cook, SolarAPP+ program lead at NREL and first author of the report. It can be more accurate, thorough, and efficient than a time-pressured local government employee would be.

Saving time and money

Sometimes, the cost of permitting can be higher than the cost of solar hardware, Cook said. It depends on the specifics of the project.

“We knew that residential rooftop solar volume was increasing across the country,” Cook said. “It took us… 20 years to get to a million PV installations. And I think we got to 2 million PV installations just a few years later. And so there’s a lot of solar volume out there. And the problem is that each one of those systems needs to be reviewed for code compliance. And so if you need a human to review that, you’ve got a million applications.”

“When regulations make it unnecessarily difficult for people to quickly install solar and storage systems, it hurts everyone,” said Senator Scott Wiener (D-Calif.) in a press statement. “It hurts those who want to install solar. And it hurts communities across California, which are being negatively impacted by climate change. We need to make it easier for people to use renewable energy—that’s just a no-brainer. Expediting solar permitting is something we can do to make this a reality.”

A coalition of stakeholders from the solar industry, the US Department of Energy, and the building code-development community requested that NREL develop the software, Cook said. The organizations represented included UL Solutions and the Interstate Renewable Energy Council. (UL Solutions is a company that addresses a broad range of safety issues; initially, it focused on fire and electrical safety.)

“What we identified is the community need for the software and we identified that there was a gap in the private sector,” Cook said. “There was no incentive to do it from any active members of the private sector, but a real potential opportunity or value to the public good if such a software existed and was publicly available and free for a local government to adopt.”

Cook estimates that hundreds of thousands of hours in plan review time would have been required to manually approve all of the residential solar permits in the United States in recent years. Approving a permit for a residential solar project can take local government staff 15 minutes to an hour, and around 30 percent of the applications are later revised.

A flood of applications

“It just inundates the staff with work that they have to do,” Cook said.

“We are seeing about 750 residential requests over the past 12 months, which is about double the number of applications we saw two years ago,” said Kate Gallego, mayor of Phoenix, at the SolarAPP+ Industry Roundtable. “When I ask people in industry what we can do to speed up deployment of solar, they ask, ‘Can you do permitting faster?’ We’re at about 30 days now. We want to get that permitted as fast as possible, but we don’t want to sacrifice safety, and we want to make sure we’re not just doing it quickly, but well. That’s why this partnership was very attractive to me.”

Up to five separate departments may review the permits—the ones that oversee structural, electrical, fire, planning, and zoning decisions, Cook said.

“There’s usually a queue,” Cook said. “Just because it takes the jurisdiction only 15 minutes to review doesn’t mean that you send it to them today—they review it an hour later and get back to you. The average is, across the country, a seven-day turnaround, but it can be 30 days plus. It really varies across the country depending on how much volume of solar is in that space.”

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