Energy

for-the-first-time-since-1882,-uk-will-have-no-coal-fired-power-plants

For the first time since 1882, UK will have no coal-fired power plants

Into the black —

A combination of government policy and economics spells the end of UK’s coal use.

Image of cooling towers and smoke stacks against a dusk sky.

Enlarge / The Ratcliffe-on-Soar plant is set to shut down for good today.

On Monday, the UK will see the closure of its last operational coal power plant, Ratcliffe-on-Soar, which has been operating since 1968. The closure of the plant, which had a capacity of 2,000 megawatts, will bring an end to the history of the country’s coal use, which started with the opening of the first coal-fired power station in 1882. Coal played a central part in the UK’s power system in the interim, in some years providing over 90 percent of its total electricity.

But a number of factors combined to place coal in a long-term decline: the growth of natural gas-powered plants and renewables, pollution controls, carbon pricing, and a government goal to hit net-zero greenhouse gas emissions by 2050.

From boom to bust

It’s difficult to overstate the importance of coal to the UK grid. It was providing over 90 percent of the UK’s electricity as recently as 1956. The total amount of power generated continued to climb well after that, reaching a peak of 212 terawatt hours of production by 1980. And the construction of new coal plants was under consideration as recently as the late 2000s. According to the organization Carbon Brief’s excellent timeline of coal use in the UK, continuing the use of coal with carbon capture was given consideration.

But several factors slowed the use of fuel ahead of any climate goals set out by the UK, some of which have parallels to the US’s situation. The European Union, which included the UK at the time, instituted new rules to address acid rain, which raised the cost of coal plants. In addition, the exploitation of oil and gas deposits in the North Sea provided access to an alternative fuel. Meanwhile, major gains in efficiency and the shift of some heavy industry overseas cut demand in the UK significantly.

Through their effect on coal use, these changes also lowered employment in coal mining. The mining sector has sometimes been a significant force in UK politics, but the decline of coal reduced the number of people employed in the sector, reducing its political influence.

These had all reduced the use of coal even before governments started taking any aggressive steps to limit climate change. But, by 2005, the EU implemented a carbon trading system that put a cost on emissions. By 2008, the UK government adopted national emissions targets, which have been maintained and strengthened since then by both Labour and Conservative governments up until Rishi Sunak, who was voted out of office before he had altered the UK’s trajectory. What started as a pledge for a 60 percent reduction in greenhouse gas emissions by 2050 now requires the UK to hit net zero by that date.

Renewables, natural gas, and efficiency have all squeezed coal off the UK grid.

Enlarge / Renewables, natural gas, and efficiency have all squeezed coal off the UK grid.

These have included a floor on the price of carbon that ensures fossil-powered plants pay a cost for emissions that’s significant enough to promote the transition to renewables, even if prices in the EU’s carbon trading scheme are too low for that. And that transition has been rapid, with the total generations by renewables nearly tripling in the decade since 2013, heavily aided by the growth of offshore wind.

How to clean up the power sector

The trends were significant enough that, in 2015, the UK announced that it would target the end of coal in 2025, despite the fact that the first coal-free day on the grid wouldn’t come until two years after. But two years after that landmark, however, the UK was seeing entire weeks where no coal-fired plants were active.

To limit the worst impacts of climate change, it will be critical for other countries to follow the UK’s lead. So it’s worthwhile to consider how a country that was committed to coal relatively recently could manage such a rapid transition. There are a few UK-specific factors that won’t be possible to replicate everywhere. The first is that most of its coal infrastructure was quite old—Ratcliffe-on-Soar dates from the 1960s—and so it required replacement in any case. Part of the reason for its aging coal fleet was the local availability of relatively cheap natural gas, something that might not be true elsewhere, which put economic pressure on coal generation.

Another key factor is that the ever-shrinking number of people employed by coal power didn’t exert significant pressure on government policies. Despite the existence of a vocal group of climate contrarians in the UK, the issue never became heavily politicized. Both Labour and Conservative governments maintained a fact-based approach to climate change and set policies accordingly. That’s notably not the case in countries like the US and Australia.

But other factors are going to be applicable to a wide variety of countries. As the UK was moving away from coal, renewables became the cheapest way to generate power in much of the world. Coal is also the most polluting source of electrical power, providing ample reasons for regulation that have little to do with climate. Forcing coal users to pay even a fraction of its externalized costs on human health and the environment serve to make it even less economical compared to alternatives.

If these later factors can drive a move away from coal despite government inertia, then it can pay significant dividends in the fight to limit climate change. Inspired in part by the success in moving its grid off coal, the new Labour government in the UK has moved up its timeline for decarbonizing its power sector to 2030 (up from the previous Conservative government’s target of 2035).

For the first time since 1882, UK will have no coal-fired power plants Read More »

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

In transition —

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

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.

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

us-solar-production-soars-by-25-percent-in-just-one-year

US solar production soars by 25 percent in just one year

Solar sailing —

2024 is seeing the inevitable outcome of the building boom in solar farms.

A single construction person set in the midst of a sea of solar panels.

With the plunging price of photovoltaics, the construction of solar plants has boomed in the US. Last year, for example, the US’s Energy Information Agency expected that over half of the new generating capacity would be solar, with a lot of it coming online at the very end of the year for tax reasons. Yesterday, the EIA released electricity generation numbers for the first five months of 2024, and that construction boom has seemingly made itself felt: generation by solar power has shot up by 25 percent compared to just one year earlier.

The EIA breaks down solar production according to the size of the plant. Large grid-scale facilities have their production tracked, giving the EIA hard numbers. For smaller installations, like rooftop solar on residential and commercial buildings, the agency has to estimate the amount produced, since the hardware often resides behind the metering equipment, so only shows up via lower-than-expected consumption.

In terms of utility-scale production, the first five months of 2024 saw it rise by 29 percent compared to the same period in the year prior. Small-scale solar was “only” up by 18 percent, with the combined number rising by 25.3 percent.

Most other generating sources were largely flat, year over year. This includes coal, nuclear, and hydroelectric, all of which changed by 2 percent or less. Wind was up by 4 percent, while natural gas rose by 5 percent. Because natural gas is the largest single source of energy on the grid, however, its 5 percent rise represents a lot of electrons—slightly more than the total increase in wind and solar.

US electricity sources for January through May of 2024. Note that the numbers do not add up to 100 percent due to the omission of minor contributors like geothermal and biomass.

Enlarge / US electricity sources for January through May of 2024. Note that the numbers do not add up to 100 percent due to the omission of minor contributors like geothermal and biomass.

John Timmer

Overall, energy use was up by about 4 percent compared to the same period in 2023. This could simply be a matter of changing weather conditions that require more heating or cooling. But there have been several trends that should increase electricity usage: the rise of bitcoin mining, the growth of data centers, and the electrification of appliances and transport. So far, that hasn’t shown up in the actual electricity usage in the US, which has stayed largely flat for decades. It could be possible that 2024 is the year when usage starts going up again.

More to come

It’s worth noting that this data all comes from before some of the most productive months of the year for solar power; overall, the EIA is predicting that solar production could rise by as much as 42 percent in 2024.

So, where does this leave the US’s efforts to decarbonize? If we combine nuclear, hydro, wind, and solar under the umbrella of carbon-free power sources, then these account for about 45 percent of US electricity production so far this year. Within that category, wind and solar now produce more than three times hydroelectric, and roughly the same amount as nuclear.

Wind and solar have also produced 1.3 times as much electricity as coal so far in 2024, with solar alone now producing about half as much as coal. That said, natural gas still produces twice as much electricity as wind and solar combined, indicating we still have a long way to go to decarbonize our grid.

When you look at the generating facilities that will be built over the next 12 months, it's difficult not to see a pattern.

Enlarge / When you look at the generating facilities that will be built over the next 12 months, it’s difficult not to see a pattern.

Still, we can expect solar’s productivity to climb even before the year is out. That’s in part because we don’t yet have numbers for June, the month that contains the longest day of the year. But it’s also because the construction boom shows no sign of stopping. As noted here, solar and wind deployments are expected to dwarf everything else over the coming year. The items in gray on the map primarily represent battery storage, which will allow us to make better use of those renewables, as well.

By contrast, facilities that are scheduled for retirement over the next year largely consist of coal and natural gas plants.

US solar production soars by 25 percent in just one year Read More »

will-space-based-solar-power-ever-make-sense?

Will space-based solar power ever make sense?

Artist's depiction of an astronaut servicing solar panels against the black background of space.

Is space-based solar power a costly, risky pipe dream? Or is it a viable way to combat climate change? Although beaming solar power from space to Earth could ultimately involve transmitting gigawatts, the process could be made surprisingly safe and cost-effective, according to experts from Space Solar, the European Space Agency, and the University of Glasgow.

But we’re going to need to move well beyond demonstration hardware and solve a number of engineering challenges if we want to develop that potential.

Designing space-based solar

Beaming solar energy from space is not new; telecommunications satellites have been sending microwave signals generated by solar power back to Earth since the 1960s. But sending useful amounts of power is a different matter entirely.

“The idea [has] been around for just over a century,” said Nicol Caplin, deep space exploration scientist at the ESA, on a Physics World podcast. “The original concepts were indeed sci-fi. It’s sort of rooted in science fiction, but then, since then, there’s been a trend of interest coming and going.”

Researchers are scoping out multiple designs for space-based solar power. Matteo Ceriotti, senior lecturer in space systems engineering at the University of Glasgow, wrote in The Conversation that many designs have been proposed.

The Solaris initiative is exploring two possible technologies, according to Sanjay Vijendran, lead for the Solaris initiative at the ESA: one that involves beaming microwaves from a station in geostationary orbit down to a receiver on Earth and another that involves using immense mirrors in a lower orbit to reflect sunlight down onto solar farms. He said he thinks that both of these solutions are potentially valuable. Microwave technology has drawn wider interest and was the main focus of these interviews. It has enormous potential, although high-frequency radio waves can also be used.

“You really have a source of 24/7 clean power from space,” Vijendran said. The power can be transmitted regardless of weather conditions because of the frequency of the microwaves.

“A 1-gigawatt power plant in space would be comparable to the top five solar farms on earth. A power plant with a capacity of 1 gigawatt could power around 875,000 households for one year,” said Andrew Glester, host of the Physics World podcast.

But we’re not ready to deploy anything like this. “It will be a big engineering challenge,” Caplin said. There are a number of physical hurdles involved in successfully building a solar power station in space.

Using microwave technology, the solar array for an orbiting power station that generates a gigawatt of power would have to be over 1 square kilometer in size, according to a Nature article by senior reporter Elizabeth Gibney. “That’s more than 100 times the size of the International Space Station, which took a decade to build.” It would also need to be assembled robotically, since the orbiting facility would be uncrewed.

The solar cells would need to be resilient to space radiation and debris. They would also need to be efficient and lightweight, with a power-to-weight ratio 50 times more than the typical silicon solar cell, Gibney wrote. Keeping the cost of these cells down is another factor that engineers have to take into consideration. Reducing the losses during power transmission is another challenge, Gibney wrote. The energy conversion rate needs to be improved to 10–15 percent, according to the ESA. This would require technical advances.

Space Solar is working on a satellite design called CASSIOPeiA, which Physics World describes as looking “like a spiral staircase, with the photovoltaic panels being the ‘treads’ and the microwave transmitters—rod-shaped dipoles—being the ‘risers.’” It has a helical shape with no moving parts.

“Our system’s comprised of hundreds of thousands of the same dinner-plate-sized power modules. Each module has the PV which converts the sun’s energy into DC electricity,” said Sam Adlen, CEO of Space Solar.

“That DC power then drives electronics to transmit the power… down toward Earth from dipole antennas. That power up in space is converted to [microwaves] and beamed down in a coherent beam down to the Earth where it’s received by a rectifying antenna, reconverted into electricity, and input to the grid.”

Adlen said that robotics technologies for space applications, such as in-orbit assembly, are advancing rapidly.

Ceriotti wrote that SPS-ALPHA, another design, has a large solar-collector structure that includes many heliostats, which are modular small reflectors that can be moved individually. These concentrate sunlight onto separate power-generating modules, after which it’s transmitted back to Earth by yet another module.

Will space-based solar power ever make sense? Read More »

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Bipartisan consensus in favor of renewable power is ending

End of an era —

The change is most pronounced in those over 50 years old.

Image of solar panels on a green grassy field, with blue sky in the background.

One of the most striking things about the explosion of renewable power that’s happening in the US is that much of it is going on in states governed by politicians who don’t believe in the problem wind and solar are meant to address. Acceptance of the evidence for climate change tends to be lowest among Republicans, yet many of the states where renewable power has boomed—wind in Wyoming and Iowa, solar in Texas—are governed by Republicans.

That’s partly because, up until about 2020, there was a strong bipartisan consensus in favor of expanding wind and solar power, with support above 75 percent among both parties. Since then, however, support among Republicans has dropped dramatically, approaching 50 percent, according to polling data released this week.

Renewables enjoyed solid Republican support until recently.

Renewables enjoyed solid Republican support until recently.

To a certain extent, none of this should be surprising. The current leader of the Republican Party has been saying that wind turbines cause cancer and offshore wind is killing whales. And conservative-backed groups have been spreading misinformation in order to drum up opposition to solar power facilities.

Meanwhile, since 2022, the Inflation Reduction Act has been promoted as one of the Biden administration’s signature accomplishments and has driven significant investments in renewable power, much of it in red states. Negative partisanship is undoubtedly contributing to this drop in support.

One striking thing about the new polling data, gathered by the Pew Research Center, is how dramatically it skews with age. When given a choice between expanding fossil fuel production or expanding renewable power, Republicans under the age of 30 favored renewables by a 2-to-1 margin. Republicans over 30, in contrast, favored fossil fuels by margins that increased with age, topping out at a three-to-one margin in favor of fossil fuels among those in the 65-and-over age group. The decline in support occurred in those over 50 starting in 2020; support held steady among younger groups until 2024, when the 30–49 age group started moving in favor of fossil fuels.

Among younger Republicans, support for renewable energy remains high.

Among younger Republicans, support for renewable energy remains high.

Democrats, by contrast, break in favor of renewables by 75 points, with little difference across age groups and no indication of significant change over time. They’re also twice as likely to think a solar farm will help the local economy than Republicans are.

Similar differences were apparent when Pew asked about policies meant to encourage the sale of electric vehicles, with 83 percent of Republicans opposed to having half of cars sold be electric in 2032. By contrast, nearly two-thirds of Democrats favored this policy.

There’s also a rural/urban divide apparent (consistent with Republicans getting more support from rural voters). Forty percent of urban residents felt that a solar farm would improve the local economy; only 25 percent of rural residents agreed. Rural residents were also more likely to say solar farms made the landscape unattractive and take up too much space. (Suburban participants were consistently in between rural and urban participants.)

What’s behind these changes? The single biggest factor appears to be negative partisanship combined with the election of Joe Biden.

For Republicans, 2020 represented an inflection point in terms of support for different types of energy. That wasn't true for Democrats.

For Republicans, 2020 represented an inflection point in terms of support for different types of energy. That wasn’t true for Democrats.

Among Republicans, support for every single form of power started to change in 2020—fossil fuels, renewables, and nuclear. Among Democrats, that’s largely untrue. Their high level of support for renewable power and aversion to fossil fuels remained largely unchanged. The lone exception is nuclear power, where support rose among both Democrats and Republicans (the Biden administration has adopted a number of pro-nuclear policies).

This isn’t to say that non-political factors are playing no role. The rapid expansion of renewable power means that many more people are seeing facilities open near them, and viewing that as an indication of a changing society. Some degree of backlash was almost inevitable and, in this case, the close ties between conservative lobbyists and fossil fuel interests were ready to take advantage of it.

Bipartisan consensus in favor of renewable power is ending Read More »

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Congress passes bill to jumpstart new nuclear power tech

A nuclear reactor and two cooling towards on a body of water, with a late-evening glow in the sky.

Earlier this week, the US Senate passed what’s being called the ADVANCE Act, for Accelerating Deployment of Versatile, Advanced Nuclear for Clean Energy. Among a number of other changes, the bill would attempt to streamline permitting for newer reactor technology and offer cash incentives for the first companies that build new plants that rely on one of a handful of different technologies. It enjoyed broad bipartisan support both in the House and Senate and now heads to President Biden for his signature.

Given Biden’s penchant for promoting his bipartisan credentials, it’s likely to be signed into law. But the biggest hurdles nuclear power faces are all economic, rather than regulatory, and the bill provides very little in the way of direct funding that could help overcome those barriers.

Incentives

For reasons that will be clear only to congressional staffers, the Senate version of the bill was attached to an amendment to the Federal Fire Prevention and Control Act. Nevertheless, it passed by a margin of 88-2, indicating widespread (and potentially veto-proof) support. Having passed the House already, there’s nothing left but the president’s signature.

The bill’s language focuses on the Nuclear Regulatory Commission (NRC) and its role in licensing nuclear reactor technology. The NRC is directed to develop a variety of reports for Congress—so, so many reports, focusing on everything from nuclear waste to fusion power—that could potentially inform future legislation. But the meat of the bill has two distinct focuses: streamlining regulation and providing some incentives for new technology.

The incentives are one of the more interesting features of the bill. They’re primarily focused on advanced nuclear technology, which is defined extremely broadly by an earlier statute as providing any of the following:

    • (A) additional inherent safety features
    • (B) significantly lower levelized cost of electricity
    • (C) lower waste yields
    • (D) greater fuel utilization
    • (E) enhanced reliability
    • (F) increased proliferation resistance
    • (G) increased thermal efficiency
    • (H) ability to integrate into electric and nonelectric applications

Normally, the work of the NRC in licensing is covered via application fees paid by the company seeking the license. But the NRC is instructed to lower its licensing fees for anyone developing advanced nuclear technologies. And there’s a “prize” incentive where the first company to get across the line with any of a handful of specific technologies will have all these fees refunded to it.

Winners will be awarded when they have met any of the following requirements: the first advanced reactor design that receives a license from the NRC; the first to be loaded with fuel for operation; the first to use isotopes derived from spent fuel; the first to build a facility where the reactor is integrated into a system that stores energy; the first to build a facility where the reactor provides electricity or processes heat for industrial applications.

The first award will likely go to NuScale, which is developing a small, modular reactor design and has gotten pretty far along in the licensing process. Its first planned installation, however, has been cancelled due to rising costs, so there’s no guarantee that the company will be first to fuel a reactor. TerraPower, a company backed by Bill Gates, is fairly far along in the design of a rector facility that will come with integrated storage, and so may be considered a frontrunner there.

For the remaining two prizes, there aren’t frontrunners for very different reasons. Nearly every company building small modular nuclear reactors promotes them as a potential source of process heat. By contrast, reprocessing spent fuel has been hugely expensive in any country where it has been tried, so it’s unlikely that prize will ever be given out.

Congress passes bill to jumpstart new nuclear power tech Read More »

planned-nuclear-fuel-has-higher-proliferation-risks-than-thought

Planned nuclear fuel has higher proliferation risks than thought

A lump of rock, next to the periodic table entry for uranium, all against a black background.

High-assay low-enriched uranium (HALEU) has been touted as the go-to fuel for powering next-gen nuclear reactors, which include the sodium-cooled TerraPower or the space-borne system powering Demonstration Rocket for Agile Cislunar Operations (DRACO). That’s because it was supposed to offer higher efficiency while keeping uranium enrichment “well below the threshold needed for weapons-grade material,” according to the US Department of Energy.

This justified huge government investments in HALEU production in the US and UK, as well as relaxed security requirements for facilities using it as fuel. But now, a team of scientists has published an article in Science that argues that you can make a nuclear bomb using HALEU.

“I looked it up and DRACO space reactor will use around 300 kg of HALEU. This is marginal, but I would say you could make one a weapon with that much,” says Edwin Lyman, the director of Nuclear Power Safety at the Union of Concerned Scientists and co-author of the paper.

Forgotten threats

“When uranium is mined out of the ground, it’s mostly a mixture of two isotopes: uranium-238 and uranium-235. Uranium 235 concentrations are below one percent,” says Lyman. This is sent through an enrichment process, usually in gas centrifuges, where it is turned into gaseous form and centrifuged till the two isotopes are separated from each other due to their slight difference in their atomic weights. This can produce uranium with various levels of enrichment. Material that’s under 10 percent uranium-235 is called low-enriched uranium (LEU) and is used in power reactors working today. Moving the enrichment level up to between 10 and 20 percent, we get HALEU; above 20 percent, we start talking about highly enriched uranium, which can reach over 90 percent enrichment for uses like nuclear weapons.

“Historically, 20 percent has been considered a threshold between highly enriched uranium and low enriched uranium and, over time, that’s been associated with the limit of what is usable in nuclear weapons and what isn’t. But the truth is that threshold is not really a limit of weapons usability,” says Lyman. And we knew that since long time ago.

A study assessing the weaponization potential of uranium with different enrichment levels was done by the Los Alamos National Laboratory back in 1954. The findings were clear: Uranium enriched up to 10 percent was no good for weapons, regardless of how much of it you had. HALEU, though, was found to be of “weapons significance,” provided a sufficient amount was available. “My sense is that once they established 20 percent is somewhat acceptable, and given the material is weapons-usable only when you have enough of it, they just thought we’d need to limit the quantities and we’d be okay. That sort of got baked into the international security framework for uranium because there was not that much HALEU,” says Lyman. The Los Alamos study recommended releasing 100 kg of uranium enriched to up to 20 percent for research purposes in other countries, as they didn’t think 100 kg could lead to any nuclear threats.

The question that wasn’t answered at the time was how much was too much.

Planned nuclear fuel has higher proliferation risks than thought Read More »

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

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

Down, but not down enough —

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

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

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

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How new tech is making geothermal energy a more versatile power source

Energy rising —

Geothermal has moved beyond being confined to areas with volcanic activity.

The Nesjavellir Geothermal Power Station. Geothermal power has long been popular in volcanic countries like Iceland, where hot water bubbles from the ground.

Enlarge / The Nesjavellir Geothermal Power Station. Geothermal power has long been popular in volcanic countries like Iceland, where hot water bubbles from the ground.

Gretar Ívarsson/Wikimedia Commons

Glistening in the dry expanses of the Nevada desert is an unusual kind of power plant that harnesses energy not from the sun or wind, but from the Earth itself.

Known as Project Red, it pumps water thousands of feet into the ground, down where rocks are hot enough to roast a turkey. Around the clock, the plant sucks the heated water back up to power generators. Since last November, this carbon-free, Earth-borne power has been flowing onto a local grid in Nevada.

Geothermal energy, though it’s continuously radiating from Earth’s super-hot core, has long been a relatively niche source of electricity, largely limited to volcanic regions like Iceland where hot springs bubble from the ground. But geothermal enthusiasts have dreamed of sourcing Earth power in places without such specific geological conditions—like Project Red’s Nevada site, developed by energy startup Fervo Energy.

Such next-generation geothermal systems have been in the works for decades, but they’ve proved expensive and technologically difficult, and have sometimes even triggered earthquakes. Some experts hope that newer efforts like Project Red may now, finally, signal a turning point, by leveraging techniques that were honed in oil and gas extraction to improve reliability and cost-efficiency.

The advances have garnered hopes that with enough time and money, geothermal power—which currently generates less than 1 percent of the world’s electricity, and 0.4 percent of electricity in the United States—could become a mainstream energy source. Some posit that geothermal could be a valuable tool in transitioning the energy system off of fossil fuels, because it can provide a continuous backup to intermittent energy sources like solar and wind. “It’s been, to me, the most promising energy source for a long time,” says energy engineer Roland Horne of Stanford University. “But now that we’re moving towards a carbon-free grid, geothermal is very important.”

A rocky start

Geothermal energy works best with two things: heat, plus rock that is permeable enough to carry water. In places where molten rock sizzles close to the surface, water will seep through porous volcanic rock, warm up and bubble upward as hot water, steam, or both.

If the water or steam is hot enough—ideally at least around 300 degrees Fahrenheit—it can be extracted from the ground and used to power generators for electricity. In Kenya, nearly 50 percent of electricity generated comes from geothermal. Iceland gets 25 percent of its electricity from this source, while New Zealand gets about 18 percent and the state of California, 6 percent.

Some natural geothermal resources are still untapped, such as in the western United States, says geologist Ann Robertson-Tait, president of GeothermEx, a geothermal energy consulting division at the oilfield services company SLB. But by and large, we’re running out of natural, high-quality geothermal resources, pushing experts to consider ways of extracting geothermal energy from areas where the energy is much harder to access. “There’s so much heat in the Earth,” Robertson-Tait says. But, she adds, “much of it is locked inside rock that isn’t permeable.”

The Lardarello plant in the Tuscany region of Italy was the first geothermal power plant in the world. It was completed in 1913.

Enlarge / The Lardarello plant in the Tuscany region of Italy was the first geothermal power plant in the world. It was completed in 1913.

Tapping that heat requires deep drilling and creating cracks in these non-volcanic, dense rocks to allow water to flow through them. Since 1970, engineers have been developing “enhanced geothermal systems” (EGS) that do just that, applying methods similar to the hydraulic fracturing—or fracking—used to suck oil and gas out of deep rocks. Water is pumped at high pressure into wells, up to several miles deep, to blast cracks into the rocks. The cracked rock and water create an underground radiator where water heats before rising to the surface through a second well. Dozens of such EGS installations have been built in the United States, Europe, Australia, and Japan—most of them experimental and government-funded—with mixed success.

Famously, one EGS plant in South Korea was abruptly shuttered in 2017 after having probably caused a 5.5-magnitude earthquake; fracking of any kind can add pressure to nearby tectonic faults. Other issues were technological—some plants didn’t create enough fractures for good heat exchange, or fractures traveled in the wrong direction and failed to connect the two wells.

Some efforts, however, turned into viable power plants, including several German and French systems built between 1987 and 2012 in the Rhine Valley. There, engineers made use of existing fractures in the rock.

But overall, there just hasn’t been enough interest to develop EGS into a more reliable and lucrative technology, says geophysicist Dimitra Teza of the energy research institute Fraunhofer IEG in Karlsruhe, Germany, who helped develop some of the Rhine Valley EGS systems. “It has been quite tough for the industry.”

Geothermal electricity has long been limited to volcanic regions where underground heat is easily accessible. But new kinds of power plants are making it possible to derive geothermal heat elsewhere in the world.

Enlarge / Geothermal electricity has long been limited to volcanic regions where underground heat is easily accessible. But new kinds of power plants are making it possible to derive geothermal heat elsewhere in the world.

How new tech is making geothermal energy a more versatile power source Read More »

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Can we drill for hydrogen? New find suggests additional geological source.

Image of apartment buildings with mine tailings behind them, and green hills behind those.

Enlarge / Mining operations start right at the edge of Bulqizë, Albania.

“The search for geologic hydrogen today is where the search for oil was back in the 19th century—we’re just starting to understand how this works,” said Frédéric-Victor Donzé, a geologist at Université Grenoble Alpes. Donzé is part of a team of geoscientists studying a site at Bulqizë in Albania where miners at one of the world’s largest chromite mines may have accidentally drilled into a hydrogen reservoir.

The question Donzé and his team want to tackle is whether hydrogen has a parallel geological system with huge subsurface reservoirs that could be extracted the way we extract oil. “Bulqizë is a reference case. For the first time, we have real data. We have a proof,” Donzé said.

Greenish energy source

Water is the only byproduct of burning hydrogen, which makes it a potential go-to green energy source. The problem is that the vast majority of the 96 million tons of hydrogen we make each year comes from processing methane, and that does release greenhouse gases. Lots of them. “There are green ways to produce hydrogen, but the cost of processing methane is lower. This is why we are looking for alternatives,” Donzé said.

And the key to one of those alternatives may be buried in the Bulqizë mine. Chromite, an ore that contains lots of chromium, has been mined at Bulqizë since the 1980s. The mining operation was going smoothly until 2007, when the miners drilled through a fault, a discontinuity in the rocks. “Then they started to have explosions. In the mine, they had a small electric train, and there were sparks flying, and then… boom,” Donzé said. At first, Bulqizë management thought the cause was methane, the usual culprit of mining accidents. But it wasn’t.

Hydrogen at fault

The mine was bought by a Chinese company in 2017, and the new owners immediately sent their engineering teams to deal with explosions. They did measurements and found the hydrogen concentration in the mine’s galleries was around 1–2 percent. It only needs to be at 0.4–0.5 percent for the atmosphere to become explosive. “They also found the hydrogen was coming from the fault drilled through back in 2007. Unfortunately, one of the explosions happened when the engineering team was down there. Three or four people died,” Donzé said.

It turned out that over 200 tons of hydrogen was released from the Bulqizë mine each year. Donzé’s team went there to figure out where all this hydrogen was coming from.

The rocks did not contain enough hydrogen to reach that sort of flow rate. One possible explanation is the hydrogen being released as a product of an ongoing geological process called serpentinization. “But for this to happen, the temperature in the mine would need to reach 200–300 degrees Celsius, and even then, it would not produce 200 tons per year,” said Donzé. “So the most probable was the third option—that we have a reservoir,” he added.

“Probable,” of course, is far from certain.

Can we drill for hydrogen? New find suggests additional geological source. Read More »

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Google, Environmental Defense Fund will track methane emissions from space

It’s a gas —

Satellite data + Google Maps + AI should help figure out where methane is leaking.

computer-generated image of a satellite highlighting emissions over a small square on the globe.

Enlarge / With color, high resolution.

Google/EDF

When discussing climate change, attention generally focuses on our soaring carbon dioxide emissions. But levels of methane have risen just as dramatically, and it’s a far more potent greenhouse gas. And, unlike carbon dioxide, it’s not the end result of a valuable process; methane largely ends up in the atmosphere as the result of waste, lost during extraction and distribution.

Getting these losses under control would be one of the easiest ways to slow down greenhouse warming. But tracking methane emissions often comes from lots of smaller, individual sources. To help get a handle on all the leaks, the Environmental Defense Fund has been working to put its own methane-monitoring satellite in orbit. On Wednesday, it announced that it was partnering with Google to take the data from the satellite, make it publicly available, and tie it to specific sources.

The case for MethaneSAT

Over the course of 20 years, methane is 84 times more potent than carbon dioxide when it comes to greenhouse warming. And most methane in the atmosphere ultimately reacts with oxygen, producing water vapor and carbon dioxide—both of which are also greenhouse gasses. Those numbers are offset by the fact that methane levels in the atmosphere are very low, currently just under two parts per million (versus over 400 ppm for CO2). Still, levels have gone up considerably since monitoring started.

The primary source of the excess methane is the extraction and distribution of natural gas. In the US, the EPA has developed rules meant to force companies with natural gas infrastructure to find and fix leaks. (Unsurprisingly, Texas plans to sue to block this rule.) But finding leaks has turned out to be a challenge. The US has been using industry-wide estimates that turned out to be much lower than numbers based on monitoring a subset of facilities.

Globally, that sort of detailed surveying simply isn’t possible, and we don’t have the type of satellite-based instruments we need to focus on methane emissions. A researcher behind one global survey said, “We were quite disappointed because we discovered that the sensitivity of our system was pretty low.” (The survey did identify sites that were “ultra emitters” despite the sensitivity issues.)

To help identify the major sources of methane release, the Environmental Defense Fund, a US-based NGO, has spun off a project called MethaneSAT that will monitor the emissions from space. The project is backed by large philanthropic donations and has partnered with the New Zealand Space Agency. The Rocket Lab launch company will build the satellite control center in New Zealand, while SpaceX will carry the 350 kg satellite to orbit in a shared launch, expected in early March.

Once in orbit, the hardware will use methane’s ability to absorb in the infrared—the same property that causes all the problems—to track emissions globally at a resolution down below a square kilometer.

Handling the data

That will generate large volumes of data that countries may struggle to interpret. That’s where the new Google partnership will come in. Google will use the same AI capability it has developed to map features such as roads and sidewalks on satellite images but repurpose it to identify oil and gas infrastructure. Both the MethaneSAT’s emissions data and infrastructure details will be combined and made available via the company’s Google Earth service.

Top image: A view of an area undergoing oil/gas extraction. Left: a close-up of an individual drilling site. Right: Computer-generated color coding of the hardware present at the site.

Top image: A view of an area undergoing oil/gas extraction. Left: a close-up of an individual drilling site. Right: Computer-generated color coding of the hardware present at the site.

Google / EDF

The project builds off work Google has done previously by placing methane monitoring hardware on Street View photography vehicles, also in collaboration with the Environmental Defense Fund.

In a press briefing, Google’s Yael Maguire said that the challenge is keeping things up to date, as infrastructure in the oil and gas industry can change fairly rapidly. While he didn’t use it as an example, one illustration of that challenge was the rapid development of liquified natural gas import infrastructure in Europe in the wake of Russia’s invasion of Ukraine.

The key question, however, is one of who’s going to use this information. Extraction companies could use it to identify the sites of leaks and fix them but are unlikely to do that in the absence of a regulatory requirement. Governments could rely on this information to take regulatory actions but will probably want some sort of independent vetting of the data before doing so. At the moment, all EDF is saying is that it’s engaging in discussions with several parties about potentially using the data.

One clear user will be the academic community, which is already using less-targeted satellite data to explore the issue of methane emissions.

Regardless, as everyone involved in the project emphasizes, getting methane under control is probably the easiest and quickest way to eliminate a bit of impending warming. And that could help countries meet emissions targets without immediately starting on some of the slower and more expensive options. So, even if no one has currently committed to using this data, they may ultimately come around—because using it to do something is better than doing nothing.

Google, Environmental Defense Fund will track methane emissions from space Read More »

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Over 2 percent of the US’s electricity generation now goes to bitcoin

Mining stakes —

US government tracking the energy implications of booming bitcoin mining in US.

Digital generated image of golden helium balloon in shape of bitcoin sign inflated with air pump and moving up against purple background.

Enlarge / It takes a lot of energy to keep pumping out more bitcoins.

What exactly is bitcoin mining doing to the electric grid? In the last few years, the US has seen a boom in cryptocurrency mining, and the government is now trying to track exactly what that means for the consumption of electricity. While its analysis is preliminary, the Energy Information Agency (EIA) estimates that large-scale cryptocurrency operations are now consuming over 2 percent of the US’s electricity. That’s roughly the equivalent of having added an additional state to the grid over just the last three years.

Follow the megawatts

While there is some small-scale mining that goes on with personal computers and small rigs, most cryptocurrency mining has moved to large collections of specialized hardware. While this hardware can be pricy compared to personal computers, the main cost for these operations is electricity use, so the miners will tend to move to places with low electricity rates. The EIA report notes that, in the wake of a crackdown on cryptocurrency in China, a lot of that movement has involved relocation to the US, where keeping electricity prices low has generally been a policy priority.

One independent estimate made by the Cambridge Centre for Alternative Finance had the US as the home of just over 3 percent of the global bitcoin mining at the start of 2020. By the start of 2022, that figure was nearly 38 percent.

The Cambridge Center also estimates the global electricity use of all bitcoin mining, so it’s possible to multiply that by the US’s percentage and come up with an estimate for the amount of electricity that boom has consumed. Because of the uncertainties in these estimates, the number could be anywhere from 25 to 91 Terawatt-hours. Even the low end of that range would mean bitcoin mining is now using the equivalent of Utah’s electricity consumption (the high end is roughly Washington’s), which has significant implications for the electric grid as a whole.

So, the EIA decided it needed a better grip on what was going on. To get that, it went through trade publications, financial reports, news articles, and congressional investigation reports to identify as many bitcoin mining operations as it could. With 137 facilities identified, it then inquired about the power supply needed to operate them at full capacity, receiving answers for 101 of those facilities.

If running all-out, those 101 facilities would consume 2.3 percent of the US’s average power demand. That places them on the high side of the Cambridge Center estimates.

Finding power-ups

The mining operations fall in two major clusters: one in Texas, and one extending from western New York down the Appalachians to southern Georgia. While there are additional ones scattered throughout the US, these are the major sites.

The EIA has also found some instances where the operations moved in near underutilized power plants and sent generation soaring again. Tracking the history of five of these plants showed that generation had fallen steadily from 2015 to 2020, reaching a low where they collectively produced just half a Terawatt-hour. Miners moving in nearby tripled production in just a year and has seen it rise to over 2 Terawatt-hours in 2022.

Power plants near bitcoin mining operations have seen generation surge over the last two years.

Enlarge / Power plants near bitcoin mining operations have seen generation surge over the last two years.

These are almost certainly fossil fuel plants that might be reasonable candidates for retirement if it weren’t for their use to supply bitcoin miners. So, these miners are contributing to all of the health and climate problems associated with the continued use of fossil fuels.

The EIA also found a number of strategies that miners used to keep their power costs low. In one case, they moved into a former aluminum smelting facility in Texas to take advantage of its capacious connections to the grid. In another, they put a facility next to a nuclear plant in Pennsylvania and set up a direct connection to the plant. The EIA also found cases where miners moved near natural gas fields that produced waste methane that would otherwise have been burned off.

Since bitcoin mining is the antithesis of an essential activity, several mining operations have signed up for demand-response programs, where they agree to take their operations offline if electricity demand is likely to exceed generating capacity in return for compensation by the grid operator. It has been widely reported that one facility in Texas—the one at the former aluminum smelter site—earned over $30 million by shutting down during a heat wave in 2023.

To better understand the implications of this major new drain on the US electric grid, the EIA will be performing monthly analyses of bitcoin operations during the first half of 2024. But based on these initial numbers, it’s clear that the relocation of so many mining operations to the US will significantly hinder efforts to bring the US’s electric grid to carbon neutrality.

Over 2 percent of the US’s electricity generation now goes to bitcoin Read More »