Iowa professor says his new solar technology is a winner

Geothermal Power Plant Risks include hydrogen sulfide leaks, toxic gases, lava flow hazards, well blowouts, and earthquake-induced releases at sites like PGV and the Geysers, threatening public health, grid reliability, and environmental safety.

Key Points

Geothermal Power Plant Risks include toxic gases, lava impacts, well failures, and induced quakes that threaten health.

✅ Hydrogen sulfide exposure can cause rapid pulmonary edema.

✅ Lava can breach wells, venting toxic gases into communities.

✅ Induced seismicity may disrupt grids near PGV and the Geysers.

If lava reaches Hawaii’s PGV geothermal power plant, it could release of deadly hydrogen sulfide gas. That’s the latest potential danger from the Kilauea volcanic eruption in Hawaii. Residents now fear that lava flow will trigger a meltdown at the Puna Geothermal Venture (PGV) power plant that would release even more toxic gases into the air.

Nobody knows what will happen if lava engulfs the PGV because magma has never engulfed a geothermal power plant, Reuters reported. A geothermal power plant uses steam and gas heated by lava deep in the earth to run turbines that make electricity.

The PGV power plant produces 25% of the power used on Hawaii’s “Big Island.” The plant is considered a source of clean energy because geothermal plants burn no fossil fuels and produce little pollution under normal circumstances, even as nuclear retirements like Three Mile Island reshape low-carbon options.

The Potential Danger from Geothermal Energy

The fear is that the lava would release chemicals used to make electricity at the plant. The PGV has been shut down and authorities moved an estimated 60,000 gallons of flammable liquids away from the facility. They also shut down wells that extract steam and gas used to run the turbines.

Another potential danger is that lava would open the wells and release clouds of toxic gases from them. The wells are typically sealed to prevent the gas from entering the atmosphere.

The most significant threat is hydrogen sulfide, a highly toxic and flammable gas that is colorless. Hydrogen sulfide normally has a rotten egg smell which people might not detect when the air is full of smoke. That means people can breathe hydrogen sulfide in without realizing they have been exposed.

The greatest danger from hydrogen sulfide is pulmonary edema; the accumulation of fluid in the lungs, which causes a person to stop breathing. People have died of pulmonary edema after just a few minutes of exposure to hydrogen sulfide gas. Many victims become unconscious before the gas kills them. Long-term dangers that survivors of pulmonary edema face include brain damage.

Hydrogen sulfide can also cause burns to the skin that are similar to frostbite. Persons exposed to hydrogen sulfide can also suffer from nausea, headaches, severe eye burns, and delirium. Children are more vulnerable to hydrogen sulfide because it is a heavy gas that stays close to the ground.

Geothermal Danger Extends Far Beyond Hawaii

The danger from geothermal energy extends far beyond Hawaii. The world’s largest collection of geothermal power plants is located at the Geysers in California’s Wine Country, and regulatory timelines such as the postponed closure of three Southern California plants can affect planning.

The Geysers field contains 350 steam production wells and 22 power plants in Sonoma, Lake, and Mendocino counties. Disturbingly, the Geysers are located just north of the heavily-populated San Francisco Bay Area and just west of Sacramento, where preemptive electricity shutdowns have been used during extreme fire weather. Problems at the Geysers might lead to significant blackouts because the field supplies around 20% of the green energy used in California.

Another danger from geothermal power is earthquakes because many geothermal power plants inject wastewater into hot rock deep below to produce steam to run turbines, a factor under review as SaskPower explores geothermal in new settings. A geothermal project in Switzerland created Earthquakes by injecting water into the Earth, Zero Hedge reported. A theoretical threat is that quakes caused by injection would cause the release of deadly gases at a geothermal power plant.

The dangers from geothermal power might be much greater than its advocates admit, potentially increasing reliance on natural-gas-based electricity during supply shortfalls.

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UK low-carbon electricity 2019 saw stalled growth as renewables rose slightly, wind expanded, nuclear output fell, coal hit record lows, and net-zero targets demand faster deployment to cut CO2 intensity below 100gCO2/kWh.

Key Points

Low-carbon sources supplied 54% of UK power in 2019, up just 1TWh; wind grew, nuclear fell, and coal dropped to 2%.

✅ Wind up 8TWh; nuclear down 9TWh amid outages

✅ Fossil fuels 43% of generation; coal at 2%

✅ Net-zero needs 15TWh per year added to 2030

The amount of electricity generated by low-carbon sources in the UK stalled in 2019, Carbon Brief analysis shows.

Low-carbon electricity output from wind, solar, nuclear, hydro and biomass rose by just 1 terawatt hour (TWh, less than 1%) in 2019. It represents the smallest annual increase in a decade, where annual growth averaged 9TWh. This growth will need to double in the 2020s to meet UK climate targets while replacing old nuclear plants as they retire.

Some 54% of UK electricity generation in 2019 came from low-carbon sources, including 37% from renewables and 20% from wind alone, underscoring wind's leading role in the power mix during key periods. A record-low 43% was from fossil fuels, with 41% from gas and just 2% from coal, also a record low. In 2010, fossil fuels generated 75% of the total.

Carbon Brief’s analysis of UK electricity generation in 2019 is based on figures from BM Reports and the Department for Business, Energy and Industrial Strategy (BEIS). See the methodology at the end for more on how the analysis was conducted.

The numbers differ from those published earlier in January by National Grid, which were for electricity supplied in Great Britain only (England, Wales and Scotland, but excluding Northern Ireland), including via imports from other countries.

Low-carbon low
In 2019, the UK became the first major economy to target net-zero greenhouse gas emissions by 2050, increasing the ambition of its legally binding Climate Change Act.

To date, the country has cut its emissions by around two-fifths since 1990, with almost all of its recent progress coming from the electricity sector.

Emissions from electricity generation have fallen rapidly in the decade since 2010 as coal power has been almost phased out and even gas output has declined. Fossil fuels have been displaced by falling demand and by renewables, such as wind, solar and biomass.

But Carbon Brief’s annual analysis of UK electricity generation shows progress stalled in 2019, with the output from low-carbon sources barely increasing compared to a year earlier.

The chart below shows low-carbon generation in each year since 2010 (grey bars) and the estimated level in 2019 (red). The pale grey bars show the estimated future output of existing low-carbon sources after old nuclear plants retire and the pale red bars show the amount of new generation needed to keep electricity sector emissions to less than 100 grammes of CO2 per kilowatt hour (gCO2/kWh), the UK’s nominal target for the sector.

 Annual electricity generation in the UK by fuel, terawatt hours, 2010-2019. Top panel: fuel by fuel. Bottom panel: cumulative total generation from all sources. Source: BEIS energy trends, BM Reports and Carbon Brief analysis. Chart by Carbon Brief using Highcharts.
As the chart shows, the UK will require significantly more low-carbon electricity over the next decade as part of meeting its legally binding climate goals.

The nominal 100gCO2/kWh target for 2030 was set in the context of the UK’s less ambitious goal of cutting emissions to 80% below 1990 levels by 2050. Now that the country is aiming to cut emissions to net-zero by 2050, that 100gCO2/kWh indicator is likely to be the bare minimum.

Even so, it would require a rapid step up in the pace of low-carbon expansion, compared to the increases seen over the past decade. On average, low-carbon generation has risen by 9TWh each year in the decade since 2010 – including a rise of just 1TWh in 2019.

Given scheduled nuclear retirements and rising demand expected by the Committee on Climate Change (CCC) – with some electrification of transport and heating – low-carbon generation would need to increase by 15TWh each year until 2030, just to meet the benchmark of 100gCO2/kWh.

For context, the 3.2 gigawatt (GW) Hinkley C new nuclear plant being built in Somerset will generate around 25TWh once completed around 2026. The world’s largest offshore windfarm, the 1.2GW Hornsea One scheme off the Yorkshire coast, will generate around 5TWh each year.

The new Conservative government is targeting 40GW of offshore wind by 2030, up from today’s figure of around 8GW. If policies are put in place to meet this goal, then it could keep power sector emissions below 100gCO2/kWh, depending on the actual performance of the windfarms built.

However, new onshore wind and solar, further new nuclear or other low-carbon generation, such as gas with carbon capture and storage (CCS), is likely to be needed if demand is higher than expected, or if the 100gCO2/kWh benchmark is too weak in the context of net-zero by 2050.

The CCC says it is “likely” to “reflect the need for more rapid deployment” of low-carbon towards net-zero emissions in its advice on the sixth UK carbon budget for 2033-2037, due in September.

Trading places
Looking more closely at UK electricity generation in 2019, Carbon Brief’s analysis shows why there was so little growth for low-carbon sources compared to the previous year.

There was another increase for wind power in 2019 (up 8TWh, 14%), with record wind generation as several large new windfarms were completed including the 1.2GW Hornsea One project in October and the 0.6GW Beatrice offshore windfarm in Q2 of 2019. But this was offset by a decline for nuclear (down 9TWh, 14%), due to ongoing outages for reactors at Hunterston in Scotland and Dungeness in Kent.

(Analysis of data held by trade organisation RenewableUK suggests some 0.6GW of onshore wind capacity also started operating in 2019, including the 0.2GW Dorenell scheme in Moray, Scotland.)

As a result of these movements, the UK’s windfarms overtook nuclear for the first time ever in 2019, becoming the country’s second-largest source of electricity generation, and earlier, wind and solar together surpassed nuclear in the UK as momentum built. This is shown in the figure below, with wind (green line, top panel) trading places with nuclear (purple) and gas (dark blue) down around 25% since 2010 but remaining the single-largest source.

 Annual electricity generation in the UK by fuel, terawatt hours, 2010-2019. Top panel: fuel by fuel. Bottom panel: cumulative total generation from all sources. Source: BEIS energy trends, BM Reports and Carbon Brief analysis. Chart by Carbon Brief using Highcharts.
The UK’s currently suspended nuclear plants are due to return to service in January and March, according to operator EDF, the French state-backed utility firm. However, as noted above, most of the UK’s nuclear fleet is set to retire during the 2020s, with only Sizewell B in Suffolk due to still be operating by 2030. Hunterston is scheduled to retire by 2023 and Dungeness by 2028.

Set against these losses, the UK has a pipeline of offshore windfarms, secured via “contracts for difference” with the government, at a series of auctions. The most recent auction, in September 2019, saw prices below £40 per megawatt hour – similar to current wholesale electricity prices.

However, the capacity contracted so far is not sufficient to meet the government’s target of 40GW by 2030, meaning further auctions – or some other policy mechanism – will be required.

Coal zero
As well as the switch between wind and nuclear, 2019 also saw coal fall below solar for the first time across a full year, echoing the 2016 moment when wind outgenerated coal across the UK, after it suffered another 60% reduction in electricity output. Just six coal plants remain in the UK, with Aberthaw B in Wales and Fiddlers Ferry in Cheshire closing in March.

Coal accounted for just 2% of UK generation in 2019, a record-low coal share since centralised electricity supplies started to operate in 1882. The fuel met 40% of UK needs as recently as 2012, but has plummeted thanks to falling demand, rising renewables, cheaper gas and higher CO2 prices.

The reduction in average coal generation hides the fact that the fuel is now often not required at all to meet the UK’s electricity needs. The chart below shows the number of days each year when coal output was zero in 2019 (red line) and the two previous years (blue).

 Cumulative number of days when UK electricity generation from renewable sources has been higher than that from fossil fuels. Source: BEIS energy trends, BM Reports and Carbon Brief analysis. Chart by Carbon Brief using Highcharts.
The 83 days in 2019 with zero coal generation amount to nearly a quarter of the year and include the record-breaking 18-day stretch without the fuel.

Great Britain has been running for a record TWO WEEKS without using coal to generate electricity – the first time this has happened since 1882.

The country’s grid has been coal-free for 45% of hours in 2019 so far.https://www.carbonbrief.org/countdown-to-2025-tracking-the-uk-coal-phase-out …

Coal generation was set for significant reductions around the world in 2019 – including a 20% reduction for the EU as a whole – according to analysis published by Carbon Brief in November.

Notably, overall UK electricity generation fell by another 9TWh in 2019 (3%), bringing the total decline to 58TWh since 2010. This is equivalent to more than twice the output from the Hinkley C scheme being built in Somerset. As Carbon Brief explained last year, falling demand has had a similar impact on electricity-sector CO2 emissions as the increase in output from renewables.

This is illustrated by the fact that the 9TWh reduction in overall generation translated into a 9TWh (6%) cut in fossil-fuel generation during 2019, with coal falling by 10TWh and gas rising marginally.

Increasingly renewable
As fossil-fuel output and overall generation have declined, the UK’s renewable sources of electricity have continued to increase. Their output has risen nearly five-fold in the past decade and their share of the UK total has increased from 7% in 2010 to 37% in 2019.

As a result, the UK’s increasingly renewable grid is seeing more minutes, hours and days during which the likes of wind, solar and biomass collectively outpace all fossil fuels put together, and on some days wind is the main source as well.

The chart below shows the number of days during each year when renewables generated more electricity than fossil fuels in 2019 (red line) and each of the previous four years (blue lines). In total, nearly two-fifths of days in 2019 crossed this threshold.

 Cumulative number of days when the UK has not generated any electricity from coal. Source: BEIS energy trends, BM Reports and Carbon Brief analysis. Chart by Carbon Brief using Highcharts.
There were also four months in 2019 when renewables generated more of the UK’s electricity than fossil fuels: March, August, September and December. The first ever such month came in September 2018 and more are certain to follow.

National Grid, which manages Great Britain’s high-voltage electricity transmission network, is aiming to be able to run the system without fossil fuels by 2025, at least for short periods. At present, it sometimes has to ask windfarm operators to switch off and gas plants to start running in order to keep the electricity grid stable.

Note that biomass accounted for 11% of UK electricity generation in 2019, nearly a third of the total from all renewables. Some two-thirds of the biomass output is from “plant biomass”, primarily wood pellets burnt at Lynemouth in Northumberland and the Drax plant in Yorkshire. The remainder was from an array of smaller sites based on landfill gas, sewage gas or anaerobic digestion.

The CCC says the UK should “move away” from large-scale biomass power plants, once existing subsidy contracts for Drax and Lynemouth expire in 2027.

Using biomass to generate electricity is not zero-carbon and in some circumstances could lead to higher emissions than from fossil fuels. Moreover, there are more valuable uses for the world’s limited supply of biomass feedstock, the CCC says, including carbon sequestration and hard-to-abate sectors with few alternatives.

Methodology
The figures in the article are from Carbon Brief analysis of data from BEIS Energy Trends chapter 5 and chapter 6, as well as from BM Reports. The figures from BM Reports are for electricity supplied to the grid in Great Britain only and are adjusted to include Northern Ireland.

In Carbon Brief’s analysis, the BM Reports numbers are also adjusted to account for electricity used by power plants on site and for generation by plants not connected to the high-voltage national grid. This includes many onshore windfarms, as well as industrial gas combined heat and power plants and those burning landfill gas, waste or sewage gas.

By design, the Carbon Brief analysis is intended to align as closely as possible to the official government figures on electricity generated in the UK, reported in BEIS Energy Trends table 5.1.

Briefly, the raw data for each fuel is in most cases adjusted with a multiplier, derived from the ratio between the reported BEIS numbers and unadjusted figures for previous quarters.

Carbon Brief’s method of analysis has been verified against published BEIS figures using “hindcasting”. This shows the estimates for total electricity generation from fossil fuels or renewables to have been within ±3% of the BEIS number in each quarter since Q4 2017. (Data before then is not sufficient to carry out the Carbon Brief analysis.)

For example, in the second quarter of 2019, a Carbon Brief hindcast estimates gas generation at 33.1TWh, whereas the published BEIS figure was 34.0TWh. Similarly, it produces an estimate of 27.4TWh for renewables, against a BEIS figure of 27.1TWh.

National Grid recently shared its own analysis for electricity in Great Britain during 2019 via its energy dashboard, which differs from Carbon Brief’s figures.

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IAEA OSART Cernavoda highlights strengthened operational safety at Romania’s Cernavoda NPP, citing improved maintenance practices, simulator training, and deficiency reporting, with ongoing actions on spare parts procurement, procedure updates, and chemical control for nuclear compliance.

Key Points

An IAEA follow-up mission confirming improved operational safety at Cernavoda NPP, with remaining actions tracked.

✅ Enhanced simulator training and crew performance

✅ Improved field deficiency identification and reporting

✅ Ongoing upgrades to procedures, spares, and chemical control

The International Atomic Energy Agency (IAEA) said yesterday that the operator of Romania’s Cernavoda nuclear power plant had demonstrated "strengthened operational safety" by addressing the findings of an initial IAEA review in 2016. The Operational Safety Review Team (OSART) concluded a five-day follow-up mission on 8 March to the Cernavoda plant, which is on the Danube-Black Sea Canal, about 160 km from Bucharest.

The plant's two 706 MWe CANDU pressurised heavy water reactors, reflecting Canadian nuclear projects, came online in 1996 and 2007, respectively.

The OSART team was led by Fuming Jiang, a senior nuclear safety officer at the IAEA, which recently commended China's nuclear security in separate assessments.

"We saw improvements in key areas, such as the procurement of important spare parts, the identification and reporting of some deficiencies, and some maintenance work practices, as evidenced by relevant performance indicators," Jiang said, noting milestones at nuclear projects worldwide this year.

The team observed that several findings from the 2016 review had been fully addressed, including: enhanced operator crew performance during simulator training; better identification and reporting of deficiencies in the field; and improvement in maintenance work practices.

More time is required, it said, to fully implement some actions, including: further improvements in the procurement of important spare parts with relevance to safety; further enhancement in the revision and update of some operating procedures, drawing on lessons from Pickering NGS life extensions undertaken in Ontario; and control and labelling of some plant chemicals.

Dan Bigu, site vice president of Cernavoda NPP, said the 2016 mission had "proven to be very beneficial", adding that the current follow-up mission would "provide further catalyst support to our journey to nuclear excellence".

The team provided a draft report of the mission to the plant's management and a final report will be submitted to the Romanian government, which recently moved to terminate talks with a Chinese partner on a separate nuclear project, within three months.

OSART missions aim to improve operational safety by objectively assessing safety performance, even as the agency reports mines at Ukraine's Zaporizhzhia plant amid ongoing risks, using the IAEA's safety standards and proposing recommendations and suggestions for improvement where appropriate. The follow-up missions are standard components of the OSART programme and, as the IAEA has warned of risks from attacks on Ukraine's power grids, are typically conducted within two years of the initial mission.

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UK Wind Power Surpasses Gas as offshore wind and solar drive record electricity generation, National Grid milestones, and net zero progress, despite grid capacity bottlenecks, onshore planning reforms, demand from heat pumps and transport electrification.

Key Points

A milestone where wind turbines generated more UK electricity than gas, advancing progress toward a net zero grid.

✅ Offshore wind delivered the majority of UK wind generation

✅ Grid connection delays stall billions in green projects

✅ Planning reforms may restart onshore wind development

Wind turbines have generated more electricity than gas, as wind becomes the main source for the first time in the UK.

In the first three months of this year a third of the country's electricity came from wind farms, as the UK set a wind generation record that underscored the trend, research from Imperial College London has shown.

National Grid has also confirmed that April saw a record period of solar energy generation, and wind and solar outproduced nuclear in earlier milestones.

By 2035 the UK aims for all of its electricity to have net zero emissions, after a 2019 stall in low-carbon generation highlighted the challenge.

"There are still many hurdles to reaching a completely fossil fuel-free grid, but wind out-supplying gas for the first time is a genuine milestone event," said Iain Staffell, energy researcher at Imperial College and lead author of the report.

The research was commissioned by Drax Electrical Insights, which is funded by Drax energy company.

The majority of the UK's wind power has come from offshore wind farms, and the country leads the G20 for wind's electricity share according to recent analyses. Installing new onshore wind turbines has effectively been banned since 2015 in England.

Under current planning rules, companies can only apply to build onshore wind turbines on land specifically identified for development in the land-use plans drawn up by local councils. Prime Minister Rishi Sunak agreed in December to relax these planning restrictions to speed up development.

Scientists say switching to renewable power is crucial to curb the impacts of climate change, which are already being felt, including in the UK, which last year recorded its hottest year since records began.

Solar and wind have seen significant growth in the UK, with wind surpassing coal in 2016 as a milestone. In the first quarter of 2023, 42% of the UK's electricity came from renewable energy, with 33% coming from fossil fuels like gas and coal.

But BBC research revealed on Thursday that billions of pounds' worth of green energy projects are stuck on hold due to delays with getting connections to the grid, as peak power prices also climbed amid system pressures.

Some new solar and wind sites are waiting up to 10 to 15 years to be connected because of a lack of capacity in the electricity system.

And electricity only accounts for 18% of the UK's total power needs. There are many demands for energy which electricity is not meeting, such as heating our homes, manufacturing and transport.

Currently the majority of UK homes use gas for their heating - the government is seeking to move households away from gas boilers and on to heat pumps which use electricity.

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Germany Energy Price Defensive Shield counters soaring gas and electricity costs with a gas price brake, VAT cut, subsidies for households and SMEs, LNG terminals, renewables, temporary nuclear extension, and targeted borrowing to curb inflation.

Key Points

A 200 billion euro package to cap energy costs, subsidize basics, and stabilize inflation for firms and households.

✅ Gas price brake and VAT cut reduce consumer and SME energy bills.

✅ Temporary electricity subsidies and nuclear extension aid winter supply.

✅ Funded via new borrowing; supports LNG and renewable expansion.

German Chancellor Olaf Scholz set out a 200 billion euro ($194 billion) "defensive shield", including a gas price brake and a cut in sales tax for the fuel, to protect companies and households from the impact of soaring energy prices in Germany.

Europe's biggest economy is trying to cope with surging gas and electricity costs, with local utilities seeking help, caused largely by a collapse in Russian gas supplies to Europe, which Moscow has blamed on Western sanctions following its invasion of Ukraine in February.

3 minute readSeptember 29, 202211:35 AM PDTLast Updated 6 days ago
Germany agrees 200 bln euro package to shield against surging energy prices
By Holger Hansen and Kirsti Knolle

"Prices have to come down, so the government will do everything it can. To this end, we are setting up a large defensive shield," said Scholz.

Under the plans, to run until spring 2024, the government will introduce an emergency price brake on gas, the details of which will be announced next month, while Europe weighs emergency measures to limit electricity prices across the bloc. It is scrapping a planned gas levy meant to help firms struggling with high spot market prices. 

A temporary electricity price brake will subsidise basic consumption for consumers and small and medium-sized companies, and complements an electricity subsidy for industries under discussion. Sales tax on gas will fall to 7% from 19%.

In its efforts to cut its dependence on Russian energy, Germany is also promoting the expansion of renewable energy and developing liquefied gas terminals, but rolling back European electricity prices remains complex.

To help households and companies weather any winter supply disruption, amid rising heating and electricity costs this winter, especially in southern Germany, two nuclear plants previously due to close by the end of this year will be able to keep running until spring 2023.

The package will be financed with new borrowing this year, as Berlin makes use of the suspension of a constitutionally enshrined limit on new debt of 0.35% of gross domestic product.

Finance Minister Christian Lindner has said he wants to comply with the limit again next year, even as the EU outlines gas price cap strategies for the market.

Lindner, of the pro-business Free Democrats (FDP) who share power with Scholz's Social Democrats and the Greens, said on Thursday the country's public finances were stable.

"We can put it no other way: we find ourselves in an energy war," said Lindner. "We want to clearly separate crisis expenditure from our regular budget management, we want to send a very clear signal to the capital markets."

He also said the steps would act as a brake on inflation, which hit its highest level in more than a quarter of century in September.

Opposition conservative Markus Soeder, premier of the southern state of Bavaria, said the steps gave the right signal.

"It gives industry and citizens confidence that we can get through the winter," he said.

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Sulphur Hexafluoride (SF6) Emissions drive rising greenhouse gas impacts in electrical switchgear, power grids, and renewables, with extreme global warming potential, long atmospheric lifetime, and leakage risks challenging climate targets and grid decarbonization.

Key Points

SF6 emissions are leaks from electrical switchgear and grids, a high-GWP gas with ~1,000-year lifetime.

✅ 23,500x CO2 global warming potential (GWP)

✅ Leaks from switchgear, breakers, gas-insulated substations

✅ Clean air and vacuum alternatives emerging for MV/HV

Sulphur hexafluoride, or SF6, is widely used in the electrical industry to prevent short circuits and accidents.

But leaks of the little-known gas in the UK and the rest of the EU in 2017 were the equivalent of putting an extra 1.3 million cars on the road.

Levels are rising as an unintended consequence of the green energy boom and the broader global energy transition worldwide.

Cheap and non-flammable, SF6 is a colourless, odourless, synthetic gas. It makes a hugely effective insulating material for medium and high-voltage electrical installations.

It is widely used across the industry, from large power stations to wind turbines to electrical sub-stations in towns and cities.

It prevents electrical accidents and fires.

However, the significant downside to using the gas is that it has the highest global warming potential of any known substance. It is 23,500 times more warming than carbon dioxide (CO2).

Just one kilogram of SF6 warms the Earth to the same extent as 24 people flying London to New York return.

It also persists in the atmosphere for a long time, warming the Earth for at least 1,000 years.

So why are we using more of this powerful warming gas?

The way we make electricity around the world is changing rapidly, with New Zealand's push to electrify in its energy system.

Where once large coal-fired power stations brought energy to millions, the drive to combat climate change and to move away from coal means they are now being replaced by mixed sources of power including wind, solar and gas.

This has resulted in many more connections to the electricity grid, and with EU electricity use could double by 2050, a rise in the number of electrical switches and circuit breakers that are needed to prevent serious accidents.

Collectively, these safety devices are called switchgear. The vast majority use SF6 gas to quench arcs and stop short circuits.

"As renewable projects are getting bigger and bigger, we have had to use it within wind turbines specifically," said Costa Pirgousis, an engineer with Scottish Power Renewables on its new East Anglia wind farm, which doesn't use SF6 in turbines.

"As we are putting in more and more turbines, we need more and more switchgear and, as a result, more SF6 is being introduced into big turbines off shore.

"It's been proven for years and we know how it works, and as a result it is very reliable and very low maintenance for us offshore."

How do we know that SF6 is increasing?

Across the entire UK network of power lines and substations, there are around one million kilograms of SF6 installed.

A study from the University of Cardiff found that across all transmission and distribution networks, the amount used was increasing by 30-40 tonnes per year.

This rise was also reflected across Europe with total emissions from the 28 member states in 2017 equivalent to 6.73 million tonnes of CO2. That's the same as the emissions from 1.3 million extra cars on the road for a year.

Researchers at the University of Bristol who monitor concentrations of warming gases in the atmosphere say they have seen significant rises in the last 20 years.

"We make measurements of SF6 in the background atmosphere," said Dr Matt Rigby, reader in atmospheric chemistry at Bristol.

"What we've seen is that the levels have increased substantially, and we've seen almost a doubling of the atmospheric concentration in the last two decades."

How does SF6 get into the atmosphere?

The most important means by which SF6 gets into the atmosphere is from leaks in the electricity industry.

Electrical company Eaton, which manufactures switchgear without SF6, says its research indicates that for the full life-cycle of the product, leaks could be as high as 15% - much higher than many other estimates.

Louis Schaeffer, electrical business manager at Eaton, said: "The newer gear has very low leak rates but the key question is do you have newer gear?

"We looked at all equipment and looked at the average of all those leak rates, and we didn't see people taking into account the filling of the gas. Plus, we looked at how you recycle it and return it and also included the catastrophic leaks."

How damaging to the climate is this gas?

Concentrations in the atmosphere are very small right now, just a fraction of the amount of CO2 in the air.

However, the global installed base of SF6 is expected to grow by 75% by 2030, as data-driven electricity demand surges worldwide.

Another concern is that SF6 is a synthetic gas and isn't absorbed or destroyed naturally. It will all have to be replaced and destroyed to limit the impact on the climate.

Developed countries are expected to report every year to the UN on how much SF6 they use, but developing countries do not face any restrictions on use.

Right now, scientists are detecting concentrations in the atmosphere that are 10 times the amount declared by countries in their reports. Scientists say this is not all coming from countries like India, China and South Korea.

One study found that the methods used to calculate emissions in richer countries "severely under-reported" emissions over the past two decades.

Why hasn't this been banned?

SF6 comes under a group of human-produced substances known as F-gases. The European Commission tried to prohibit a number of these environmentally harmful substances, including gases in refrigeration and air conditioning, back in 2014.

But they faced strong opposition from industries across Europe.

"In the end, the electrical industry lobby was too strong and we had to give in to them," said Dutch Green MEP Bas Eickhout, who was responsible for the attempt to regulate F-gases.

"The electric sector was very strong in arguing that if you want an energy transition, and you have to shift more to electricity, you will need more electric devices. And then you also will need more SF6.

"They used the argument that otherwise the energy transition would be slowed down."

What do regulator and electrical companies say about the gas?

Everyone is trying to reduce their dependence on the gas, and US control efforts suggest targeted policies can drive declines, as it is universally recognised as harmful to the climate.

In the UK, energy regulator Ofgem says it is working with utilities to try to limit leaks of the gas.

"We are using a range of tools to make sure that companies limit their use of SF6, a potent greenhouse gas, where this is in the interest of energy consumers," an Ofgem spokesperson told BBC News.

"This includes funding innovation trials and rewarding companies to research and find alternatives, setting emissions targets, rewarding companies that beat those targets, and penalising those that miss them."

Are there alternatives - and are they very expensive?

The question of alternatives to SF6 has been contentious over recent years.

For high-voltage applications, experts say there are very few solutions that have been rigorously tested.

"There is no real alternative that is proven," said Prof Manu Haddad from the school of engineering at Cardiff University.

"There are some that are being proposed now but to prove their operation over a long period of time is a risk that many companies don't want to take."

Medium voltage operations there are several tried-and-tested materials. Some in the industry say that the conservative nature of the electrical industry is the key reason that few want to change to a less harmful alternative.

"I will tell you, everyone in this industry knows you can do this; there is not a technical reason not to do it," said Louis Schaffer from Eaton.

"It's not really economic; it's more a question that change takes effort and if you don't have to, you won't do it."

Some companies are feeling the winds of change

Sitting in the North Sea some 43km from the Suffolk coast, Scottish Power Renewables has installed one of world's biggest wind farms, in line with a sustainable electric planet vision, where the turbines will be free of SF6 gas.

East Anglia One will see 102 of these towering generators erected, with the capacity to produce up to 714MW (megawatts) of power by 2020, enough to supply half a million homes.

Previously, an installation like this would have used switchgear supplied with SF6, to prevent the electrical accidents that can lead to fires.

Each turbine would normally have contained around 5kg of SF6, which, if it leaked into the atmosphere, would add the equivalent of around 117 tonnes of carbon dioxide. This is roughly the same as the annual emissions from 25 cars.

"In this case we are using a combination of clean air and vacuum technology within the turbine. It allows us to still have a very efficient, reliable, high-voltage network but to also be environmentally friendly," said Costa Pirgousis from Scottish Power Renewables.

"Once there are viable alternatives on the market, there is no reason not to use them. In this case, we've got a viable alternative and that's why we are using it."

But even for companies that are trying to limit the use of SF6, there are still limitations. At the heart of East Anglia One sits a giant offshore substation to which all 102 turbines will connect. It still uses significant quantities of the highly warming gas.

What happens next ?

The EU will review the use of SF6 next year and will examine whether alternatives are available. However, even the most optimistic experts don't think that any ban is likely to be put in place before 2025.

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