States have big hopes for renewable energy. Get ready to pay for it.

Bitcoin Energy Consumption drives debate on blockchain mining, proof-of-work, carbon footprint, and emissions, with CCAF estimates in terawatt hours highlighting electricity demand, fossil fuel reliance, and sustainability concerns for data centers and cryptocurrency networks.

Key Points

Electricity used by Bitcoin proof-of-work mining, often fossil-fueled, estimated by CCAF in terawatt hours.

✅ CCAF: 40-445 TWh, central estimate ~130 TWh

✅ ~66% of mining electricity sourced from fossil fuels

✅ Proof-of-work increases hash rate, energy, and emissions

The University of Cambridge Centre for Alternative Finance (CCAF) studies the burgeoning business of cryptocurrencies.

It calculates that Bitcoin's total energy consumption is somewhere between 40 and 445 annualised terawatt hours (TWh), with a central estimate of about 130 terawatt hours.

The UK's electricity consumption is a little over 300 TWh a year, while Argentina uses around the same amount of power as the CCAF's best guess for Bitcoin, as countries like New Zealand's electricity future are debated to balance demand.

And the electricity the Bitcoin miners use overwhelmingly comes from polluting sources, with the U.S. grid not 100% renewable underscoring broader energy mix challenges worldwide.

The CCAF team surveys the people who manage the Bitcoin network around the world on their energy use and found that about two-thirds of it is from fossil fuels, and some regions are weighing curbs like Russia's proposed mining ban amid electricity deficits.

Huge computing power - and therefore energy use - is built into the way the blockchain technology that underpins the cryptocurrency has been designed.

It relies on a vast decentralised network of computers.

These are the so-called Bitcoin "miners" who enable new Bitcoins to be created, but also independently verify and record every transaction made in the currency.

In fact, the Bitcoins are the reward miners get for maintaining this record accurately.

It works like a lottery that runs every 10 minutes, explains Gina Pieters, an economics professor at the University of Chicago and a research fellow with the CCAF team.

Data processing centres around the world, including hotspots such as Iceland's mining strain, race to compile and submit this record of transactions in a way that is acceptable to the system.

They also have to guess a random number.

The first to submit the record and the correct number wins the prize - this becomes the next block in the blockchain.

Estimates for bitcoin's electricity consumption
At the moment, they are rewarded with six-and-a-quarter Bitcoins, valued at about $50,000 each.

As soon as one lottery is over, a new number is generated, and the whole process starts again.

The higher the price, says Prof Pieters, the more miners want to get into the game, and utilities like BC Hydro suspending new crypto connections highlight grid pressures.

"They want to get that revenue," she tells me, "and that's what's going to encourage them to introduce more and more powerful machines in order to guess this random number, and therefore you will see an increase in energy consumption," she says.

And there is another factor that drives Bitcoin's increasing energy consumption.

The software ensures it always takes 10 minutes for the puzzle to be solved, so if the number of miners is increasing, the puzzle gets harder and the more computing power needs to be thrown at it.

Bitcoin is therefore actually designed to encourage increased computing effort.

The idea is that the more computers that compete to maintain the blockchain, the safer it becomes, because anyone who might want to try and undermine the currency must control and operate at least as much computing power as the rest of the miners put together.

What this means is that, as Bitcoin gets more valuable, the computing effort expended on creating and maintaining it - and therefore the energy consumed - inevitably increases.

We can track how much effort miners are making to create the currency.

They are currently reckoned to be making 160 quintillion calculations every second - that's 160,000,000,000,000,000,000, in case you were wondering.

And this vast computational effort is the cryptocurrency's Achilles heel, says Alex de Vries, the founder of the Digiconomist website and an expert on Bitcoin.

All the millions of trillions of calculations it takes to keep the system running aren't really doing any useful work.

"They're computations that serve no other purpose," says de Vries, "they're just immediately discarded again. Right now we're using a whole lot of energy to produce those calculations, but also the majority of that is sourced from fossil energy, and clean energy's 'dirty secret' complicates substitution."

The vast effort it requires also makes Bitcoin inherently difficult to scale, he argues.

"If Bitcoin were to be adopted as a global reserve currency," he speculates, "the Bitcoin price will probably be in the millions, and those miners will have more money than the entire [US] Federal budget to spend on electricity."

"We'd have to double our global energy production," he says with a laugh, even as some argue cheap abundant electricity is getting closer to reality today. "For Bitcoin."

He says it also limits the number of transactions the system can process to about five per second.

This doesn't make for a useful currency, he argues.

Rising price of bitcoin graphic
And that view is echoed by many eminent figures in finance and economics.

The two essential features of a successful currency are that it is an effective form of exchange and a stable store of value, says Ken Rogoff, a professor of economics at Harvard University in Cambridge, Massachusetts, and a former chief economist at the International Monetary Fund (IMF).

He says Bitcoin is neither.

"The fact is, it's not really used much in the legal economy now. Yes, one rich person sells it to another, but that's not a final use. And without that it really doesn't have a long-term future."

What he is saying is that Bitcoin exists almost exclusively as a vehicle for speculation.

So, I want to know: is the bubble about to burst?

"That's my guess," says Prof Rogoff and pauses.

"But I really couldn't tell you when."

Related News

• Electricity Forum News

• Renewable Energy News

Tesla Supercharger Billing Update details kWh-based pricing that now includes HVAC, battery thermal management, and other HV loads during charging sessions, improving cost transparency across pay-per-use markets and extreme climate scenarios.

Key Points

Tesla's update bills for kWh used by HVAC, battery heating, and HV loads during charging, reflecting true energy costs.

✅ kWh charges now include HVAC and battery thermal management

✅ Expect 10-25 kWh increases in extreme climates during sessions

✅ Some regions still bill per minute due to regulations

Tesla has updated its Supercharger billing policy to add the cost of electricity use for things other than charging, like HVAC, battery thermal management, etc, while charging at a Supercharger station, a shift that impacts overall EV charging costs for drivers. 

For a long time, Tesla’s Superchargers were free to use, or rather the use was included in the price of its vehicles. But the automaker has been moving to a pay-to-use model over the last two years in order to finance the growth of the charging network amid the Biden-era charging expansion in the United States.

Not charging owners for the electricity enabled Tesla to wait on developing a payment system for its Supercharger network.

It didn’t need one for the first five years of the network, and now the automaker has been fine-tuning its approach to charge owners for the electricity they consume as part of building better charging networks across markets.

At first, it meant fluctuating prices, and now Tesla is also adjusting how it calculates the total power consumption.

Last weekend, Tesla sent a memo to its staff to inform them that they are updating the calculation used to bill Supercharging sessions in order to take into account all the electricity used:

The calculation used to bill for Supercharging has been updated. Owners will also be billed for kWhs consumed by the car going toward the HVAC system, battery heater, and other HV loads during the session. Previously, owners were only billed for the energy used to charge the battery during the charging session.

Tesla says that the new method should more “accurately reflect the value delivered to the customer and the cost incurred by Tesla,” which mirrors recent moves in its solar and home battery pricing strategy as well.

The automaker says that customers in “extreme climates” could see a difference of 10 to 25 kWh for the energy consumed during a charging session:

Owners may see a noticeable increase in billed kWh if they are using energy-consuming features while charging, e.g., air conditioning, heating etc. This is more likely in extreme climates and could be a 10-25 kWh difference from what a customer experienced previously, as states like California explore grid-stability uses for EVs during peak events.

Of course, this is applicable where Tesla is able to charge by the kWh for charging sessions. In some markets, regulations push Tesla to charge by the minute amid ongoing fights over charging control between utilities and private operators.

Electrek’s Take
It actually looks like an oversight from Tesla in the first place. It’s fair to charge for the total electricity used during a session, and not just what was used to charge your battery pack, since Tesla is paying for both, even as some states add EV ownership fees like the Texas EV fee that further shape costs.

However, I wish Tesla would have a clearer way to break down the charging sessions and their costs.

There have been some complaints about Tesla wrongly billing owners for charging sessions, and this is bound to create more confusion if people see a difference between the kWhs gained during charging and what is shown on the bill.

Related News

• Electricity Forum News

• EV Infrastructure News

BC Tidal Energy Micro-Grids harness predictable tidal currents to replace diesel in remote Indigenous coastal communities, integrating marine renewables, storage, and demand management for resilient off-grid power along Vancouver Island and Haida Gwaii.

Key Points

Community-run tidal turbines and storage deliver reliable, diesel-free electricity to remote B.C. coastal communities.

✅ Predictable power from tidal currents reduces diesel dependence

✅ Integrates storage, demand management, and microgrid controls

✅ Local jobs via marine supply chains and community ownership

Many remote West Coast communities are reliant on diesel for electricity generation, which poses a number of negative economic and environmental effects.

But some sites along B.C.’s extensive coastline are ideal for tidal energy micro-grids that may well be the answer for off-grid communities to generate clean power, suggested experts at a COAST (Centre for Ocean Applied Sustainable Technologies) virtual event Wednesday.

There are 40 isolated coastal communities, many Indigenous communities, and 32 of them are primarily reliant on diesel for electricity generation, said Ben Whitby, program manager at PRIMED, a marine renewable energy research lab at the University of Victoria (UVic).

Besides being a costly and unreliable source of energy, there are environmental and community health considerations associated with shipping diesel to remote communities and running generators, Whitby said.

“It's not purely an economic question,” he said.

“You've got the emissions associated with diesel generation. There's also the risks of transporting diesel … and sometimes in a lot of remote communities on Vancouver Island, when deliveries of diesel don't come through, they end up with no power for three or four days at a time.”

The Heiltsuk First Nation, which suffered a 110,000-litre diesel spill in its territorial waters in 2016, is an unfortunate case study for the potential environmental, social, and cultural risks remote coastal communities face from the transport of fossil fuels along the rough shoreline.

A U.S. barge hauling fuel for coastal communities in Alaska ran aground in Gale Pass, fouling a sacred and primary Heiltsuk food-harvesting area.

There are a number of potential tidal energy sites near off-grid communities along the mainland, on both sides of Vancouver Island, and in the Haida Gwaii region, Whitby said.

Tidal energy exploits the natural ebb and flow of the coast’s tidal water using technologies like underwater kite turbines to capture currents, and is a highly predictable source of renewable energy, he said.

Micro-grids are self-reliant energy systems drawing on renewables from ocean, wave power resources, wind, solar, small hydro, and geothermal sources.

The community, rather than a public utility like BC Hydro, is responsible for demand management, storage, and generation with the power systems running independently or alongside backup fuel generators — offering the operators a measure of energy sovereignty.

Depending on proximity, cost, and renewable solutions, tidal energy isn’t necessarily the solution for every community, Whitby noted, adding that in comparison to hydro, tidal energy is still more expensive.

However, the best candidates for tidal energy are small, off-grid communities largely dependent on costly fossil fuels, Whitby said.

“That's really why the focus in B.C. is at a smaller scale,” he said.

“The time it would take (these communities) to recoup any capital investment is a lot shorter.

“And the cost is actually on a par because they're already paying a significant amount of money for that diesel-generated power.”

Lisa Kalynchuk, vice-president of research and innovation at UVic, said she was excited by the possibilities associated with tidal power, not only in B.C., but for all of Canada’s coasts.

“Canada has approximately 40,000 megawatts available on our three coastlines,” Kalynchuk said.

“Of course, not all this power can be realized, but it does exist, so that leads us to the hard part — tapping into this available energy and delivering it to those remote communities that need it.”

Challenges to establishing tidal power include the added cost and complexity of construction in remote communities, the storage of intermittent power for later use, the economic model, though B.C.’s streamlined regulatory process may ease approvals, the costs associated with tidal power installations, and financing for small communities, she said.

But smaller tidal energy projects can potentially set a track record for more nascent marine renewables, as groups like Marine Renewables Canada pivot to offshore wind development, at a lower cost and without facing the same social or regulatory resistance a large-scale project might face.

A successful tidal energy demo project was set up using a MAVI tidal turbine in Blind Channel to power a private resort on West Thurlow Island, part of the outer Discovery Islands chain wedged between Vancouver Island and the mainland, Whitby said.

The channel’s strong tidal currents, which routinely reach six knots and are close to the marina, proved a good site to test the small-scale turbine and associated micro-grid system that could be replicated to power remote communities, he said.

The mooring system, cable, and turbine were installed fairly rapidly and ran through the summer of 2017. The system is no longer active as provincial and federal funding for the project came to an end.

“But as a proof of concept, we think it was very successful,” Whitby said, adding micro-grid tidal power is still in the early stages of development.

Ideally, the project will be revived with new funding, so it can continue to act as a test site for marine renewable energy and to showcase the system to remote coastal communities that might want to consider tidal power, he said.

In addition to harnessing a local, renewable energy source and increasing energy independence, tidal energy micro-grids can fuel employment and new business opportunities, said Whitby.

The Blind Channel project was installed using the local supply chain out of nearby Campbell River, he said.

“Most of the vessels and support came from that area, so it was all really locally sourced.”

Funding from senior levels of government would likely need to be provided to set up a permanent tidal energy demonstration site, with recent tidal energy investments in Nova Scotia offering a model, or to help a community do case studies and finance a project, Whitby said.

Both the federal and provincial governments have established funding streams to transition remote communities away from relying on diesel.

But remote community projects funded federally or provincially to date have focused on more established renewables, such as hydro, solar, biomass, or wind.

The goal of B.C.’s Remote Community Energy Strategy, part of the CleanBC plan and aligned with zero-emissions electricity by 2035 targets across Canada, is to reduce diesel use for electricity 80 per cent by 2030 by targeting 22 of the largest diesel locations in the province, many of which fall along the coast.

The province has announced a number of significant investments to shift Indigenous coastal communities away from diesel-generated electricity, but they predominantly involve solar or hydro projects.

A situation that’s not likely to change, as the funding application guide in 2020 deemed tidal projects as ineligible for cash.

Yet, the potential for establishing tidal energy micro-grids in B.C. is good, Kalynchuk said, noting UVic is a hub for significant research expertise and several local companies, including ocean and river power innovators working in the region, are employing and developing related service technologies to install and maintain the systems.

“It also addresses our growing need to find alternative sources of energy in the face of the current climate crisis,” she said.

“The path forward is complex and layered, but one essential component in combating climate change is a move away from fossil fuels to other sources of energy that are renewable and environmentally friendly.”

Related News

• Electricity Forum News

• Renewable Energy News

Little Haiti Garbage Truck Power Outage in Miami after mechanical arms snagged power lines, snapping power poles; FPL crews, police, and businesses faced traffic delays, safety risks, and rapid restoration efforts across the neighborhood.

Key Points

A Miami incident where a garbage truck snagged power lines, toppling poles and causing outages and traffic delays.

✅ Mechanical arms caught overhead lines; three power poles snapped

✅ FPL dispatched, police directed traffic; restoration prioritized

✅ Dozens of businesses affected; afternoon rush hour congestion

On January 16, 2025, a significant incident unfolded in Miami's Little Haiti neighborhood when a garbage truck collided with power lines, causing three power poles to collapse and resulting in widespread power outages and traffic disruptions.

Incident Details

Around 1:30 p.m., a garbage truck traveling west on Northeast 82nd Street toward Interstate 95 became entangled with overhead power lines. The truck's mechanical arms caught the lines, leading to the snapping of three power poles and plunging the area into darkness, a scenario echoed by urban incidents like a manhole fire that left thousands without power. Witnesses reported a loud boom followed by an immediate power outage. One local business owner described the event, stating, "There was a loud boom, and suddenly the power went out."

Impact on the Community

The incident caused significant disruptions in the Little Haiti area. At least a dozen businesses were affected by the power outage, and in wider Florida events restoration can take weeks depending on damage, leading to operational halts and potential financial losses. The timing of the crash, during the afternoon rush hour, exacerbated traffic congestion as commuters were forced to navigate through the area, and similar disruptions occur when strong winds knock out power, further complicating the situation.

Response and Recovery Efforts

In response to the incident, Miami police directed traffic to alleviate congestion and ensure public safety. Florida Power & Light (FPL) crews, known for their major outage response, were promptly dispatched to the scene to assess the damage and begin restoration efforts. The priority was to safely remove the damaged power poles and restore electricity to the affected area. FPL's swift action was crucial in minimizing the duration of the power outage and restoring normalcy to the community.

Safety Considerations

This incident underscores the importance of safety protocols for vehicles operating in areas with overhead power lines. Garbage trucks, due to their design and operational mechanisms, are particularly susceptible to such accidents, and in broader disasters some regions require a power grid rebuild to recover, highlighting the stakes. It is imperative for operators to be vigilant and adhere to safety guidelines to prevent similar occurrences.

Community Resilience

Despite the challenges posed by the incident, the Little Haiti community demonstrated resilience. Local businesses and residents cooperated with authorities, while utilities elsewhere have restored power to thousands after major events, and the prompt response from emergency services highlighted the community's strength in the face of adversity.

Related News

• Electricity Forum News

• Utility Operations News

Manitoba Hydro Allegations Investigation reveals RCMP and OPP probes into 1960s abuses in northern Manitoba, affecting Fox Lake Cree Nation, citing racism, discrimination, sexual assault, and oversight by the IIU and Clean Environment Commission.

Key Points

A coordinated probe into historic abuses tied to Manitoba Hydro projects, led by OPP and IIU after RCMP referral.

✅ OPP to investigate historical cases involving Hydro staff and contractors.

✅ IIU to examine any allegations implicating Manitoba RCMP officers.

✅ Findings follow CEC report on racism and abuse near Fox Lake.

Manitoba RCMP have called in outside investigators to probe alleged assaults linked to hydro projects in the province’s north during the 1960s.

RCMP say any historical criminal investigations involving Manitoba Hydro employees or contractors will be handled by the Ontario Provincial Police.

The Independent Investigation Unit of Manitoba, the province’s police watchdog, will investigate any allegations involving RCMP officers.

A report released last month by an arm’s-length review agency outlined racism, discrimination and sexual abuse at the Crown-owned utility’s work sites dating back decades, while projects like Site C COVID-19 updates provide contemporary examples of reporting.

Much of the development at that time was centered around the community of Gillam and the nearby Fox Lake Cree Nation.

The report said the presence of a largely male construction workforce led to the sexual abuse of Indigenous women, some of whom said their complaints were ignored by the RCMP, and in a different context, Hydro One worker injury highlights safety risks in the sector.

Premier Brian Pallister says his government is taking the right approach to addressing alleged sexual assaults and racism by Manitoba Hydro workers against members of a remote northern First Nation, while pandemic cost-cutting at Manitoba Hydro has shaped recent operations.

Pallister made his first public comments about the allegations after a private meeting with Prime Minister Justin Trudeau on Tuesday evening, as COVID-19 reshaped Saskatchewan and other Prairie priorities were in focus.

The allegations, made by members of Fox Lake Cree Nation, were revealed in a report produced by the Clean Environment Commission. The report was released by the provincial government in August, although it was completed in May.

Allegations against Manitoba Hydro workers: What you need to know

"My reaction would be that's deplorable behaviour, and I have to admit, my puzzlement is why this wasn't investigated sooner or didn't come to light sooner," Pallister said, adding that he believes his government has taken the right approach by referring the information to the RCMP.

Some members of Fox Lake Cree Nation say the government didn't give them any advance notice of the release of the report, so the community was traumatized when it hit the news.

Pallister said his government didn't want to delay the release of the report.

'Pure trauma': Fox Lake members stricken after hasty release of troubling report

"I think the right thing to do is release the report. A lot of this information was in the public domain over the last number of weeks and months anyway. It wasn't the case of it being new in that respect," he said.

However, he accepted criticism of the timeline of the report's release.

"I would rather accept those criticisms, than accept the argument that we were in any way covering up information that is important to be released," he said.

Fox Lake Chief Walter Spence has said he expects Pallister to visit the community.

The premier said Tuesday he was not sure of the effectiveness of such a trip.

"I think most of the communities would prefer that there be electricity jobs for young Canadians created in their communities, that there be better water, many other tangible things rather than symbolism," he said.

"That's what I'm hearing and I've been in dozens of First Nations communities in the last two years."

Related News

• Electricity Forum News

• Workforce Safety News

ITER Nuclear Fusion advances tokamak magnetic confinement, heating deuterium-tritium plasma with superconducting magnets, targeting net energy gain, tritium breeding, and steam-turbine power, while complementing laser inertial confinement milestones for grid-scale electricity and 2025 startup goals.

Key Points

ITER Nuclear Fusion is a tokamak project confining D-T plasma with magnets to achieve net energy gain and clean power.

✅ Tokamak magnetic confinement with high-temp superconducting coils

✅ Deuterium-tritium fuel cycle with on-site tritium breeding

✅ Targets net energy gain and grid-scale, low-carbon electricity

It sounds like the stuff of dreams: a virtually limitless source of energy that doesn’t produce greenhouse gases or radioactive waste. That’s the promise of nuclear fusion, often described as the holy grail of clean energy by proponents, which for decades has been nothing more than a fantasy due to insurmountable technical challenges. But things are heating up in what has turned into a race to create what amounts to an artificial sun here on Earth, one that can provide power for our kettles, cars and light bulbs.

Today’s nuclear power plants create electricity through nuclear fission, in which atoms are split, with next-gen nuclear power exploring smaller, cheaper, safer designs that remain distinct from fusion. Nuclear fusion however, involves combining atomic nuclei to release energy. It’s the same reaction that’s taking place at the Sun’s core. But overcoming the natural repulsion between atomic nuclei and maintaining the right conditions for fusion to occur isn’t straightforward. And doing so in a way that produces more energy than the reaction consumes has been beyond the grasp of the finest minds in physics for decades.

But perhaps not for much longer. Some major technical challenges have been overcome in the past few years and governments around the world have been pouring money into fusion power research as part of a broader green industrial revolution under way in several regions. There are also over 20 private ventures in the UK, US, Europe, China and Australia vying to be the first to make fusion energy production a reality.

“People are saying, ‘If it really is the ultimate solution, let’s find out whether it works or not,’” says Dr Tim Luce, head of science and operation at the International Thermonuclear Experimental Reactor (ITER), being built in southeast France. ITER is the biggest throw of the fusion dice yet.

Its $22bn (£15.9bn) build cost is being met by the governments of two-thirds of the world’s population, including the EU, the US, China and Russia, at a time when Europe is losing nuclear power and needs energy, and when it’s fired up in 2025 it’ll be the world’s largest fusion reactor. If it works, ITER will transform fusion power from being the stuff of dreams into a viable energy source.

Constructing a nuclear fusion reactor
ITER will be a tokamak reactor – thought to be the best hope for fusion power. Inside a tokamak, a gas, often a hydrogen isotope called deuterium, is subjected to intense heat and pressure, forcing electrons out of the atoms. This creates a plasma – a superheated, ionised gas – that has to be contained by intense magnetic fields.

The containment is vital, as no material on Earth could withstand the intense heat (100,000,000°C and above) that the plasma has to reach so that fusion can begin. It’s close to 10 times the heat at the Sun’s core, and temperatures like that are needed in a tokamak because the gravitational pressure within the Sun can’t be recreated.

When atomic nuclei do start to fuse, vast amounts of energy are released. While the experimental reactors currently in operation release that energy as heat, in a fusion reactor power plant, the heat would be used to produce steam that would drive turbines to generate electricity, even as some envision nuclear beyond electricity for industrial heat and fuels.

Tokamaks aren’t the only fusion reactors being tried. Another type of reactor uses lasers to heat and compress a hydrogen fuel to initiate fusion. In August 2021, one such device at the National Ignition Facility, at the Lawrence Livermore National Laboratory in California, generated 1.35 megajoules of energy. This record-breaking figure brings fusion power a step closer to net energy gain, but most hopes are still pinned on tokamak reactors rather than lasers.

In June 2021, China’s Experimental Advanced Superconducting Tokamak (EAST) reactor maintained a plasma for 101 seconds at 120,000,000°C. Before that, the record was 20 seconds. Ultimately, a fusion reactor would need to sustain the plasma indefinitely – or at least for eight-hour ‘pulses’ during periods of peak electricity demand.

A real game-changer for tokamaks has been the magnets used to produce the magnetic field. “We know how to make magnets that generate a very high magnetic field from copper or other kinds of metal, but you would pay a fortune for the electricity. It wouldn’t be a net energy gain from the plant,” says Luce.

One route for nuclear fusion is to use atoms of deuterium and tritium, both isotopes of hydrogen. They fuse under incredible heat and pressure, and the resulting products release energy as heat

The solution is to use high-temperature, superconducting magnets made from superconducting wire, or ‘tape’, that has no electrical resistance. These magnets can create intense magnetic fields and don’t lose energy as heat.

“High temperature superconductivity has been known about for 35 years. But the manufacturing capability to make tape in the lengths that would be required to make a reasonable fusion coil has just recently been developed,” says Luce. One of ITER’s magnets, the central solenoid, will produce a field of 13 tesla – 280,000 times Earth’s magnetic field.

The inner walls of ITER’s vacuum vessel, where the fusion will occur, will be lined with beryllium, a metal that won’t contaminate the plasma much if they touch. At the bottom is the divertor that will keep the temperature inside the reactor under control.

“The heat load on the divertor can be as large as in a rocket nozzle,” says Luce. “Rocket nozzles work because you can get into orbit within minutes and in space it’s really cold.” In a fusion reactor, a divertor would need to withstand this heat indefinitely and at ITER they’ll be testing one made out of tungsten.

Meanwhile, in the US, the National Spherical Torus Experiment – Upgrade (NSTX-U) fusion reactor will be fired up in the autumn of 2022, while efforts in advanced fission such as a mini-reactor design are also progressing. One of its priorities will be to see whether lining the reactor with lithium helps to keep the plasma stable.

Choosing a fuel
Instead of just using deuterium as the fusion fuel, ITER will use deuterium mixed with tritium, another hydrogen isotope. The deuterium-tritium blend offers the best chance of getting significantly more power out than is put in. Proponents of fusion power say one reason the technology is safe is that the fuel needs to be constantly fed into the reactor to keep fusion happening, making a runaway reaction impossible.

Deuterium can be extracted from seawater, so there’s a virtually limitless supply of it. But only 20kg of tritium are thought to exist worldwide, so fusion power plants will have to produce it (ITER will develop technology to ‘breed’ tritium). While some radioactive waste will be produced in a fusion plant, it’ll have a lifetime of around 100 years, rather than the thousands of years from fission.

At the time of writing in September, researchers at the Joint European Torus (JET) fusion reactor in Oxfordshire were due to start their deuterium-tritium fusion reactions. “JET will help ITER prepare a choice of machine parameters to optimise the fusion power,” says Dr Joelle Mailloux, one of the scientific programme leaders at JET. These parameters will include finding the best combination of deuterium and tritium, and establishing how the current is increased in the magnets before fusion starts.

The groundwork laid down at JET should accelerate ITER’s efforts to accomplish net energy gain. ITER will produce ‘first plasma’ in December 2025 and be cranked up to full power over the following decade. Its plasma temperature will reach 150,000,000°C and its target is to produce 500 megawatts of fusion power for every 50 megawatts of input heating power.

“If ITER is successful, it’ll eliminate most, if not all, doubts about the science and liberate money for technology development,” says Luce. That technology development will be demonstration fusion power plants that actually produce electricity, where advanced reactors can build on decades of expertise. “ITER is opening the door and saying, yeah, this works – the science is there.”

Related News

• Electricity Forum News

• Power Generation News