Credit: Hepzi Rattray

How sustainable is our reliance on sustainable energy?

By John Harris

Writer John Harris takes a look at the consistency of renewable energy, and what alternative options are on offer.

Last year the energy company EDF announced they will be decommissioning their last coal-fired power station in the UK. As one of only two coal-fired power stations still in operation, the news that it would be placed on standby was a positive step towards meeting the government’s target of taking coal off the grid by 2025. However, this march to progress was halted on Tuesday 6 September, when the National Grid ESO asked them to fire it right back up again following a perfect storm of soaring gas prices and a lower-than-expected output from wind farms. This incident has raised important questions about the future of energy consumption. Just how reliable are renewables? And, more importantly, what can we fall back on if they fail to produce the energy we need? 

Renewable energy sources such as wind and solar come with one unfortunate problem: they rely on the weather. To put it into numbers, energy efficiency for power stations is measured as a “plant load factor”. This is the percentage of energy generated each year in relation to its potential output, if it was to run at full capacity all the time. The load factor of wind is around 26.6% for onshore and 40.4% for offshore turbines. Gas sat at around 43% in 2019 but peaked at 61.1% in 2010. Of course, there are a few different reasons load factors can go up and down, like expense and maintenance issues; but the key thing to take away is our main source of renewable energy isn’t as efficient as our main fossil fuel… at least not yet. When we get a particularly still period of weather, like last month, the turbines just stop turning. It’s a similar story with solar panels: we can’t rely on them to bring us energy around the clock.

“Renewable energy sources such as wind and solar come with one unfortunate problem: they rely on the weather.”

So, we need a backup source of power, at least in the short term whilst we get to grips with renewables and work on their efficiency. Currently, that consists of coal and gas. Considering the damage caused by fossil fuels and our commitments to phase them out, this is problematic. The grid has been left looking for an alternative and asking: could that alternative be nuclear power?


Unsurprisingly, the Nuclear Industry Association certainly thinks so. They have claimed this backtrack to coal power has highlighted an urgent need to invest in more nuclear power stations. Chief Executive, Tom Greatrex, said the situation “underscores the urgency of investing in new nuclear capacity, to secure reliable, always-on, emissions-free power, alongside other zero-carbon sources”. “Otherwise,” he stated, “we will continue to burn coal as a fall-back and fall well short of our net zero ambitions.” Calls for nuclear have wormed their way into Westminster where an All-Party Parliamentary Group (APPG) report into nuclear energy published in June claimed that the UK needs to restore nuclear capacity to at least 10GW (gigawatt) by the early 2030’s, if we are to stay on track for emissions targets. 

Even Boris Johnson has jumped on the nuclear bandwagon as part of his ten-point plan for a green industrial revolution. He has pledged to advance “nuclear as a clean energy source, across large scale nuclear” and “develop the next generation of small and advanced reactors”. A lot of weight and money (both public and private) is being thrown behind nuclear energy as the solution to plugging holes in a mixed energy grid.

“Even Boris Johnson has jumped on the nuclear bandwagon as part of his ten-point plan for a green industrial revolution.”


So, what are the benefits of nuclear power and why do they claim it is so integral to a clean energy network? An inescapable benefit of nuclear power is efficiency. In 2019, the plant load factor for the UK’s existing nuclear power stations was 62.9%. Whilst a drop from the 2016 high of 80.1%, it still blows wind right out of the water. Nuclear power can provide consistent power throughout the year regardless of the weather conditions, putting it at a considerable advantage to our current renewable options.

But more crucially, in the current climate, lies the argument that nuclear power is a relatively clean source of energy – cleaner than fossil fuels, at least. Although there are a lot of negative emissions from construction, decommissioning, and mining activities required for the uranium fuel, nuclear fission produces no greenhouse gases when generating energy. Over a nuclear plant’s life cycle, the carbon dioxide-equivalent emissions per unit of electricity produced is estimated to be on par with wind and lower than solar. 

For these reasons, industry groups such as the World Nuclear Association argue that nuclear power has an important role to play in both meeting the world’s energy needs and reducing emissions from the energy sector. Is nuclear really all sunshine and greener pastures, then? Not exactly.

“Over a nuclear plant’s life cycle, the carbon dioxide-equivalent emissions per unit of electricity produced is estimated to be on par with wind and lower than solar.”


International environmental organisations aren’t all convinced that the good outweighs the bad with a nuclear solution. Greenpeace has maintained a consistent stance against generating nuclear energy from the start. One of the key concerns they cite is over the safety of nuclear plants. While major accidents are rare, the potential for these to become large-scale disasters is a high price to pay for clean energy, especially while we have other options. Nuclear energy still lives in the shadow of its major catastrophes. The 1957 Windscale fire in Cumbria, the Kyshtym explosion in the Soviet Union, the 1986 Chernobyl disaster, and more recently the 2011 Fukushima disaster in Japan rank as the most serious.

Interestingly, the United Nations report into the aftermath of Fukushima found no increased public health risk linked to the radiation. This doesn’t mean it’s all positive. We’re only 10 years on from the disaster, and it’s well known that the radiation toxicity is an insidious process. Cancer diagnoses in some workers have already been linked to radiation exposure during the clean up.

On the topic of cancer, issues for workers in the wider nuclear industry have been found to include the raised risk of lung cancer documented in North American uranium miners. Even if exposure risks to the general public (including in the aftermath of a disaster) were minimal, they remain a significant cause for concern amongst the industry’s workers. This is without even going into concerns over the measurable impact on wildlife and the environment.

These risks don’t go away when you decommission the station either. High level nuclear waste must be carefully stored for at least 100,000 years before it will be considered safe, and right now we don’t have a permanent storage facility. Plans are underway for a below ground storage facility in the north of England. However, the locals are understandably not thrilled by the idea of hosting thousands of tons of radioactive material.

“On the topic of cancer, issues for workers in the wider nuclear industry have been found to include the raised risk of lung cancer documented in North American uranium miners.”

Older nuclear power stations, along with nuclear weapons projects, have already produced 500,000 cubic metres of high and intermediate-level nuclear waste. This will only increase, and while the nuclear industry is quick to point out the lower waste levels from newer plants, it is still just more barrels that we have nowhere for. Even if they can convince a community to accept the waste, it will need monitoring and security for generations to come. I suppose you could take comfort in all the employment opportunities for your great-great-great-great-grandchildren, guarding waste from energy production that charged your phone. I don’t think a few low paying jobs in return for the burden of literal tonnes of radioactive material is going to go down well though.

To complicate matters further, the UK will also be losing a lot of its nuclear capacity over the coming decade, with plans to decommission older plants and permanently close others with safety concerns. Hinkley Point B in Somerset and our local Hunterston B in North Ayrshire are set to close next year after cracks were found in their graphite cores, filling us all with nothing but confidence in the potential structural integrity of other stations, I’m sure. The government move to promote nuclear as part of a wider zero-emissions energy network will help direct more money towards replacing them, but industry setbacks aren’t helping the cause. 

Hinkley Point C, part of the new generation of nuclear power stations being championed by EDF, has suffered repeated delays and is now unlikely to open until 2026. It has also seen massive budget increases with the original estimated cost of £18bn soaring to £23bn. On balance, costs and implementation timescales across the industry have begun to decrease as development becomes more standardised. However, the issue still remains: nuclear power has a much higher set up cost than most renewables. 

Despite some of its impressive benefits, nuclear power isn’t on track to revolutionise the UK energy network in the short time we have left to meet emissions-lowering commitments. Until it has a handle on its waste storage problem, I think it would be unwise to keep making more radioactive material. To top it all off, I’d be lying if I said the idea of workers succumbing to illnesses caused by exposure, or the potential – however remote –  for a major accident to turn sections of the country into no-go zones doesn’t start to raise red flags. 


What can we fall back on to make up for the issues prevalent in renewable energy? Well one option could be increasing the capacity of our battery storage stations. To make sure the power from renewables is available in times of reduced output and continued demand, battery stations are used to store excess energy. Currently the UK only has the capacity to store 1.3GW of power, while over the past year renewables accounted for around 6.9GW of the UKs energy consumption, 5.42GW from wind alone. So obviously that capacity needs to be increased alongside the amount of renewable power sources.

“…one option could be increasing the capacity of our battery storage stations.”

The biggest benefit of this method as opposed to nuclear energy is that it is relatively cheap. That might be the crucial selling point in a system which has demonstrated a willingness to put money before environmental needs time and time again. It also has a much shorter set up time; vital whilst we work against the clock.

So, as renewables become better at providing us with energy (with huge potential from moveable offshore wind and estimated increases in efficiency for their fixed counterparts), it is foreseeable that, with more battery storage stations, they can provide their own fallback solution. In the short-term, we may just need to occasionally revert to some fossil fuels to keep us moving. 

The occasional backslide to fossil fuels isn’t as big an issue as it may first seem. Dave Jones, electricity analyst at Ember (a think tank promoting the shift away from fossil fuels), reminds us that “as long as you know you can make it to that fixed date, which is still three years away, it’s OK. We’re well on track for that journey; probably ahead of schedule.” We shouldn’t be taken in by all the hype that “renewables are failing” based on a few small setbacks. Especially when it’s not the renewable setbacks that cost us an extra £5bn, or leave workers living with the effects of radiation poisoning.

The National Grid states that the UK needs to have 80% of power from a mix of wind and solar to meet climate targets. To help us get here, it’s important to note that we don’t need to have a massive increase in our nuclear capacity – at most, we just need it to be maintained in the short-term. And, with lengthy build times, unforeseen setbacks, and opposition to both new power stations and waste storage facilities by groups across the country, there is no way that nuclear will realistically be able to replace coal within the next three years. Putting aside its potential benefits and concerns over detrimental impacts, we simply don’t have time to wait around for the promise of nuclear power.The government would do well to keep their focus on proven renewable resources instead of getting too bogged down in the nuclear power industry. Nuclear is still the energy of tomorrow, but we need our clean energy today.


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