I’ve posted before on the proposed Lime Down Solar farm expressing the reasons why large scale solar is needed.

I’m not connected with the developers behind Lime Down in any way, and I do understand some of the concerns the local opposition group ‘Stop Lime Down’ have regarding scale, construction traffic, and the nature of the area. However the group has continued to publish what I consider to be exaggerated posts, and many of the comments on their social media feed border on what in my opinion are the same tactics used by climate change denial pro-fossil fuel groups. So I was very surprised to see a recent video call with Professor Richard Skeffington. I’ve linked the video below so you can see the video yourself if you wish.

Professor Skeffington’s talk starts at 13 minutes.

Professor Skeffington is a former Professor at the University of Reading with an interest in climate change and in particular water. He has worked in the power industry as a consultant. So as an open minded person I was interested to hear what he had to say on Lime Down. I note that he lives in Sherston, an area affected by Lime Down Solar.

At 17 mins Professor Skeffington notes that the panels are 4.5 m high tracking panels. He neglects to mention that as they are tracking panels, they will only be 4.5m high early at the beginning and end of the day. He goes on to describe the substations, though uses a photo which as he says is three times larger than the actual substation, but I see this gives context.

The cable route is then described, which will be underground. This is surely preferable to overhead pylons? Whist this is major work, as Professor Skeffington says it will be covered over and recover in a couple of years.

Professor Skeffington goes on to critique some of the ecological mitigations for the proposed scheme, and I understand most of these points having observed many local housing developers tree planting efforts. However there are studies of successful biodiversity and nature recovery within solar farms. For example a joint study by Cambridge University and the RSPB demonstrated how bird numbers can increase with solar farms [6].

At 35minutes Professor Skeffington describes the ‘alleged need to cover the countryside with solar panels‘, this is where we start to diverge.

The Need for Ground Mount Solar

So what is the ‘alleged need to cover the countryside with solar panels’? Well unusually for someone that’s spent their academic life modelling climate change effects on water quality, the Professor doesn’t mention climate change in his presentation.

If you have any doubts about the urgent need to act on climate change please see the recent National Emergency Briefing

The UK’s Climate Change committee in their Seventh Carbon Budget [1] states:

“UK-based renewable energy provides the bulk of generation in a larger, future electricity system. Electricity then replaces oil and gas across most of the economy, including EVs, buildings, and much of industry. This requires twice as much electricity as today by 2040. As well as being low carbon, electric technologies are highly efficient. Ending the combustion of fossil fuels in boilers and cars leads to cleaner air in homes and neighbourhoods.

Low-carbon supply: by 2040, our Balanced Pathway sees offshore wind grow six-fold from 15 GW of capacity in 2023 to 88 GW by 2040. Onshore wind capacity doubles to 32 GW by 2040 and solar capacity increases to 82 GW. Alongside renewables, storable forms of energy including nuclear, low-carbon dispatchable generation (either gas CCS or hydrogen), and batteries, as well as interconnection to neighbouring markets, ensure a reliable supply of electricity even in adverse weather years. These technologies need to be accompanied by rapidly expanding the transmission grid, upgrading the distribution network, and speeding up the grid connection process.”

So the Seventh Carbon Budget pathway recommended by the UK’s Climate Change Committee increases solar capacity to 82GW by 2040. This is a huge leap from the 18GW we are currently at.

Yes it could be argued that there are alternate routes to achieve this decarbonisation, but that is the Seventh Carbon Budget.

But what’s the current target?

Well, in the last election the Liberal Democrats [2] had a manifesto pledge for 90% of the electricity generation mix to be renewable.

The Lib Dems’ manifesto confirms that the Party, if elected, would strive to move the UK’s legally binding net-zero target forward to 2045 and set a 2030 target for 90% of the electricity generation mix to be renewable.

Labour had a similar manifesto pledge [3]: Under the Labour Party’s 30 by 2030 plan, the UK should be on the path to a net-zero carbon energy system by the 2030s. The manifesto promises that almost 90% of electricity and 50% of heat will be supplied by renewable or low-carbon sources by 2030.

So the vast majority of elected MPs including those in the Lime Down region had a manifesto pledge to decarbonise the grid 90% by 2030. Whilst our local MPs and Councillors might argue that whilst this was in their manifesto, this isn’t the way the way they would do it and they stood for election opposing Lime Down, to me that seems disingenuous. You can’t have a manifesto pledge to build out renewables without having to actually build out renewables! That’s having your cake and eating it!

They would after all have access to the same civil servants and experts regardless of the party in power, and being set the parameter of 90% decarbonisation by 2030 (or 90% renewable energy generation by 2030 in the Lib Dem manifesto), those civil servants and groups would come out with a broadly similar roadmap.

So we have the National Energy System Operator (NESO) [4] Clean Power for 2030 plan.

The NESO projects the required energy mix as:

Renewables:
• 43-50 GW of offshore wind
• 27-29 GW of onshore wind
• 45-47 GW of solar power

Flexibility:
• 23-27 GW of battery capacity
• 4-6 GW of long-duration energy storage
• development of gas carbon capture utilisation
& storage and hydrogen to power
• 10-12 GW of consumer-led flexibility

The Solar part of this has produced a solar roadmap [5]

Looking at the Solar Roadmap we can see that at best rooftop solar is around 40 to 50% of the total and the rest are larger scale ground mount projects.

From the 2030 roadmap: ‘As seen in Figure 2, under the Current Policy scenario, of the capacity installed by 2030, around 60%-65% could be large-scale projects, around 20% domestic rooftop and around 15%-20% commercial rooftop and ground mount. Removing barriers for rooftop deployment could increase residential rooftop to around 10GW and commercial rooftop and ground mount to more than 10GW by 2030.’

So 483 democratically elected MPs from the Lib Dems and Labour had a manifesto pledge to decarbonise the grid by 90% by 2030, and given that pledge and the elected Labour Government, both NESO and Solar UK produced a Solar Roadmap to achieve that goal. The Solar Roadmap requires 60% to be large scale ground mount solar projects.

Note: I come at this from someone that volunteer admins a community rooftop solar scheme.

What about Food Production?

Professor Skeffington then describes the agricultural nature of the land and that approximately 30% would be classed as Best Most Versatile land. He then states that the UK imports nearly half of our food.

It’s true that parts of this proposal are on Best Most Versatile land, and I wouldn’t support tenant farmers being evicted.

Regarding food security, there is a lot of scaremongering regarding solar farms. The 60% figure often quoted (75% for what can be grown in the UK) is in terms of economic value. On the link for the UK food security report below [7], pages 96 and 99 show that domestic production of grain, meat, dairy and eggs broadly match UK consumption.

P 83 notes that soil degradation and climate change are key threats to food security, with indicator 2.3.2 on p134 highlighting the cost of soil degradation.

The link for Defra R&D SP08016 [8] demonstrates that the reversion of arable land to pasture is highly effective at enabling recovery of soil organic matter and has a range of additional environmental benefits that stem from this. By securing a long fallow, solar farms secure soil health on currently arable land. The agricultural land classification (ALC) grading used in planning assumes a good standard of management, so an assessment of arable land ignores that the soil organic matter has become depleted.

Whereas 70% of UK land is agricultural, the Solar Roadmap [5] estimates that just 0.4% of UK land is required to meet our solar needs. For me the debate is really how best to locate that solar, and whether the scale of this project concentrated in one area is appropriate. But you can’t meet our solar needs without actually building solar, and as previously mentioned 60% will need to be ground mount.

Storm Bert

At 52 minutes Storm Bert is mentioned. Though no mention of the causes of climate change is made, which is odd given it’s Professor Skeffington’s apparent area of expertise.

In the National Emergency briefing [7] below Professor Hayley Fowler provides insight as to the causes of extreme weather and future scenarios. This is of course why we need to reduce our carbon emissions to net zero and adapt and become resilient to increased flooding.

In simple terms for every degree C temperature rise we hold approximately 7% more water in the atmosphere. The jet stream is entering blocking patterns and slowing, and this is caused by the reduced temperature differential between the equator and the arctic as the arctic warms.

Of course it wouldn’t make sense to build solar, battery, and substations in a flood zone, but we are in a chicken and egg situation here.

What about Batteries?

From the NESO 2030 plan [4] we need 23-27 GW of battery capacity. As Professor Skeffington acknowledges at 55 mins Battery fires are rare events. [10] The UK Government Research briefing [10] is a useful resource.

“even with billions of lithium-ion cells
in circulation, there are very few safety incidents involving them”. It estimates
that only one in 40 million battery cells experience failure that results in fire. [11]

There have been at least two documented incidents of BESS fires in the UK: a
fire at a BESS site in Liverpool in September 2020 and a fire at a BESS project
under construction in Essex in February 2025.

A research paper on the incident by the Electric Power Research Institute
(EPRI), an organisation based in the United States which conducts research
on the generation, delivery, and use of electricity, notes that BESS design has
improved since the Liverpool BESS was installed in 2018:
Some newer system designs use smaller, modularized cabinets with a few
racks of batteries. The system layout limits damage because of thermal
runaway and allows a more targeted first responder approach in the event of a
fire. A report by EPRI [12] states that the global failure rate for grid-scale BESSs has decreased significantly since 2018, from almost 10 failure events per GW of storage per year, to less than one failure event per GW per year since 2020

There is much more I could say on batteries, but suffice to say they are an essential part of grid decarbonisation and fires are extremely rare.

Again we are addressing a climate emergency decoupling from a fossil fuel system that is a continuous extract and burn process. We will require 30 million tonnes of minerals by 2040 to decarbonise vs 7.5 billion tonnes of fossil fuels extracted last year. Note the *billion.*. We are also increasing energy security by moving away from volatile fossil fuel markets.

The Embodied carbon of large scale solar farms

We then move onto the section of the video that really had me rubbing my eyes. I had wondered why Stop Lime Down had started making claims regarding the embodied carbon of the solar farm which certainly don’t align with my own research or the best expert consensus.

At 1 hr

“Cables, transformers, inverters etc have a huge amount of embodied carbon”

“it’s quite possible this will certainly reduce the carbon benefits of the scheme, but it’s quite possible there will be no carbon benefits at all”

Professor Skeffington then advocates “small scale solar going into local grids with no high voltage underground power lines or pylons with a much lower carbon footprint.”

So what’s the evidence behind the claim that the embodied carbon of this solar farm will never pay back? No research papers are presented, so let’s take a look..

It’s absolutely true that carbon emissions are produced in the manufacture of Solar Panels, batteries, transformers, inverters, and cables. This will continue to be the case until the whole supply chain is decarbonised. This carbon is referred to as embodied carbon with the concept of a payback time. For example, if we emitted 1 tonne of CO2e to manufacture a number of solar panels, but they produced electricity in one year that would save 1 tonne of CO2 that would have been generated by fossil fuels, then we have paid back in 1 year. This is simplistic, but you get the concept. If equipment is made in an area with a carbon intensive electricity supply then the embodied carbon is higher and the payback longer. It should be highlighted that the issue here is fossil fuels never payback. We just extract and burn.

So what research is there on the embodied carbon in large scale solar farms?

This 2024 US study from the department of energy [13] examines several scenarios from High carbon manufactured imports to low carbon imports. A key factor in the carbon payback is whether the panels are recycled at end of life or land filled. I thinks it’s reasonable and crucial to assume that they will be recycled. In the recycling and partially recycling scenarios the longest carbon payback time is two years. Though we can’t directly compare this study like for like, it does give a firm indicator that with a 60 year life we can expect to payback many times providing we recycle at end of life.

The respected organisation Carbon Brief [14] publicised the following study published in Nature [15] Solar, wind and nuclear have ‘amazingly low’ carbon footprints, study finds

“It shows that the carbon footprint of solar, wind and nuclear power are many times lower than coal or gas with carbon capture and storage (CCS). This remains true after accounting for emissions during manufacture, construction and fuel supply.”

“Some critics have argued renewable energies could come with high hidden greenhouse gas emissions that would negate their benefits to the climate. Our study now shows that the opposite is true,” Luderer says in a statement.

In fact, the indirect lifecycle emissions in a 2C pathway are much lower than in a world without climate policy, where methane leaks during coal and gas extraction are significant.

The paper says:

“The indirect greenhouse gas emissions induced by upscaling wind, solar and nuclear power are small compared with other emissions sources, and thus do not impede the transformation towards climate-friendly power supply.”

Isn’t it just to make money?

Professor Skeffington questions – why such a big scheme, and concludes the only reason is for MacQuarie to make money.

Well that’s probably true, as a private company I don’t think MacQuarie are doing this out of the goodness of their heart. But the truth is we haven’t been able to build our own energy infrastructure without investment for decades. The formation of Great British Energy is a positive step forward, but has its limitations. It really comes down to how government ensures this is a good contract for the taxpayer with check and balances built in for whole life cycle cost, particularly end of life.

Why are our energy bills so high?

Professor Skeffington then shares a slide of renewable subsidies from the Renewable Energy Foundation (an organisation linked to the opaquely funded Global Warming Policy Foundation climate sceptic group). He states this is why people can’t afford their electricity bills.

For me this is where the whole presentation completely derails.

Before examining the argument it’s worth highlighting the investigative group Carbon Brief’s analysis of the Renewable Energy Foundation [16]

So what’s the truth as to why energy bills are so high in the UK?

From Money Week [17] “The UK is a net importer of natural gas and unusually exposed to the volatility in the global market. And in this country, the price of electricity has long been determined mostly by the gas price – far more so than in other similar countries, and even though the role of gas in the overall energy mix is falling.”

Two big reasons. First, the auction method by which energy retailers source their supplies. This isn’t a free-for-all auction where producers compete on cost to attract customers. It’s a marginal pricing system – similar to that seen in some commodity markets – where the “wholesale electricity price” for the whole market is set by the most expensive power station needed to meet the overall demand.

This reflects the fact that energy is critical to national security so all players need to be incentivised to keep the lights on. In the UK, gas plants are the most expensive almost all of the time (98% in 2023), whereas the European average for fossil fuels was just 58% – meaning that energy bills are much higher here.

The second reason is that while the UK is getting good at producing renewable energy, it’s terrible at scaling up its storage capacity. Despite improvements in battery technology, the UK’s current capacity is “far too small to store the volumes of energy needed to make a real dent in electricity prices”, says The Economist. [18]

So – the marginal cost of gas in the electricity mix, and a need to scale up battery storage.

From the respected Carbon Brief

“The UK has been particularly exposed, as gas sets its wholesale power prices 98% of the time – and gas remains three times more expensive than before the crisis.

Nevertheless, some have sought instead to misleadingly blame the UK’s high electricity prices on “green levies” that support the expansion of clean power, as well as on the target for net-zero emissions by 2050.”

This evidence can be repeated from energy companies, consultancy groups, research sources across the UK.

The marginal cost of gas is the reason our electricity prices are so high.

However if you’re worried about electricity bills and think nuclear is the better solution, consider that Hinkley C will add 1 billon per year to all our electricity bills [20]

I’m not personally against nuclear in the mix, but it isn’t cheap.

Conclusions

I believe that there are genuine concerns regarding the scale of the Lime Down solar farm, its construction, and impact on the landscape. There are also genuine concerns around the citing of some of the solar on Best Most Versatile land. So I understand some of the local concerns regarding the proposals.

However Ground Mount Solar is absolutely necessary in order to decarbonise our grid as 60% of the solar roadmap, it cannot be done by rooftops alone. The arguments put forward that ‘renewables are the reason our bills are high’ and that the embodied carbon at Lime Down will never pay back, simply don’t stack up, and i’m surprised that speculation like this is even put forward. It’s very similar information to that funded and published by pro-fossil fuel climate change denial groups. This is a pity as I personally think it dilutes focussing on the parts of the scheme that could be improved.

Similarly Battery Storage is absolutely needed as part of the energy transition as defined in the NESO 2030 plan.

Politically both the Lib Dems and Labour had manifesto policies that required 90% grid decarbonisation by 2030. These policies are there because it’s the right thing to do for both climate change and energy security.

The final decision will lie with the Planning Inspector and National Government.

References

[1] The Seventh Carbon Budget – Climate Change Committee

[2] Lib Dems outline vision for net-zero by 2045 in new manifesto – edie

[3] Labour manifesto on energy policy and climate change

[4] Clean Power 2030 | National Energy System Operator

[5] Solar roadmap – GOV.UK

[6] Solar farms managed for nature can boost bird numbers and biodiversity

[7] National Emergency Briefing on climate & nature

[8] https://www.gov.uk/government/statistics/united-kingdom-food-security-report-2021

[9] https://sciencesearch.defra.gov.uk/ProjectDetails?ProjectId=15536

[10] CBP-7621.pdf