How a solar farm in southeast England could bring a new dawn for renewables

The Conversation UK

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Alastair Buckley, University of Sheffield

The largest solar power plant ever proposed in the UK will be reviewed by the secretary of state within the next six months. Cleve Hill solar farm will occupy the north coast of Kent and, if built, provide up to 350MW (megawatts) of generating capacity.

The plan is for Cleve Hill to generate the lowest cost electricity on the UK network without needing subsidies to stay afloat. There have been subsidy-free solar installations before but nothing like Cleve Hill’s 1,000-acre development. The plant will also include battery storage – giving the operators the option of storing when the price of electricity is low and selling when it’s high.

So why is this such a landmark moment for the UK’s electricity supply? Well, there are now nearly a million solar systems in the UK, which includes everything from solar panels mounted on roofs to farms occupying entire fields.

The rate of deployment has waxed and waned over the last ten years – largely determined by the level of subsidy the government was willing to offer. When subsidies were high, the installation rate grew exponentially, with the peak number of installations doubling every few months. When subsidies fell, installation rates plummeted.

The government has so far controlled solar power growth by controlling subsidies. This boom and bust model meant companies failed and installers lost their jobs in the bad times and companies were created or changed business models in the good times.

Today, the installation rate is very low because there is virtually no subsidy and it’s very hard to make money out of solar. However, Cleve Hill could show that money can be made without subsidy, and where one project goes, others will follow. This could be the moment that solar installations start to grow again.

Small and large-scale solar power

When we at Sheffield Solar, a research group based in the University of Sheffield started researching the impact of solar on the UK electricity grid back in 2010, we wondered what would happen when solar power generation became so cheap that the government couldn’t control the growth of installation anymore via subsidies and incentives.

Cleve Hill seems to mark the moment when solar energy becomes self-reliant. But maybe it’s not so simple. Cleve Hill makes financial sense because it’s so big. But big comes with implications.

Some of the public support for energy generated by photovoltaics (PV), the technology that converts sunlight into electricity, comes from its easy integration into the built environment. Solar panels on roofs make sense to the public because electricity generation is happening at the point of use. Solar farms make sense to investors because they are cheaper to install per unit of electricity but also bigger – so finance can be accessed in larger chunks and investors can make more money.

Rooftop solar can patch gaps in energy grid supply but its output is hard to measure.
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If Cleve Hill signals the start of subsidy-free solar – but only for huge systems that take up vast swathes of countryside – what does that mean for solar roofs? Can global growth in solar generation reduce the costs of rooftop systems so that we start to see a balance of large and small systems being installed without subsidy?

Cleve Hill has to get agreed at the highest level of government and has to be developed with input from local authorities and electricity network operators – it can be planned into the national infrastructure. Subsidy-free rooftop solar would be far less controlled. This could be a big problem – or perhaps a golden solution.

Solar farms can be planned into national supply grids, but their construction has an environmental cost.
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A green energy windfall

The UK has benefited this year from an unusually sunny summer. In June and early July, PV generation peaked at over 9GW (gigawatts) each day for a week. At midday on Saturday June 30, solar supplied 30% of the national demand for electricity. If that day had also been windy then a further 30% could have come from wind. There have been several days in this period when 50% of UK energy demand has been met with wind and solar.

The UK also has a 7GW nuclear power capability that can’t really be switched off. This combination of nuclear, wind and solar means that on several occasions this year the contribution from gas and other fossil fuels has fallen to about 20% of the national demand.

The sunshine has been a boon for solar power generation.
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Imagine if subsidy-free solar is a real possibility and solar installations were to double in number over the next few years to create a 25GW peak capacity. If these new systems were rooftop then they would be embedded deep within the electricity network at points where there is high electricity demand – although there would still be a problem with balancing supply and demand. We’d also need to know where all the energy was coming from – rooftop solar is hard to track and measure.

Cleve Hill, and other large scale solar facilities, are controversial because of their potential environmental impact – the lowest cost installations will always involve finding huge areas of land that can be exploited cheaply and there will always be an environmental cost in construction.

They also create problems for the network operators because they create large and uncontrollable power flows according to the weather. However, from a grid control point of view, a 350MW solar farm with a battery store is the perfect solution – the power flows will be monitored and easy to predict as any additional generation will be stored onsite.

So maybe there is no conflict between solar farms and solar roofs after all. Instead of a future dominated by one or the other approach, maybe we’ll see subsidy free solar farms to start with, and as costs drop further, and there aren’t any sensible solar farm locations left, rooftop deployment will become economically viable again.

The ConversationWhat is certain is that if Cleve Hill can make money without subsidy in 2019 then a low carbon future that includes a large solar contribution looks almost inevitable.

Alastair Buckley, Senior Lecturer in Organic Electronics, University of Sheffield

This article was originally published on The Conversation. Read the original article.

Comments

7 responses to “How a solar farm in southeast England could bring a new dawn for renewables”

  1. MacNordic Avatar
    MacNordic

    Most of the environmental cost should be minimised by the sensible setup of the installation:

    – Use existing landscape vs. planing everything (as often done in the US, but seldom to never in Europe or the UK). Also a cost- cutting measure, as you save on earthworks.
    – Sow in a bee- friendly plant mix across all of the the PV- plant grounds to benefit pollinators – saves on upkeep. Maybe even collaborate with a local bee- keeper to produce “pv honey” as a marketing tool.
    – For keeping the plants low, use flocks of sheep a few times a year. Chance is, that they were grazing on the very site planned beforehand. So no change of land use;-)
    – Follow the geography of the land for the PV direction; respect the old man- made divisions of the land, be they stone walls or hedgerows: eases planning permission process and enables a trace- free removal of the PV systems, should any change of land utilisation should occur in the future.
    – Maybe even plant new hedgerows or a stretch of trees around the plant to minimise visual impact – always a critical point in England.
    – Use underground cabling for areas of outstanding natural beauty or nice views, if no current overhead wires exist.

    Any (negative) environmental impact remaining?

    1. Ian Avatar
      Ian

      No matter how pretty you dress a pig it remains a pig. 1000 acres of countryside in England covered in solar panels is not kind to the environment.

      The same problem exists in Australia where the very thin well watered and biologically diverse coastal strip is covered with all sorts of development including glazed acres of industrial solar pv whilst the much larger dry interior is left empty.

      It’s a very good use of existing roof space and asphalted parking lots to deploy solar pv but greenfields and agricultural land not so much.

      1. MacNordic Avatar
        MacNordic

        From an environmental perspective, there might actually be a bonus on a usage change to a PV plant with associated bee- friendly meadows sown in underneath and around the panel structures, as maps shows at least part of the area to be farmed (plowed) fields directly next to The Swale. With associated runofs of fertiliser, frequent disturbance of the soil and wildlife and all other issues…

        Add in the displacement of FF enabled by the plant, and I can see the PV plant achieving a more positive overall environmental impact than the current setup. There are ongoing consultations with the relevant nature protection interests, which might lead to even less local impact.

        [view of the site as can be seen here: https://www.google.com/maps/search/cleve+hill+solar+farm/@51.3439949,0.9277529,3639m/data=!3m1!1e3?hl=en%5D
        More details on the plant: https://www.clevehillsolar.com/

        1. Coley Avatar
          Coley

          If, as you suggest, the land underneath is managed for the benefit of wildlife then great, but, also, as often happens, it is just mowed and controlled for the ease of site maintenance, then, not so “great”

      2. MacNordic Avatar
        MacNordic

        As to the land use vs. rooftop:

        There were 626MW of solar PV capacity installed during 2017 (data source: statista), of which 62MW were elegible for a FiT, 564MW for a renewable obligation.
        Rooftop installation is simply more costly (today) and takes far longer to install the same capacity than in a ground mount. If the speed of RE uptake can be (significantly) accelerated and there are so many tons of CO² left in the ground, I prefer to at least listen to the arguments for the ground mount very thouroughly….

  2. phillyc Avatar
    phillyc

    “What is certain is that if Cleve Hill can make money without subsidy in 2019 then a low carbon future that includes a large solar contribution looks almost inevitable.”
    This is what I like. We need ever more renewables. Subsidy free is even better as it takes away the FF proponents arguments (despite the FF getting massive subsidies in various ways).

  3. itdoesntaddup Avatar
    itdoesntaddup

    The battery is mooted at 350MW/350MWh i.e. 1 hour duration at capacity. It is also sited at the grid connection point for the London Array offshore wind farm in the Thames estuary, which has a nominal capacity of 630MW and supposedly about 45% utilisation factor (though not at the moment, with the hot still weather resulting in no output). The solar project is not popular with the local greens:

    https://www.kentlive.news/news/kent-news/everything-know-plans-huge-solar-1423044

    Musk was rumoured to be interested in the battery, but that has since been denied. He has quite a bit on his plate at the moment.

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