Solar power, a growing global energy source

Solar energy has seen increasing interest and uptake over the past decade as an alternative to fossil fuels. Last year, solar accounted for 3.72% of global energy generation, have grown by almost 25% year on year[i]. In the IEAs (International Energy Agency) recent ‘World Energy Outlook’ report for 2022, if current government policies (many of which have been enacted in response to energy security fears following Russia’s invasion of Ukraine) were to continue, then solar energy would see the greatest additions of electricity generated between 2021 and 2030. This is compared with all other energy sources assessed by the IEA, where solar would add 3,008 TWh- enough to meet Saudi Arabia’s energy use in 2021[ii].

Figure One: Change in electricity generation in the Stated Policies Scenario between 2021 and 2030

‍Source: IEA

One of the main challenges with solar adoption is the required space, and whilst uptake of solar panels on residential homes has grown, this still remains somewhat niche, with 2019 estimates of just 3.3% for UK homes with solar[iii]. On a commercial scale, the average solar farm requires approximately 25 acres of land for every 5 megawatts (MW) of installation, while 6 to 8 acres will be needed for a 1MW farm[iv].

Yet the UK is at a solar energy cross-roads

With the space requirements of solar, agricultural land has become a much-talked-about location for installation of larger solar farms, seeing strong arguments both for and against- the latter revolving around fears that loss of farmland will hamper food production and security. Currently, in the UK, ground-mounted solar covers an estimated 230 square kilometres, just under 0.1% of land in the UK[v]. In comparison, CarbonBrief finds that around 70% of the total landmass of the UK is devoted to agriculture, with feed and pastures for beef and lamb taking up the vast majority of this land[vi].

On energy strategy, whilst UK Prime Minister Rishi Sunak has reimposed the ban on fracking overturned by his predecessor Liz Truss, there has not yet been confirmation of his approach to solar energy. During his summer leadership bid, he pledged to protect domestic food production during hustings with the NFU (National Farmers Union), saying: “Ultimately if we want to deliver it then we have to recognise that prime agricultural land needs to be protected to produce food. That means we have to take a different approach on solar farms, it means rewilding cannot come at the expense of food production when it is prime agricultural land, and we need to make sure policy reflects that.”[vii] As such, it may require a more innovative approach if UK solar infrastructure is to grow substantially over the coming decade.

Lessons from France: utilising car parks as a source for solar

Taking an innovative approach to address the space issue associated with solar power, France has recently passed legislation for all large car parks to be covered by solar panels in a form similar to large carports covering rows of vehicles. According to the Guardian, new and existing car parks with space for 80 or more vehicles must be covered by solar panels. Those car parks with between 80 and 400 spaces will have five years to implement the measures, and those with more than 400 spaces, just three years to comply. At least half of the area of the larger sites must be covered by solar panels[viii]. From these changes, the French government believes up to 11 gigawatts of power could be generated, increasing this to 24 gigawatts when compared with today[ix]; for comparison, it was estimated that the UK’s entire solar network had the capacity to generate 13.2 gigawatts in 2019[x]. In addition, French politicians are also examining proposals to build large solar farms on empty land by motorways and railways, as well as on farmland. Dezeen.com notes that the legislation still needs to be reviewed and finalised by France's National Assembly. In its current form, it would exempt only those car parks dedicated to heavy goods vehicles and placed next to "remarkable" heritage or architectural sites[xi]. This early iteration of the bill does not contain details on how the scheme will be funded, nor does it detail the penalties for non-compliance[xii]. Solar car parks are already a feature in some EU countries, and a number of large commercial sites across France facilitate solar canopies, including supermarkets and shopping centres.

Could the British council and privately-run car parks offer opportunity?

In place of a national directive towards diversifying car parks to host solar, local authorities are well placed to consider backing and encouraging such schemes in their area of jurisdiction. For example, in Ireland, Wicklow County Council approved and began construction of a 300kWp solar carport project at its County Buildings site to cover 107 car parking spaces, making it the largest such installation in Ireland. In Wicklow’s case, the council is signed up to the SEAI (Sustainable Energy Authority of Ireland) Partnership programme for public bodies, which helps support these entities in meeting energy efficiency requirements, providing guidance and support as necessary. Commenting at the time of work commencing, Wicklow County Council Chief Executive Officer, Frank Curran, stated: “The installation of the solar panel carports at County Buildings in Wicklow is a great example of using existing sites, such as car parks, to generate renewable energy and assist in achieving Climate Change targets.”[xiii]

Source: Wicklow News

This raises the question of whether local councils and authorities could undertake similar schemes in the UK, where, in 2015, it was estimated there were between 17,000 and 20,000 non-residential car parks (including council and privately owned)[xiv]. There is a case to be made for offering funding or incentives for privately held car parks to retrofit solar canopies and an argument that government could do more to assist and advise British councils in applying innovative solutions, such as solar canopies within car parks. Further hurdles will lie in identifying car parks of an appropriate size. Initially, the French scheme (discussed earlier) sought to identify appropriate car parks by square footage; however, it has been decided to instead base suitability on the number of car parking spaces. UK authorities could take a similar approach, using this metric to ascertain the feasibility for ground-level car parks. Further, car parks with solar generation canopies could become dual-use, charging EVs (electric vehicles) as they sit parked beneath. Additionally, planning laws and restrictions in areas of outstanding natural beauty, or those in heritage areas, are likely to mean solar canopies are incompatible. Yet, there is an abundance of retail park, business park, and supermarket land currently designated for parking vehicles, which, if incentives can be applied correctly, could see solar added.

References

[i] Global Electricity Review 2022 | Ember (ember-climate.org)

[ii] Primary energy consumption by world region (ourworldindata.org)

[iii] UK-housing-Fit-for-the-future-CCC-2019.pdf (theccc.org.uk)

[iv] Everything You Need to Know About Solar Farm Requirements | The Renewable Energy Hub

[v] Factcheck: Is solar power a ‘threat’ to UK farmland? - Carbon Brief

[vi] Q&A: Will England’s National Food Strategy help tackle climate change? - Carbon Brief

[vii] Sunak vows to protect prime farmland from solar and rewilding - Farmers Weekly (fwi.co.uk)

[viii] France to require all large car parks to be covered by solar panels | France | The Guardian

[ix] France: photovoltaic solar energy capacity 2022 | Statista

[x] The UK's Solar Capacity Explained (2021) | GreenMatch

[xi] Solar panels to cover all large car parks in France under new mandate (dezeen.com)

[xii] France to require all large parking lots to be covered by solar panels (electrek.co)

[xiii] Wicklow County Council install new solar car port - WicklowNews

[xiv] Car Parks - data.gov.uk

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