Stephen Cadogan: The era of solar farms has truly arrived

Significantly, what the industry calls utility-scale solar has passed out rooftop installations. In other words, the solar farm has arrived, and there is increasing competition for hectares, between farms for food and farms for solar (which are much more profitable).

Capital investment in EU solar had increased to €60bn in 2023. In 2024, 11% of the EU's electricity came from solar, overtaking coal, according to industry estimates.

Every member state is getting in the act. Ireland has a government target to go from 1.4GW of solar energy generation to 8GW by 2030 as part of the target to have 80% of electricity demand supplied by renewables.

The EU's Joint Research Centre scientific agency says most of the EU's huge untapped potential for solar energy is in rural areas, with their large open spaces and strong solar radiation. However, in Italy, the government has banned new ground-mounted solar farms in agricultural areas. Agrivoltaic (agriculture under the solar panels) is the only option in Italy for solar plants on farmland.

In the several EU member states where agrivoltaics are promoted, farmers can have hectares of panels, but keep their EU farm payments at the same time. This departs from the EU norm that land under solar panels is considered non-agricultural, and not qualifying for BISS entitlement payments.

Solar power in Ireland

Here in Ireland, Taoiseach Micheál Martin has reflected on the need to find a balance between effective use of solar power, and the necessity of food production, and aesthetics, in terms of how the country looks. 

Speaking last October in the Dáil, before he became Taoiseach, he said the country would not appreciate the 40 shades of green being replaced with 40 shades of grey.

But his government has of yet no new planning guidelines specifically for solar farm development. Proposals for such developments are subject to the Planning and Development Act 2000, as amended, to be dealt with by local authorities or An Bord Pleanála. 

In 2024, there were 18 An Bord Pleanála decisions made on appeals in respect of solar farms, and 17 of these were to grant planning permission. Meanwhile, work continues on the new planning guidelines.

Agriculture Minister Martin Heydon has said the new guidelines will provide certainty in the development of solar energy in agriculture. His department will have some input, due to the potential impact on agricultural land.

He said renewable energy can offer diversification opportunities for farmers, but food production must not be negatively impacted by solar farms.

Planning guidelines

What factors are likely to be taken into account in preparing the new guidelines?

In Ireland, farmers have embraced solar energy, but generally prefer it to come from their shed roofs, or from small ground-mounted installations. Tax write-offs and grant aid make these solar installations more attractive than ever, to keep farm electricity bills down. 

But a solar farm which might need 200 hectares locally is a different proposition. It further reduces the availability of land for agricultural expansion. It's a sensitive topic in counties such as Kildare, where and more hectares are being covered with solar panels.

It will be a difficult task for the government to come up with new planning guidelines specifically for solar farms that farmers can be happy with. Nor will it be easy to find local communities that welcome hectares of solar panels with their power substations, grid connections, and battery storage.

However, the government hopes such misgivings might be eased by renewable energy community projects, in local ownership and control, with farmers involved as members or by leasing out land. That is on offer in the new Small-Scale Renewable Electricity Support Scheme.

For a solar project covering 20-30 acres and producing 5,694 MWh annually, the income would be about €683,280, at a €0.12/kWh tariff. With total costs estimated at €5.4 million, the payback period is roughly eight years.

Ideally, solar farms would go only on abandoned or unproductive land (of which there isn't much in Ireland). But this hasn't stopped some landowners renting flat fertile areas, easy to work, to be covered with panels by energy companies.

Solar panels v agriculture

Will agrivoltaics reconcile clashes between energy production and agriculture? But combining agriculture with panels is a relatively unexplored idea, and France, under pressure from farmers, has imposed limits on agrivoltaics, stipulating that agricultural yields do not drop by more than 10%, when combined with panels.

Could the EU force member states with the highest emissions to produce extra renewable energy? Could it be a way for Ireland, with emissions per capita more than a fifth higher than the EU average, to dodge EU climate fines?

Environmentalists might be happy with that, and would probably love to see solar farms on pastures, a land use they do not look on kindly (and which they say is a better location for solar farms than "natural" forests, wetlands, and grasslands).

In the new "A Vision for Agriculture and Food" document, Brussels has for the first time acknowledged the role of solar in agriculture, to reduce greenhouse gas emissions and improve energy security, while providing additional income opportunities for farmers. Not surprisingly, the solar industry has said this is "a landmark moment".

It could be momentous for the Iberian Peninsula, the lowlands of Romania, and some parts of Central-Eastern Europe and the Mediterranean. These areas are thought to have the greatest potential for solar, and could become major energy exporters.

They are more likely to have space for solar than the productive agricultural areas further north in Europe, where the conflict of interest between the production of food and the production of energy is greater (although solar cells work better with some humidity, than in arid regions).

Solar is certainly good for Europe (new wind and solar capacity added over the last five years are together estimated to have saved the EU €59bn in energy bills). But ground-based solar can reduce the organic matter of the soil, alter its temperature and humidity, and compromise biodiversity, with consequences for agricultural productivity.