According to Met Éireann, last month was the warmest May on record with an average temperature of 13.08°C.

For most of our readers, May will be remembered as yet another broken month with limited and tight working windows.

Met Éireann’s stats also show that monthly sunshine totals were below average.

However, despite this, it was a record month for solar PV generation across the island. According to data collated and analysed by Green Collective, May 2024 was the strongest month yet for solar farm generation in Ireland, producing 94.2GWh, or 2.9%, of the month’s all-island electricity demand.

Both figures are an all-time high for solar and this is the second month in a row that Irish solar has set new records.

Solar output exceeded 500MW (a threshold first crossed only in April) on several occasions, peaking at 566MW at one point on Friday 10 May.

Friday 10 May was the first day that total all-island solar generation exceeded 5GWh. This was enough to fulfil 5% of that day’s electricity demand.

Solar continued strong the following day and, with the weekend’s relatively low demand, solar power at one point, on Saturday 11 May, was fulfilling 12.9% of all-island demand, a fraction off the current record of 13% set on Sunday 21 April.

Solar capital Meath

Co Meath continues to be the leader in Irish solar power, with 52% of the month’s solar generation taking place there.

However, Rosspile solar farm, in Co Wexford, had the second-largest generation of all Irish solar farms during the strong solar weekend of 9 to 11 May.

Over 20 planning applications relating to new solar farms have been lodged in Meath since 2021, with just one 306ac solar farm refused permission.

The county has a healthy pipeline of projects in development and continues to be an attractive location for solar farm developers.

A developer typically looks for a block of relatively flat ground, 200 to 300 acres, with access to a strong grid in an area with good sunshine.

Meath ticks all of these boxes and explains why the county has seen a significant surge in solar farm construction over the years.

Renewable energy generation

Electricity from renewable generation and discharging storage met 29% of Ireland’s all-island electricity demand during May 2024. Wind is the backbone of Irish renewable generation, but this generally dips in the summer months. However, even so, winds in May were unusually low.

There were no days with gales, strong gusts or storms reported over the month according to Met Éireann.

The equivalent to 20.5% of the month’s all-island demand was met with wind, the lowest May percentage since 2017, according to Green Collective.

Wind Energy Ireland’s monthly wind report states that Cork took the lead in terms of wind power generation during the month, producing more electricity than any other county (76GWh).

It was closely followed by Kerry (68GWh), Galway (50GWh), Tipperary (45GWh) and Tyrone (39GWh).

Other sources of renewable generation in May were hydro (1%), biomass/waste (3.6%), discharging pumped storage (0.9%) and discharging batteries (<0.1%).

Despite record solar generation, this was renewables’ lowest monthly share of demand so far in 2024.

During the first four months of 2024, renewable generation was equivalent to 45% of electricity demand. Unusually low wind generation contributed heavily to this drop.

Green Collective estimates that for each KWh of electricity generated in May, the Irish grid emitted between 109g and 436g of CO2, with an average of 281gCO2/kWh.

This is the highest monthly grid carbon intensity so far this year, but it is significantly lower than May 2023’s average of 332gCO2/kWh.

The elimination of peat generation, increased solar generation and ongoing reliance on imports, which are not counted on our energy carbon balance, are some of the reasons for this.