Preparing for the heat: How solar farms can stay resilient during UK heatwaves

Darren Lewis | 7/7/2025

As temperatures continue to climb across the UK, solar farms are facing a new operational reality: heatwaves are no longer rare, they’re part of the climate norm. And while sunshine is a welcome friend to solar generation, extreme heat brings its own set of risks.

At Solar Group Utilities, we manage utility-scale ground mount solar sites across the country. Here’s how we help sites stay efficient, compliant, and safe when the heat is on:

1. Monitoring Module Temperatures in Real Time

Solar panels are tested at 25°C — but on a 35°C day, module surfaces can easily exceed 60°C, leading to thermal derating. We use real-time SCADA alerts to monitor temperature spikes and respond early, preventing output drops and long-term stress on equipment.

2. Keeping Inverters Cool

Inverters and transformers are the real workhorses of any solar site — and they’re especially vulnerable to overheating. During a heatwave, we focus on cooling performance: cleaning air filters, checking fans, and making sure air pathways are unobstructed.

3. Staying Ahead of Fire Risk

High temperatures and dry vegetation are a dangerous combination. Our O&M teams carry out pre-summer vegetation clearance and check for any signs of wear, arcing, or degradation in cabling — a simple but critical prevention step.

4. Planning Around Grid Stress

During heatwaves, grid operators may issue flexibility requests or impose curtailments to maintain stability. We liaise directly with DNOs and grid partners to understand where the risks are — and how best to keep sites generating within safe limits.

5. Looking After People, Not Just Panels

Maintenance doesn’t stop in summer — but our approach changes. We adjust shift schedules to avoid the hottest parts of the day, and make sure our teams have access to shade, water, and proper welfare facilities when working on site.

6. Dealing with Dust and Soiling

Dust buildup is a hidden output killer — and when it mixes with light rain, it becomes a sticky, performance-reducing layer. We track soiling losses and, when needed, deploy panel cleaning in the days following extreme heat.

Heatwaves aren’t just about short-term performance dips, they impact system longevity, health and safety, and compliance. At SGU, we treat seasonal stress the same way we treat everything else: proactively, thoroughly, and backed by data.