Grid-tied renewables still need old-school reliability

• WearCheck turns 50 this year
• South Africa’s wind and solar build-out is accelerating
• A regular condition monitoring programme is the best weapon in the war against component failure.

South Africa’s wind and solar build-out is accelerating, but the novel assets that quietly convert renewable energy into dispatched, grid-compliant power are still likely to fail for familiar, preventable reasons. Step-up transformers, MV switchgear and high-power inverters remain vulnerable to heat, contamination, moisture ingress, insulation ageing and poor electrical connections.

WearCheck, a leading condition monitoring specialist, supports renewable operators with a practical reliability toolkit that includes transformer oil analysis (including dissolved gas analysis - DGA), thermography and broader asset reliability care services. The goal? Identify early warning signs, intervene timeously, and keep availability high without expanding headcount.

Technical manager for WearCheck, Steven Lumley, outlines why these failures bite harder in renewables. ‘Renewable plants operate in ways that can accelerate wear. Output variability means cyclic loading and frequent thermal swing - cloud transients and wind changes create hot–cold cycles that stress connections and insulation systems. Environmental exposure is also a constant - coastal plants contend with salt-laden air and corrosion risk, while inland sites face dust and wide diurnal temperature ranges. Add lean, geographically spread maintenance teams, and the logical outcome is that reliability must be engineered through prevention, not firefighting.

‘Typically, problems progress predictably - a loose termination becomes a hotspot, moisture ingress reduces dielectric strength and erodes insulation margin, a contaminated inverter filter throttles cooling, triggering derates or nuisance trips. Each failure mode is manageable, but only if detected early enough. A regular condition monitoring programme is the best weapon in the war against component failure.’

WearCheck’s transformer division manager, Gert Nel, agrees. ‘For grid supply unit and collection-level transformers, routine oil condition monitoring remains one of the fastest and most cost-effective windows into asset health. Trending breakdown voltage and moisture helps maintain insulation integrity, particularly as temperatures rise and loading increases. Watching acidity and oxidation indicators supports transformer life management by prompting action before sludge impedes cooling. DGA provides early warning of developing electrical and thermal faults - partial discharge, overheating or arcing - often before protection alarms trip.’

WearCheck turns 50 this year – keeping the power on by catching faults before they trip.