When we first walked their site, the roof was doing nothing. Ten years on, the same roof has offset the majority of their daytime electricity load and paid for itself several times over.
A single-storey manufacturing facility with roughly 6,000 m² of unshaded roof running broadly east-west. Heavy daytime electrical load driven by process machinery, compressors and HVAC. Grid electricity had climbed to over 28p/kWh with no sign of easing.
Roughly 85% of generation is consumed on-site during production hours. The remainder is exported under a Smart Export Guarantee tariff. Combined with the first-year Corporation Tax relief from Full Expensing, net capex was recovered in under four years.
"We treated the roof as a stranded asset for two decades. In hindsight we should have done this a lot sooner."