Self-storage solar economics — the realistic picture
Single-storey suburban self-storage (10,000 sqm roof): 200 kW PV optimal (larger array exceeds roof self-consumption capacity). Annual generation: 190,000 kWh at 950 kWh/kWp/yr. Self-consumption at 65%: 123,500 kWh saved at 24p/kWh = £29,640/year. Export: 66,500 kWh at 10p/kWh = £6,650/year. Total: £36,290/year. At £1,200/kW installed (200 kW = £240,000): payback 6.6 years. After-tax AIA: 5.1 years. Multi-storey urban self-storage (5,000 sqm roof): 150 kW PV, higher self-consumption (74% — HVAC-intensive climate control). Total annual value: £28,500. Payback 6.3 years. Adding 4 × 22 kW customer EV charge points: additional 30-40 kW solar absorption, self-consumption to 82%, annual value £32,000, payback 5.6 years.
EV customer charging — the key economic lever
Self-storage customers visiting units during the day (10:00-17:00) drive vehicles to the facility. EV customer charge points (typically 7-22 kW AC) absorb solar during the visit window — significantly improving self-consumption. For a self-storage facility with 30+ daily customer visits: 4-8 charge points (7 kW AC) absorb 28-56 kW additional solar during peak generation. Revenue model: either free charging (customer attraction and retention benefit) or paid charging (£0.30-£0.40/kWh — generates additional revenue stream while maintaining solar preference). OZEV Workplace Charging Scheme: £350/socket grant available for charge points used by customers and employees.
Climate-controlled unit expansion and solar
The UK self-storage market is growing rapidly in climate-controlled storage (temperature and humidity regulated). Major operators (Safestore, Big Yellow, Lok'nStore) are retrofitting existing facilities and building new climate-controlled units. Climate control adds significant HVAC load — typically 30-60 kW per 1,000 sqm of climate-controlled space. This load directly improves solar self-consumption: a 10,000 sqm facility adding 2,000 sqm of climate-controlled units adds approximately 60-120 kW of HVAC load, improving self-consumption from 65% to 78-82% — worth an additional £6,000-£10,000/year in savings.
Self-storage portfolio economics — brand level
Major UK self-storage operators (Safestore: 195 sites, Big Yellow: 110 sites, Lok'nStore: 50 sites, Shurgard: 140 sites) manage significant property portfolios. Multi-site portfolio solar delivers: (1) standardised system designs (reduced per-site design cost); (2) consolidated monitoring platform (one ESG report per brand per month); (3) single corporate PPA or asset finance facility (one credit approval); (4) portfolio-level Safestore/Big Yellow/Lok'nStore net zero reporting (solar generation data feeds directly into brand sustainability report). We have experience with self-storage portfolio rollouts.
Common questions
What payback should I expect for self-storage solar?
6-8 years standard (without EV charging). 5.5-6.5 years with EV customer charge points. 5-6 years with significant climate-controlled HVAC load. After-tax AIA: subtract 1-1.5 years. 25-year IRR: 12-16%. Self-storage is lower consumption than distribution, so economics are modest by warehouse standards — but still a positive NPV investment.
Is self-storage solar worth it compared to distribution solar?
Distribution solar: 4.5-6 year payback, 18-25% IRR. Self-storage solar: 6-8 year payback, 12-16% IRR. Both are positive NPV over 25 years. Self-storage makes sense particularly where: (a) EV charging is added; (b) climate-controlled HVAC is growing; (c) brand ESG commitments require Scope 2 reduction (Safestore, Big Yellow net zero programmes); (d) planning for on-site generation is long-term (self-storage buildings have 50+ year lifespans).