A battery is not an automatic add-on to rooftop solar. On a site that consumes almost everything it generates during the working day, it adds cost without adding much return. On a site with heavy export, sharp demand peaks or expensive red-band consumption, it can be the single best line item in the project.
Solar generated at midday is stored and released into an evening or early-morning load. Best on sites exporting more than roughly 25% of generation.
Trims short, sharp demand spikes so your available capacity charge and half-hourly peaks fall. Strong on sites with compressors, chillers or start-up surges.
Discharging through late-afternoon red-band periods avoids the most expensive distribution charges of the day, every working day.
Keeps critical loads, cold storage or process lines alive through a grid outage. Valued on operational risk, not just on payback.
Indicative UK commercial ranges. Real figures come out of half-hourly data at feasibility stage.
Single-shift daytime operations that already self-consume nearly all their solar output rarely justify storage on economics alone. Same for sites with flat demand profiles and no red-band exposure. We would rather size the array properly and revisit storage when tariffs or your load profile change.
Batteries need floor or compound space, fire separation, ventilation and a DNO conversation about export and import limits. Warranty is typically 10 years or a stated throughput, whichever comes first. Degradation of roughly 2% a year is normal and should be built into any model you are shown.
Figures on this page are indicative planning ranges. Battery business cases are highly site-specific and depend on your half-hourly consumption data, tariff structure and DNO constraints.