Solar Battery Storage — Strategic Tool, Not a Bolt-On

Case study: Aelio battery at a GP practice

One of KMM's most-referenced battery installs is at a GP practice — a daytime-load clinical site where the question was whether the battery added value beyond direct solar self-consumption. The answer turned out to be yes, but for a specific reason: time-of-use tariff arbitrage on the practice's commercial supply, combined with backup support for critical clinical loads during grid outages. The system uses an Aelio commercial battery, and the modelling combined tariff arbitrage savings with clinical resilience benefits.

Commercial battery and arbitrage

Commercial sites with significant time-of-use exposure can use battery storage for tariff arbitrage — buy electricity off-peak, discharge during peak. With UK commercial tariffs increasingly half-hourly settled and peak / off-peak spreads widening, this is a real revenue stream on top of solar self-consumption. KMM models the arbitrage case alongside the solar self-consumption case rather than treating battery as 'solar accessory only'.

Virtual Power Plants and grid trading

Some commercial and domestic batteries can participate in Virtual Power Plant (VPP) schemes — aggregated battery fleets that respond to grid signals (frequency response, balancing services) in exchange for revenue. The schemes are evolving quickly; revenue per kWh varies; eligibility depends on hardware and tariff. KMM advises on which battery ecosystems give you the option to participate later (rather than locking you out), without over-promising current VPP revenue.

Octopus tariff ecosystem and battery integration

Octopus Energy has built a UK tariff ecosystem (Cosy, Intelligent, Agile, Go, Flux) that pairs explicitly with home battery storage. Integration with the right battery brand means automatic battery scheduling against the tariff signal — the battery charges when grid prices are low, discharges when they're high. KMM works with Octopus-integrated battery ecosystems, with Sigenergy being a particularly strong fit for whole-home installs combining solar, battery, EV charging and tariff signals.

Sigenergy whole-home ecosystem

Sigenergy is increasingly the KMM default recommendation for domestic whole-home installs where the client wants integrated solar + battery + EV charging in a single co-ordinated ecosystem rather than three separate boxes from three separate brands. The system handles tariff-aware scheduling, EV charging integration and (where available) grid services participation. We size and configure rather than pushing a single SKU.

Large domestic battery installs

UK domestic battery sizing has expanded materially — installs of 20–40 kWh are now reasonable on larger homes with high evening loads, EV charging needs and time-of-use tariff strategies. KMM scopes these against your specific usage and tariff position rather than over-sizing for the sake of it. A right-sized system pays back; an over-sized system has wasted capex sitting idle.