Powering Change
Installing since 2010 · 0118 951 4490 · info@spiritenergy.co.uk
Generate over 70% of your electricity on site, and dramatically reduce what you pay for the rest.
A well-designed solar and battery storage system can cover the majority of a typical household's annual electricity demand, reducing reliance on the grid and protecting against future price rises. This page explains the key benefits and how they work together.
Smart meters have enabled a new generation of time-of-use electricity tariffs, where the price you pay for electricity varies depending on the time of day. These tariffs reward households that can shift their consumption, charging a battery overnight at a low rate and using that stored electricity during the more expensive daytime and evening peak.
The most popular tariffs for battery owners are Octopus Go and Octopus Agile. Octopus Go offers a fixed cheap overnight rate, currently around 9.5p per kWh during off-peak hours, while Agile offers fully dynamic half-hourly pricing that tracks wholesale electricity costs, with rates sometimes falling to near-zero or even going negative during periods of high renewable generation.
For a household on a standard flat tariff of 22.36p per kWh, the opportunity to buy at a significantly lower overnight rate and use that electricity during the peak period represents a meaningful saving, even before solar generation is factored in.
Looking ahead, time-of-use export tariffs are also developing, with the potential to earn comparatively high rates for households that can export electricity back to the grid during the winter evening peak (typically 4–7pm). Households with battery storage will be well placed to take advantage of these as they become more widely available.
A well-designed residential solar and storage system should provide over 70% of your annual electricity requirement, with grid top-up needed mainly during the darker months of November to March.
Without a battery, most households use around 50% of the solar electricity they generate, the rest is exported to the grid, currently earning around 15p per kWh under the Smart Export Guarantee. With a battery, that surplus is stored and used in the evening instead, displacing grid electricity that costs 22.36p per kWh. The financial difference between exporting and self-consuming is significant and continues to grow as electricity prices rise.
Every unit of solar electricity you use on site is worth 22.36p to you — the cost of the grid electricity it displaces. Every unit you export earns only 15p. The case for maximising on-site consumption is therefore straightforward, and a battery is the most effective way to do it.
The likely annual saving from a residential solar and storage system, combining solar self-consumption, time-of-use tariff optimisation, and reduced grid import, is analysed in detail on our storage economics page.
The UK's electricity grid is undergoing rapid change. The government's Clean Power 2030 Action Plan has identified battery storage as central to grid stability as renewables make up an increasing share of generation. The government is targeting between 23GW and 27GW of installed grid-scale battery capacity by 2030, up from around 7GW at the end of 2025.
As the grid evolves, periods of instability or localised outages remain a real possibility, particularly during extreme weather events or periods of high demand. A home battery system with backup functionality gives you a meaningful degree of energy independence: if the grid goes down, your battery and solar panels continue to supply your home automatically.
Both the Tesla Powerwall 3 and Sigenergy SigenStor, our current recommended systems, include whole-home backup as standard, switching automatically in the event of a power cut with no manual intervention required.
For more detail on how backup works and how to size it correctly, see our solar panel backup page.
Using electricity at or close to the point of generation minimises transmission losses and reduces demand on the wider grid. Storing surplus solar energy for use during the evening, rather than exporting it and reimporting grid electricity later, reduces the carbon intensity of your household's electricity consumption.
As the grid decarbonises further, the marginal carbon benefit of storage will evolve, but for now, maximising on-site solar self-consumption remains one of the most effective ways for a household to reduce its direct carbon footprint.
For more information, call us on 0118 951 4490 or download our free guide to energy storage:
