Solar battery storage is getting increased attention at the moment, as energy – because of its rapidly increasing cost and its sourcing challenges – is hitting the headlines for all the wrong reasons. Businesses and householders are looking for ways to reduce their reliance on energy companies, reduce their grid-bought electricity therefore reducing their bills, and get the most out of their solar photovoltaic arrays – after all, it’s unlikely energy use in domestic or business settings will match with the sunniest days that offer maximum generation potential, and while PV panels generate electricity during the day, homes generally use more power at night time. This is where solar batteries come in.

Solar battery storage now becoming popular

While solar photovoltaic systems have become a relatively common sight on roofs and in fields over the past two decades, on-site solar energy storage – in the form of a batteries – has only really become commercially viable in relatively recent times. It’s only now, with the rising cost of electricity, that the payback periods for such solar battery systems have come within reasonable timescales (given that solar battery life is finite). Whereas before the drivers behind solar battery installation were requirements such as off-grid living, or having an uninterrupted supply in the event of a power cut, financial considerations are now looming larger, and the figures are starting to stack up.

Solar batteries make increasing financial sense

The Feed-In Tariff scheme for solar PV was set up to pay households and businesses for the electricity that their photovoltaic systems generated, but was not used on site – typically, it’s said that systems export around 60-70% of the electricity generated back to the Grid. Given the export tariffs (plus there has historically been no export metering for small systems, payments were based on a ‘deemed’ tariff), and the cost of electricity, it has always made sense to use as much of the PV energy generated as possible on site. With energy costs increasing massively (a 36% rise between 2020 and 2021, with more big increases in 2022), it is now even more financially beneficial to use more of the energy generated by solar PV systems, to the point where solar batteries make economic sense.

Considerations when planning solar battery installation

While solar batteries are gaining traction in the UK, as their costs begin to stack up more viably, it’s still important to consider a variety of factors to ensure the investment is a sound one from a practical and financial perspective:

  • Although they are becoming more financially viable, solar battery systems are still expensive, partly due to supply issues and increased demand. This means it’s important that they are carefully sized and priced if cost saving is the primary goal.
  • Even if installing a solar battery on a new PV system, the array itself should not be significantly oversized, as this would likely result in large amounts of energy being unable to be used or stored in the summer months. It’s important to look at energy usage during the key period of March-October, and consider how the increased generation will be used.
  • The actual daily energy usage of the property needs to be measured before the solar battery size is specified, to make sure the correct capacity is chosen.
  • The use of off-peak or smart tariffs should be considered, to see whether charging the battery from the Grid at cheaper rates could reduce overall costs when solar power alone is not sufficient to match need. Battery losses also need to be taken into account here.
  • Remember that batteries have a finite lifespan, and manufacturers’ warranties should be reviewed carefully before a final selection is made.
  • Before design and specification, consider whether the battery will be required to provide back-up power in the event of a power cut. This isn’t provided as standard, and may require further alterations to the property during installation.

To find out more about how we can help you with making decisions about solar photovoltaics and solar battery storage systems, call us on 01206 266755 or email