FAQs

The simple answer is that the home battery system stores electricity for use in your home at another time. The demand for energy within the home isn’t at one level all day, especially if there are periods when some or all of the family are out of the house. This means that for some periods of the day, the electricity being generated by their solar panels isn’t being fully utilised. Of course, when the sun goes down or the weather is particularly bad, the solar PV can’t generate electricity, and you need to draw from the grid to power your home. A home battery means that you have solar energy stored to use before you need to take form the grid. 

The life of a solar battery depends on the battery technology. Typically, the solar battery’s useful. lifespan ranges between 5 to 15 years. If you install a solar battery today, there is a good chance you will need to replace it at least once if you want to match the 25 year lifespan of your solar panel system. However, just as the lifespan of your solar panels has increased significantly in the past decade, solar battery technology is starting to see dramatic technological advancements that are improving its life, performance and value. 

Temperature. That’s why the primary factor impacting how long your batteries will last is proper storage in a reasonably cool location. The battery’s temperature profoundly affects the lifespan of a solar battery backup, so it is crucial to ensure the enclosure is maintained correctly, there is proper cooling to reduce heat, and protection from freezing temperatures. If a solar battery’s temperature drops below 30 degrees Fahrenheit, it will require more voltage to reach maximum charge; when the same battery rises above the 90 degrees Fahrenheit threshold, it will overheat and require a reduction in charge. To help with this problem, many leading battery manufacturers, like Tesla, LG and Q Cells, provide temperature moderation as a feature. Choosing a quality battery manufacturer, along with maintenance efforts to ensure proper temperature controls, will significantly extend the life of your batteries.

If your household has very high energy requirements in the evenings, especially during longer winter nights, smaller battery storage systems may not be able to hold enough power for all of your needs at night. For example, if your wanted to run several thirsty appliances at once in the evening, such as kettles, microwaves, washing machines, along with TVs, lights, fridges, etc, your battery would discharge at a much quicker rate than that of a less busy household with lower energy demands. Home battery systems are also limited to the amount of electricity output they can give at any one time. It’s important to choose a battery storage system for your home which is best matched to your household’s needs. 

The size of home battery system that you need will depend on the size and energy requirements of your home. The average household uses between 8-10 kWh of electricity per day. Home storage batteries start at around 2.5-5 kWh in capacity for small systems, up to the larger systems which offer around 13-15 kWh of energy storage.

We would typically size a system by following a two step approach:

Economically, the ideal size for a battery is one that would cover your evening and nighttime usage (with a little to spare, just in case). Your electricity demand will empty the battery by next morning, meaning it has the maximum possible space to capture the next day’s sunshine.

We then sense check this against the size of your solar PV system. Obviously, there’s no point having a large battery if your generation is small – as you’d never be able to fill it.

So in practice, some home battery systems are sized to the demand of the home, but in some cases they are sized to what the solar PV system can produce. Getting this right is complex, which is why our expert engineers are on hand to help you find the right system for your home.

You will need to bear in mind that home storage batteries might well not receive enough energy to charge every day (depending on the weather and how much solar electricity your home generates and uses). Find out more about how this can work around the year here.

With a correctly-sized battery system for your home in the UK, you should ideally have enough energy waiting to meet your evening and overnight needs for the majority of the year, but are likely to need to draw electricity from the grid in the winter months.