A battery energy storage system is a rechargeable battery system. It can store electric energy from different sources, including solar PV panels and the electric grid, for people to use later.
Battery storage can be very useful for the average household. It can allow householders to store up energy from the electric grid during off-peak periods (when energy is cheaper) and let them use this store of energy when they need it.
Even better is when you combine a battery storage system with a solar PV (photovoltaic) system. This means it can store clean, green solar energy, generated during the day, and use it in the evening when it is most needed.
It depends on the storage size of each battery, but we’d estimate around 2–4. How much battery storage you need depends partly on how much energy you use.
According to Smarter Business, the average household uses 8.5–10kWh (kilowatt-hours) of electricity per day. According to Octopus Energy, the average electricity usage of a small family (3–4 people) in a 3-bedroom house is 3100kWh per year — an average of 8.5kWh per day.
At Ploughcroft, the Prime Hybrid Energy system offers storage in 5kWh batteries, so you’d probably need 1-2. You can connect several batteries in one system, offering up to 10kWh of energy storage. If your solar panels don’t generate enough, you can also top them up from the grid; likewise, you can sell any surplus energy you don’t need back to the grid.
Batteries commonly contain a chemical composition to store energy — usually lead-acid or lithium-ion. The Prime Hybrid Energy system uses lithium iron phosphate (LiFePO4) batteries.
First of all, a solar PV system involves PV panels that absorb light energy from the sun and convert it into electric energy. A solar battery stores the energy your panels produce — or the excess energy that you’re not using straight away. But remember — using the energy from your solar panels and storing it in a battery both require an inverter.
Let’s get technical for a moment. In a solar PV system, the electricity from the panels goes through a solar inverter to change it from direct current (DC) to alternating current (AC) and make it suitable for you to use around the house. Adding battery storage means you’ll need a battery inverter, which can change back and forth between AC and DC, to allow the battery to charge and discharge.
A hybrid inverter is designed to do both. Instead of having two inverters for your solar panels and your solar battery, a hybrid inverter (such as the Prime Hybrid Inverter) combines the two. This is what allows your solar battery to charge from your panels and to power your home.
Many solar batteries will last up to 15 years, but of course it depends on what kind. A Prime Hybrid Energy battery has an estimated lifetime of 15 years or longer but come with a 10-year guarantee.