The solar battery plays a critical role in solar self-sufficiency by allowing you to store solar energy for use when the solar panels cannot.
What are solar batteries?
Solar batteries are designed to store solar energy for later use – empowering your renewable system with an additional energy supply by allowing you to store solar energy during the day when there is more sun, then access that power at night when needed most. Solar batteries also allow you to draw on stored solar power in times of high demand, so your PV panels continue producing clean electricity even if the grid goes offline due to extreme weather events or other problems.
So what does a solar battery do?
A solar battery is like a giant rechargeable battery, and it allows you to continue powering your home and appliances with renewable solar energy during the evening and at night. Solar PV panels convert solar energy into usable electricity and, more often than not, they’re producing more electricity than can be used. Without a solar battery, this excess is delivered to the National Grid or stored in smart meters. This means that you’ll miss out on using the energy yourself and will have to rely on your energy supplier once the sun has set.
How many solar batteries will I need?
When designing any solar power system, it is important to ensure you have enough solar power for your needs. It’s always worth thinking about how much solar power you need throughout the day, as it can be difficult to generate solar energy after dark. Taking this into consideration is key to getting solar battery storage right for you and your home.
A solar battery will have enough solar storage capacity to power your home for an evening or at night. This should be more than the solar inverters (the device that converts solar energy into usable electricity) maximum load output, plus ten percent. So you should take this figure and multiply it by 1.1 to get your solar battery size estimate.
What do I need to consider when purchasing a solar battery?
There are several important things that you need hold in mind before buying a solar battery:
- Solar batteries don’t last forever. You should take into account how long you want your solar battery to last and find out about its expected lifespan
- Solar batteries often come with restrictions around the solar self-consumption ratio or solar feed in tariff. Find out if there are any solar restrictions when purchasing your solar battery
- The solar battery’s warranty should provide peace of mind that it will continue to work during its lifetime
- You should also consider how long the solar battery takes to recharge. For example, does it take eight hours to charge using solar energy overnight? Or does it need to be charged with electricity from the grid first? And what about environmental conditions like temperature and humidity levels, do they affect solar charging?
What is a solar inverter?
The solar inverter converts solar energy into usable electricity so you can power your appliances directly. It’s useful for homes where you want solar energy converted from direct current (DC) that is generated by the solar PV panels to an alternating current (AC). This lowers the voltage of the electricity safely to power your home.
What types of Invertors are available?
There are four common types of inverters:
- String Inverters
- Micro Inverters
- Power Inverters
- Hybrid Inverters
The string convertors is probably the most common with PV Panels that direct electricity direct into the national grid. This is because battery storage has only recently gathered pace, being adopted by most experts and installers.
Micro inverters are fitted to each panel and will last a lot longer than the normal string convertors.
Power Inverters rely on smart technology to optimise power from individual panels, this may be because one panel gets a lot of shade at certain points in the day. These tend to be more expensive but generally have a longer warranty on the product.
Hybrid Inverters are what would be installed with your solar battery storage unit. This installation will control the power directly from the panels or battery.
What happens if I don’t want solar storage?
On average, solar batteries range from around £2,000 to £10,000 and there are different types of solar batteries you can choose from too. There are flow batteries that use liquid electrolyte solutions to store energy and flooded lead acid batteries which work the same way as the ones in your car. Solar batteries also vary in size and capacity depending on how much power they generate and store.
The solar battery can be sited remotely from your solar PV installation and the solar panels, or they could be co-located with solar inverters in a centralised solar inverter system. The latter means that there is less equipment to install and therefore less cabling too. This makes it an attractive option for larger solar power systems, especially when you’re considering solar battery storage.