As the technology improves, alternative sources of electrical power are becoming more accessible and affordable to everyday consumers.
The time to explore solar power for the home is now, and if you have already delved into the requirements for setting up your own home power supply system, you’ll know that one of the most important components in a home solar kit is the solar battery.
A solar battery is a specialised power cell designed to store energy captured by photovoltaic (PV) panels, and use that stored energy when solar energy cannot be accessed directly (i.e. when it’s dark), or when there is an interruption on the grid (such as during load shedding or maintenance). There are a number of different types of batteries that can be used in solar power systems, depending on output requirements and affordability.
Lead acid batteries contain cells in which electrolytes are suspended – similar to car batteries. These are heavy units that can be stacked in a system to create more power output, but they are not ideal when you do not have a lot of space in which to store them. They have a low depth of discharge (DoD) – meaning you shouldn’t use more than 40% of the available battery power before the battery needs to be recharged again. This, as well as regular maintenance, is important to maintain its lifespan (3-5 years).
Lithium batteries are the most popular form of energy storage for everyday use (such as in watches, cell phones, electric cars, shavers, cordless power tools, etc.). While more expensive than lead acid batteries, lithium batteries are more compact and have a higher DoD: they can be discharged up to 80% before needing to be recharged again. They also have a longer lifespan (approximately 10 years) and require less maintenance than lead acid batteries.
Solar batteries can be used as one individual unit (one battery) or stacked (two or more batteries connected to each other) to act as one big battery with greater capacity. This is what is referred to as a battery bank – the total capacity you have stored in your solar battery/ies.
There are many different types and sizes of solar batteries. In South Africa, lead acid and lithium ion batteries are categorised based on their output. The size of your home and the number of essential appliances you have running daily will determine how much battery capacity you will need.
Use our calculator to determine what your solar battery requirements will be.
A solar battery can cost anywhere from R1,200 to R30,000, depending on its size and capacity. So the real question is: how much will it cost me to keep the lights on and keep my basic electricity consumption needs met?
Depending on the intended use of your solar battery/ies – be it as a backup to keep the lights on during power interruptions or to store electricity generated from your off-grid system for future use – you may only need two or three batteries of 1,5 kW each. Larger premises with higher power demands will obviously need more. Use our convenient calculator here to determine your solar battery requirements.
As consumer demands for alternative power increase, so too will the variety of solutions. Before you invest in an off-grid or backup power system, it’s worth it to consult with experts on the exact requirements for your home.