Our previous article discussed how to set up a simple rainwater harvesting system to provide your home with some water security. We turn our attention to energy in the next six articles in this series. We can assume that load shedding is here to stay, so let’s find the best ways to deal with it.
Let’s start with inverters and batteries. Basically, batteries store energy and inverters convert the stored energy into a current that appliances can use.
An inverter converts Direct Current (DC) power into standard, Alternating Current (AC). The batteries of alternating power systems store only DC power but household appliances need AC power. There are primarily two types of power inverters:
Although more expensive, pure sine wave inverter’s operational value is significantly more and they are preferred in most instances.
The most common batteries are either Lithium Iron or Lead Acid/Sealed Lead Acid (SLA) batteries.
Lithium Iron batteries can be completely discharged without causing any damage, whereas damage is done to Lead Acid batteries if they are discharged lower than about 30%.
Also, Lithium has ten times the cyclic life of SLA under most conditions. Although more expensive, lithium can last longer than SLA in cyclic applications, like load shedding.
Figure 1 shows the deterioration of the cycle life of Sealed Lead Acid batteries (SLA) compared with Lithium Iron (LiFePO4) over time.
Knowing what size inverter and battery capacity you need will depend on what you want to keep powered up during the outages. In our next article, we guide you through the calculations and approximate costs.
Ready to invest in a power or water saving solution for your home? If you’re an SA Home Loans client, we'll help you finance it through your home loan.
Our full guide to SUSTAINABLE ENERGY & WATER is available for you to download, absolutely free
Cost estimates provided in the Sustainable Living in South Africa series of articles are approximate and valid at the time of publication.