How do you go about choosing the best battery backup system & should it be with or without solar?

Do you want to learn about solar power? Our aim is to teach you, then partner with you, to achieve your electricity goals. Let us walk you through the basics of back up solar power for your home or business.

A solar system typically uses three technologies namely:

  • Solar PV Panels/Modules
  • Inverters
  • Batteries
learn about solar power

The first question you should be asking yourself is, “Do I want a backup system to ensure I have electricity during loadshedding or, am I looking to reduce my annual electricity bill?” If you want to have power during loadshedding, you definitely need batteries.

Loadshedding backup system

Batteries – all you need to know:

Charging your batteries using Eskom power

If you decide you want to charge your batteries using Eskom’s power, you then need to decide what appliances you want to run and for how long. We have offered a free calculator for this. The calculator will show you three important bits of information namely:

  1. The inverter size required
  2. The total amount of power in watts required based on your electricity demand
  3. The size of the battery you need

At this stage, you could ask us to assist you with your estimates.

Charging your batteries with Solar PV panels

If you’re interested in charging your batteries using Solar PV panels you may want to benefit from the financial relief Solar PV panels offer. This can will require a few extra steps, but we are the pros, and are happy to walk through them with you.

The primary goal is still to have the batteries fully charged for loadshedding, but the secondary goal is to run as many power hungry appliances using the sun’s energy. When we program the system, we tell the inverter to allocate enough power towards charging the batteries to ensure they are fully charged for loadshedding. The extra power coming in from the solar panels is used to run appliances such as washing machines, dishwashers, geysers, pool & borehole pumps. If you were to log the electricity demand throughout the day, you would notice a spike in demand at some point. We refer to this as this peak demand. This is important information as it tells us how big the inverter needs to be.

Let’s say for instance your peak demand reaches 4500w (4.5kw), we would then supply you with a 5kw inverter.

To measure your peak demand we will install a logger on your mains electrical board for 7 days. We charge R1500 ex vat for this service to cover transport and time costs; but we credit this amount against any product or system you buy from us after the test. Contact us to set this up.

What is an inverter?

An inverter is called an inverter and not a converter because it does 2 things:

  • First, it converts the AC into DC. AC can not be stored because it keeps on varying wrt time i.e. alternating in nature.
  • Second, it then stores it in the batteries… Since its behaviour is to convert AC to DC for storing purposes and DC to AC for application, the name given is “inverter”.

What is a hybrid or multi-mode inverter?

A hybrid inverter is an inverter that can simultaneously manage inputs from both solar panels and battery banks, charging batteries with either solar panels or the electricity grid (depending on which is more economical or preferred). Their capabilities may go beyond this, however – some devices also handle inputs from wind turbines, generators, and other power sources.

Reminder, when buying a solar system, you want to know:

  • Battery, type & size
  • Inverter, type & size
  • Solar PV panels, type & array size
  • Do you want to feed back into the grid

To know how many solar PV panels you need for your specific demand, we need to know your peak demand and battery size required. Before you start spending money on logging systems, you most probably want to know the rough cost of a solar system, right?

We’ve created another free calculator to give you a rough estimate of a solar system for you to use.

Is a solar system even viable when looking at the current costs of electricity from Eskom?

Reduce your electricity bill

Instead of investing in batteries (which offer loadshedding backup & less reliance on Eskom’s ever-rising tariffs), one could invest in a solar system without batteries.

The benefit of this is the cost is largely reduced (how much?). You could either buy a solar system large enough to run all of your appliances during the day, or you could invest in a smaller solar system that only powers select items such as your geyser, pool’s pump or borehole pump.

A solar system is a financial system that enable you to hedge against the rising cost of electricity. When you partner with First Energy Solar Solutions you will receive a comprehensive proposal that details exactly how much of your electricity bill your solar panels will offset as well as the payback period.

We use these two metrics (offset & payback) to design an affordable solution, tailored to you, that makes financial sense.

Making money from your solar system

Did you know if you oversize your Solar PV panels you can feed that excess power back into Eskom’s grid? The current tariff approved by the National Energy Regulator of South Africa is 78.98c/kWh. The city’s incentive (on top of the tariff) of 25c/kWh remains as it is; making it R1.04/kWh that you can make from your solar power system.

Once your system is installed you would need to have it registered at your local municipality. We can do it for you. Once the system is registered you need to apply to feed into the grid, your municipality will charge you a once-off R11500 for a special meter as well as R235 per month as a service charge.

Below is an interview with Cape Town Mayor Geordin Hill-Lewis, discussing his plans where residents will begin to receive payment from the COCT for energy they sell back to the grid.