This is the third and final part of the “Sizing Your Solar Energy Panels” series. Have you done some calculations for your future solar power system yet? If you have been doing those mini exercises, you’ll most likely find a suitable solar panel for your home by now.

The next step requires us to find an appropriate-sized battery bank, inverter and charge controller. Let’s look at each of these:

1. The Inverter

The inverter you choose has to be sized according to the demands of the alternating current (AC) side of the circuit. Therefore you will choose a specification according to the loads in your house (with a little buffer in case you increase your loads over time). Pretty straightforward.

2. The Charge Controller

You’ll at least need a basic charge controller to begin with. Until you get fussy about how advanced you want this component to be, more affordable models will do just fine. You’ll need to get a specification that fits the output current (Amps) of your solar panel arrays. If you intend to scale up your solar power generator, you’ll do better with a larger charge controller with room to accommodate more solar panels than with two smaller-sized ones.

3. The Battery Bank

The size of your battery bank depends on how you want to use your solar panels. You can size your battery banks such that it can get you through thick clouds that pass by, or you can size them so you can get through three solid days of solar eclipse and a power outage at the same time. It really depends on you. But take note that over-sizing isn’t always realistic. You have to take into consideration the space they occupy and the how much they’ll cost you.

If your home is grid-tied, provided there aren’t frequent power outages, the size of your battery bank isn’t critical. Just size it to take care of cloudy days will do. You can still maintain your lifestyle by drawing power from the grid.

When you design your battery bank, you’ll have less power loss (through wires) if the voltage is higher. If you are able to design a 48-volt system, you can conserve more power than when you use a 24-volt or 12-volt system.

Continue Reading:

1. DIY Solar Panels — Charge Controller Basics
2. Sizing Your Solar Energy Panels – Part 1
3. Sizing Your Solar Energy Panels – Part 2