I started out with a 12 volt system. I didn’t know anything and it was how many non professionals start. It worked just fine, and in fact RV systems use 12 volt so they can work great with 12 Volt systems on a large scale. However now I am considering going to 24 Volt. Here is why.
The first reason is that the 1KW solar generator I am looking at is a 24 volt system. The reason that 24 volt systems are used is that they can produce many more watts. Why is this important? People like things with high watts even if you don’t understand them. Most people like to use hair driers, air conditioning, electric heaters, microwaves which all have high watts. With a 12 volt system it is more difficult to support those items.
The truth is that most of those items are AC because they were made that way. We are focusing on DC power at the moment, so we will return to these items in another post.
Now you can get 24 volt or even higher systems that have a large amount of watts. There are things that you can do with that. Welding for example. However we are talking about why the average person cares to have a 24 watt system. It boils down to efficiency and cost.
A 24 volt system is more efficient in how it can transfer power. Since it is more efficient and has lower amps, the cables don’t need to be as thick for the same wattage as a 12 volt system. This means that if you were building a power system for an RV or cabin let’s say, a 24 volt system would cost less. Why? It wouldn’t need as thick as cables as a 12 volt system and that directly saves a-lot of money.
Remember before how I shared that I once had an AC heater that overheated and started to melt the power cord I attached it to? In the same way the wires in a 12 volt system can overheat if you are trying to pull more current than they were designed to handle. For systems like mine that only had a 100W panel, the 12 volt is fine. However now that I am getting more power, I will also be getting more solar panels and I don’t want to risk overheating cables with this project.
For wattages under 400Watts, 12 volt systems are fine. For over 400Watts 24 volt systems might be a better choice. I am only at 100Watts but soon I will probably need to buy more panels so I am just preparing for this. For a house system that can cost $10-15K you might even have 48 volts that are being used.
If you are serious about solar, 24 volt systems are the way to go unless you work with a professional and they support and install a 48 volt system. Living in an apartment, this isn’t an option for me, but I am certainly doing everything I can to be energy indepedent.