AC vs DC : 44/100

A few posts back I talked about solar for our cabin. That was the start of a multi part series about how we designed the system and then may have parts of the installation of the system.

In the first part I talked about Grid Tie vs Off Grid and some of the ins and outs of the two types of solar systems. In this part I will talk a little about AC vs DC and why with off grid solar we need to have both.

AC stands for Alternating Current and it is how electricity comes from most wall outlets. AC power can be transmitted across long distances with little power lost. However it cannot be stored.

DC stands for Direct Current and it is how electricity is delivered from a battery. This means that in an off grid system you will at least have to deal with DC. This is fine for many electrical items: lights, charging phones, and anything with a USB cable.

Unfortunately we live in an AC world. For example while laptops run on DC batteries, their chargers only work off of AC outlets. So if you want to charge your laptop you will need AC power. Same goes for all modern appliances: blenders, toasters, instant pots, air fryers, etc.

In order to generate AC power from DC power you use an inverter. An inverter converts DC power into AC power with some power lost in the process. This means that AC power drains the batteries even faster than DC.

Inverters come in a variety of shapes and sizes. The basics that you need to consider are: pure sine wave and amount of watts. You want to get a pure sine wave inverter. Period. Modern electronics will emit a high pitch tone with any other types. The amount of watts is determined by your most powerful appliance in terms of watts. In our case that is our Vitamix blender. It tops out at 1800 watts so we went with a 2000 watt inverter. However I noticed that the 3000 watt inverter was only $75 more and we grabbed that up.

DC comes in a variety of voltages. 12volt is the most common and is what we use. In the next episode of the solar system series we will talk about batteries and why we ended up with what we did.

Workout details

Today was a day of errands. We drove to my mom’s and picked up a washing machine. This is the first washing machine we have owned in 6 years. It had to run off the generator for its first run but it did great. All this is to say that I did not get much exercise in except for lifting a washing machine a few times.


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