I was researching wind generators, and I kept reading something about wind generators needing a big battery bank (300-400 Ah) or a charge controller with a dump or power diversion mode to maintain a draw on the generator at all times.
Who am I ?
Hi, I’m Erik Astrand and the man behind this site.
My story? I am about to be 50 and all my life I have been interested in technical things. Not sure if the special interest for the wind, and how to use the wind, started when I as a 5 year old boy and got my first sail dinghy.
Anyway, wind power and to build my own wind generator was a dream for several years. I studied many websites and also bought many courses before I finally built my own windmill. This site is about that journey and you will also find some more general articles about wind power.
Enjoy! and check out the about me page to read more.
Some wind generators will overspeed if they don’t have a load. Even if they don’t, using a charge controller with a dump load lets you use energy that would otherwise be wasted; even if the use doesn’t gain you much, it’s better than not having the energy at all and you didn’t have to pay extra to get it.
The generator doesn’t care whether you draw power or not. The issue with most wind generators is that when it has the most power to generate, there is very little demand from the owner, and so the power must either be stored, sold to the utility company, or lost. So, if you’ve spent all that money, you’d not want to waste all that generated power. You can store it in batteries, but there are substantial losses, and you’d need lots of batteries, which are expensive and have limited lifetime. Therefore, if you can, you want to sell the generate power to the electric utility company. Then, when you need to use electricity, you’ve essentially paid for it through the power that you sold from the generator. In general, you’ll come out slightly ahead, since the power sold is usually during the day, at higher prices, than when you buy, which is usually at night, at lower prices.
It’s not constant power draw. The voltage is that of the battery bank, the current is variable, depending on wind speed. You don’t even need batteries if you use a grid-tied inverter, which I design.