An electrical load is normally required all the time to work a wind or hydro turbine. The energy generated from these sources needs to be redirected elsewhere when the batteries are fully charged. This is where the diversion load steps in.
"Diversion load" refers to any sufficiently large load that can accept all the power generated by your renewable source. If you're producing excess energy, it would be better to use it more productively. Why waste this extra energy when others are paying for it and you paid for your turbine or PV system?
With a 2kW wind turbine operating at maximum capacity over 5 hours while you are on vacation, your system will output:
2 kW output x 5 hours of operation = 10,000 watt-hour (Wh)
If the house loads are at a minimum (since no one is at home), where can this energy go?
It can help offset the energy that is consumed by other electrical systems in the home such as water and space heating. During the swimming season, you can channel this energy to your swimming pool or hot tub.
PV-based systems will produce much of this excess energy during summer when there is no need for air heating whereas wind systems offer maximum power in late winter or spring periods. Think over your choices carefully; nobody wants the air heater switched on when the temperature is high.
Extra Features
Modern charge controllers are very different to the older, simple little box with four wires and a "charged" light. Advanced computing technology and sophisticated software development have redesigned charge controllers to provide many features to maintain your batteries in great condition, such as:
- battery-charging configuration specifications that are user controlled
- alarm and disconnection when the voltage is low for battery
- automatic reminder and equalization charging function
- control of auxiliary generator
- energy metering for battery and renewable source
- adjustment of battery temperature activated when the electrolyte temperature is above ambient