What is AC power?

As you read the TESUP turbine descriptions you may notice that TESUP’s turbines all produce AC power, but what does that mean?

AC power stands for Alternating Current power, this is opposed to DC power or Direct Current.

Direct Current is the more simple form of power: A constant voltage signal which is the result of electrons in a wire moving one after another. DC power is preferable for use in household electronics as it provides more consistent power to the device. This is why most of your devices will have a DC power converter from the socket at the wall.

AC power is the type of power transmission used by national grids and electricity suppliers. It is the signal generated by electrons moving backwards and forwards in a wire. The signal itself consists of a simple sine wave, where the voltage cycles between positive and negative. Depending on how many phases of sine waves are used, the signal will be a combination of overlapping sine waves. Generally the more different phases a signal has, the more stable the voltage of the signal.

TESUP turbine generators use 3-phase generators (just like the larger scale generators you might see in a large power plant), this is the best way to generate electricity from a rotating motion, the sort of motion you get from a wind turbine. (If you are curious about 3-phase generators TESUP has another post about these!) This means the electricity they generate is 3-phase AC power. Due to the variability in wind conditions and therefore rotation speed of the generator, the AC power generated under real conditions is not a stable set of sine waves but rather sine-like waves which vary in amplitude and frequency.

The 3-phase AC is output from the turbine in 3 separate wires, these wires attach to the charge controller which uses an AC to DC conversion circuit to convert the input AC power to DC power (surprisingly enough). This makes the power suitable for use in charging batteries.

If you also choose to have an inverter in your system, this device converts the power back from DC to AC to match the power type used in national grids. In this state, you can sell energy generated by your turbine to the grid!