Inverters and chargers are devices which convert the DC (direct current) electricity generated by wind turbines or photovoltaic modules and stored in batteries into 230V 50Hz AC ( alternating current) power required to run conventional appliances - these are known as stand-alone inverters. Some inverters can also feed power back into the grid and are known as "Grid connect" or synchronous inverters.
Smaller battery based systems with only a few appliances or lights usually use just DC power for simplicity, but most wind/solar systems include an inverter. Modern inverters are both reliable and efficient allowing the use of low energy lighting and the majority, if not all loads to be operated on AC. Often both AC & DC are used where each is most effective and economical- many DC appliances use less power than their AC equivalents ( especially refrigeration, lighting & electronics); - but DC appliances tend to be harder to find & more expensive.
Different types of inverter produce different AC waveforms and have different characteristics so are suitable in different situations. Look for these features:
High Efficiency - to ensure least possible power is used in converting from DC to AC.
Low Standby Losses - efficient when no loads are operating.
High Surge Capacity - to run peak loads and start motors.
Battery Charging Capability - allows inverter to work as a battery charger.
Clean Output Waveform - allows all loads to be run without problem or interference.
Reliability.
Protective Circuits - shuts down the inverter.
Square Wave Inverters.
These produce a square wave output. The quality of output is very poor and we do not recommend this type of inverter for domestic supplies.
Modified Sine Wave Inverters.
This output approximates to a sine wave. These are a good choice for some applications, however some appliances will not operate or will run noticeably less well, eg some computer equipment, light dimmers, some variable speed drills, some TV's, some audio equipment, some digital clocks, some microwave ovens and some central heating ignition systems.
Sinewave Inverters.
These supply a "mains"quality output. They can be used to run sensitive electronics, audio equipment. In fact a complete domestic supply. Powerful, efficient and affordable true sinewave inverters are available to run all types offload.
We use Sinewave Inverters manufactured by Xantrex in USA and Victron Energy.