Power Inverters

The energy we receive off the electronic grid that feeds our home is of a type known as Alternating Current or (AC).  In AC current systems the electrons cycle back and forth.  Normally the cycle occurs 60 times per second or what is known as 60 hertz. There are significant advantages for the electrical grid in using AC current.  One of the most significant advantages is that the energy can travel a greater distance without needing to be boosted. However, most small electrical generators such as those used in Solar Energy and Wind Power systems are designed to produced Direct Current (DC).  Consequently there is an inherent mismatch that needs to be resolved.   This is where inverters come in.

Inverters are electrical components that will convert DC current into AC current.  Inverters are an essential component when using solar or hybrid photovoltaic systems because the energy produced by the solar panels needs to connect to the electrical grid and therefore be the same type of current.  Most inverters also boost the voltage from 12-48 volts to the 120 or 240 volts typically used in most home circuits. 

Inverters are extremely reliable components with failure rates of less than 1%.  Also, like most electrical system components they require little or no maintenance.

In grid-connected wind systems in which the turbine generates DC current, the inverters are usually positioned to receive the electricity coming from your turbine convert it to AC current, and then pass the converted AC current to the electrical grid via your electrical panel.  In off-the-grid systems where batteries are used to store electricity inverters are also needed to convert the current coming from the batteries because batteries store electricity in DC form. Early inverters tended to allow fluctuations in voltage but modern inverters use micro circuitry to stabilize the voltage and provide nice steady voltage output.

Before purchasing an inverter you will need to determine the wattage you need to support. If you to draw more watts from the inverter then it can deliver it will go into a shut down mode.  As you might expect the more wattage the more expensive the inverter.  Most households will probably require a 2000 plus watt inverter, though you can go with less if you are not planning to run large high-demand appliances like refrigerators, washing machines or microwave ovens. Mid-size inverters of 600 to 1000 watts can probably handle a small cabin or vacation home including lighting and most conventional entertainment equipment such as TV's and DVD players.

Larger household inverters now come with a number of enhancements that can be extremely useful when using renewable energy systems.  Many will come with LCD displays that can display graphic volt and amp meters.  They can also be used for charging batteries in off-the-grid or hybrid systems.