Grid Tie Inverters

When we capture the energy of the sun with solar panels we get DC (or Direct Current) electricity. Since most household appliances are wired to use AC (or Alternating Current) electricity, there needs to be a process built into the energy's path that converts the DC energy into AC energy. This is accomplished by the use of an inverter. It takes the DC energy directly from either the solar panel where it was collected, or from the DC battery where it was stored, and changes it into AC energy that is suitable for most appliances and devices.

What distinguishes grid tie inverters from other inverters? Whereas the regular simple inverter is designed to convert DC to AC for your appliances, a grid-tie inverter accomplishes that same conversion, but then funnels that energy back to the utility company. Consequently, with a grid tie solar inverter you can collect energy from the sun, and then send it to the utility grid that you are tied into (hence the name). There is no need to store this energy because the entire utility grid functions like a huge battery for you.

You're probably already wondering whether or not this could be a DIY project. Is it possible to fabricate a home built grid tie inverter? Although there are anecdotal stories floating across the internet about people trying to build a grid tie inverter themselves, it is very important to understand that the function of a grid tie inverter is extremely complex.

For example, these inverters must be constantly working to synchronize their frequency with the utility's AC frequency, and must keep the two systems in phase with each other. This enables your system to feed excess energy back into the utility's grid. As you can imagine, this is very precise work and all components in your inverter should meet or exceed industry standards.

So let's reconcile ourselves to purchasing our grid tie inverter rather than undertaking the folly of attempting to build our own.

The next logical question to pop into your mind will now be “how about a refurbished grid tie inverter?” Happily, there are many factory refurbished grid tie inverters on the market and they are usually sold complete with a warranty, saving you significant amounts of money.

Speaking of money, how much should you expect a brand-new name-brand grid tie inverter to cost you? For our example let's use a Sharp grid tie inverter, the Sharp SunVista 3500. Featuring active cooling, the unit maintains stable power output despite fluctuations in the weather. A prolific inverter, over 60,000 have been sold. You should expect to spend under $2000 for the unit.