Buying a simple grid-tie solar system

February 12, 2010
If you’ve done any amount of home improvement, then setting up a simple solar system isn’t a challenge. However, it would be good to know a few basics and what parts you need.

Please keep in mind you may have to contact your power company to learn specific code requirements. Where I live, our house wasn’t required to be wired to code; therefore I simply discuss what will work from a technical standpoint.

Jump in Head First

If you want to jump right in and buy a simple low cost package that outlines all the details, here they are:
There are probably more out there, but this remains constant for a simple low cost package: small inverter, few (or one) solar panels. Note in particular the micro inverter, which I will discuss details in another article.

How These Systems Work

These systems are very simple. Think of it as battery charger working in reverse, except the battery is the solar panel. A solar panel is connected to the inverter, which is connected to your breaker box. The inverter is “charging” your house using the solar panel “battery.”

If you’re familiar with inverters used in cars for laptops, they are very similar. However, there is a serious difference between a grid tie inverter, and a basic inverter. A grid tie inverter synchronizes with the frequency (60Hz) and phase of the voltage from the power company. (Think of it as two people flipping a switch at the same time, in the same direction.)

Buying Parts Separately

The essential parts you need for a simple grid tie system is a solar panel and an inverter. You need to consider both items at once for a complete working system.


The inverter is what converts the input VDC (voltage, direct current) from the solar panel to the output VAC (voltage, alternating current) to your home. You need to consider voltage, both input and output. This will determine the voltage of your solar panel and how to connect it in your breaker box.

Good inverters can work with a range of voltage input, like 10-30 volts DC or 40-60 volts DC. Output voltage is usually ~120VAC, ~240VAC, or ~208VAC. You need not worry about the last one, it’s for commercial three phase power systems. Check out my article Is solar power really affordable? for additional information.

Power Source

Solar panels come in lots of flavors and output voltages vary widely. (See my article about choosing solar panels for details.) Here’s a list with some common voltages according to open circuit voltage (Voc) and optimum operating voltage (Vmp):
  • ~18Voc (12Vmp)
  • ~36Voc (28Vmp)
  • ~58Voc (47Vmp)
Alternately, you could use a wind generator. Typical voltages are:
  • 12V
  • 24V
  • 48V


As for mounting hardware, you could use angle iron or angle aluminum usually available at a local hardware store, Lowe’s, or Home Depot. Wood or angle brackets are other options, but I recommend against duct tape.

If you go with a wind generator, tower kits are usually sold separately. You may also have to buy galvanized steel pipe for a guy-wire tower kit. See some examples here.

Putting Everything Together

After you’ve got the parts, all there is left to do is wire it and mount it. With such a simple system, all you have to do is connect the solar panel to the inverter. Afterward, you connect the inverter to your breaker box or just plug it in a standard household outlet. I’ll discuss wiring details in another article.