Terms and other things you should know when installing a Solar Energy System.

1. Why is the South side of my roof the best location for roof mounted Solar Panels?
2. Why do I need to know my Latitude and what is it?
3. What is an Inverter, AC & DC current and why is it important?

 

Why is the South side of my roof the best location for roof mounted Solar Panels?

In North America, the sun will always be on the south side of your home. And because Solar Panels work best when they are facing the sun, they too should be on the South side of your home. If they are facing any other direction than towards the sun, they will not be as efficient as they could be. However it is possible to get mounts that will fit on other sides of your roof that will tilt the solar panels south towards the sun.

 

Why do I need to know my Latitude and what is it?

Latitude is a unit of measurement to indicate how far North or South something is on the Earth. This is important to know when installing solar panels because solar panels in Alaska will need to be at a different angle to foce towards the sun then a solar panel in Houston, Texas. By knowing your latitude you can easiily calculate the angle that your solar panels need to face to maximize their use of the suns energy.

The rule of thumb for the correct angle for your solar panels is that you should point your panels south and tilt them to the latitude for your location (North American City Latitude chart). During the Winter time you will add 15 degrees to that latitude. During the Summer time you subtract 15 degrees from that latitude.

For example Dallas, Texas has a latitude of 32.78°. During the Summer you should subtract 15° from that giving you an angle of 17.78°. Winter time will give you an angle for your solar panels of 47.78°.

 

What is an Inverter, AC & DC current and why is it important?

A Power Inverter is needed to change the DC electrical current produced by the Solar Panels to AC electrical current. In AC(Alternating Current) the movement (or flow) of electric charge periodically reverses direction. (See Figure 1)

Figure 1

An Alternating or AC electric charge would for instance move forward, then backward, then forward, then backward, over and over again. In direct current (DC), the movement (or flow) of electric charge is only in one direction and doesn't change. DC current is what you get from a battery and AC current is what you get from a wall outlet. The difference is that DC (Direct Current) electrical current will not operate some of your appliances, while AC (Alternating Current) electrical current will run them correctly.

AC current was the brainchild of Nikola Tesla who discovered that AC current traveled much distances without fading. Thomas Edison insisted that DC current was the way to go and the two became adversaries over the matter. This feud became known as the "War of the Currents".