HOW A SOLAR (PV) ELECTRIC POWER GENERATION SYSTEM WORKS

“We are like tenant farmers chopping down the fence around our house for fuel when we should be using Natures inexhaustible sources of energy — sun, wind and tide. … I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that.”

   -Thomas Alva Edison

SO, HOW DOES IT WORK?

Solar PV electric power generation systems produce clean, free energy using the ultimate renewable energy resource, our own Sun.

A home with unshaded roof space during at least the middle 6 hours of the day will produce satisfactory amounts of power. A southern exposure is ideal, though eastern and western orientations can work as well.

In a typical residential installation solar panels are mounted on the roof, using an aluminum racking system and flashing with stainless steel bolts. Photovoltaic (PV) cells beneath the tempered glass surface, convert the sun's light into DC electricity.

That power is produced without emitting any harmful green house gasses or other pollutants. Putting a 10kW system on your roof can have the same beneficial environmental effects as planting 5 acres of trees or not driving your car for one million miles.

The panels are typically connected to each other in series, in one or more strings. Similar to the way that batteries in a flashlight are connected. The DC power is brought down off the roof in conduit to one or more inverters mounted on exterior or interior walls. Inverters convert DC electricity into AC power the home can use. The power is routed to the home's main electrical service panel. Whenever the solar PV system is generating power, the home will use that power first instead of drawing from the utiliity.

The utility installs a net meter, that can track current flowing in both directions accurately. When the solar system is producing more power then the home needs, it flows backwards through the meter into the electrical grid creating an automatic credit on the account. When the system is not producing enough power for the home or it is completely off at night, power is drawn from the utility as needed.

At the end of the monthly billing cycle, if the system produced the amount of power that the home needed, the meter will appear to have not moved. If there was any excess power, it is carried forward as a credit in your 'energy bank' to be used the following month. At the end of the year any excess power is purchased by the utility.

Solar electric power systems are much more efficient in cold weather. However they produce more power in the summer, due to the significantly longer days.

On Long Island residential solar installations are not subject to state or local sales tax and are exempted from increasing the property taxes for 15 years.

A LISEIA Member Contractor professional will come to your home and discuss how you can start using the power of the sun today. Save money, protect the environment, increase the value of your home.

Then sit back and watch your meter spin backwards.

Use the sun, it's lots of fun!