Solar Basics

There are three kinds of solar energy:
1. Passive solar energy
This is solar heat that warms your home or workplace. To capture passive solar heat, the building must be designed and built with large south facing windows to collect the sunshine and heat absorbent surfaces to collect the warmth of the sun. Good passive solar design also includes overhangs that shade windows from summer heat when the sun is high in the sky.

2. Solar thermal energy
This is solar heat energy that is captured by collectors, usually to heat hot water. Flat plate collectors are tempered glass covered boxes that absorb heat into copper pipes that transfer the heat to your hot water. Evacuated tube collectors are glass tubes that concentrate the sun’s heat and transfer this energy to your hot water. Solar water heating can be used for domestic hot water or for home heating using low temperature applications such as radiant floor heating.

3. Photovoltaics, or “PV”
This is solar electricity that is generated when photovoltaic solar panels collect photons from sunshine and produce voltage. This solar electricity can be stored in batteries or can be connected to utility power lines and produce a credit toward your electric bill.

We Install Solar Water Heating
We install indirect solar water heating systems that are freeze-protected. The solar energy heats a non-toxic antifreeze fluid that transfers the solar energy to your hot water through a heat exchanger. The solar heated water is usually stored in an 80-gallon solar storage tank. This serves as a preheater for an electric or fuel-fired water heater. When solar energy is abundant, the back-up water heater is seldom needed. The best site for solar water collectors is a south sloping pitched roof that has minimal shading from 9 a.m. to 5 p.m. A two-collector system is typical for domestic hot water. Home heating would require a larger bank of collectors, depending on the heat requirements of your building.

There is a $2,000 residential tax credit for solar water heating systems purchased and installed before 2009. Call us for more details!

We Install Solar Pool Heating
Solar pool heating can extend your swimming pool season by 2 – 3 months. Solar collectors for swimming pools are usually high-grade black plastic ribbed mats installed on a south sloping roof. These pool collectors are connected to your swimming pool pump and the pool water is pumped directly through them when the mats get hot. The water picks up the solar energy from the mats and returns to the pool, nicely heated. Most solar pools will heat to about 78º from May to October in Pennsylvania.

To heat an indoor swimming pool all year round requires solar hot water collectors. See Solar Water Heating.

We Install Photovoltaics
PV systems consist of photovoltaic panels wired together and mounted to a south sloping roof with no shading. The PV panels produce DC current which is usually wired to an invertor. The invertor changes the DC to AC current and supplies it to your electric panel box. PV systems can be any size if they are connected to the utility grid. The larger they are, the bigger the credit will be to your electric bill. To power your entire building off the grid requires careful sizing of the PV system to your electric load. A stand-alone PV system requires a bank of deep-cycle batteries for storage.

Small stand-alone PV systems can power specific applications, such as outdoor lighting or water pumping. Small PV systems can also provide emergency backup for critical systems such as furnace ignition and emergency lighting.

In Pennsylvania, a 1 KW photovoltaic system produces about 4 – 5 KW hours per day. Many homes use about 20 – 30 KW hours per day of appliance use, not including electric heat or air conditioning. Obviously, a large PV system would be needed to power an entire home, unless steps were taken to drastically reduce electric use. Most customers purchase smaller systems that are grid-tied and also take steps to conserve electricity.

An interconnection agreement must be filed with the electric company.

There is a $2,000 residential tax credit for photovoltaic systems purchased and installed before 2009. Call us for more details!


WIND ENERGY GENERATORS
We Install Small Wind Generators

Wind generators consist of a turbine engine driven by the spinning action of aerodynamic blades. The generator is mounted on a tower that is 35’ – 120’ high. Larger turbines require a higher minimum height. The higher the tower the better the wind will perform. The DC current produced usually runs to an inverter that changes the DC to AC power and connects to the electric panel box for the building. If grid-tied, an interconnection agreement must be filed with the electric company.

Or, a small wind generator can power a single DC application such as water pumping with DC battery storage.

Pennsylvania has enough wind in many locations to produce wind energy. It can be difficult and expensive to measure the wind resource with a scientific wind study. However, you can study wind maps in your location to help determine if you have a possible wind site.

The wind generators Solair Energy installs are suitable for homes, farms and businesses. They range from 400 watts to 10 KW and can produce from 500 watt hours per day to 50 KW hours per day depending on the wind resource and the tower height.

Indicators of a good wind site are:
• Wind map shows a wind power of 2 or more and a wind speed of 12 mph or greater.
• Large open area that is elevated
• View to northwest
• Trees that are bent windward from steady wind
• Enough distance from trees or high buildings that would disturb wind currents