Alternative Energy Company



		Houlihan's Restaurant LEED certification enhanced at new restaurant location. Photovoltaic power generation by The Alternative Energy Company. The Alternative Energy Co. at the American Solar Energy Society Solar tour.

There are several options for home power generation.

Grid tied
Grid tied with battery back-up
Off-grid

Grid tied = Uses your power company as the battery. Your solar array generates D.C. electricity. Your Inverter converts D.C. electricity into useable A.C. power. When the sun is shining your meter will run backwards--feeding power back to the utility. Simple, low maintenance, and the least expensive option. (more)

Grid tied w/ battery backup = Feeds your power company and charges your batteries in case of a power outage. The best of both worlds, you get to use your utility for regular power while not using up your batteries. In case of an outage (ice storm) you will not lose power. Your batteries and inverter will leap instantly to the occasion and you probably not notice that everyone else in the area is without electricity. This option is more expensive with little maintenance but offers complete power security. (more)

Off grid = Energy independence. Your solar array keeps your large bank of batteries charged so you can use your electricity day or night. Long stretches of overcast weather can deplete your batteries. A backup generator is recommended and can be controlled by your inverter. While more expensive because substantially more batteries are needed this offers complete independence from the power company. It is perfect for remote locations where utility power is cost prohibitive or impossible. Regular battery, generator maintenance and generator fuel are required. (more)

Solar-Photovoltaic is renewable clean energy from the sun. What could be more perfect? In Missouri the average solar isolation values (the intensity of sunlight) range from 4.75 to 5.02 kWh/m2/day (kilowatt hours per meter squared per day). That is truly excellent. Germany, which has the highest amount of photovoltaic solar installations in the world, has an average of 3.0 kWh/m2/day. We have equivalent values to Florida, and many parts of California and Texas!

Sunlight striking solar cells in a photovoltaic panel or module cause the flow of electrons from one material to another. By wiring the two materials, a circuit can be created allowing the flow of electrons to produce electric voltage and current. Connecting a number of solar cells in a module provides usable power. Connecting a number of modules in an array increases this usable power greatly.

To optimize the conversion of sunlight to usable power, a photovoltaic solar module needs:

Clear orientation to the southern sky. That is true south, not magnetic south.
On average, a mounted angle should equal your latitude. In Missouri this is approximately 37-39 Degrees from the horizon. For ground mounts it is advantageous to have an adjustable mount with 27 degrees for the summer, and 47 degrees for the winter. This allows for the seasonal effect of the sun being higher or lower in the sky.
Shading during the solar window (10 AM – 3 PM) should be eliminated. Any shading will greatly degrade the power output of a module- even if it is only covering a couple of cells in the module.

Can you get by with less than an optimal installation? Sure. We can calculate exactly how much output degradation your system will have if you are not oriented true south or if some shading exists.

You can further optimize your solar collection by using a dual access tracking system. These systems are ground mounted and they move in line with the movement of the sun- always keeping your solar array in perfect orientation- both horizontally and vertically

Recognizing that effective energy conservation is a key element in achieving sustainability, The Alternative Energy Company seeks to help businesses and homeowners identify and implement cost effective solutions to increase their energy efficiency and their use of renewable energy. (back to top)

Grid tied - the long version

In a grid tied system power is generated and consumed by the owner. Excess power is returned to the local utility through the electrical grid; this power is repurchased by the utility at an avoided cost (wholesale), retail rate, or power credit depending on what the utility company offers. An agreement is put in place to spell out the safety and sell back terms for the owner and utility. This is called a Net Metering Agreement. When the alternative energy system supplies insufficient power, the grid supplies power to the owner and charges him a retail rate or uses any credits that have been earned. (back to top)

A grid tied systems consists of a solar array, an inverter (to convert DC power produced by the modules to stable 120 or 240v AC power usable by the grid and your house). The system’s inverter will shut down in the event of a loss of power. This is a safety feature so that your alternative energy system- be it solar, wind or micro-hydro- will not back feed the grid during an outage. The Net Metering Agreement is usually completed by the system’s installer. A licensed electrician will need to sign off on the Net Metering Agreement to certify the safe and correct wiring of the system. (back to top)

Grid tied with battery back up - the long version

The above grid tied information applies except you don't lose power. In case of an outage, your lights flicker then your inverter and batteries supply your power. Usually this emergency power is for a limited set of uses. Your refrigerator, lights, a few outlets (computer) and security system are normal choices. If frequent power outages occur battery maintenance will be necessary. (back to top)

Off-grid the long version

In an off-grid system, power is generated and consumed by the owner. Excess power is used to charge batteries or in some cases fuel cells. These batteries are used to supply all your power needs. When the power supplied by the alternative energy source is insufficient to supply the demand a generator is switched on automatically and keeps you in constant electricity. In an battery back up and off-grid system, there is an extra component called a controller. These devices insure that the batteries are not overcharged by modulating the rate of charge.

An off-grid system requires regular maintenance of the batteries to keep the system operating optimally and to improve the life of the batteries. (back to top)