Cheap Energy - How Solar Grid-Tie Work?

What is it and how does it work?

Grid-tie systems generate electricity, sending this energy back to your utility company’s company grid. In effect, this means, the utility company paying you to produce energy for them, since the energy you produce counts against the energy your home or business uses.

Your solar panels will produce DC (Direct Current) electricity. This electricity will be run through an inverter to produce AC (Alternating Current) electricity. This energy is then run into your AC power panel, which feeds energy back to your utility companies power grid. If your solar power array produced enough electricity, your utility meter would begin to run backward!

What are the main components of an Grid-Tie system?

1. Solar panels - You’ll need solar panels to collect the emery and convert this to DC power. The number and type of solar panels will determine how much emery you can produce, as will your geographic location.
2. Combiner box - This box gathers all of the Solar panel connections.
3. Inverter - Your array’s breaker safely shuts down your solar system at a moment’s notice, allowing for safe maintenance, repair, and inspection.
4. Grid disconnect - A grid disconnect allows you to stop the flow of electricity between your solar power system and your electrical system. This provides for the safe maintenance of electrical and utility systems.

How to size your Solar Grid-Tie system?

1. Gather up your last 12 months electrical energy bills.
2. Total the kWh from all 12 electric bills and divide it by 365 days. (kWh equals 1000
watts). For example, you paid 438,000 watts in total for the whole year. 438,000 / 365 = 1,200 watts per day.
3. Look on a Solar isolation map and find the average Peak Sun hours for your area. (http://en.wikipedia.org/wiki/Insolation). For example, West USA is 40 watts per square meter per day.
4. Divide lines two and three. For example, 1200 / 40 = 30 watts.
5. To allow for heat losses in the solar modules, voltage loss in long wire runs, power loss
in the inverter (inverters use energy to operate) add 15%. For example, 30 * 1.15 = 34.5 watts.
6. Get a site shading survey, This will track the sun’s path and give the effect a tree, fence
or house might have. Add this percentage to the above. (normally a dealer only item)

What is Solar tracker?

It is a device for orienting a day lighting reflector, solar photovoltaic panel or concentrating solar reflector or lens toward the sun. The sun’s position in the sky varies both with the seasons (elevation) and time of days as the sun moves across the sky. Solar powered equipment works best when pointed at or near the sun, so a solar tracker can increase the effectiveness of such equipment over very fixed position, at the cost of additional system complexity.

What is Photovaltaics (PV)?

It is technology term of solar cells and energy by converting sun energy (sunlight or sun ultra violet radiation) directly into electricity. Many countries including Australia, Germany, Israel, japan and the United States have supported solar PV installations such as preferential feed-in tariffs.

How much the system cost?

The cost varies, depends on what equipment you need and and the labor cost.

How to get free solar panels?

1. Suggested by DrillingFab (http://www.drillingfab.com/solarpanels), what you need to do is find a traffic sign rental contractors in your area. There are 100s of highway equipment rental contractors nation wide. Ask for the shop maintenance manager or head mechanic and ask him for free damaged panels.

2. Find a company that install the system for free i.e. no installation fee, no upfront investment, etc. All you need to do is sign the long term contract with them. The company like Citizenre (http://renu.citizenre.com/index.php) supports this schema.

3. Find political financial incentives you your town. The political purpose of incentive policies for PV is to facilitate an initial small-scale deployment to begin to grow the industry, even where the cost of PV is significantly above the grid parity, to allow the industry to achieve the economies of scale necessary to reach grid parity. The policies are implemented to promote national energy independence, high tech job creation and reduction of CO2 emissions.

Three incentive mechanisms are used (often in combination):

Investment subsidies: the authorities refund part of the cost of installation of the system
Feed-in Tariffs (FIT)/Net metering: the electricity utility buys PV electricity from the producer under a multiyear contract at a guaranteed rate.
Renewable Energy Certificates (RECs)

References