Solar Is CONTINUALLY Evolving!
Solar Photovoltaic (PV)
Solar panels aka photovoltaics are "semi-conductor devices that convert sunlight into direct current electricity (DC)." Solar panels are usually installed as a grid type system. One of three scenarios can exist:
- "Off The Grid": Building's solar panels generate enough energy that the building owner doesn't need to buy energy from his/her power company, or the owner's building is "off the grid." It is self-sufficient.
- Buy Energy: Building's solar panels produce only some of their energy needs so the owner must buy power from his/her energy company, which is often at the regular rates. However, the owner would need to buy less energy from the power company than if s/he did not have solar panels.
- "Feed In Tariff": Building's solar panels generate more energy than the building actually uses so the owner can "sell" or "feed into the grid system." The building owner would receive a payment usually at a premium rate from his/her power company.
Types of Mounts
- Roof Ballasted (held down by stones or weights)
- Raise Waves: Where there is a photovoltaic module on one side and a reflector (mirror) on the other side.
- Roof Mounted (screwed or welded to the roof)
- Flat: Photovoltaics are attached to the roof, laying flat or flush with the roof
- Raised: Racks that are attached to the roof with the modules in a "v" shape.
- Axis Tracking Array: Often in the yard where it pivots to follow the sun.
Benefits and Costs of Solar Photovoltaic Panels Include:
- Energy savings and energy cost stabilization: If you're "off the grid," you'll stabilize your energy costs as you will be creating your own energy and won't have to pay future price hikes from your energy company.
- Long-lasting: Typical systems are expected to last 20-30 years
- Reduces Global Warming
- Gain credits for Green Globe and LEED projects
- Lowers Carbon Footpring
- Rebate Programs: Current federal and state rebate programs combined with energy company grants can produce a 5-7 year payoff, with up to 90% off of installation costs.
Solar credits and energy pricing rates are county dependant. Contact us and/or check with your particular energy company in your area on the rebates and cost incentives that exist for installation of a solar photovoltaic system.
Example of Solar Photovoltaic Savings:
- To SOLELY power a three bedroom home through solar energy, the house would need approximately eleven 4 ft x 8 ft solar or photovoltaic panels.
- A 4 ft x 8 ft solar panel will generate about 450 watts or about 51 kWh/month. (3.8 hrs avg peak sun hours in MN/day x 450 watts x 30 days / 1000 watts = 51.3 kWh/month). Xcel Energy representatives state that a typical household uses about 600 kWh per month, so if a house had one 4 ft x 8 ft solar panel, the household would generate 51 kWh through the panel and would need to purchase 549 kWh from Xcel Energy for a total of 600 kWh for the month.
Many Solar-Photovoltaic PV Cell Types Exist.
Some of the main ones are:
- Crystalline Silicon: The highest efficiencies on silicon have been achieved on monocrystalline cells at 22-25%
- Thin-film solar cells: Three main types of thin film solar cells average about 18% efficiencies:
- Cadium telluride solar cell
- Copper-Indium selenide
- Gallium arsenide multijunction
- Multiple-junction solar cells: The record for this type is disputed. Teams led by the University of Delaware, the Fraunhofer Institute for Solar Energy Systems, and NREL all claim the world title at 42.8, 41.1, and 40.8%, respectively."
