Solar Electric (aka Photovoltaic or PV)

Wood Pellet BoilersWhat it is:

Most people think about solar energy being harnessed by photovoltaic panels (PVs), which is transformed into electrical power. The electricity is then used to power lights and appliances, or if not needed, is fed to the electricity grid.

A typical American home uses from about 4,000 to well over 10,000 Kilowatt hours of power per year1. In the Northeast US, a fixed panel at an optimized angle receives on average through the year roughly 4-5 kWh/m2 per day (about 1600 kWh/m2/year) of solar radiation. Considering that today's PV panels convert on average about one-tenth2 of available solar radiation into electricity, one would need anywhere from about 25 m2 to over 60 m2 of PV panels to get to an annualized electricity-neutral position3. If one were to attempt to heat with PV generated electricity, or even just to run a heat pump and circulators, then naturally, the PV array would have to be sized much larger to get to an electricity-neutral position. PV systems can, of course, be sized to provide a portion of the electricity demand.

Solar electric systems are made up of PV panels mounted on south-facing roofs. The panels are hooked up to the electrical box and include a DC/AC converter and a device to prevent the flow of electricity toward the panel from the grid when the sun isn't shining.

There are many manufacturers of PV panels, here in the US, in Germany, China, Japan, Korea, and other places. World demand for PV panels is high, and the manufacturing process is energy-intensive and expensive, so prices are high. Fortunately, there are many generous incentives offered by local, state and the federal government, which brings the cost down and brings payback periods down to a level that’s comfortable for many people.

Advantages:

  • Non polluting.
  • Free electricity once the panels are installed.

Disadvantages:

  • PV panels are expensive, even with incentives factored in.
  • They make the most sense in areas of the country where there is lots of sun.
  • The efficiency of PV panels drops over time.
  • Production of panel components are very energy intensive.

Interested in getting more information on solar electric heating systems? Simply fill out our short online request form and we can help with design an EcoHeat solution that's right for you.

 

  1. The US DOE's Energy Information Administration has published a figure of of 10,656 kWh/year per household, on average, for 2001.
  2. Estimate from US Dep't of Energy's Energy Information Administration
  3. A typical roof for a 2-story 2,000 sq. ft home might have as much as about 600 ft2 of south-facing area. That converts to 55.7 sq. meters of available roof area for PV panels.

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