On Power Converting Skylights to Energy-Saving Solar Power Units

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Metallic roofs and dome-like skylights reflect solar light.

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uploaded by Tomitheos Linardos

When the Ontario Power Authority announced the province's new feed-in-tariff program on September 1st, 2009, many companies leasing the building space seized the incentive to design, build and own the rooftop solar system at no expense or risk.

The companies can then apply to connect the system to the grid as part of the Ontario Power Authority's feed-in-tariff program, where the payment for large commercial rooftops averages around 62 cents per kilowatt-hour.

Payment to the property owner can be reimbursed as a percentage of annual electricity revenues from the system or a fixed price per square-foot of rooftop being used to host the rooftop solar system.

Solar Power Entrepreneurs Looking for Customers

Greta Energy is one of dozens of emerging ventures that are approaching commercial property owners with a 20-year rooftop access offer and a square footage plan that is difficult to refuse.

The square-footage approach (which on average works out to about 30¢ per ft²) translates to a 250 kilowatt system whereas 10,000 ft² (or 929 m²) of space would result in an annual payment of $3000 to the building owner.

Rooftops need to be assessed and inspected to ensure they are strong enough for the solar energy transition. The building structure should be evaluated for its ability to handle both the weight of the solar panels and the winter snow before any solar conversion contracts are signed.  

Solar Power vs Skylights

n the summer, skylights make it more difficult for air conditioning to cool the space; in the winter heat escapes through them resulting in excessive energy loss.

A 2 x 4 foot clear glass skylight requires 240 extra kilowatt hours of electricity every year, enough to power the average television.

There are exceptions to the rule: metallic roofs and dome-like skylights reflect solar light from the daylight sun without the excessive heat gain of traditional skylights.

Many flat rooftops with skylights - apartments buildings, hospitals, hotels, manufacturing plants, warehouses, office hi-rises and schools - have great potential to convert solar rays into emission-free electricity and solar entrepreneurs are noticing.

If rooftops skylights were converted accordingly, the changeover will reduce carbon emissions every year by an amount equal to that produced by at least 1 million cars.