These pretty glass tiles from Sweden offer yet another way to create a net zero home, by harvesting energy from the sun all through those sunny Middle East winters. SolTech Energy tiles are engineered to harvest the heat needed to heat your home by trapping rooftop sunshine and then feeding that heat through the house.
The idea is to turn your entire roof space into a solar heat farm.
The glass roof tiles trap heat under the glass and feed it through the home heating system.The heated liquid is sent through pipes to connect with the home heating system via a heat exchanger.
How it works:
Under the glass is a waterproof and heat absorbing fabric to trap the hot air in a pocket woven of technical nylon fibers and coated with a heat and light-absorbing layer.
It transfers heat to lined spaces between the roof joists carrying the hot air by being blown by a fan. The hot air is fed through a conversion device that transforms it to a heated liquid.
Once it passes through the heat conversion device the heat can be sent through the house. It works whether the home is heated with heated water or with heated air.
The energy potential:
Each square meter can generate between 300 and 500 kWh (in BTU equivalent) of heat per year, say the inventors.
A roof of about 20 sq meters – or 200 sq feet – would make about 8,000 kWh a year that a home would need to stay toasty through cold but sunny winters. You will easily have that much space – 20 feet by 10 feet – on the average home.
Hot weather uses:
In warmer climates it could also be hooked up to an air conditioning unit that uses a heat-absorption chiller. It would also be applicable for use in heating a swimming pool.
For aesthetics sake, you would want to do the entire roof in the same glass tile, and ideally the roof should be angled at about 20 degrees, (depending on your region’s insolation) but anything works, as long as it gathers sunshine. While it will work most effectively on portions of the roof that face south, south-east or south-west, the north-facing portion of the roof could be sealed separately underneath so it will not lose heat for lack of sun.
These glass roof tiles are engineered for super strength and break resistance and have a longer life span than conventional roof tiles in clay or concrete, since the glass is UV resistant and is much more resistant to erosion.
Because the heated glass is warm, shiny and smooth, any snow that accumulates slides off easily, so the roof can keep harvesting the sun’s heat in regions that get snow in winter.
This a great commonsense green building idea. I’m not surprised that he company has won the Nordbygg Gold Medal this year for the best green building innovation in the Swedish construction market.
Images: SolTech Energy