Regardless of whether and how they are subsidized, solar photovoltaics (PVs) panels are gaining in popularity around the world, found on increasing number of roofs in sunny and even not so sunny countries. They continue to be installed in significant numbers even in places where they get little credit for any net generation into the network, as in Queensland, Australia. In such cases, customers adjust the size of the installations mostly for self-consumption.
Traditionally, a customer with an existing roof would call a contractor to install them, paying out of pocket, or increasingly leasing them with little or no upfront investment. The result is generally an ugly, incongruous after thought, and an expensive one at that. Many roofs have protruding chimneys and other obstacles resulting in panels distributed in odd and unpleasant patterns. Other roofs are in wrong angles to the sun or shaded by neighbours‘ houses or trees, making them unsuitable for solar PVs.
Today, an increasing number of architects and engineers are designing individual houses and entire subdivisions with solar panels in mind. The same goes for many commercial buildings, especially warehouses, parking garages, office buildings, shopping malls, airports, train stations – anything with large flat roofs. Including solar panels at the time the roof is being built reduces installation costs substantially, by some estimates as much as 20%.
But why build a roof and then add solar panels on the roof? Why not simply make the roof and the solar panels the one and the same? It would make the building far more aesthetically pleasing.
Going a step further, sun does not simply shine on a building‘s roof but also on the sides, especially the side facing the afternoon sun. With the cost of solar panels falling, it does not take much to cover the sunny exteriors of buildings with panels.
Moreover, solar panels now come in all shapes and forms, some resemble windows, allowing light to get through. They can be applied to any surface, flat, curved, or otherwise, offering architects and engineers more flexibility and versatility to virtually integrate them into the exterior design of buildings – which is broadly referred to as building integrated PVs, or BIPVs.
In the last couple of years, a number of new and some refurbished old buildings have appeared with such integrated designs, and by and large, they are stunningly more beautiful than haphazardly adding a few solar panels to an existing roof.
Today‘s BIPVs tend to be more expensive than traditional buildings, but save energy over time. The payback can be expected to drop just as did with expensive light emitting diodes (LEDs) of yesteryears, now virtually commonplace in most new buildings.
Imagine future skyscrapers, warehouses, office buildings and shopping malls generating more energy than they consume, acting as decentralized power plants within major load centers.
Fantasy? Not according to researchers who are advancing the state of the art, moving the technology to the marketplace. This editor recently visited one such laboratory operated by Australia‘s Commonwealth Scientific and Industrial Research Organization (CSIRO) where many of the visuals in this article came from. Under CSIRO‘s Manufacturing Flagship project, researchers aim to not only advance manufacturing processes, but reduce the costs and performance of panels that can literally be rolled off an assembly machine like a plastic wrapper.
Another stunning example of BIPVs can be found at roof of London‘s recently refurbished Kings Cross Train Station (photos below, exterior on left, interior roof on right). Not many passengers are even aware of the solar panels embedded in the station‘s glass roof, but there they are.
The station, built during Queen Victoria‘s reign, is still in use, over a century later.
Which goes to show that buildings generally last a very long time, especially if they are solidly built. Which goes to say that investing a little extra to make them more functional, more energy efficient and more elegant is likely to pay off, sooner or later.
Perry Sioshansi is president of Menlo Energy Economics, a consultancy based in San Francisco, CA and editor/publisher of EEnergy Informer, a monthly newsletter with international circulation. He can be reached at [email protected]