Solar Energy Off the Roof
Windows that produce energy? Taking solar panels off the roof and onto the window so everyone can benefit, both in terms of energy produced and natural lighting available is a goal worth working toward. But the common trade off is either a good solar panel or a good window – not both.
Several years ago I spent some great years learning about energy efficiency with the experts at Progressive Insulation & Windows. It was there that I first learned how important energy efficient windows are in completing the thermal envelope of a home. Basically, windows are big openings in the home that allow heat/cold to pass unregulated. There are steps you can take to regulate your window openings.
Did you know that 3M makes a window tinting product that can block sunlight from entering your home? The tinting excludes light and heat and keeps your house cool during the hot summer months. 3M says, “Prestige films were tested and were proven to perform their best at the hottest part of the day when the sun is high. They reject up to 97% of the sun’s infrared light and block 99.9% of the sun’s harmful ultraviolet rays. This helps to keep buildings and homes cool, reduces energy demands and prevents premature refinishing or replacement of carpet, hardwood floors, furniture, art and window coverings due to sun and UV damage.” Of course, tinting does nothing to resolve airflow around a poorly installed window.
The one thing better than window tinting, is a window constructed by design for efficiency ensuring “that air, drafts, dirt, and solar heat gain are not able to use your windows as a path into your home.” Three features that accomplish this are, “low E glass, low conductivity and draft minimizing installation.”
Lance Wheeler of NREL developed glass that turns black after absorbing infrared radiation and returned to clear when removed from heat. A black window may produce good solar energy, but fails to be a good window letting in natural lighting, only demonstrating how difficult it is to have both.
The Solgami window seems to have achieved the best of both worlds. This solar window provides an origami design that not only produces good natural lighting, but a much higher rate of solar energy.
Without totally blocking the light, an origami screen turns your windows into solar panels. Whether for a business on a level lower than the roof, or in an apartment with a reluctant landlord, getting solar panels is not a simple matter. Approval, access, acceptance. These hurdles and more face the energy conscious individual.
Origami Style Blinds
But the origami-style blinds, hanging inside the window, not only generates electricity as the light reflects from multiple surfaces of the implanted solar panels, but allows a natural light to infuse the home or business. Think of the pervasive result of such a product in high-rise buildings throughout a business district. That result is reflected in the goal of Prevalent, an Australia based design firm, as expressed by Ben Berwick, architect and director, “We’re looking at repositioning the city as a place of production, not just a place of consumption.” Prevalent is currently working with a manufacturer in Japan to develop a prototype of the design, called Solgami.
Solar on windows isn’t a new idea, and others have created coatings that can go directly on glass. But the alternatives have been inefficient and darken rooms. “Largely, it’s reducing the quality of your light–why would you put something in your window that’s going to cut your light by 50% just to gain a small amount of electricity?” says Berwick. Solgami’s design, by contrast, can make an apartment brighter as it works. “It’s a bit of a reconnection to the natural setting,” he says. “It’s making your apartment a better place to be.” [FastCompany article]
Bouncing Light Absorption
One of the fascinating aspects of the origami design is its ability to both reposition to maximize interaction with the light at various times of day or solar cycle, and at the same time by its design “allow the light to bounce off the interior of the solar cell-coated panel multiple times, maximizing light absorption” for greater solar cell efficiency. Even the most advanced solar cells have only a 25% efficiency with light received bounced back into the sky. The origami design seeks to increase efficiency both for producing electricity and for distributing light in the living space with a more natural look.