Gone are the days when the role of windows in the house was just limited to being a source of fresh air and natural light. U.S. Department of Energy and National Renewable Energy Laboratory (NREL) have recently developed photovoltaic windows that can generate energy from the sunlight apart from functioning as regular windows. With between 5-7 billion square meters of glass surface in the United States alone, electricity generating solar windows promise to open up ‘windows’ to new possibilities.
Why Solar Windows When We Already Have Solar Panels?
Traditional solar panel arrays take up a lot of space and look unsightly, but solar windows are virtually invisible. They are just like ordinary windows in appearance – transparent and see-through. This means they can be used as window panels at the same time as acting like solar cells, providing clean energy solution for modern building design.
How Does It Work?
Solar windows, developed by the U.S. Department of Energy and National Renewable Energy Laboratory (NREL), work on temperature triggered thermochromic technology. When solar energy heats up the windows, molecules of methylamine used in the window are driven out. This causes them to darken. The opposite happens when the sun is not shining. The window cools down, and the molecules of methylamine are reabsorbed into the window, making it appear transparent again. This is what transforms the windows into efficient solar cells and allows for the partial absorption of sunlight.
What Makes It so Desirable for Modern Buildings?
Solar windows only convert invisible wavelengths of light, i.e. infrared and UV light. So, the visible light which allows us to see is not obstructed. It is for this reason that we can see through the cell, making it a desirable material for future buildings.
Moreover, according to EPA data, commercial, residential and industrial buildings account for roughly one-third of the United States’ electricity use. So, it would be great to have solar power producing windows that boost energy efficiency and help capture enough energy to offset our power needs.
Is It Cost-Efficient?
Adding solar cell layers to traditional windows is predicted to be very cost effective in the long run due to the following reasons:
- The cost of installation would be canceled out by solar energy payback.
- Unlike traditional solar panels, you don’t have to buy expensive glass that encapsulates the solar panel because it’s already there in your window.
- Since the windows turn dark as the temperature rises, you save on building cooling costs too.
- The tint would range from very dark to semi-transparent, which means homeowners won’t require window shades.
Commercialization of the Technology – How Far have We Reached?
Commercialization of this new technology is being explored in order to develop viable ways to make it available to future homes and other buildings. It is, for this reason, a market strategy, SwitchGlaze, is underway for this product. It is currently in the proof-of-concept stage and is undergoing many developments before it can be rolled out to power the buildings of future. The strongest potential lies in the high-rise buildings, which are commonly sheathed in glass. Automotive and Residential windows also offer lucrative opportunity.
Today, building a dream home involves more than just attractive design and comfort. With the growing concern for the environment, homeowners are looking for ways to convert their homes into sustainable power generators that can generate and provide abundant clean energy while contributing to the nation’s progress. That’s exactly a future anyone would be proud to be a part of!
