energy startup Pythagoras Solar is dreaming big and it has
sold the owners of one of America's most iconic skyscrapers on its vision.
Chicago's Willis Tower (formerly known as the Sears Tower) is among the most
recognizable man-made landmarks in the country. Towering over local
high-rises, its 108 stories make it the tallest building in the U.S. and the
structure in the world.
During summer months solar heating contributes to energy costs and sun glare
can be an issue at times.
Pythagoras Solar power has cooked up a novel solution -- transforming the
building into the nation's largest vertical
solar farm. The farm will produce up to 2 MW of solar energy,
reducing the building's reliance on the power grid.
Its panels -- to be installed on the building's southern-facing windows that
get the highest sun exposure -- will help remedy both issues, while preserving
the view and producing electricity.
The company's pane design is dubbed high-density photovoltaic glass units
(HD-PVGUs). The device acts similar to louvered windows (think slat blinds).
It contains a thin layer of monocrystalline silicon, sandwiched between
glass, which acts as a cell. An internal plastic prism directs angled
(direct) sunlight onto the cell, while allowing diffuse daylight and horizontal
(less intense) sunlight through.
The result is that you still have attractive views out the window, without the
glare or heating. Meanwhile your panel produces electricity that
Pythagoras Solar claims is on par with rooftop panels.
If the installation is a success, it could set a precedent for high-rises
across America. The Willis Tower installation alone is expected to
produce as much power as a 10-acre ground installation would.
Conserving land, particularly in a city, is obviously a tremendous concern.
The Willis Tower project could serve as a blueprint for skyscraper
owners to reduce their energy costs and improve their buildings'
sustainability in years to come.
Cost and maintainability are obvious concerns in the long run for solar window
panels from companies like Pythagoras Power. Indeed, Pythagoras Power
offered little insight into how it would handle the extra maintenance burden or
what the cost-per-window might be.
That said, even if the company did provide such metrics, it'd be hard to fairly
judge them, as this project is the first of its kind on this kind of magnitude.
Initial implementations of any technology typically start off high in
terms of maintainability problems and cost, but eventually bring down both
And the cost must not be overly exorbitant. After all, the panels are
good PR for the Willis Tower's owners, but they are in business to make money.
If the panels were overly expensive, the project likely wouldn't have
received the green light to begin.
quote: Why? It is clearly very close to ramping scale and efficiency to the point of competing