Solar energy is the utopian dream of the green energy set, and with good reason. Sunlight is abundant, free, and completely clean in all meaningful senses, especially as compared to other forms of energy harnessed by Man. It has also proven notoriously difficult to transfer into usable energy sources – and by that I mean: electricity – in any kind of efficient measure. The promise of solar power keeps running into the obstacles of transfer efficiency and stable supply.
It’s not like we’re not trying, however, even though many of the recent attempts have been more political cronyism than true engineering efforts. Photovoltaic solar cells have been vastly improved over the past few decades and systems designed to track the sun to keep those cells pointed at the optimum angle for collection have gotten more precise, less expensive, and more robust. Still, they aren’t quite cost-effective in spite of these advancements. More importantly, there are places where the angle of the sun or the amount of daylight available simply won’t permit current solar collectors to ever be effective given the current technology.
A German architect named André Broessel appears to have a key piece of this puzzle figured out with a spherical collector lens. If he does, this could change everything. Via The Mind Unleashed:
…it’s a spherical sun-tracking solar energy-generating globe — essentially a giant glass marble on a robotic steel frame. But this marble is no toy. It concentrates both sunlight and moonlight up to 10,000 times — making its solar harvesting capabilities 35 percent more efficient than conventional dual-axis photovoltaic designs.
André Broessel was a finalist in the World Technology Network Award 2013 with the globe’s design and afterward produced this latest version, called Betaray, which can concentrate diffuse light such as that from a cloudy day.
Emphasis mine. That’s a staggering bit of data, if accurate. One of the critical issues with solar power is the fact that it’s near useless on a cloudy day, and completely non-usable at night. If Broessel’s design can address that shortcoming then this becomes a truly disruptive technology.
The Betaray consists of a 1.0 – 1.8 meter diameter sphere that can focus sunlight from literally every angle. Rather than take the traditional approach of setting up a tracking system to move the lens, Broessel devised a collector plate that slides around the opposite side of the sphere, keeping the solar cells in the focal point regardless of where it moves.
By moving only the collector plate and the thin arm attached to it, his system presents a much smaller target to the wind and weather, making his system far more robust in more varied environments. Raising the collection efficiency up by as much as 35% could take solar collector systems from being relatively expensive “feel-good” oddities to actually effective power systems. If it can be made at a cost-effective level, it could be used as a power augmentation system even if it wouldn’t completely replace the grid connection for a building. Having a system like this would make it far, far easier to deploy remote communications systems, radar and sensor arrays, navigation beacons and so on.
The idea of a spherical concentrator lens isn’t new and its efficiency in collecting sunlight was proven dramatically by the Mythbusters who were able to fashion a sphere out of water ice and use it to start a fire with concentrated sunlight.
The Betaray system, according to the datasheets at the company’s site (the company is called “rawlemon,” believe it or not), can be paired with a heat exchanger on the back of the collector plate to gather the thermal energy that’s gathered by the act of concentrating the sunlight. That got me thinking of the Cyclone Energy steam engine I wrote about a few weeks ago. That device was able to run the steam engine with any heat source, even waste heat like this one. Pairing that engine with the Betaray would give you power generation two ways simultaneously, and neither would cost you a dime in fuel or generate a wisp of emissions.
This is the kind of technology advance I love to see and I sincerely hope we can start to see such systems actively deployed in the very near future.