Extreme Tech has a look at techniques for increasing the amount of power generated per area using stacked solar wafers - MIT stacks solar panels like pancakes, increases their power output by up to 20x.
What’s better than one pancake? A whole stack of pancakes! Using the same logic, a team of MIT researchers have stacked a bunch of photovoltaic solar cells together to produce up to 20 times the power output of conventional solar power installations. ...
Basically, photovoltaic cells themselves aren’t all that expensive — according to MIT, they’re only around 35% of the total cost of a solar power installation. The main issue with solar power (and its main cost) is its low energy density, and thus the sheer surface area required to generate a sizable amount of electricity. This is why you need to cover your whole roof with cells to power your light bulbs, and why solar power plants would have to occupy tens of square miles of desert to produce as much power as a nuclear power plant.
To combat this issue, MIT has built 3D stacks of photovoltaic cells. These have the same footprint of a conventional, flat solar power setup — but as you can see in the picture above, the total surface area is much, much larger. The team built a variety of 3D designs, including a cube, and in all cases they produced between two and 20 times as much power as a flat panel. The most interesting facet of this discovery, though, is that these 3D stacks produce lots of extra power whenever the sun is near the horizon, i.e. in the morning, evening, winter, or at latitudes far away from the equator. With conventional, flat cells, it’s hard to capture low-angle light, but with an accordion structure (as pictured) the relative angle would be closer to 45 degrees.