The solar industry is growing rapidly and thanks to that growth, renewable energy is now eclipsing coal as an energy source. But solar energy has notorious shortcomings: it does not generate electricity at night and not very well when it is cloudy. As you will surely find out, solar energy needs the sun.
But what if it wasn’t? What if there was a solution to the solar problem of solar energy? It turns out there are researchers around the world looking for one, and there are a number of suggested solutions that could make it happen. Here is a brief tour of the technologies and techniques that scientists are researching.
The “Antisolar Panel”
If you want to generate electricity from an alien source of energy (also known as the sun), as you do with solar panels, but want to generate that electricity at night, one option is what some have called an “anti-solar panel”. This option is based on generating energy from the cold of space rather than the warm light of the sun.
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It sounds a little strange, but it’s science based. The idea is that you point the panel towards space in the evening and it is warm in relation to the coldness of space, which causes it to emit heat as invisible infrared light. You can then capture that infrared light to generate electricity.
Aaswath Raman, assistant professor of materials science and engineering, told Digital Trends that this would help you generate power at night, but not nearly as much power as a solar panel from the sun.
“The sun as an energy resource is far more powerful than what you can get out of this nightly cooling effect – radiation cooling,” says Raman. “From a power generation perspective, I think it will always be additive at best.”
Raman says that if you’ve already invested in installing solar panels, it can help you get more bang for your buck by improving the “economics of the underlying system”.
Capture more wavelengths
Solar panels capture a large part of the solar radiation, but not all. They are great for generating electricity from direct sunlight, but not as good for generating electricity on cloudy days. One solution to this proposed problem is to capture invisible ultraviolet light, even when it is cloudy, and then convert it to visible light to generate electricity, as would normally be done with a solar panel.
“There are things that come from the sun at long wavelengths that a solar panel doesn’t normally convert,” says Raman. “It’s just going in the heat, and people have suggested and … shown how to convert some of that light into light that a solar panel could convert into electricity.”
Build bigger batteries
When all else fails, there is also an established workaround for the fact that solar panels don’t produce electricity at night: store excess energy while the sun is shining on batteries. For example, you might have seen the microgrids that Tesla built around the world.
Raman says batteries will be a crucial part of solving solar power’s biggest problem, but we’re not currently in a place where batteries can store enough electricity to run a city, for example. He says we still have to develop new battery technologies to store that much energy.
“There are options today that are feasible and usable for relatively small scales. It’s really a question of how big you can go, ”says Raman. “The scales get pretty daunting when you think about how much battery power you need.”
The researchers are studying everything from flow batteries to compressed air to store energy. According to Raman, the solution to solar energy problems doesn’t have to be just batteries or some other idea. He says we can use different technologies to solve this problem.
“You are sure to be using a tremendous amount of battery. Will that be all I guess not, ”says Raman. “I suspect there will be other ideas.”