- Why? Why do we want to put solar panels in space? Why is it more efficient than just having them here on Earth?
- How? If we decided to do this now how would it even work? How would they get the power back to earth?
- Who? Who are the people working on this technology. What kinds of breakthroughs have they had?
This will hopefully give you a pretty good idea of what’s going on with this technology. So, let’s get into it!
So, why even put solar panels in space? Putting them here on earth works just fine and rockets are expensive so why bother? But what if I told you that Solar panels can be over twice as efficient as normal ground based solar panels. The atmosphere blocks a large amount of sunlight from actually reaching the surface. Also due to the day/night cycle earth based power is only in direct sunlight about 30% of the time. If placed in the right orbit and with mirrors helping it it could remain in the sun 99% of the time. And one more advantage is that because of the way that a SBSP satellite transmits its power to Earth, it could beam power almost anywhere as long as they had the equipment to receive power. It is also worth mentioning that other than the rocket launches these satellites would be totally clean and have no environmental effects on the planet because they aren’t even on the planet. These satellites are not without downsides however, Some estimates say that it could almost cost a trillion dollars. But this is equal to less than $200 per person on earth.
Alright, so how would these satellites work? They would have three main parts to the actual system. These parts are:
- Solar panels
- Microwave transmitter
- Ground based batteries
The solar panels are just like normal panels on earth except optimized to be as light and packable as possible. A way that could work for these is to have a thin sheet of solar panels that is folded up for launch, allowing you to have a lot of surface area for solar collection but being easily packable for launch. A concept like this has been theorized for solar sails which are another item that would need to be launched into space and have a huge area.
The next part is the microwave transmitter. This will not teleport kitchen appliances from orbit but instead convert the electricity collected by the panels into microwave energy that can be sent to the surface in a beam without loosing too much energy. This part could also be a laser pointed at the target. The last part is where the power would be stored. It would need to be able to store the energy being sent by the satellite and collect it from the microwave beam. There are other parts that might end up being included in a design such as mirrors orbiting the planet and focusing more sunlight on the collection arrays.
Finally, Who? Who is working on this. The U.S had a project based on SBSP but it was abandoned in 1999. One group that is working on a space based solar project is Caltech. They have an extremely light and promising prototype that they are working on. It is a modular project that is made up of many foldable elements that each can beam energy down to earth on their own making it less complicated and reducing weight. They have done tests and have working power transmission. To learn more about them there’s a link to their website here. Another group that is working with SBSP is JAXA or the Japan Aerospace Exploration Agency. They have goals to study both microwave and laser transmission. JAXA also says that they plan to have their system operational in the 2030s I have linked their website here.
So, to recap:
- Space based solar power is more efficient than earth based by about double
- They are also a clean source of energy that will not contribute to global warming
- The actual device has three parts; panels, transmitters and batteries
- SBSP is being studied by JAXA and Caltech who are making progress toward it being a reality
