A literal moonshot-launching solar farms into space!
Climate change is a constant battle of achieving environmental sustainability in an economy that relies on consumerism. Protests after protests, we hear that we can solve the crisis through banning sing-use plastics, or stopping the production of oil, searching for a solution. hm, that doesn’t seem to be working, or at least, not fast and significant enough.
There has to be another way. What if that solution was building a solar farm in space?
pssst by the way… I made a video with the same content as this article. If you are more of a visual and auditory learner, here you go:
In our status quo, the policies and organizations set in place are rooted too deep. Government officials have a conflict of interest. If we were to put financial restrictions on the growth of oil companies, that would create an economic recession. ‘Too big to fail’ companies, like Shell, an oil company are crucial to the stability of our economy. While, at the same time, they are a significant polluter and stub environmental progress.
Let’s switch gears, and stop pointing fingers.
We can continuously grow our economy, while still consume at our current rates.
To understand this, it’s crucial to note that climate change is not the problem, it’s the result of multiple problems. One of those problems being that humans have changed the natural greenhouse balance, through burning fossil fuels like coal and oil… hm, so it’s the energy sector.
Let’s focus on that.
Why do people choose oil over renewable energy?
Because it’s cheap. It makes the most economical sense, end of the story, period.
If you were to personally choose solar energy over oil, obvious sacrifices must be made. Solar technology just isn’t good enough yet.
Solar energy isn’t as efficient as oil is, so it jacks up the price. The average solar panel is in the efficiency range of 15%–22%. Whereas oil’s efficiency rate is 85%, only 15% is lost in the conversion. If we made solar energy even more efficient than oil, solar energy wouldn’t be considered a “second choice” or “sacrifice.” Therefore, less propaganda or persuasion will be needed. If sustainable alternatives were the first choice economically, then people will naturally make more eco-friendly decisions. If being a good person meant that you became richer, then everyone would want to be Gandhi.
Frankly, solar energy is unreliable and inefficient. How can we solve this?
Answer: Launching solar pannels into space.
The sun’s energy is infinite, constant, and abundant. The sun’s total power that hits Earth in a single hour can power what the entire world consumes in a year. Now that’s wild. We just need to get better at harnessing that power.
A lot of the sun’s energy is reflected back into space by clouds, atmospheric particles, and bright surfaces on the ground. Further, more is absorbed in the ozone and atmosphere. Solar rays are filtered through the atmosphere, and a lot doesn’t even hit Earth. There’s so much more energy than we can harness if we put the panels in front of the filter.
Obviously, solar panels only work for half of the day. Solar energy isn’t affected by nighttime, so the energy you get is consistent in orbit.
So, regarding the efficiency problem… we already get twice as much energy from the sun when we put the panels in orbit. However… a significant amount of energy is lost during conversions. Solar panels transfer electricity through wireless power transmission. There is a lot of technicalities involved in increasing the efficiency of wireless power transmission, and the efficiency of a solar cell.
Wireless Power Transmissions
Space solar panels consist of two main components:
- The satellite
- Receiver station
Solar power satellites are launched into orbit. They would receive sunlight and transmit wireless energy back onto a receiving station on the Earth.
The photons (sun’s ray) that hit the solar PV panels have to be converted into electricity by the cells, which converts into microwaves. Microwaves get beamed down, through Earth’s atmosphere to hit receiver stations on Earth. The receivers would have to transfer microwaves back into electricity.
As you can imagine, lots is lost just with transportation. Shockingly and perhaps embarrassingly, only 9% of the energy received in space will reach consumers on Earth. However, if more energy is received originally in space than it would on Earth, the energy we are able to receive isn’t that insignificant.
Let’s look at this theoretically.
A solar panel in space receives 100 joules in a day. However, it can only use 9% of it. In the end, you get 9 joules.
Solar panels on Earth only receive 50 joules in a day(considering nighttime). 22% of 50 is 11. You get 11 joules.
Although solar panels on Earth are more efficient, it is dependent on atmospheric weather, nighttime, and seasons… adding to its unreliability. Whereas, space solar pannels eliminate those factors and purely focus on optimizing the efficiency of a solar cell.
Ali Hajimiria is a professor of electrical engineering at the California Institute of Technology and director of the university’s Space Solar Power Project. He sums it up down below.
“You don’t have to deal with the day and night cycle, and you don’t have to deal with clouds or seasons, so you end up having eight to nine times more power available to you,” -Ali Hajimiri
Although lots of energy is lost in conversion, there is much more potential to innovate better technology to harness that greater energy better.
We can do this by optimizing and being selective about what parts of systems and satellite models to use. For example, SPS1 (a model of solar space satellite) uses lasers, instead of microwaves. Lasers work faster and concisely in space. To optimize efficiency, we can use a combination of both laser and microwaves; where each form is used when it’s in an environment it works most efficient in.
The SPS3 model requires less complex power management and distribution of arrangement. The process is moved by direction and light, rather than physical electrical infrastructure. The model is a reflective system. Unlike SPS1 and SPS2, it doesn’t require large photovoltaic pannels but uses mirrors. It collects light with mirrors, to bounce them down to smaller PV panels that will convert that energy into microwaves beamed down to Earth.
JAXA and NASA are working on projects, specifically using the SPS3 model. JAXA is planning on launching its solar panel in orbit by 2030. They designed a model that uses two large solar reflectors. The reflectors would focus the light received from the sun on a collector. The collector converts energy into microwaves, that will beam down to the surface of Earth.
NASA is working on the SPS-alpha model. It’s in the shape of a giant bell. The bell will capture the energy and funnel it into a PV collector before it gets beamed down.
Beyond optimizing efficiency per cell, and conversions…there’s a lot more to figure out. Solar panels on Earth last for about 30 years. How do we create robust strong structures that avoid the disturbances of asteroids? How do we dispose of the waste? Currently, there is a huge problem with space junk. Do we just want to follow an ‘escapist’ mindset, where space is our new trashcan?
Perhaps we could reuse solar panels, following precedent as to what SpaceX is doing with rockets. To make the launch easier, we could add elements of self-assembly, such as using origami.
For the time being, we have to think bigger, to think beyond government policies. Remember, if clean energy became more efficient, it lowers the price; eventually to an ideal point where solar energy became cheaper than oil… where we live in a world where nonnegotiably, being green is the first choice.
Solar energy faces problems such as efficiency and reliability. Solar space farms are a definitive answer to improving technology and moving us into the right direction of prioritizing green energy.
