THE ESA (European Space Agency) is analyzing alternative solutions for the bloc’s energy supply, as rising tensions with Russia, due to the invasion of Ukraine, have compromised Russian gas supplies, and it is no secret that the campaign to shut down the plants nuclear weapons, particularly in Germany, was taken up by Kremlin-sponsored NGOs.
One of the alternatives presented by the space agency is a long-term plan (and put a long way in it) involving a constellation of satellites that will work as solar farms, to capture and transmit solar energy to Earth via microwave. The plan borders on insanity, and at least today, it’s completely unfeasible, but still, at least they’re thinking of something.
In early 2022, ESA commissioned two independent studies, to two strategic consulting companies, the British Frazer-Nash and the German Roland Berger, to detail the costs, benefits, advantages and disadvantages of a program aimed at the use of satellites. geostationary devices for capturing solar energy, in order to retransmit it towards the ground, where it will be captured and used in the European consumption grid.
Both studies were published by the agency and are available for public consultation; the plan, with the unoriginal name of the Solaris Program, is defended by the director of ESA Josef Aschbacher, as an alternative to the use of fossil fuels in the block for the generation of energy, but to work, it is necessary that all the
22 27 member countries of the European Union are committed to the undertaking.
The specifications of the project, which in theory would replace the thermoelectric plants, the consumption of gas coming from Russia, and even the generation of nuclear energy, is quite bold, to say the least; Aschbacher believes that if the EU gives the green light to the project, work will begin as early as 2025.
However, there are a number of points to be considered
The Energy That Came From Space
Both reports address an obvious point, which is the non-existence of technologies that make it possible to implement the Solaris Project today, and on several fronts. Currently, Europe consumes 3,000 TWh per year, bringing together all forms of generation active today, whether coal, gas or nuclear. Reports point out that stations in orbit now respond between 1/4 and 1/3 of the total energy generated, and this is where the problems begin.
According to the documents, to enable an orbital system of solar farms capable of generating a third of the energy that Europe consumes, it would be necessary to launch a constellation with dozens of satellites, equipped with gigantic solar panels, in which each unit would have to be at least , ten times larger than the ISS (International Space Station).
By way of comparison, the ISS is 73 meters wide, 109 meters long, weighs 444,615 kg and took years to complete. Now multiply those numbers by 10. Several times.
Of course, it gets more complicated. The ISS is between 413 km (perigee) and 422 km (apogee) in altitude, much lower than a geostationary orbit, or 35,786 km. This means that smaller rockets are unsuitable for transporting such equipment, and large rockets such as the SLS and Arianespace, which are not recoverable, would incur absurd costs for the program.
One solution, much to ESA’s dismay, would be to use SpaceX rockets such as the Super Heavy/Starship kit, in which both reports claim the format will become the norm in the coming years, out of cost-cutting necessity, or technological evolution. They weigh against that Europe has nothing like it, and the EU, as well as the US Congress, also doesn’t like Elon Musk, who charges much less and is taking opportunities from local agencies.
According to the Frazer-Nash report, considering all the difficulties and an ability we still don’t have, to put super satellites in geostationary orbit (after all, neither the Starship nor the SLS have actually flown yet), ESA would be able to launch a solar farm at every 4 or 6 years, provided the agency also develops a reusable rocket capable of launching heavy payloads into geostationary orbit.
Even so, the most optimistic forecast points to 2050 as the year in which the grid would come into operation, at the cost of hundreds of billions of euros to public coffers, to, again, account for between 25% and 33% of European energy consumption. . It does not stop there.
ESA and the efficiency issues
Putting satellites into orbit is already quite a problem, but collecting and converting energy on the ground is not far behind. On the one hand, solar farms will not have problems with day and night, or weather situations that make energy storage impossible. Each will be able to operate 24/7, which is a good thing, not least because the next step is quite problematic.
In the impossibility of pulling extensions between the European grid and the satellites, the transmission of collected solar energy would be done by microwaves, where appropriate stations, with antennas and photovoltaic cells, would capture the flow and reconvert it into electrical energy. If you know how a wireless cell phone charger works, understand the low energy efficiency of the method, much of the energy would be wasted.
Again, we don’t have technologies advanced enough to guarantee maximum energy efficiency in the process, some energy (a lot, in fact) WILL be lost, which undermines the whole viability of the plan. It’s no use having a supply from the Sun all the time, if you’re not going to enjoy everything.
The plan has numerous critics, who attack this very point. In 2019, physicist Casey Handmer pointed out that collecting solar energy in space, and relaying it back to Earth, is a method at least three orders of magnitude more expensive than any we use today, pointing out that logistical, and energy loss would be critical impediments to solar farms becoming competitive. In short, the energy bill for the consumer would be very expensive.
Elon Musk also criticized the plan years ago, but was far less kind than Handmer in what he called the proposal “the stupidest idea ever”. For the CEO of SpaceX, the double conversion process annihilates all the advantage of capturing solar energy all the time, in which he says he would be the first interested in embracing the plan if it were feasible.
For Musk, keeping solar farms on Earth is the only way to make the system competitive.
Finally, both reports commissioned by ESA do not attack the main point, to economically justify the undertaking. The system in orbit will never be viable, because the infrastructure would be so expensive and complicated to implement, that the final value of the kWh for the consumer would be much higher than what he pays today, in gas energy from Russia, from thermoelectric plants, or from nuclear.
Even if the ESA gets the green light from the EU to start work on the Solaris Program, it is unlikely that we will see results even in the long term; in an optimistic scenario, it would take a few decades to have something viable and, more importantly, energy efficient and financially competitive. Even so, you have to start from somewhere.
Source: European Space Agency