ESA’s SOLARIS project

ESA aims to build sci-fi orbital solar power plants capable of providing abundant, green energy to EU countries. What is the SOLARIS program.

Credit: ESA

The European Space Agency (ESA) has developed an ambitious program called SOLARIS to determine whether it will be possible to follow the path of solar energy from space. It’s a renewable, constant, clean and virtually limitless source—the Sun technically has an estimated lifespan of another 5 billion years—to tap into, but some aspects still need to be verified, which the space agency’s program will try to find. . An answer should come before 2025. The good news is that two preliminary studies related to the Space-Based Solar Power project have just confirmed the technical feasibility of building huge orbital solar power plants, thanks to which it would be possible to pursue the objective grid zero (carbon) emissions in the EU by 2050.

Solar energy from space would make a fundamental contribution to freeing us completely from fossil fuels, considering that with only solar (solar), wind, geothermal and other renewable sources – although fundamental – we believe that the desired ecological transition will not can be fully achieved. It is no coincidence that many are still turning to the latest generation of nuclear fission and especially to futuristic nuclear fusion power plants (and still only on paper). This is because wind power, like solar power, is intermittent, inconstant: the first is conditioned by the weather and by the fact that the Sun naturally rises and sets every day and gives way to night; the other of the “caprices” of the wind, not present everywhere and at least not at regular intervals.

But up there in space the Sun never sets and is not obscured by clouds in the Earth’s atmosphere; it is a permanently lit “bulb” capable of providing abundant and clean energy. Probably. Hence the idea of ​​collecting it via orbital solar power plants and sending it to Earth; already half a century ago people started thinking about these plants, but it is only now that there are concrete projects. But how do these plants work? In very simple terms, an orbital solar power plant consists of three main structures: a gigantic orbital station consisting of square kilometers solar panels very high efficiency; an antenna capable of converting the cells’ stored energy into microwaves to be “broadcast” to the mainland; a land-based power plant based on a huge “rectenna” that receives microwaves, converts them into electricity and sends it to the national grid. The first to patent this system was engineer Peter Glaser in the early 1970s.

A rectenna.  Credit: ESA

A rectenna. Credit: ESA

But building such infrastructures requires investments of several billion euros and significant technological advances in various sectors, as explained by ESA in a press release. These include the ability to build infrastructure in space, robotic construction (based on fundamentally autonomous robots), high-efficiency photovoltaics, high-power electronics and beamforming, radio frequencies. The potential impact of microwaves on human, animal and ecosystem health as well as compatibility with air and satellite traffic should also not be underestimated. Orbital solar power plants would be built in geostationary orbit (to always remain in contact with receiving facilities on Earth) at an altitude of about 40,000 kilometers. Much higher than the International Space Station (ISS), which orbits about 400 kilometers above sea level.

“These are the kinds of technical questions that SOLARIS will investigate to further explore the feasibility of the concept so that in 2025 Europe can make an informed decision on whether to pursue a solar space program in the future,” he declared. Professor Sanjay Vijendran, SOLARIS project manager at ESA. “As an added benefit, any results obtained in these areas will be valuable in themselves, applicable to many other spaceflight researches,” the scientist added. If we talk about feasibility for Europe, the US and especially China are already ahead. China could even build its first orbital solar power plant before the end of the decade, while Europe’s first, if all goes according to plan, would arrive around 2040. But a decision needs to be made quickly. For this reason, the green light will not or will not be given to the project in 2025.

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