Solar energy can now be produced very cheaply in many places in the world. Germany also wants to significantly increase its share in the electricity mix. However, in the production of the necessary solar panels, there is a risk of dependence on China which is not without concern. In principle, however, solar energy has the disadvantage that production fluctuates. The sun does not always shine brightly. There is also the alternation between day and night. Solar energy is therefore only suitable as base load energy to a limited extent. In theory, however, this only applies to solar energy produced on Earth. On the other hand, if solar panels were placed in space, this problem could be avoided. Because the sun always shines there. From a purely technical point of view, such a project is also less futuristic than you might initially think. However, huge investments are needed to set up the necessary infrastructure. On the other hand, there are also great opportunities.
The satellites would be many times larger than the ISS
For example, the European Space Agency (ESA) has proposed to the concerned governments to start a new program called Solaris. Studies and targeted technological developments should enable the generation of “Space-Based Solar Power”. Building on this, construction of the power supply from space could start in 2035. For this, about twenty satellites with large solar panels would have to be placed in space. At first glance, this seems a feasible task. However, each of these satellites would have to be many times larger than the International Space Station. A reusable heavy-duty rocket capable of launching into space once a week would therefore be necessary for the construction of the system alone. The electricity generated in space would then be sent to Earth via microwaves. There, power stations with an area of 70 square kilometers would have to be built to receive green electricity from space.
The experts at ESA assume that from 2050 about 800 terawatt hours of electricity per year can be generated in this way. After all, this would correspond to one-third of the current electricity production in the European Union. As mentioned before, solar energy could also be used as base load energy. Large fossil power plants could actually become redundant as a result. In addition, the need for energy storage would be reduced. The ESA also had the consultancy Frazer-Nash calculate the case in detail. According to these figures, a total of 418 billion euros should be invested in 2070 to generate the planned amounts of green energy in space. In return, 601 billion euros in savings and financial benefits could be realized. In the end, the business would be profitable. A study by management consultancy Roland Berger came to a similar conclusion. It is now up to policymakers whether they are willing to take the risks.