Energy from renewable sources, what does space have to offer?

There is plenty of room for renewable energy in space. From photovoltaic panels orbiting Earth to satellites that monitor energy supply, through the search for new high-tech solutions to improve the efficiency and reliability of terrestrial solar and wind systems, development opportunities are growing.

In recent years, both space agencies and government institutions have launched programs for exploration beyond the Earth's atmosphere, taking into account the direct and indirect impact that these actions can have on the energy transition and on the development of technologies capable of promoting the penetration of renewables. Placing solar panels in space, to give a simple but effective example, would reduce land consumption and guarantee the continuous production of clean energy without the consumption of land mass, consequently promoting social sustainability. And it is precisely from this perspective, which brings with it complex and not yet fully overcome technological challenges, that we start this journey.

Achieving a consistent result in terms of orbiting solar farms requires overcoming many existing challenges. The current frontier of research is to exploit space photovoltaics (which in itself has been a reality for powering satellites, spacecraft, and space stations for over half a century) taking it a step further and bringing energy to the Earth, even if only for purposes of demonstration: for example, in June 2023 the California Institute of Technology (Caltech) managed for the first time to transfer solar energy from space to Earth, powering some LEDs. To make this process more efficient, without a physical conductor linking orbiting panels to the Earth, this is what companies such as Space X and Blue Origin are researching – however – without a tangible outcome yet.

And the problem of the resistance of materials to cosmic rays also remains unsolved, to prevent the devices from being consumed within just a few months, as well as happened to the demonstration Tesla Roadster that Elon Musk launched with the Starman on board in February 2018. This is an additional technological challenge with no immediate solution.

Remaining in the photovoltaic sector, a crucial element has always been the semiconductor material required for cells. Silicon, thin film, and the all so-called third-generation technologies are already widely marketed and another effective and already tested solution involves the use of cadmium telluride (CdTe). In addition to being cheap, light, and efficient, this kind of cells can withstand the difficult environmental conditions in space. The invention, conceived in the laboratories of the United Kingdom, is a concrete example of the possible positive effects of research on renewable plants on Earth. Identifying materials capable of producing energy in extreme conditions, such as those found in space, is useful for building power plants in less-than-hospitable environments such as deserts, oceans, or mountains.

Even if it gets less media coverage than other fields, space activity also has a positive impact on renewable energy plants located on our planet, as orbiting satellites can act as watchkeepers for power plants. Already nowadays, and increasingly so in the coming years, thanks to these eyes from the sky it is possible to monitor climate changes and optimize energy production and supply processes of wind and photovoltaic systems.

The same satellite constellations could soon play a strategic role in energy storage, providing connections between storage systems located throughout the planet. For example, their usefulness has been demonstrated for quickly providing energy in the most remote areas and for efficiently managing blackouts. In short, space is also a resource for promoting the sustainable development of still low-tech countries and resolving ethical and social issues such as access "for all" to clean energy.