Comment: The way to a clean energy future with space-based solar power

The first wireless transmission of energy from space to Earth via microwave transmitters took place earlier this year and innovation in this area is advancing apace. As demand for fossil fuel substitutes grows and new investments drive research activity, opportunities to harness solar power in space are becoming increasingly viable.

Solar energy: the new space race

Mounting regulatory pressures to fulfil net-zero commitments have prompted renewed interest in space-based solar power. For example, Florida-based Made in Space is using innovative technologies to facilitate communications across a system of satellites and control a beam of energy back to Earth from at least one of them. Similarly, Mitsubishi Electric has developed technology capable of beaming microwaves from a plurality of satellites, in phase with one another.

Earlier this year the California Institute of Technology (Caltech), which owns a number of patents in this field, successfully transmitted solar energy to Earth using an experimental technology known as the Microwave Array for Power-transfer Low-orbit Experiment (MAPLE). Utilising semiconductor chips to operate an array of microwave transmitters, the technology enables a precise transmission of energy to a specific location on Earth.

In the UK, advancements in space-based solar power are being led by the Space Energy Initiative (SEI) – a consortium of companies, universities and governmental bodies, which aims to establish the first space-based solar power system by 2030, with a view to it becoming operational by 2040. Its members include Space Solar, a British start-up planning to use CASSIOPeiA, a solar power satellite developed by UK-based International Electric Company (IECL), to harvest and transmit baseload power to Earth via a safe beam of microwaves.  

The solar opportunity

Early-stage research and development (R&D) programmes in the field of space-based solar power represent a major opportunity to decarbonise energy supplies. Terrestrial solar panels still only account for 4.5 per cent of the energy generated globally and their capability is limited by variations to weather. If it can be reliably harvested in space and transmitted to Earth, the abundant radiation emitted by the sun could become a vital new renewable energy resource. For example, satellites could be positioned to ensure that the sun’s radiation is captured 24/7, for uninterrupted energy generation. Should technological advancements allow access to this limitless power source, space-based solar could provide up to one quarter of the UK’s energy demand by 2050.

In addition to the possibility of unlimited energy at a low environmental cost, space-based solar power could open opportunities for space colonisation and geoengineering capabilities. For instance, one patent application has proposed the use of space-based power systems to leverage microwave energy for weather alteration on Earth, with the intention of dissipating events such as hurricanes. Greater access to solar energy in space could also provide power for future space settlements on the Moon.

Barriers to space-based solar power

Despite growing interest in the commercialisation of space-based solar power, several key obstacles remain. For example whilst the cost of a rocket launch is gradually coming down, due to the activities of well-funded private companies such as SpaceX, sending equipment into orbit remains a multi-million-pound endeavour. For space-based solar to become a viable power source, launch costs would need to decrease dramatically – to as much as $100–$200 per kilogramme of payload, according to research conducted by NASA. This issue has led to the development of lightweight satellites, compactable solar power generators and more efficient solar panels to help curb expenses.

Maintenance of solar power satellites poses a further problem for innovators as their extreme location makes them difficult to repair and susceptible to damage from solar radiation, orbital debris and micrometeoroids. To overcome these problems, research engineers have developed a range of potential solutions. US company Virtus Solis is developing modular solar power generation-transmission satellites that can be interconnected to form huge arrays, enabling them to be repaired and replaced individually. Japanese company Nippon Electric Glass have a patent application for an innovative glass substrate containing titanium dioxide to mitigate the effects of ultraviolet radiation.

Other concerns arising within the sector include the environmental impact of launching multiple satellites into space. As such, innovators will need to ensure that the pursuit of space-based solar power delivers a net gain for the environment.

Innovating towards a brighter future

Growing awareness of the effects of climate change and concerns about energy security are driving interest in space-based solar power globally and increased investment is bringing a plethora of commercial opportunities.

It is crucial, therefore, that inventors patent their innovations at an early stage to protect them from being reverse engineered and to open up licensing opportunities. In doing so, they could secure a commercial stake in the space-based renewable energy industry of the future.

Dr Peter Heins, patent attorney and space industry expert in the Advanced Engineering Group at Withers & Rogers.