Space-Based Solar Energy Transmission Nears Feasibility, According to Expert

The concept of harnessing solar energy from space, known as space-based solar power (SBSP), is inching closer to becoming a viable reality, according to Matteo Ceriotti, senior lecturer in Space Systems Engineering at the University of Glasgow.

While the idea has been around since the late 1960s, challenges related to cost and technology have hindered its progress. However, recent advancements and evolving concepts suggest that SBSP could play a significant role in the transition to green energy, noted Ceriotti's opinion piece published in The Conversation.

Solar Power Generation

Ceriotti noted that current solar power generation methods have limitations, as they rely on land availability and are impacted by varying light and wind conditions.

In contrast, SBSP using satellites in geostationary orbit (GEO) presents a promising solution. Satellites in GEO are exposed to the Sun for over 99% of the year, enabling them to produce continuous green energy.

Wireless power transmission using microwaves is considered to transmit energy collected in space to the ground. This method minimizes energy loss through the atmosphere and allows for efficient energy transfer even in cloudy conditions.

The microwaves are focused on a ground station equipped with antennas that convert them back into electricity. Various SBSP designs have been proposed over the years.

CASSIOPeiA, for instance, features two steerable reflectors that direct sunlight onto an array of solar panels, while SPS-ALPHA uses modular reflectors called heliostats.

Recently, Caltech launched the MAPLE satellite experiment, demonstrating the feasibility of beaming power to Earth. Ceriotti highlights SBSP's potential impact on the UK's goal of achieving net-zero emissions by 2050.

An independent study cited by Ceriotti suggests that SBSP could generate up to 10GW of electricity by that year, contributing significantly to the country's energy demand. Moreover, SBSP could stimulate a multi-billion pound industry and create around 143,000 jobs across the UK.

Challenges Remain

Despite the potential, challenges remain. The main hurdle is the substantial mass and associated launch costs of SBSP satellites. Companies like SpaceX and Blue Origin are developing heavy-lift launch vehicles to reduce costs through reusability.

Yet, launching an SBSP satellite would still require multiple launches, Ceriotti said. Moreover, maintaining large structures in space, managing fuel and toxic chemicals, and mitigating potential environmental impacts pose additional challenges.

"The challenge of building platforms like this in space like this may seem daunting, but space-based solar power is technologically feasible. To be economically viable, it requires large-scale engineering, and therefore long-term and decisive commitment from governments and space agencies," Ceriotti noted.

"But with all that in place, SBSP could make a fundamental contribution to delivering net zero by 2050 with sustainable, clean energy from space," he concluded.