Space-Based solar Power: Overview Energy’s Infrared Approach
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The quest for sustainable energy is driving innovation in space-based solar power (SBSP), a concept that aims to collect sunlight in space and beam it to Earth. While many challenges remain, companies like Overview Energy are developing novel solutions to make SBSP a viable reality. Overview’s approach, focusing on infrared transmission, addresses key limitations of previous concepts and could pave the way for gigawatt-scale power delivery by the 2030s.
A Former DARPA Program Manager’s Leap of Faith
Don Jaffe, a former program manager at the Defense Advanced Research Projects Agency (DARPA), was initially skeptical of SBSP.However, a presentation by Overview energy fundamentally changed his perspective. Jaffe recalls thinking, “It really seems like it gets around a lot of the showstoppers for a lot of the other concepts. I almost felt like the problem had been solved.” This realization led him to leave his position at DARPA to join Overview Energy, driven by the potential of their technology.
Addressing the Power Density Challenge
A central challenge in SBSP is managing power density. Lower power density beams are safer, minimizing the risk of concentrated energy impacting a small area on Earth. However, lower density reduces transmission efficiency. Higher density beams are more efficient but require robust safety mechanisms. Overview energy’s solution lies in utilizing infrared wavelengths.
Startup Overview Energy demonstrates how space-based solar power could be beamed to Earth from satellites
Overview Energy
Infrared vs.Microwaves: A Spectrum Advantage
Many SBSP researchers have focused on using microwaves for power transmission. However, Jaffe points out a significant obstacle: the microwave spectrum (2 to 20 gigahertz) is heavily allocated for existing applications like 5G cellular networks. Even with a fully functional microwave-based SBSP satellite and receiver, operation would be unachievable due to spectrum limitations.
“If you somehow magically had a fully operational solar power satellite that used microwave power transmission in orbit today-and a multi-kilometer-scale microwave power satellite receiver on the ground magically in place today-you could not turn it on as the spectrum is not allocated to do this kind of transmission,” Jaffe explains.
Overview energy bypasses this issue by employing less-dense, wide-field infrared waves. These waves can be received by existing utility-scale solar farms, eliminating the need for specialized receiver infrastructure. According to Berte, “your receivers are already built.”
Roadmap to Gigawatt-Scale Power
Overview energy’s plan involves a phased approach. The next step is a prototype demonstrator in low Earth orbit (LEO). Following successful demonstration, the company aims to have geostationary orbit (GEO) satellites delivering megawatts of power by 2030, scaling to gigawatts later in the decade.
Challenges and Future Outlook
Despite the promising advancements, significant hurdles remain. The feasibility of SBSP is still debated, with concerns surrounding the cost of launch, the risk of orbital debris, and the complexity of deploying large-scale structures in space. Overview’s satellites will be constructed on Earth in a folded configuration and unfolded once in orbit.
Reducing the cost per unit mass for launch is critical, jaffe emphasizes. “Then, it just becomes a question of increasing the specific power. A lot of the technologies we’re working on at Overview are squarely focused on that.”
Key Takeaways
- Overview Energy is pioneering space-based solar power using infrared transmission.
- Infrared offers a solution to the power density challenge and avoids spectrum allocation conflicts associated with microwaves.
- Existing solar farm infrastructure can be utilized to receive beamed energy.
- The company aims for megawatt-scale power delivery by 2030 and gigawatt-scale by the end of the decade.
- Significant challenges related to launch costs and orbital debris remain.