The potential of space-based solar power (SBSP) is no longer confined to the realm of science fiction. This technology, which involves deploying solar panels in Earth’s orbit to harness constant, intense sunlight, could fundamentally alter the global energy landscape. Unlike terrestrial solar panels, which are subject to day-night cycles and weather conditions, orbital solar arrays can generate power 24/7, 365 days a year. This continuous power generation could provide a stable, baseload energy source, addressing one of the key challenges of renewable energy integration.
The innovation doesn’t stop at power generation. The electricity produced in space is converted into microwaves or laser light, beamed down to Earth with minimal losses, and reconverted into electricity at receiving stations called rectennas. This wireless power transmission technology is not new; it’s been used in military radar systems for decades. The real breakthrough is in applying this technology to solar power generation in space. “It’s not really that different from solar PV,” Dr. Leet Wood, chief energy advisor for the Space Frontier Foundation, explained. “There are a number of different architectures that have been considered over the years, and I should point out that this concept has been around for a number of decades, but the one that we’re most focused on is a large-scale satellite with a large solar PV array in geosynchronous orbit.”
The constant sunlight in space, coupled with the ability to predict eclipses, makes SBSP a highly reliable energy source. The power generated can be beamed to any location within the satellite’s line of sight, offering unprecedented flexibility in power distribution. “You have a lot more transmission opportunities in terms of siting,” noted Alex Gilbert, a fellow at the Payne Institute for Public Policy. “You can figure out where on the transmission grid that is the least constrained to put a rectenna station and have the power being joined in the grid. You can potentially split the beam. You can go to multiple different markets.”
The environmental impact of SBSP is relatively low, with the primary emissions coming from rocket launches. However, as launch technologies advance, the cost and environmental impact of launching equipment into space are decreasing. SpaceX, Blue Origin, and Rocket Lab are leading this transformation, making space more accessible and affordable. “That’s where we’ve seen a significant transformation in the space sector over the last 10 to 15 years,” said Gilbert. “Initially started and catalyzed most by SpaceX or more recently other types of launch vehicle providers like Blue Origin and Rocket Lab, we’re seeing a transformation in how space is done. It’s no longer space for government applications with government oversight of traditional contractors; it is commercial space for government and commercial users, and the cost of launch is going down significantly.”
The U.S. is on the brink of having operational super-heavy launch vehicles, which could significantly reduce the cost of launching large-scale SBSP stations into space. The reusability of these launch vehicles further enhances the economic viability of SBSP. “Because, right now, we throw away the entire rocket every time we put something into space, which is obviously an immense cost. If you could even reuse it once or twice, that fundamentally changes the economics of launch,” Wood explained.
The rapid growth of satellite constellations, such as SpaceX’s Starlink, demonstrates the feasibility and reliability of solar power in space. These constellations are already generating dozens of megawatts of solar power, and this number is expected to grow significantly in the coming years. However, while the U.S. leads in space technology, its SBSP program lags behind other countries. China, the European Union, and Japan have explicit government policies to develop SBSP, while the U.S. lacks a dedicated program.
This disparity highlights a critical challenge: the U.S. government’s approach to energy innovation is not well-suited to support SBSP. The Department of Energy does not have a dedicated SBSP program, and NASA has been cautious about pursuing this technology for Earth applications. This lack of government support could hinder the U.S.’s ability to lead in this emerging sector. As other countries forge ahead with SBSP, the U.S. risks falling behind in this potentially revolutionary energy technology. The development of SBSP could reshape the global energy landscape, providing a stable, baseload energy source that is flexible and environmentally friendly. However, realizing this potential will require overcoming significant technical and economic challenges, as well as securing government support and investment. The future of energy is not just on Earth; it’s in space.
