Space Solar Power Is Happening Sooner Rather Than Later – CleanTechnica

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The futuristic idea of beaming solar power down to Earth from space has been getting closer to the here and now, despite a slew of financial and technological obstacles. That’s yet another reason for fossil fuel stakeholders to start looking over their shoulders. Progress has been slow, but in the past year or so the pace of space solar development has been gaining momentum faster than you can say stranded assets.

Space Solar Power Is Coming For Your Fossil Fuels

Despite the cost and technology hurdles, the allure of wirelessly beaming solar power down to Earth on a 24/7 basis regardless of the weather is, well, alluring. The solar receivers would require some land, but overall the access to space-sourced solar power would reduce land use issues related to solar development here on Earth.

To the extent that fossil energy stakeholders have been ginning up opposition to new solar arrays in the US and elsewhere, space solar provides an alternative pathway to renewable energy.

The space solar news has been coming thick and fast over the past year. Just last month, for example, CleanTechnica took note of a UK startup with the forward-thinking name of Space Solar, which anticipates that a demonstration-scale iteration of its solar power technology will launch into orbit somewhere around 2027.

Startups Are Hot For Space Solar Power

Over here in the US, the California startup Reflect Orbital is also on the chase. The company’s bare-bones website holds it close to the vest, but Reflect Orbital co-founder and CEO Ben Nowack has been dropping updates on the social media platform formerly known as Twitter to the effect that he and co-founder/CTO Tristan Semmelhack are “developing a constellation of revolutionary satellites to sell sunlight to thousands of solar farms after dark.”

“By precisely reflecting sunlight that is endlessly available in space to specific targets on the ground, we can create a world where sunlight powers solar farms for longer than just daytime, and in doing this, commoditize sunlight,” Nowack said on March 13.

Our friends over at Space.com report that Nowack presented Reflect Orbital at the International Conference on Energy from Space in London last week. The plan is to send a web of 57 mirror-equipped satellites up to an altitude of 370 miles, where they will maintain a Sun-synchronous polar orbit.

“In that orbit, the satellites would circle the planet from pole to pole while the planet rotates underneath them,” Space.com explains. “The satellites would fly over each spot on Earth at the same time of the day, making two passes per 24 hours.”

Those of you familiar with orbits may be thinking that’s not the same as 24/7 solar power availability, and you are correct. The idea is to enable solar power plants on Earth to suck up an additional 30 minutes of sunshine after dark or before dawn. That may sound like small potatoes, but the clean kilowatts can add up when utility-scale solar arrays are involved.

Scaling Up Space-Based Solar Power

As for the sales pitch, we’re guessing that the mirror-based technology could enable Earth-bound solar developers to pick sites for large-scale solar arrays in areas where land use issues are less fraught, along with providing a power boost for existing arrays. It’s also possible that Reflect Solar is counting on lower costs, compared to orbiting solar cells and wireless electricity transmission.

If you have any thoughts about that, drop us a note in the comment thread. Meanwhile, work is continuing apace on the idea of beaming solar power down to Earth from orbiting solar arrays. In the latest development, a team of scientists from the Korea Aerospace Research Institute and the Korea Electrotechnology Research Institute took a holistic look at the emerging space solar industry in a study posted online on April 16 at Science Direct. In particular, the study considers the holistic context of multinational competition and space debris removal in consideration of the gigantic, multi-gigawatt potential for scaling up orbiting solar arrays.

“The increasing significance of Space Based Solar Power (SBSP) in the global transition towards renewable energy sources…is gradually being acknowledged. This paper emphasizes the need for a global agreement to ensure a sustainable and responsible approach to SSPS deployment,” the research team notes.

“Of paramount importance is the necessity to articulate a comprehensive disposal methodology for the mega size structures associated with SBSP.”

One solution is to crash spent solar equipment on the dark side of the Moon, where it could be retrieved and repurposed by anyone who happens to be living up there at the time. If you have any thoughts about that, drop another note in the comment thread.

Scaling Down For Space-Based Solar Cells

Another new development involves a forthcoming test of a tiny 400-pound satellite, designed to beam solar power down to Earth from an altitude of 250 miles.

The new satellite is a product of Japan’s OHISAMA initiative, housed at the organization Japan Space Institute. We couldn’t track down the details from the JSP website, but Space.com got the lowdown from OHISAMA’s presentation at the International Conference on Energy from Space.

The test satellite is expected to launch in 2025, at a limited run of just 1 kilowatt.

“The spacecraft will use a 22-square-foot (2 square meters) onboard photovoltaic panel to charge a battery. The accumulated energy will then be transformed into microwaves and beamed toward a receiving antenna on Earth,” Space.com reporter Tereza Pultarova explains.

“Because the spacecraft travels very fast — around 17,400 mph (28,000 km/h) — antenna elements will have to be spread over a distance of about 25 miles (40 km), spaced 3 miles (5 km) apart, to allow enough energy to be transmitted,” she adds.

The battery-enabled setup adds another layer of complication. Although the transmission can be completed within minutes, the battery requires several days to recharge.

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Next Steps For Space Solar

If you’re wondering where NASA stands on space solar power, that’s a good question. The US space agency has plenty of experience with in-space solar technology but earlier this year the NASA Office of Technology, Policy, and Strategy indicated that space solar is not a priority investment for its R&D dollars.

However, they also noted that other key areas of technology development track with space solar, including ” in-space servicing, assembly, and manufacturing (ISAM) and autonomy.”

Meanwhile, NASA launched a newsworthy solar mission of its own earlier this week, in the form of a new, lightweight “solar sail.”

“Solar sails use the pressure of sunlight for propulsion, angling toward or away from the Sun so that photons bounce off the reflective sail to push a spacecraft,” NASA explains. “This eliminates heavy propulsion systems and could enable longer duration and lower-cost missions.”

The first iteration of the sail measures approximately 860 square feet. NASA anticipates that it could be visible from Earth under the right conditions, so keep your eyes peeled. Don’t be surprised if space solar stakeholders are eyeballing the new solar sail, too.

NASA cites solar sail lead engineer Alan Rhodes, who notes that the device can “roll up into a shape that fits in your hand.”

“The hope is that the new technologies verified on this spacecraft will inspire others to use them in ways we haven’t even considered,” Rhodes adds.

For more news about space solar, keep an eye on the goings-on over at the California Institute of Technology, which put a space solar prototype into orbit last year.

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Image (screenshot): The California Institute of Technology is among the research institutions developing space-based solar technology (courtesy of CalTech).