Factories in Space (www.factoriesinspace.com)
has tracked space solar power and wireless power transfer companies since 2018. There are 52 primarily commercial entries as of September 2023, which makes it one of the largest public lists.
Survey of Space Based Solar Power Efforts as of 2023
In this survey, the range of solutions and applications is wider, but there must be a space connection and an element of wireless energy transfer. For example, solar panels on the Moon, wired to the consumer, is not space solar power in this survey. It is lunar solar power, space energy and a space utility, but here space solar power assumes some type of power beaming to align with the original concept.
In 2023, several solutions and new types of solar cells are close to market readiness. One is a thinfilm low-cost silicon solar cell, for example developed by Solestial. Their thinness helps to decrease mass and volume. Self-curing is very beneficial to extend lifetime. In longer-term and at large quantities, prices below $1 per watt have been quoted. Silicon solar cells are widely used in terrestrial solar farms thus production capacity solutions are known. The current efficiency of silicon cells is less than for multi-junction, about 20%, but some architectures for the large-scale space solar power plants should be able to negate that thanks to microgravity.
Perovskite solar cells could be printed.
Power Beaming (Wireless Power Transfer)
Very simplistically, telecommunications and TV broadcasting spacecraft in GEO have done power beaming since the 1960s using similar S-band or Cband frequencies. Differences are that the output power would be much larger, no data would be sent, and the antenna will be much larger to ensure small
divergence of the beam.
Electronically steerable phased arrays been used for decades in military applications, but the cost has now decreased enough to find commercial applications like Starlink Dish. They enable e.g. to use a near-field system, which Emrod has described.
Launch
Access to space has two critical factors, price per kilogram and mass to orbit within a time frame. SpaceX’s Starship is aiming to solve both.
Starship is being designed for 3 flights per day and be fully reusable. One rocket could theoretically fly 1000 times per year. More, the goal is to build hundreds if not thousands of Starships. With each launch having a payload of about 100-250 tons, the mass to orbit per year can increase enormously.
In terms of cost, the goal is to decrease cost per Starship to below $10 million in a few years. Longerterm, it could even cost a few million dollars in the future. Assuming $10M and 100,000 kg equals $100 per kilogram. In the most optimistic case, assuming $3M and 300,000 kg gives $10 per kg. NOTE: I, Nextbigfuture, adjusted the most optimistic case based upon improved 1337 engines.
In-Space Assembly, In-Space Robotics
The best known examples for assembly in space are the Mir and International Space Station. Kilometer-scale space solar power plants have been
compared to the football-field size of the ISS.
However, such large size is an engineering problem, to build it autonomously and rapidly at low cost, and not a fundamental scientific problem.
As of 2023, several new in-space assembly and in-space manufacturing demonstration missions are in development. For example, the OSAM-1 mission
is planned to launch in 2025. Its SPIDER payload will assemble 7 elements using a robotic arm to form a 3 meter diameter communications antenna.
Wireless Power Transfer
Numerous companies are pursuing terrestrial applications for large-scale wireless energy transfer. Including a wireless energy grid, part of which may be based in space. Remotely powering electric airplanes should make them easier with existing batteries.
Selected Space Based Solar Companies
Overview Energy is a VC-backed aerospace startup founded in 2022 and based in the US. Overview is solving fundamental problems in aerospace manufacturing, GNC, and space power systems and will be building a constellation of large, deployable satellites. They aim to build the most economical spacecraft ever flown to GEO, at unprecedented scale.
They are in stealth mode but it is known to be related to space solar power and/or power beaming. PitchBook says they raised $6.8M seed in
July 2023 while Crunchbase says they raised $3M seed in July 2022.
Northrop Grumman Corporation is an American multinational aerospace and defense technology company with about 95,000 employees.
In 2015, Northrop Grumman signed a sponsored research agreement with the California Institute of Technology (Caltech) for the development of the Space Solar Power Initiative (SSPI).Northrop Grumman will provide up to $17.5 million to the initiative over three years.
In 2018, The U.S. Air Force Research Laboratory (AFRL) awarded Northrop Grumman a $100M contract to develop a payload to demonstrate key components of a space solar power system. Called Arachne, it could prototype a space-based system to provide solar power to remote military bases.
The Space Solar Power Incremental Demonstrations and Research (SSPIDR) is scheduled to launch in 2025 to show the capability of beaming RF energy down to the planet. In 2022, they announced the successful demonstration of the ability to beam radio frequency energy toward various antennas by
steering the beam.
Aquila, founded in 2022 in Australia, is building energy networks of light. In June 2023, they announced raising of ∼$2.1M ($3M AUD).34 Plan is to
direct light beams at receivers integrated into power systems, which convert energy into electricity.
Aquila is build and operate a dynamic, lightbased energy network that can extend and improve the capabilities of their energy distribution infrastructure. By beaming energy with lighthouse modules, redirecting it with mirrors, and capturing it with specialized solar panels, they can rapidly create transmission pathways and shift renewable energy worldwide, accelerating their uptake. Their long-term vision is a globe-spanning energy network consisting of thousands of optical relay satellites directing gigawatts of power worldwide.
Currently, they are focusing on creating lightbased energy products to serve small drone operators to supply power continuously to drones in-flight.
Aquila published a whitepaper titled ”Global Energy Interconnection” in July 2022. Tom McLeod from Startmate published their investment notes on
Aquila in September 2022.
Emrod was founded in 2019 in New Zealand. Emrod is proposing a global Wireless Energy Matrix (WEM), which would beam renewable energy via satellite between any two points on Earth. In an article by Loz Blain at New Atlas from 2022, Emrod was looking at another proposal that would place
satellites in much lower orbits closer to 100 km – those would only need to be 30-40 meter across, and thus much cheaper to build and launch.
Financial Review wrote in October 2022 that Emrod has raised $3.3M seed capital via its founder, the New Zealand government, PowerCo and US-based
crowdfunding and angel investors. This includes over $1M raised via crowdfunding in 2021. In May 2023, Emrod announced joining ESA BIC Bavaria and setting up up an office in Munich, Germany, close to partners at DLR, Airbus, OHB, and others. They also stated that they are targeting 2025
to commence in-orbit testing.
PowerLight was founded in 2007 as LaserMotive. Since then, PowerLight has set three world records for beaming power over light, won two NASA government awards and advanced five generations of technology systems. They are the first team to develop technology platform that demonstrated transfer of 400 watts over 1 kilometer. According to Crunchbase, they have raised over $4.1M but have more in grants.
In 2009, they won $900,000 in a NASA-sponsored contest to power cable-climbing robots. In 2021, they were finishing a $9.5M project for the U.S. Naval Research Laboratory. In 2019, PowerLight showed that its power-beaming system can transmit 400 watts of power. In 2020, it demonstrated a
lightweight power receiver suitable for drones.
Solaren was founded in 2001 to make space solar power reality. In 2009, California’s biggest energy utility (Pacific Gas & Electric) announced a 15-year deal to purchase 200 megawatts of electricity that would be beamed down to Earth from outer space, beginning in 2016. Solaren’s system would be ”competitive both in terms of performance and cost with other sources of baseload power generation.“
Gary Spirnak (CEO), said the company consisted of about 10 engineers and scientists, and plans to employ more than 100 people in a year. ”The impetus for forming Solaren was the convergence of improved high-energy conversion devices, heavy-launch vehicle developments, and a revolutionary Solaren-patented SSP design that is a significant departure from past efforts and makes SSP not only technically but economically viable.”
In June 2023, they announced raising $2.5M in an initial Series D round.
Solestial, previously Regher Space, was founded in 2015 and raised $10M seed in 2022. Solestial is developing thin-film, flexible, mass-manufactured, radiation-hardened and low-cost silicon solar cells and solar blankets.
Solestial announced In-orbit demonstration planned for 2024 with German DCubed.space. Following product launch next year, 1kW solar array product due in 2025 and 10kW version in 2026.
Solestial believes the new space revolution will require 3–4 orders of magnitude more space solar capacity to make it possible. Nextbigfuture believes the growth of space based solar power is to make many megawatts of solar power in space and beam to other orbiting satellites and addressing other niche high value markets on earth or in space.
In Nov 2023 DCUBED, the German NewSpace hardware manufacturer, and Solestial, the U.S. solar energy company for space, announced a new solar array product designed to make space more affordable. The new product, a scaled demonstration of which will be on show at this week’s SpaceTechExpo trade show in Bremen, will marry the specialist technologies of both companies, using DCUBED’s in-space manufactured back structure and Solestial’s thin and flexible silicon solar blanket. The back structure element, essentially the support structure for the solar array, will be built in-space when deployed.
Given the high-power consumption of smaller satellites that are now forming the vast bulk of communication constellations, the new deployable smallsat solar array will make an invaluable contribution to reducing mission costs, by reducing both material costs and mass. The companies estimate that those savings could be as much as ten times—one order of magnitude—cheaper than existing solutions.
Virtus Solis was founded in 2018 in the USA. They say they have designed the world’s first spacebased solar power energy generation system able to
directly compete with all forms of energy.
The process and details are:
1. Solar power gathered in space by small satellites with high efficiency solar panels. Each 1.65 m satellite delivers 1 kW of power to ground.
2. Satellites are grouped into massive arrays, 100,000 satellites for 100MW, allowing for a highly scalable energy platform up to multi-GW level.
3. Satellites are in sunlight all of the time with long dwell time over the northern/southern hemisphere due to orbital characteristics. Using
highly elliptical Molniya orbit constellation.
4. Solar energy is converted to 10 GHz microwaves to beam energy to ground – rectennas gather microwave energy and convert to electricity.
They won $200,000 in 2022 as one of the 7 winning teams of Phase 2, Level 1 of NASA’s Watts on the Moon Challenge. The challenge describes delivering energy across 3 km from a variable source and delivering it to a load at the other end. They solved it with their core wireless power transfer technology and a novel energy storage system.
In March 2023, they demonstrated power beaming live over 100 meters. It consisted of one power satellite of 1.92m aperture, which had 6400 transmitting antenna elements. One receiving antenna (rectenna) of 1.32m x 1.62m aperture had 1944 receiving antenna elements.
In May 2023, they were accepted to Seraphim Space Accelerator. In June 2023, they together with the University of Bristol in the UK were awarded
£353,000.
Virtus Solis has not publicized fundraising amounts but they are likely to be one of the best funded, and among some of the furthest along, space solar power startups.
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
Known for identifying cutting edge technologies, he is currently a Co-Founder of a startup and fundraiser for high potential early-stage companies. He is the Head of Research for Allocations for deep technology investments and an Angel Investor at Space Angels.
A frequent speaker at corporations, he has been a TEDx speaker, a Singularity University speaker and guest at numerous interviews for radio and podcasts. He is open to public speaking and advising engagements.
DARN. My first reaction on reading the title and looking at the image was “At Last! Someone is taking the right approach to getting energy to the surface! But why put it on Deimos, and how can they get it done in 2024??”
… Oh. DEMOS. Oh well.
Its going to cook every migrating bird like Colonel Sanders on crack!
The computation (done since the 80s) is to have a beam strength of about 20% noon sunlight, so even if a bird should land on top of a rectenna (never mind flying through it), the best it’ll get is sunburn. This means that rectennas will have to be a lot larger than they would be, but you can use the ground beneath it to plant beans or whatever, and then you get some nice dual use of it. Or paint it white, then the reflected sunlight would more than cancel out the added energy. More information: https://www.agci.org/wp-content/uploads/imported-files/2022/07/03S2_DCriswell_0710.pdf
Or perhaps you think you are the first to conceive of this problem?
If it only increases the amount of energy/sunlight hitting a particular patch of earth by 20%, then what is the point? Why not just add 20% more solar panels to a solar farm? The paper you linked to was written in 2003. In 2003 solar panels cost $4.50 a watt. Maybe in someones mind it was economical to design, manufacture, launch and maintain a giant space based mirror or solar panel system that will glow in the evening sky like a neon mini moon (something that will piss off every astronomer and the entire Dark Skies movement), as opposed to adding 20% more solar panels to a ground installation, but times have changed since 2003. Solar panels are now 80 cents a watt and falling. How can launching a space based system of orbiting collectors/reflectors be cheaper than adding 20% more solar panels to a solar farm? Virtus Solis is talking about a 10 ghz microwave beam. I don’t know how much of that hits the rectifiers, but if it can’t transmit enough extra power to cook a Sparrow, how can they economically compete? Powerlight after 15 years in business can transmit only 400 watts? A single ground based solar panel makes 300 watts. How can their collection and beaming technology contain cheaper components than a solar panel after paying for a ride to outer space? I love Brian’s exhaustive research in this area, hes one of the best. I will be spending the week trying to figure out how I can short any of these space based energy systems or the funds that invest in them. My prediction is that the entire field of space based power systems will lose all their investors money as fast as the Hyperloop companies did.
The effects of waste heat are a pretty open question. There is little science on the subject. Most people talk about electricity but don’t mention heat from vehicles. The mainstream number is 1%. Many respectable people out there have much larger numbers in mind. I’m convinced it’s huge because I watch metro areas destroy weather fronts constantly on radar, which really didn’t happen much not so long ago.
How is beaming energy to earth not going to contribute to global warming? It would be far more prudent to invest in simple ways to use energy already available to us.
Because the atmosphere is transparent to the wavelength of microwaves that would be used to beam power back to Earth. If the atmosphere wasn’t transparent to the chosen wavelength then you would be wasting energy and scattering it.
Oh and you’d think that “Maineman” would want some more global warming. Maine is rightly “vacationland” in summer but the winters are pretty awful.
The energy is being beamed to the earth’s surface. It doesn’t disappear. It stays there. We love our cold winters in Maine, simple as that.
The energy is absorbed by a ground based rectenna where it is converted directly to electricity.
You really need to do a better job of thinking this through. If the energy was hitting the ground then how would you get electricity? If you weren’t getting electricity then why did you spend tens of billions of dollars? If the energy was being wasted in an attempt to warm the ground then the energy hitting the ground could not be greater than the energy hitting the solar panels in orbit so basically it would be no stronger than sunlight.
It IS an input of energy to the system. Of course, you can say the same of burning coal: It releases heat, that’s why we do it!
The theory here is that while burning fossil fuels releases GH gasses which then result in the retention of much more energy than they produced by burning, the microwave energy in question doesn’t produce those gasses. So the secondary contribution to heating, (The much larger contribution!) is absent.
In principle, of course, you could station a SPS at the L1 point, and block more sunlight than the microwaves you beamed down. Mind, the antenna size you’d need to make that work would be absurd… But it could be done.