Advances in Solar Tech Making Space-Based Solutions Plausible

For quite some time now, extensive research on ways to capture and utilize space-based solar power is underway. Scientists and technology experts believe that space-based solar power could be an efficient addition to the available set of sustainable energy sources. 

Functionally, the set-up would have energy collection and harvesting panels at orbital levels, which will beam back solar energy to their receiving counterparts placed on planet Earth. And since it involves space, the planet Earth, and the transmission route between these two points, it has to be constituted of sophisticated technology solutions. 

Promisingly, advances achieved in solar tech worldwide have been making the production of space-based solar power plausible. But before we delve deeper into them, let us have a quick look at what space-based solar power solutions mean and what their advantages are. 

Space-Based Solar Power and Its Advantages

According to data presented by the United States Department of Energy, every hour on Earth, we receive more solar energy than we can use in a year. Nearly 30% of this energy goes back unutilized to space by the atmosphere. This energy can be captured and used efficiently if we get robust space-based solar power mechanisms in place. 

In this system, satellite-based solar panels can capture and transmit more energy than what is captured by solar panels placed on the surface of the earth. They perform better because of the advantages they have of being in space. According to the DEA's description, these: 

“Solar panel equipped, energy transmitting satellites collect high intensity, uninterrupted solar radiation.” 

The supply is uninterrupted because, in space, there are no clouds and no nighttime. 

The technology involves deploying giant mirrors that reflect huge amounts of solar rays onto smaller solar collectors so they can be wirelessly beamed to Earth in a safe and controlled way as either a microwave or laser beam. 

Since this process involves sophisticated technology, it attracts innovative solutions from all across the world. NASA has now published a report on Space-Based Solar Power to equip itself with the ‘information it needs to determine how it can support the development of this field of research.'

The report tries to assess the parameters that would have a crucial role to play in making space-based solar power a competitive option, where the final destination would be to achieve net-zero greenhouse gas emissions. 

Some technological bottlenecks that NASA has identified for researchers and technologists active in this field to work on are as follows:

• They would have to find ways for large systems to be assembled and maintained in orbit.
• Research would be required to make those systems operate autonomously and have efficient power-beaming to bring the harvested energy to Earth. 
• The NASA report also makes it a point that before bringing space-based solar power systems into use, it's important to tackle the costs of launching and building them. This is because sending all that material into space would need many continuous missions to transport the infrastructure into orbit.

The NASA report believes that space-based solar power systems may become fully productive and operational by 2050. Through the report, some of the milestone advances made in this field have come to light. For instance, it has reminded us of the JAXA scientists who proved that it was possible to wirelessly transmit energy accurately as microwaves across a notable distance to ultimately turn it into usable electricity. 

Carrying forward the gist of this achievement, Caltech scientists, in March 2023, came up with the Space Solar Power Demonstrator (SSPD-1) as the first spacecraft to wirelessly transmit solar energy harvested in space to Earth.

NASA has also offered some estimates on the economic feasibility of space-based solar power. Some of the experts attached intimately to this area for long have challenged those estimates as well. However, there has been hardly any denial of the benefits that this power generation system promises to deliver. It could help in disaster relief, powering remote sensors, and removing the existing bottlenecks of our traditional energy production system and its supply chain. 

Looking at its benefits, national governments of all developed countries have started investing in it. Large business entities who have the resources to invest, like Airbus and Northrop Grumman, have also been working on it relentlessly. 

We will now look into some of their achievements in the segments to come. However, one needs to keep in mind that it is an evolving space and many of the endeavors are still at the stage of prototyping.

#1. Airbus Power Beaming

One of the major companies to work on advancing solar tech to make space-based solutions possible is Airbus. Its Power Beaming technology, developed by the company's Central Research & Technology and Blue Sky Departments, has made credible demonstrations of how this could be a game-changer in the space-based solar technology scene. 

According to Jean-Dominique Coste, who is responsible for developing Power Beaming along with Yoann Thueux and their colleagues: 

“The potential of the technology is to capture sunlight and then beam it wirelessly.” 

These scientists believe this energy solution could be capable of adequately supplying power to cities, factories, households, and airplanes with electricity.

The Airbus technology developers first demonstrated Power Beaming at the company's X-Works Innovation Factory on September 27, 2022. Even though it was carried out on a smaller scale, the demonstration could sufficiently explain what it took to make power beaming work. 

Coste, Thueux, and their colleagues used microwave beaming to transmit green energy between two points that represented ‘Space' and the ‘Earth.' The distance between these two points was 36 meters. The demonstration also produced green hydrogen to power up a model city. 

After the demonstration was over, Yoann Thueux said: 

“Now that we have successfully tested the key bricks of a future space-based solar power system on a small scale for the first time, we are now ready to take Power Beaming to the next level.”

Airbus expects this technology to become a reality shortly. It believes the first operating Power Beaming prototypes will become available for use by the early 2030s. 

In its ultimate applied form, the technology would have a solar panel placed on the geostationary orbit, around 36,000 km above Earth. This solar panel will be paired with a solar panel of the same size on Earth. 

The power collected in the space would be beamed down over an area that would have many antennas spread through it. These antennas would pick up the beams for energy to be reassembled to produce electricity. 

Once this system reaches a specific scale, it would cost the same to produce energy with it as it costs in large-scale energy projects on Earth that depend on nuclear power, oil, or other renewable energy sources. According to estimates, one geostationary solar farm would generate as much as two gigawatts of electricity. 

On February 15, 2024, Airbus published its full-year 2023 results, reporting annual revenues of 65.4 billion, with an adjusted EBIT of 5.8 billion Euros. 

#2. Northrop Grumman

Another major global entity to have completed necessary tests that validate its solar space tech capabilities is Northrop Grumman. The company successfully demonstrated its ability to beam radio frequency energy towards various antennas by steering the beam. It is confident about coming up with its prototype by 2025. 

This prototype would exhibit the company's capability of beaming RF energy down to the planet. The technology is developed by Northrop Grumman's Space Solar Power Incremental Demonstrations and Research (SSPIDR). 

According to Tara Theret, the program director for SSPIDR: 

“Now, it's just building, testing, and integrating the rest of the hardware on a challenging timeline.”

Further work to be done in this process includes shrinking electronic components and scaling up the number of ‘sandwich tiles.' Sandwich tiles are nothing but photovoltaic cell panels that collect solar energy and convey power to the next layer, which have components that enable solar-to-RF conversion and help form the beams. 

The company is also manufacturing the necessary flight hardware for it to put together the system and launch it on the company's ESPAStar platform. The ESPAStar platform is a satellite bus that empowers payloads with necessary propulsion, power, attitude control, and communication. 

In a validation of the work it has been doing, the US Air Force Research Laboratory encouraged Northrop Grumman's efforts with a US$100 million contract in 2018, whereby it would develop a payload to demonstrate key components of the prototype space solar power system.

The Air Force authorities aimed to catalyze the development efforts required to build a prototype space-based system that could energize the US military bases with solar power. 

Overall, in pointing out the potential that space-based solutions in solar tech hold for the future, Tara Theret said: 

“Space solar power beaming has the potential to provide energy anywhere on Earth at any time. This technology could make power available to remote locations that need medical and communications equipment.”

Northrop Grumman registered total sales of US$36.6 billion in the year ending on December 31, 2022. Revenue earned from the Space Systems stream was close to US$12.3 billion, a notable increase from the previous year's US$10.6 billion. Out of the US$12.3 billion revenue earned in 2022, 94% came from the US government, while the rest of the 3%, 2%, and 1% came from international sales, sales to other customers, and intersegment sales, respectively. 

#3. CESI

CESI, based in Milan, Italy, has three decades of experience in conducting research, developing, and producing solar cells that are highly efficient for space applications. More importantly, it is one of the most sought-after global suppliers of multi-junction cells that use Gallium Arsenide and Indium Gallium Phosphide. 

CESI has a range of triple junction space cells. These cells, apart from Gallium Arsenide and Indium Gallium Phosphide, also include Germanium. These cells prove effective for Low Earth Orbit and Geostationary Orbit satellites. These products are also compliant with the required ECSS E ST20-08C standards. CESI is now en route to roll out four junction cells that will have higher levels of efficiency than three junction cells. 

In the future, CESI aims to offer a vast range of space solar cell products that will meet any space program requirement. To date, CESI's efforts have resulted in more than 200,000 solar cells, powering over 70 civil satellites for clients spread across 25 countries. 

CESI has its proprietary technology to manufacture solar cells in Milan. Over the years, it has built a closely knit and deep network with many international space agencies and actors. 

Like Northrop Grumman, CESI also works with the Italian National Government and has received funding from the Italian National Space Agency (ASI) and the European Space Agency (ESA). It has manufactured advanced solar cells to meet the European Space Program's needs and that of many interplanetary missions. 

According to the latest available financial disclosure, the company earned a revenue of more than 87 million Czech crowns in the financial year ending December 31, 2022. 

Advances in Space Solar Tech: The Road Ahead

Space solar tech has found its place by proving its worth to the global community, leading national governments worldwide to start investing in it with much enthusiasm. In the United States, this translated into action when the Naval Research Laboratory conducted an experiment in 2020 to capture sunlight and turn it into direct current electrical energy. It used the Air Force's X-37B space plane for this purpose. 

Meanwhile, international efforts are also gaining momentum. The Chinese authorities have set ambitious goals with their 2028 plan for a space-based demonstration led by the China Academy of Space Technology. In Europe, Solaris stands out as a well-funded three-year research program, having received the green light from the European Space Agency. The United Kingdom, too, is in the race, as it has been offering grants for studies on harnessing solar power in space. 

Evidently, innovative companies, large and resourceful global organizations, and governments across the world have been working together to capture and leverage the energy that space has to offer us. With such uninterrupted, unutilized solar energy waiting to be harnessed and leveraged for the benefit of the planet, the future looks indeed looks promising.

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