How CASSIOPeiA’s Innovative Technology Can Help Us Reach Net Zero

The global mission to reach Net Zero by 2050 is exceptionally difficult with our existing weather dependent renewables. Affordable and reliable energy is central to the quality of life for all; that’s why we must develop more capable technologies, if we are to achieve the energy transition.

When there’s no wind for days or the sun refuses to shine, we find ourselves without the power of renewables, and reliant once again on fossil fuels. We are overbuilding the infrastructure to enable everything to run smoothly, but even if there was sufficient storage we still would not have the energy security we need. That’s the real issue for achieving Net Zero; as we work towards decarbonising heat and transport, and Artificial Intelligence powered by energy hungry data centres proliferates, our electricity generation needs will treble. As it stands, we simply don’t have the technology and infrastructure to fulfil that need, affordably and reliably.  

That’s where Space Based Solar Power (SBSP) comes into play; it’s a clean, continuous and reliable source of energy that can provide affordable energy within the existing system. 

CASSIOPeiA, designed by Space Solar’s Chief Architect Ian Cash, is a very capable solar power satellite; just one of the small handful of designs that can provide the continuous power needed to achieve Net Zero globally;

1.7 km in diameter and 4 km long, it comprises hundreds of thousands of integrated power modules which include both photovoltaics and electronics for wireless power beaming. The satellite, which is typically in geostationary orbit but can uniquely use a range of orbits, features large lightweight solar panels, with a system of mirrors which reflect and concentrate the sunlight onto the panels. The electricity generated by the solar panels is converted into high frequency radio waves (microwaves) and beamed to a rectifying antenna (a ‘rectenna’) on the ground, which converts the electromagnetic waves into electricity.

CASSIOPeiA (Constant Aperture Solid State Integrated Orbital Phased Array) VS. other SBSP satellites.

In Geostationary orbit, roughly 36,000 km from Earth, CASSIOPeiA will harvest solar energy from the sun the whole time it goes round the orbit, whilst continuously beaming the microwaves to a fixed point on Earth. Since the angle between the satellite, sun and Earth is constantly changing, it requires a rotating joint which both collects and transmits energy through 360º.

Cash explains that different designs can achieve this in different ways, for example, the Chinese MR-SPS concept which is a gravity gradient design. “With its transmitter always looking at the Earth, it uses multi-rotary joints to rotate the solar panels so that they point towards the sun. It requires a huge frame, big motors and kilometres of transmission cables making it very heavy, and costly to manufacture.” 

Cash’s CASSIOPeiA concept differs, as it uses a sun-pointing design to provide continuous power. It has big primary reflectors to ensure the satellite always faces the sun, continuously reflecting sunlight onto the photovoltaic modules, which convert the energy into electricity. That electricity is then converted into microwaves, using high efficiency RF power amplifiers, to form a coherent beam which can be steered back to the ground station using our innovative 360º beam steering which was showcased recently through Space Solar’s HARRIER demonstrator (Horizontal Array for Receiving RadIo Energy Retrodirectively).

With a helical array and 360º azimuth steering, we ensure a constant aperture looking toward the ground, delivering firm power with pinpoint accuracy – and without the mechanical actuators used in other SPS concepts. Without these moving parts, the CASSIOPeiA concept proposes a much lighter and lower mass system, which is more reliable and cheaper in comparison. 


Economics is everything. Where other gravity gradient stabilised SPS designs can only be used in Geostationary orbit, CASSIOPeiA’s sun-pointing design also works in elliptical orbits. This means we can beam energy to high latitudes, with smaller cheaper systems, giving real operational advantages to different energy markets on Earth.

Space is traditionally expensive because we have always built one-off monoliths. CASSIOPeiA’s modular design features hundreds of thousands of identical modules, and this high volume manufacture allows us to lower the unit production costs and build at scale. We’ll have the ability to build multiple at a time, commissioning tens of Gigawatts of generation capacity every year. 

The potential of CASSIOPeiA as the leading design is undeniable; when compared to another concept like-for-like, in identical HEO orbit, Cash and his team found that CASSIOPeiA offered 3 times higher specific power (power per unit mass) and 4.6 times specific energy (power delivered per year). It has the power to provide continuous, dispatchable power at a gigawatt scale, 24/7, 365 days a year. In fact, just a single satellite could potentially deliver as much as 2GW of carbon-free power, enough to supply a city of 2 million people, 24 hours a day, seven days a week.

And because CASSIOPeiA is much smaller than others on the market, the cost of the energy produced is also much cheaper. It’s low cost, but high yield – a huge benefit for our ever-expanding energy demands. 

Space solar energy for people, planet and profit. 

Five billion people in the world use less electricity than a fridge, and two billion don’t have access to electricity at all. SBSP is all about creating affordable, abundant and reliable energy for all – including island nations and developing countries. It’s clean, continuous, and complements our existing technologies. So, as we work towards Net Zero, we must look to solutions which optimise our energy systems; our space based solar system CASSIOPeiA will do just that. With the backing of the UK government, we now have the opportunity to build international partnerships and bilateral agreements. Alongside regulatory standards, a capable supply chain and Cash’s market leading design, Space Solar is well placed to make the next iteration of constant clean energy, available to all.