Can photovoltaics conquer space? They're already on their way!

The photovoltaic industry has ushered in a new track.

On January 8th, photovoltaic stocks generally rose, with perovskite and space photovoltaic concepts being particularly active. By the close, Maiwei Co., Ltd. rose 15.65%, Haiyou New Materials Co., Ltd. rose 14.20%, Autowell Co., Ltd. rose 11.85%, and Junda Co., Ltd. (002865) hit the 10% daily limit, achieving two limit-up days in three trading days. Oriental Sunrise Co., Ltd., Jiejia Weichuang Co., Ltd., Trina Solar Co., Ltd., and Jinko Solar Co., Ltd. all rose by more than 5%.

This surge in popularity didn't come out of nowhere; it started with a vision that sounded like something out of a science fiction movie.

Recently, Elon Musk proposed an ambitious plan: to deploy a 100GW solar satellite network into space annually, using the infinite sunlight in space to power Earth and future AI facilities and computing systems. Previously, he had even stated bluntly: building nuclear fusion reactors is foolish; the sun itself is a free super reactor, and space photovoltaics are the future.

This concept quickly sparked global discussion, with several major domestic photovoltaic companies making public statements, and others already undertaking related work such as cooperation with aerospace and on-orbit verification, attempting to be among the first to establish a foothold in this future sector.

1. Why did space photovoltaics suddenly explode in popularity?

First, let's define the concept. Space photovoltaics refers to solar power generation systems that provide continuous power to satellites, space stations, future computing constellations, and deep space missions in space environments such as Low Earth Orbit (LEO) and Medium/High Earth Orbit (MEO/GEO).

This idea wasn't proposed in recent years. As early as the 1960s, American scientist Peter Glasser had systematically envisioned this path. He proposed building large-scale solar power generation devices in space, converting the acquired energy into electromagnetic waves, and then transmitting it wirelessly to a receiving end for use.

What truly makes space photovoltaics worthy of "serious re-discussion" is its inherent physical advantages. Compared to terrestrial photovoltaics, the space environment almost completely avoids all variables affecting the stability of power generation. There are no cloud cover, no day-night cycle, and the intensity of solar radiation remains consistently high. Theoretical calculations show that solar energy intensity in space can be several times that on Earth, multiplying the power generation potential for the same area.

More importantly, there's the stability. Data shows that low-Earth orbit satellites can orbit the Earth approximately every 90 minutes, receiving over 60% sunlight and avoiding interference from nighttime and weather. Furthermore, geostationary orbit satellites only experience brief solar eclipses during the spring and autumn equinoxes, enjoying stable sunlight for about 99% of the time. This high rate of sunlight gives space photovoltaics properties close to those of baseload power sources, giving it a completely different strategic significance in energy storage systems.

In addition, the space environment simplifies the system structure to some extent. Without the energy loss caused by the atmosphere and without the environmental risks of wind, sand, and corrosion, component design can be much lighter.

It is precisely these seemingly counterintuitive advantages that have gradually transformed space photovoltaics from a distant concept into a cutting-edge direction worthy of investment from capital and industry.

2. Space Solar PV: A Real Breakthrough or Just Another Conceptual Frenzy?

Upon reading this, many people's first reaction is still: space solar PV sounds more like science fiction than a real industry. But if we shift our focus back to the energy structure, you'll find that this concept didn't just appear out of thin air.

The current global energy system faces structural contradictions. On one hand, there's the long-term pressure to decarbonize traditional energy sources; on the other hand, there's the rapid expansion of AI computing power, large-scale models, and data centers, leading to an extreme dependence on stable, continuous power. Ground-based solar and wind power installations are growing rapidly, but they are inherently constrained by day/night cycles, weather, and geographical conditions; this intermittency has become an unavoidable hard constraint.

In August 2023, Caltech completed the on-orbit verification of a space-based solar prototype system, achieving wireless power transmission from space to the ground.

Meanwhile, the technological roadmap for space solar PV is gradually becoming clearer. Currently, high-value space missions still primarily rely on triple-junction gallium arsenide (GaAs) cells. These types of batteries have a photoelectric conversion efficiency exceeding 30% and exhibit extremely stable performance in terms of radiation resistance and high-temperature resistance, making them widely used in scenarios with extremely high reliability requirements, such as communication satellites and deep space exploration.

However, gallium arsenide (GaAs) faces an unavoidable practical problem: its high cost. Due to the scarcity of gallium resources and the complexity of its manufacturing process, the cost of its space-grade modules is 1000-2000 yuan/watt higher, far exceeding that of terrestrial photovoltaic systems. This is why the industry does not expect GaAs to undertake the large-scale deployment of space photovoltaics.

According to institutional research reports, space photovoltaics will undergo a clear generational evolution: in the short term (2024-2027), triple-junction GaAs will continue to serve high-end aerospace applications; in the medium term (2026-2030), P-type HJT cells will begin to attempt to enter low-Earth orbit missions; and in the long term (after 2028), breakthroughs will be needed through perovskite and its tandem approach.

The frequent mention of perovskite is not accidental.

From a performance perspective, its theoretical photoelectric conversion efficiency can reach 45%, significantly higher than traditional materials. Moreover, in the space environment, the two major factors hindering perovskite's performance—water and oxygen—are virtually absent.

More importantly, perovskite's power generation capacity far exceeds that of gallium arsenide for the same mass. Industry calculations show that each kilogram of perovskite material can generate 10-30 watts of power, while gallium arsenide generates approximately 3.8 watts. In the aerospace field, weight is almost equivalent to cost. A 200-kilogram reduction in module weight means a reduction of millions of dollars in single-satellite launch costs.

Furthermore, the flexibility of perovskite opens up new possibilities for space structure design. Foldable and deployable solar arrays are better suited for future large-scale energy platforms.

Therefore, space photovoltaics is not merely a conceptual frenzy. It's more like a technology track with a clear long-term future and a short-term verification window. While a surge in installations is not expected in the short term, once successful, it will reshape the boundaries of energy supply.

3. Not Science Fiction, But a Tough Battle

If we only consider parameter tables and theoretical models, space photovoltaics seems to have few shortcomings. But what truly determines the fate of a technology is never its imagination, but its ability to bridge the gap between concept and engineering. Space photovoltaics stands at the starting point of this gap.

First and foremost is the unavoidable cost barrier. Reusable rockets have indeed reshaped the economic model of space launches, but cost reduction does not equate to affordability. Space photovoltaics faces not just single-satellite missions, but power plant-scale, and even network-scale deployments. Sending hundreds or thousands of tons of structural components, power generation arrays, and support systems into orbit is itself a massive investment.

More realistically, space photovoltaics is not a one-time investment that guarantees long-term success. Component aging, system upgrades, on-orbit maintenance, and decommissioning and replacement will continuously consume funds. This means that in the short term, space photovoltaics is more of a test of capital and patience than a quick-in-quick-out business.

Secondly, there is the inherent complexity of systems engineering. Space photovoltaics is far more than simply moving photovoltaic panels into space; it is a highly coupled systems engineering project. Especially at the megawatt or even gigawatt scale, existing aerospace engineering experience offers almost no ready-made solutions. This is why, even with a clearer technological roadmap, global implementation remains primarily focused on prototype verification and small-scale demonstrations.

Furthermore, there's the unavoidable reality: microwave or laser transmission is considered a key pathway for the practical application of space photovoltaics, and progress has been made at the experimental level. However, at the engineering level, it demands extremely high precision in energy focusing, transmission efficiency, and system stability. Even minute deviations can cause a sharp drop in efficiency.

Finally, there's the safety issue. The space environment places far greater demands on photovoltaic systems than on terrestrial applications. Modules must withstand extreme temperature differences of -150°C to 150°C, high-energy particle radiation, and atomic oxygen erosion, among other challenges. In addition, on-orbit heat dissipation is an underestimated problem. A gigawatt-scale system implies a massive heat load, and space relies solely on radiation for heat dissipation. The required deployable heat dissipation area could reach tens of thousands of square meters, far exceeding the engineering scale of existing spacecraft.

But as industry development has repeatedly demonstrated, truly valuable technologies are never without difficulties, but rather those that, despite numerous challenges, are still worth pursuing.

Space photovoltaics are no exception. It won't change the energy landscape overnight, but it has moved from science fiction to the threshold of engineering verification. As for whether they can cross this threshold, the answer is slowly emerging over the next decade.