The Global Energy Challenge
Our global energy consumption is around 20 billion tonnes of coal equivalent per year. Fossil resources are running out, and conventional nuclear energy is insufficient from a long-term perspective. The cosmos offers an unexpected opening: the Sun on a silver platter.
The SPS Concept
Solar Power Satellites (SPS) are immense orbital solar panels that would continuously capture light energy — without day/night alternation, without clouds — to redistribute it on Earth in the form of microwave or laser beams, then converted into electrical current by ground-based receiving antennae.
According to specialists, a network of SPS could supply more than a quarter of all electricity consumed on Earth. The power captured in space, without atmospheric losses, is of the order of 1.4 kW/m² continuously — compared to 0.2 kW/m² on average for a terrestrial solar panel.
The Key Role of the Lunar Base
The link with the lunar base is direct: each SPS weighs 50,000 tonnes. Building it from Earth requires daily launches of 400 to 500 tonnes of materials for months. But from the Moon, where gravity is six times lower, twenty times less energy is needed to place loads in orbit — a cost reduction of at least 30%.
Studies on the lunar production of fibreglass and solar cells from regolith offer encouraging results. Ultimately, several plants providing some 960,000 gigawatts between 2000 and 2070 would generate an estimated net profit of hundreds of thousands of billions of dollars — transforming the lunar base into a profitable investment on a civilisational scale.
"A single Solar Power Satellite in geostationary orbit could power a metropolis of several million inhabitants — built from lunar materials."
