Back to the future

PRISM: BACK TO THE FUTURE — WHAT MIRRORS IN SPACE CAN TEACH US ABOUT INNOVATION FOR SUSTAINABILITY

Introduction

Technological innovation is crucial in addressing climate change. However, emerging climate technologies often face challenges related to return on investment (ROI), risk, uncertainty, high capital costs, and long payback periods. One promising example is the concept of energy from space, which involves deploying mirrors in orbit to reflect sunlight onto Earth-based solar farms.

Historical Context

In 1968, Peter Glaser, an expert from Arthur D. Little (ADL), proposed the idea of harnessing solar energy from space using microwaves. Although the concept faced technical and safety hurdles, it laid the groundwork for future innovations. Glaser continued to work on groundbreaking projects, including the Apollo 11 lunar Laser Ranging Retroreflector array.

Recent Developments

ADL, in collaboration with Thales Alenia Space France, Dassault Aviation, Engie, and Air Liquide, has revived the energy-from-space concept with a new study for the European Space Agency (ESA) on Direct Solar Reflection (DSR). DSR involves deploying a constellation of mirrors in space to reflect sunlight directly onto Earth-based solar farms, effectively extending the hours of sunlight available.

How DSR Works

• Global Installed Solar Photovoltaic (PV): Reaching around 2,000 gigawatts (GW) in 2024.
• DSR Concept: Large mirrors in low Earth orbit (LEO) can add up to two extra hours of peak sunlight per day, significantly increasing energy production.
• Deployment Plan: An array of 4,000 mirrors, each 1 km in diameter, at an orbit altitude of 890 km. The array is designed to cover multiple solar farms, with each farm receiving additional sunlight during dawn and dusk.

Environmental Impact

• Carbon Emissions: DSR infrastructure at full scale is estimated to avoid around 8.8 billion tons of carbon emissions over a 30-year operational period.
• Energy Footprint: The project has a negligible energy footprint compared to its energy production capacity.
• Hydrogen Production: At full scale, 18 million tons of hydrogen would be produced annually, more than 10% of the projected European consumption in 2050.

Economic Benefits

• Value Proposition: DSR could provide up to 60% additional energy output from each solar farm, reducing the need for additional capital expenditure (CAPEX).
• Cost Reduction: For a single PV+electrolyzer station with an installed capacity of 8.8 gigawatt peak (GWp), DSR could save $5 billion in capital investment, reducing hydrogen production costs by 50%.
• Hydrogen Efficiency: Solar fuel cells (SFC) can convert solar energy directly to hydrogen without generating electricity as an intermediate step, increasing efficiency from 12% to around 40%.

Profitability for Space Operators

• Investment Costs: The primary cost is launch and deployment, estimated at around $60 billion for 4,000 mirrors.
• Minimum Viable Product (MVP): An array of at least 800 mirrors is needed to provide a competitive green hydrogen generation cost, making it a minimum viable product.

Conclusion

DSR represents a promising approach to enhancing the efficiency and sustainability of solar energy systems. While the upfront investment is substantial, the potential benefits in terms of energy production, environmental impact, and cost reduction make it an attractive innovation for achieving sustainability goals.