Streaming Sunshine: Space Based Solar Power, Minus the Sci-Fi - Martin Soltau, CEO Space Solar

Space Solar has a revolutionary vision to enable Net Zero and global energy security with Space-Based Solar Power.

An 80 × 80 m satellite in low-Earth orbit, continuously exporting one megawatt of electricity to a ground station, is not science fiction. According to Martin Soltau, co-CEO of Space Solar, that first-of-its-kind demonstrator will fly within five years.

In this conversation Mark and Jeremy Think On Paper about the engineering reality and the policy headaches behind space-based solar power (SBSP):

• Cassiopeia’s solar array converts sunlight to 5.8 GHz microwaves at up to 85 % efficiency

• The down-link beam peaks at ≈230 W m⁻², less than a quarter of midday sunlight, so it warms rather than cooks anything it touches.

• A rectenna two-to-three-kilometres wide re-converts the RF to DC with ≥ 85 % efficiency delivering “plug-ready” power around the clock.

• Today’s launch prices already model to < $30/MWh levelised cost of electricity; a further order-of-magnitude drop could push SBSP below $10/MWh—one-tenth the cost of nuclear baseload today.

• Sun-to-plug efficiency is about 18 %, versus 1–5 % for ground solar once night-time and weather are included.

• Regulatory and diplomatic knots

• Spectrum allocation through the ITU, debris-safe autonomous assembly, and international rectenna standards are the next gating items—not new physics.

• Why AI cares

• Data-centre power demand is “asymptotic,” with forecasts that AI workloads could swallow > 90 % of U.S. electricity this century. Off-grid rectennas over a server farm could bypass decade-long grid-connection queues.

• Failure modes worth losing sleep over

• Beam divergence, spectrum crowding, orbital debris and the inevitable “Death-Star” headlines—all solvable, but only with transparent public engagement. A Royal Society survey found strong public support once safety was explained.

Soltau also outlines the mid-2030s scale-up to tens of gigawatts per year and why modular, robot-assembled satellites could deliver that pace faster than any terrestrial baseload technology.

Please enjoy the show. And share with a curious friend.

--

Learn More: https://www.spacesolar.co.uk/

-- 

Timestamps 

(00:00) Disruptors And Curious Minds 

(01:34) Space Based Solar Satellites 

(05:10) The Ground Infrastructure 

(07:37) SBSP V Nuclear, Coal & Gas 

(12:05) Launch Costs 

(13:55) Data Centers In Space 

(15:36) Scaling Space Based Solar Power 

(18:08) Manufacturing In Space 

(20:25) The Eisenhower Of SBSP 

(23:10) The Politics Of Space Based Solar Power 

(28:35) Energy Is Everything 

(31:05) The Government Perspective 

--

Follow and Support Thinking On Paper:

PODCAST: www.thinkingonpaper.xyz

INSTAGRAM: https://www.instagram.com/thinkingonpaperpodcast/

X: https://x.com/thinkonpaperpod