Japan Aerospace Exploration Agency (JAXA) have begun to develop the hardware for deploying a 1 gigawatt space based solar power system by 2030. These we will small lab tests.
JAXA, which plans to have a Space Solar Power System (SSPS) up and running by 2030, envisions a system consisting of giant solar collectors in geostationary orbit 36,000 kilometers above the Earth’s surface. The satellites convert sunlight into powerful microwave (or laser) beams that are aimed at receiving stations on Earth, where they are converted into electricity.
The researchers will use a 2.4-meter-diameter transmission antenna to send a microwave beam over 50 meters to a rectenna (rectifying antenna) that converts the microwave energy into electricity and powers a household heater
JAXA ultimately aims to build ground receiving stations that measure about 3 kilometers across and that can produce 1 gigawatt (1 million kilowatts) of electricity — enough to power approximately 500,000 homes.
Low earth orbit spaced based solar power could be more easily scaled
Space Island Group has almost completed financing for a prototype 10-25 megawatt system that it claims will be in orbit within 18 months, at a total cost of $200 million.
"It will 'site-hop' across base stations in Europe, beaming 90 minutes of power to each one by microwave." If the test proves successful, a 1 gigawatt installation for the UK domestic market would be the next step.