July 10, 2009

Powersat Space Based Solar Power Plans and Patent

PowerSat Corporation estimates they can make 2500 megawatts of space based solar power plants for roughly $3-4 Billion. PowerSat is anticipating being able to transmit power to commercial customers in 10-12 years.

Launching a powersat is very similar to launching a communications satellite, and uses the same technology and equipment. Where PowerSat’s satellites differ is in the way they travel from low earth orbit (LEO) to geosynchronous earth orbit (GEO). Unlike any other satellite, PowerSat satellites use electrical thrusters instead of chemical propulsion to move between LEO and GEO, thus decreasing the total weight of the system by 67% and the cost of launch by roughly $1 billion for a 2,500 MW power station. The base structure is inflatable – sent it up in a tight package, and then blown up to full size.

Ars Technica has some more details

The company's models predict that it can get about 17MW out of a single 10-ton unit.

Powersat will launch into low earth orbit, inflate and use ion engines powered by the solar power to transfer to geosynchronous orbit in 6-8 months.

The satellites will receive a pilot signal from the ground and use that to coordinate their energy-carrying return signal to the ground-based receiver. "The satellites act as a radio frequency cloud to create a phase array of phased arrays," Maness says. When the microwave signal hits the ground, the transmission from each satellite should be additive—all of which dramatically cuts down the weight and complexity of the hardware that has to be put into orbit

The microwave power sent by the satellites is received by a structure that's about a mile wide and between one and two miles long, depending on how far north of the equator it's based. Maness says that there are chunks of unallocated microwave frequency that can easily handle the 230 watts per square meter that's allowed by the EPA. Despite the size, the cost of the ground stations are only a small fraction of the total expense; PowerSat estimates it at $100 million or so. That's largely because the hardware is very diffuse. Rain and sun can pass right through it, and Maness suggested the ideal location might be over an orchard or corn field, where the added heat could be advantageous.

And there is some added heat; models suggest about two degrees Fahrenheit for every 10 minutes in the core of the signal—about a quarter of what you'd get on a sunny day at the beach


PowerSat Corporation (, a pioneer in safe and reliable energy generation from space, today announced the filing of U.S. Provisional Patent No. 61/177,565 or “SPACE-BASED POWER SYSTEMS AND METHODS.” The patent includes two technologies, BrightStar and Solar Powered Orbital Transfer (SPOT), which enable the reduction of launch and operation costs by roughly $1 billion for a 2,500 megawatt (MW) power station.

Solar Power Orbital Transfer (SPOT) propels a spacecraft to an optimal, Geosynchronous Earth Orbit (GEO) using electronic thrusters that are powered by the same solar array that is eventually used for wireless power transmission. Until now, all satellites have had to use chemical propulsion or a chemically fueled “space tug” to move from Low Earth Orbit (LEO), which is 300-1,000 miles in altitude to GEO, which is 22,236 miles in altitude.

BrightStar, allows individual powersats to form a wireless power transmission beam without being physically connected to each other. This “electronic coupling,” conceptually similar to cloud computing, effectively eliminates the need to handle large (gigawatt) levels of power in a single spacecraft. Because of BrightStar, one transmission beam may now come from hundreds of smaller powersats. Another advantage of Brightstar is increased reliability. If any of the individual component satellites fail they can be easily replaced without significantly affecting the performance of the system, thus establishing much greater reliability.

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