Purdue University Designs a Swarm Solution to Bringing Space Solar Power to Earth
In a report titled “Lightweight Solar Power Constellation,” the Purdue University team designed a constellation of satellites to collect solar energy and beam it to the ground.
Spoke and Hub
The constellation uses a Spoke and Hub architecture: a set of smaller “spoke” satellites with large mirrors to reflect sunlight are launched with a single, larger “hub” satellite to collect and transmit the power to Earth. The team calculated that this design would allow them to concentrate the energy of “400 suns” onto the hub collector – a design choice that would a huge premium on the ability to dissipate heat to keep the hub from melting down. This would require advances in technology that are in the experimental phase today but not yet ready for deployment in space.
The spoke satellite design uses a lightweight, highly reflective, mylar mirror to focus sunlight. The hub design contains highly efficient concentrated solar cells to collect the reflected light. Power is beamed to the ground via microwave transmission from the hub.
Seven to Eleven MW from Space
The Lightweight Solar Power Constellation is placed in a GEO orbit by a single Falcon Heavy launch. A system of 15 spoke satellites with one hub satellite that can produce a range of seven to eleven MW depending on the time of day. The cost of a single system on a Falcon Heavy launch is $240 million. The LSPC will have political considerations with the amount of power moving through the low earth orbit band and the atmosphere. The total efficiency of the LSPC from collecting solar power to electrical energy in the grid is 21.98% with a collection rate of 300W/m.
The report concludes that, even allowing for technology advance, space solar power still faces daunting economics that make it unlikely to be commercial viable for many years to come. The team also predicted that only a very large scale of operation – many times greater than their design – would be able to generate power on a commercially competitive basis.
Meet the Team
The Purdue University team (pictured above) are undergraduate engineering students at the School or Aeronautics and Astronautics and active members of the Purdue chapter of SEDS. They are:
You can read the full report from the Purdue University team here. See a full description of the Solving the Space Solar Puzzle Problem, conducted in partnership with the Students for the Exploration and Development of Space.