He then walks through a few scenarios for getting that much energy, ranging from a planetwide array of solar cells togather the energy (estimated time: 40 million years) to an asteroid made of antimatter to simply firing a moon at 50 miles per hour at the planet.
The camera should be able togather enough data to allow all four possible avenues for exploring dark energy: galaxy clusters, supernovae, large-scale galaxy clumping and weak gravitational lensing, at the same time.