What would be the energy source for accelerating an object with the mass of an SUV to 7,500 fps?
Depending on how much lift you want to allocate to getting the installation set up - solar photovoltaic and solar thermal will both work just fine, especially with a capacitor farm. Remember, solar works a lot better up there than it does down here.
You can reduce the immediate instantaneous power demand by setting a lower acceleration rate and using a longer track.