I don't know the specifics of solar radiation well enough to say how much power the deflection would require, but there is an easy order of magnitude calculation to figure out how much energy setting up a field that size would require. It's not the same as consumption but it's a start.
The energy in a uniform field is very simple to calculate: a sphere with a radius of 6371 km (radius of earth, diameter of mars) and 50,000 nT would store about a 10^18 joules, about 6.5% of US annual electricity consumption. At the extremal 500,000 nT that would be 10^20 joules, around 2x the global electricity consumption.
A dipole field would require ~10x more energy, a zetajoule. That's around 2x the global human annual energy consumption, including for heat/transport/industry/etc.
Correct on both points. I started with a uniform field because it requires 10% of the energy- it would mean building a distributed network of satellites, but if we're inserting exajoules of energy into near-mars orbit, making a lot of satellites is probably within our means.
50,000 nT was their suggestion of what actually starts providing relevant protection. 5,000 nT was where they started seeing it at all, which would be 10^16 joules/2 megatons of TNT. I believe the massively stronger field is needed because the protection they are looking at for terraforming would need to be much better than Earth's. We still lose 94,608 tonnes of hydrogen annually to atmospheric escape, despite having 263% stronger gravity.
No, the Martian Lagrangian point L1 is the only stable point that can be used. If you tried to move the blocker closer to the sun, the device would have to orbit faster than Mars. L1 is the point where the gravity of the sun and Mars cancel out.
The only other place you could have it would be directly on mars, where it would have to be much larger.
The energy in a uniform field is very simple to calculate: a sphere with a radius of 6371 km (radius of earth, diameter of mars) and 50,000 nT would store about a 10^18 joules, about 6.5% of US annual electricity consumption. At the extremal 500,000 nT that would be 10^20 joules, around 2x the global electricity consumption.
A dipole field would require ~10x more energy, a zetajoule. That's around 2x the global human annual energy consumption, including for heat/transport/industry/etc.