Could you harvest more helium from the solar wind? Fusion involves very small amounts of changed atoms for very large amounts of power.
I have a friend still alive who flew anti-sub blimps in WWII. He describes the Goodyear blimps as toys. But how many Niagara-year-power-equivalents it would take to fill one of those toys is beyond my abilities to calculate any more. IIRC it would start with ergs per He atom and proceed through Avogadro's number x 2 atoms per 4 grams of He... that's a LOT of atoms but then ergs are so small compared to the power generated, I get lost.
What's that old line about powering a city for a year on a liter of sea water?