Interestingly, the ISS solar panels are actually below Earth-surface power efficiency despite getting ~33% more incoming energy per area. It looks like the big

Interestingly, the ISS solar panels are actually below Earth-surface power efficiency despite getting ~33% more incoming energy per area. It looks like the biggest reason (other than "it's 20+ year old tech") is that triple-junction panels weren't used to save weight. Rather than optimizing power-per-inch or power-per-manufacturing-cost like we would on Earth, NASA was targeting power-per-ounce, which meant gathering only the highest-power wavelengths. Add to that some issues with panel degradation from radiation, and it's a surprisingly tough way to gather energy long-term. Short of sci-fi stuff like a space elevator or extraplanetary manufacturing, I'm not sure how solvable this is. Does anyone know of ways of getting high power output in space other than nuclear?