from Jenny “@solar_chase” Chase. Lots of interesting solar-power factoids, like: 12. A lot of current household PV systems are designed suboptimally and may not make economic sense or even perform well. Also, most countries will move to paying a pittance for solar exports, so self-consumption rate is becoming the most important financial parameter. 13. To financially assess a proposed rooftop solar system, you will need at least a year’s data on hourly electricity consumption to estimate selfconsumption. Also, get it built when you have scaffolding up for something else, scaffolding is expensive.