Helen, a Helsinki-based energy company, has unveiled plans for a large-scale district heating plant complex. Germany's MAN Energy Solutions is supplying a 33 MW air-to-water heat pump, the largest ever used for a district-heating plant, with ambient air and renewable electricity for heat generation.
What about when you don’t have excess solar power? People need heat when they need heat, not just on sunny days. So, you’d need a massive battery for that, which has some undesirable implications. Instead, a thermal plant (be it solar, geothermal, or nuclear) can be designed to reliably satisfy heating and electricity demand with excess electricity going to hydrogen production for emissions-free steel, fertilizer, and vehicle fuel.