future investments in the heat sector
In the heat sector, the Energy [R]evolution scenario would require also a major revision of current investment strategies. Especially solar, geothermal and heat pump technologies need an enormous increase in installations, if these potentials are to be tapped for the heat sector. Installed capacity for direct heating (excluding district heating and CHP) need to be increased up to around 2,300 GW for solar thermal and up to 1,400 GW for geothermal and heat pumps. Capacity of biomass use for heat supply needs to remain a pillar of heat supply, however current plants need to be replaced by new efficient technologies.
Renewable heating technologies are extremely variable, from low tech biomass stoves and unglazed solar collectors to very sophisticated enhanced geothermal systems and solar thermal district heating plants with seasonal storage.Thus it can only roughly be calculated, that the Energy [R]evolution scenario in total requires around $ 4,950 billion to be invested in renewable direct heating technologies until 2050 (including investments for replacement after the economic lifetime of the plants) - approximately $ 124 billion per year.

