Adds researchable solarthermal panels and heat accumulators.
Vanilla heat pipes, heat exchangers and nuclear research are rebalanced
(optionally) to fit to the new equipment.

Solarthermal panels work similar to standard solar panels but
generate heat instead of electricity. A single solarthermal panel has
the same power as a vanilla solar panel but it receives a neighbour
bonus like a reactor. Consequently, large arrays have to be used
to get an advantage which is worth the cost and complexity.
If enabled in the mod settings, solathermal arrays and heat accumulators
can be upgraded to Mk2 and Mk3.

Heat accumulators store heat energy in a compact way like vanilla
heat pipes and reactors. The heat capacity of heat exchangers
and heat pipes has reduced heat capacity so you will need
heat accumulators now in medium to large nuclear setups.
This rebalance can be disabled with a config option.

The nuclear power technology is spilt into "nuclear power" and the new
"advanced heat engines" technology which is required before
researching nuclear power and the new technologies.

Compatible with Bob's Mods and Krastorio 2.

License: GNU GPLv3 (https://opensource.org/licenses/gpl-3.0),
Uses modified graphics from Factorio - (C) Wube Software