Meanwhile:
http://www.interfax.ru/world/550084
http://echo.msk.ru/news/1928668-echo.html
It appears that Ukraine has enacted the state of emergency in it's energy sector. The stated cause for it is... Ukrainian activists blocking supply of coal from the separatist held areas to the Kiev controlled ones.
p.s. while this development may not be critical (Ukraine has ~1 month worth of reserves left) it is pretty important, as Ukraine and Russia did not prolong the electricity export agreement (from Russia to Ukraine - Ukraine was in due to their deficit and Russia was in for the transit of electricity to Crimea, now Crimea is supplied directly from Russia and Ukraine, should it renew it's coal deliveries, is no longer facing shortages). This means that unless the coal deliveries begin Ukraine would suffer power shortages in the summer.
The reason why Ukraine cannot switch to another means of generation is simple - it doesnt have the money to build that capacity. Nor can it transit to another kind of coal b/c Donbas coal was very high quality and would be too expencive to buy elsewhere or to shift to a different kind of coal (the later is hard b/c you need to modify boilers).