Fig. 21

Time series plot showing how the (power-controlled) heating of the FE experiment at Mont Terri rock laboratory was started. The ‘deepest’ heater H1 was backfilled and turned on first. The first power step at 500 Watt was started on 15th of December 2015. After 1 month the power was increased to 1000 Watt. Finally, on 16th, 17th and 18th of February 2015, all three heaters were turned on successively to a power level of 1350 Watt for each heater