However, because there is a substantial amount of work that can be accomplished with the boiler on line, the additional time would be much less than the number of high electricity demand months that are accommodated by this approach.
The boiler that is currently on line does not have the ability to finish much work. 
mnli hypothesis: The boiler that is currently on line does not have the ability to finish much work.  premise: However, because there is a substantial amount of work that can be accomplished with the boiler on line, the additional time would be much less than the number of high electricity demand months that are accommodated by this approach.