I have a similar story. We used to keep the house at 62-63 degrees, and now its at 68-70 degrees with coal.
For the past 5 winters we heated the home with electricity. During that period we ranged from about 27,000 KWH to 33,000 KWH of annual usage, based on how heavy the winter was, and how many of the kids (now all adults) were still at home and not off at college, or off getting married, etc... My winter months electrical usage generally ranged from 4,500 to 6,500 KWH per month, particularly for Dec, Jan, and Feb, and March.
Now I can already see that I'm down to using only about 550 KWH of electricity per month during the winter months. But it is costing me more in coal usage than I had initially anticipated, perhaps to the tune of about one ton of extra coal annually.
I initially assumed that the AHS Coal Gun would be between 82% and 86% effieicent, but now I know that my overall system efficiency (coal burning efficiency) has in reality been only in the range of perhaps as low as 65-70%. There have obviously been areas where I miscalculated. Things such as inneficient coal consumption on warm days when few to no BTU's are really required have thrown me off, and with this odd winter, we have had our share of such warm days. Also the cost of the extra 6-8 degrees of round the clock warmth was not initially considered, and I'm certain that other efficiency matters related to soild fuel heating were also not considered.
Our coal burning efficiency seems to be great when its grippingly cold, so what is really needed is a more normal winter (or a really nasty one) to see how that affects the system efficiency.
Last edited by lsayre
on Fri Feb 17, 2012 7:12 pm, edited 3 times in total.