So Pablo's plugged in tonight with a new engine block heater. The dealer has to remove a sub-frame member to install it because the manufacturer doesn't want to add $5 to the manufacturing cost. So it's 3.5 hours labour making for about a $400 total all in. Youch, but I knew that going in. $1 per watt ironically, as confirmed by the WattsUp meter.
Anyway, I'm hoping to save 13 cents worth of gas each weekday morning by spending 8 cents worth of electricity to do so. My mother used to mention pennywise - pound foolish or something like that, well this certainly is. I reckon the payback is about 40 years assuming 75% seasonal usage.
Anyway, tonight there's no timer involved so it's 32 cents and 11,000 BTUs of warmth for the engine. Watch me get the typical 18 LHK on my first leg tomorrow and see no difference.
11,000 BTU/day would take the tesla (or forkenswift) about 11 miles.
In environmental terms it is an additional 1.35 tons of Co2 a year.
1.35 tons seems a bit steep - perhaps reasonable though...
11,000*365 = 4.015 million BTU
Anthracite coal = 227.4 lbs of CO2 per million BTU
= 913.011 pounds CO2 or roughly 39.7 gallons of gasoline burned in a warmed up car (about 22lb/gallon)....
Without sources - purely anecdotal.... I've noticed my car to take about .5 gallons to reach operating temp (within 10 degrees F) in my winter time. If I drove every day - that's a cost of 182.5 gallons of fuel or ~4015 lbs of CO2.
So the question is... Does using 11,000BTU/day save 41.5 gallons of fuel annually? allow me to warm up within 0.39 gallons?
Intuition tells me.... Maybe. Bear in mind that I'm in a southern climate
That assumes 100% of your power comes from anthracite coal....
If we assume 100% comes from NG(methane)
Methane = 115.258 lbs of CO2 per million BTU
= 462.76 pounds of CO2 or roughly 21 gallons of fuel
21 gallons of fuel = 462lb CO2
161.5/365=.44 gallons per day to warm up to break even CO2 wise.
This seems more feasible for me....
Remember, that' anecdotal for someone that lives in a warm climate...
If you get your power from nuclear, hydro, etc. etc. - uncontrollable environmental impact is further reduced (a lot).
Yah, I need to look a little more closely at the kwh to lbs of CO2 conversion factor. It might be more like 1.5 lbs CO2 per kwh to the socket in the wall in the states, more like .5 lbs CO2 per kwh in ontario.
Are you assuming that the .5 gallons of warmup does not include any driving?
Im thinking on the warm days you will see the advantege of preheating in just a hour or two. Eaven in the cold cold nights, I bet most of the heating will happan in just a few hours. Any more then that is just keeping the water warm.
Hmm, I'm still not convinced that there is an "advantage", especially on warm days.
If you start your car and go then it will warm up without using any extra electricity. If you start your car and let it sit there till it is complete warm then you should be beotch slapped.
I'm ignoring the monetary costs here (including $400 installation fees) as an "advantage".
So the question is: Does the energy used by the heater offset the drop in mpg you see during the first couple minutes of driving? Note: You only need to drive enough to get the engine up to the temperature where the heater would have for this comparison.