100 CF of natural gas to 100 watts/hr of electricity. What produces more kilo calories?
Support answer. Trying to price local natural gas, which is very high, to electric use, which is cost effective. Thank you in advance.
Support answer. Trying to price local natural gas, which is very high, to electric use, which is cost effective. Thank you in advance.
September 11th, 2009 at 6:35 am
See this PDF file, page 10 and 11:
http://geoheat.oit.edu/ghp/survival.pdf
It says energy per unit is:
Propane – 90,000 Btu/gal
Natural gas – 100,000 Btu/therm (1,000 Btu/ft3)
Electricity – 3,413 Btu/kWh
Simplifying all the math, adding in efficiency and local cost per unit they list equations to come up with the cost of a mega-BTU.
Propane is stupid expensive here (> $3/gal) and electricity really cheap ($0.078). I swapped out my propane water heater for electric two years ago with nice results.
for $3.06/gal propane and 87% efficiency, = $39.04/M-BTU
for $0.078/KWhr electricity, = $22.85/M-BTU
September 11th, 2009 at 6:35 am
First of all, watt/hr is meaningless. I hope you mean watt-hr, a unit of energy.
From my calculator:
100 watt-hr = 0.1 kw-hr = 360 kJ = 341 BTU = 86 kcal.
You may mean 100kw-hr, a much more reasonable unit
100kw-hr = 360 MJ = 341000 BTU = 86000 kcal
one standard cubic foot of natural gas produces around 1,030 British Thermal Units (BTUs)
100 ft³ therefore = 103000 BTU = 30 kW-hr = 109 MJ = 26000 kcal
January 22nd, 2011 at 5:15 pm
good job Bill Russell, watt/hr does not apply here…