How much coal does it take to power a 100 Watt Light Bulb for 1 year?

lsayre · Post by **lsayre** » Mon. Feb. 11, 2019 10:30 am

The shocking answer is 714 lbs. of coal when burned in a 40% efficient coal burning electrical power plant.

https://science.howstuffworks.com/environmental/e ... ion481.htm

lsayre · Post by **lsayre** » Mon. Feb. 11, 2019 11:10 am

I did the math for anthracite, and I got 610 lbs.

100 Watts/Hr. x 24 hours/day x 365.25 days/year = 876,600 Watt/Hours

876,600/1000 = 876.6 KWH

876.6 / 0.40 efficiency factor = 2,191.5 KWH

2,191.5 KWH x 3,412 BTU's/Kw = 7,477,398 BTU's

7,477,398 BTU's/12,250 BTU's/Lb. = 610.4 Lbs.

The 714 Lb. figure must be average run of the mill coal, spanning anthracite, bituminous, and lignite.

lsayre · Post by **lsayre** » Mon. Feb. 11, 2019 11:16 am

So 610 Lbs. of anthracite can either keep a 100 Watt light bulb burning for one year, or heat your entire house for about 15 winter days. The choice is yours.

oros35 · Post by **oros35** » Mon. Feb. 11, 2019 12:53 pm

So that's about 2.9 million BTU's of heat produced by that light bulb. At 100% efficiency after production and distribution losses.

Or about 7.9 million BTU's for equivalent in coal. So for an average efficiency of a coal stove around 75%, That's about 5.9 million BTU's.

So in reality, it takes twice as much electric. And around 60% of electric is fossil fuels, burning coal in your home is still about 10% less fossil fuel consumption!

lsayre · Post by **lsayre** » Mon. Feb. 11, 2019 1:17 pm

Since 100 Watts is roughly 341 BTU's, and a typical house situated in roughly a 6,300 annual HDD's environment can be heated by about 28 BTU's per sq-ft, each 100 Watt light bulb should heat about 12 sq-ft of floor space. For a 1,600 sq-ft house, it would only take about 133 of such light bulbs to heat it on the coldest day of the year.

The final correction that needs to be applied here is that only roughly 90% of the 100 Watts go to directly to heat, whereas the other 10 Watts actually make light.

So in reality it is 133 / 0.90 = ~148 incandescent light bulbs rated at 100 Watts are required to heat a typical 1,600 sq-ft house.

148 x 100 x 0.90 x 3.412 = ~45,450 BTUH output

Ballpark 1 x 100 Watt light bulb per every 11 sq-ft of floor space.

McGiever · Post by **McGiever** » Mon. Feb. 11, 2019 2:01 pm

But incandesents are being phased out, but the math is amusing still.

But...as for the reasoning of summer shut down and then to apply long term heat (resistance, watts) used as a corrosion deterent in a stove or boiler, one can vastly reduce WattHours consumed with the simple addition of a thermostat control and placing a over-wrap blanket of insulation for conservation of applied heat.
A 0.01 watt LED pilot light could signal all is well within...

Summer time cooling is another "perk" towards justification of the overall WattHour totals too.

BigBarney · Post by **BigBarney** » Mon. Feb. 11, 2019 2:11 pm

Actually all 100 watts would end up as heat in a closed

space because as the light strikes a surface heat is released

to the surface.

Incandesents create more heat than what we want which is the

light so LEDS are much better and long lasting especially in a

building your trying to cool in the summer.

BigBarney

warminmn · Post by **warminmn** » Mon. Feb. 11, 2019 3:17 pm

I think it just means we have to mine more coal

Interesting post.

Bubbalowe · Post by **Bubbalowe** » Mon. Feb. 11, 2019 3:28 pm

The Amish got it right.

BigBarney · Post by **BigBarney** » Mon. Feb. 11, 2019 3:31 pm

The Amish...

Sell firewood at a high price......

Buy coal to heat their houses....

Simple....

BigBarney

McGiever · Post by **McGiever** » Mon. Feb. 11, 2019 4:22 pm

BigBarney wrote: ↑
Mon. Feb. 11, 2019 3:31 pm
The Amish...

Sell firewood at a high price......

Buy coal to heat their houses....

Simple....

BigBarney

Dem dumb English

Bubbalowe · Post by **Bubbalowe** » Tue. Feb. 12, 2019 9:58 am

Funny, burning anthracite like an Amishman discussing electricity. Another Amish thing is Fasnacht, Shrove Day, Fat Tuesday, Donut Day coming March 5 this year. Giant Eagle has been selling Paczki for a while but Amish donuts are better if you can get them, IMHO.

lsayre · Post by **lsayre** » Tue. Feb. 12, 2019 11:33 am

Bubbalowe wrote: ↑
Tue. Feb. 12, 2019 9:58 am
Funny, burning anthracite like an Amishman discussing electricity.

Around here many of the Amish sects have embraced solar panels, battery banks, inverters, and generators. They seem to be generally well more knowledgeable of their workings than the average English. They refer to it as connecting to God's grid.

Bubbalowe · Post by **Bubbalowe** » Tue. Feb. 12, 2019 11:51 am

True, various sects like Mennonites do embrace more modern technologies. I respect Anabaptist for their ability to live without needs of excess and the ability to take care of their own.

lsayre · Post by **lsayre** » Tue. Feb. 12, 2019 12:49 pm

Bubbalowe wrote: ↑
Tue. Feb. 12, 2019 11:51 am
True, various sects like Mennonites do embrace more modern technologies. I respect Anabaptist for their ability to live without needs of excess and the ability to take care of their own.

I'm specifically referencing Amish, not Mennonites. As long as they can make the energy by themselves, they can utilize it.

Admittedly, some stricter sects do not see it this way. But around here they are in the minority.