ALCOHOL 39 
Gas engines operating on natural gas 
or on illuminating gas from city mains 
will, on fluctuation of load with the reg- 
ular work, average about 12,000 heat units 
per brahe horsepower hour, or 20 per cent 
thermal efficiency. Exploding engines 
operating on crude oil will average about 
25,000 heat units per brake horsepower 
hour, which is equivalent to about 10 per 
cent thermal efficiency. Exploding en- 
gines using gasoline should operate at a 
thermal efficiency of about 19 per cent un- 
der similar operating conditions. 
The efficiency of an alcohol engine may 
be asSumed at this time to be unknown, 
but as alcohol can be burned in engines 
designed for gasoline, it may be assumed 
that such an engine will have with alcohol 
fuel the same thermal efficiency as with 
gasoline, to-wit, 19 per cent for fair work- 
ing conditions. 
From the above brief discussion of the 
efficiency of different methods of power 
generation from different fuels it appears 
that quite a range is possible, though not 
SO great a range as exists in the case of 
cost of fuel energy. Efficiency is seen to 
lie somewhere between 2!. and 20 per cent 
for all the fuels under working conditions. 
It is known that actual thermal efficiency 
under bad conditions may be less than one 
per cent and under the best conditions 
as high as 40 per cent, but these are rare 
and unusual cases. The range given is 
sufficient to indicate that a highly effi- 
cient method may make the fuel cost per 
unit of power less with quite expensive 
fuel than it would be with cheaper fuel 
used in a less efficient machine. It is 
also perfectly clear that without proper 
information on the efficiency of the ma- 
chine or the efficiency of the plant it is 
impossible to tell what the cost of fuel 
per horsepower hour will be, even though 
the price of the fuel per ton or per gal- 
lon be known. From the figures given on 
the cost of fuel and a fair average for 
plant efficiency the cost of fuel per horse- 
power hour is computed as given in the 
following tables: 
Cost of Energy in Fuels 
N uniber | of 
4 } » * * 
Kind of Fuel Cost of Fuel Grition sherpa) units bought 
for $1 
Small anthracite.........0 0. ..... $2.50 per ton.. . .| 12,500 per pound.. .., 40,000,000 
Large anthracite. . 6.25 per ton..... 14,000 per pound... .. .| 4,500,000 
Tiluminating gas... iw 1.00 per 1,000 cubie feet. 550 per cubic foot..... 550,000 
Natural gas. . -10 per 1,000 cubic feet.; 1,000 per cubic foot ...) 10,000,000 
Crude oil.... . .O4 per gallon. Cuan 20,000 per pound... 3,650,000 
Kerosene...... 0.6.0 ...e. -10 per gallon... ..... 20,000 per pound.. eae ,200, 
6 ra -30 per gallon... . . .' 20,000 per pound.. ..... 400,000 
Gasoline... .. 2... ce. eee .10 per gallon... ... .| 20,000 per pound.. | 1,200,000 
O ..... .30 per gallon. . 20,000 per pound... ..... 400,000 
Grain aleohol. . .80 per gallon. ........ 12,000 per pound........ | 279,000 
do cee oe woe ea! 
Seemann Earnerey eel ee Fert ete MI 
: British 
Fuel required | thermal 
per units Te- 
Fuel and type of plant quired per 
horsepower | horsepower 
per hour | hour 
Anthracite coal: 
Large steam plant.. 2 pounds..... 25,000 
's (oan 2 pounds..... 25,000 
Small steam plant.. 7 pounds..... i 100,000 
wee wees pounds.....; 100,000 
Producer was plant. 1% pounds 14,000 
do ..... ...| 1}4 pounds...) 14,000 
qo 2 pounds..... 25,000 
Seer 2 pounds..... 25,000 
Iluminating MAS oo. e ee 24 cubic feet..! 12,000 
Crude oil. ............. 1.4 pints..... 28,000 
Gasoline............05- 1.1 pints..... 13,400 
GO eee cee 1.1 pints..... 13,400 
Aleohol.. 0. cc bec cee wee ene fu eee e ete e ane 
oo cn 
-40 per gallon... . 
.! 12,000 per pound........ 
Fuel Cost of Power 
Cost of 
Thermal fuel per 
efficiency Cost of fuel horsepower 
per hour 
Per cent Cents 
$2.50 per ton..... ..... 0.25 
10 6.25 per ton. oF 
21% 2.50 per ton. 1.00 
ai 6.25 per ton........... 2.20 
18 2.50 perton..... ..... 14 
18 6.25 per ton........... .ol 
10 2.50 per ton see eee . 25s 
10 6.25 per ton........45. oT 
20 1.00 per 1, “060 cubic feet. 2,20 
10 .O4 per gallon scene eece . 68. 
19 15 per gallon......... 1.70 
19 .30 per gallon......... 3.40 
al9 30 per galion......... 5.00 
al9 40 ner gallon ....... 6.70 
a Efficiency of alcohol is assumed to be the same as that of gasvline for identical condi- 
tions of use. 
