The sun., 1916-01-30
GROWTH OF ELECTRIC
POWER is UNUSUAL
Distribution of Electric Service Due to CAREFUL,
Planned System-Notes on Electric Power
Development.

extremely large, and perhaps an ab-
normal size.
In the development OF these turbo-
generator units previous experience in
the construction of engines and gen-
orators was set aside and designers had
To Hrope their way along until they
could accumulate enough experience to
undertake bigger things
The advance was steady and contin-
uuus. so that by 1905 units of capaci-
ties equal to the largest engine type
generators had already been built.
With Increased experience the advance
in size has continued until at the present
time units of 10000 XIV. to $4,000 XIV
are in operation, and even much larger
sizes. up to 10000 XIV. or 1000 XIV
are contemplated. Apparently the upper
limit will depend upon the total con-
centration of power permissible in single
units.
Increase In the size Of power general
ing stations has kept pace with or gone
beyond the increase Of power i'm indi-
Vidual generating units The capacity
or steam boilers with modern stokers
and forced draft has been wonderfully
increased. while the efficiency of the
! turbine has. also been raised greatly
by the use Of highly superheated high
pressure steam and the modern very
high vacuum condenser
All OF this development has led to the
reconstruction of power stations
| equipped with machinery still not old
and in condition as good as new. Thus.
four of the large lnterborough 1000 XIV.
engine type units, above referred to- still
a. good as new, have recently been
replaced by three 10000 XIV. turbo-
! generator units. These new units pro-
duce electrical power with n steam con-
sumption OF pounds per horse power
| hour. against about 10 pounds per horse
power hour for the old units with re-
/ ciprocatinS engines; that is, 10000 XIV
OF engine and generator capacity goes
into the space occupied formerly by aS,-
oo0 XIV. and by the use of new s1okers
some changes in draft and the addition
of superheaters the same toilers furnish
steam for 10000 XIV. that formerly sup.
! piled but $4,000 XIV This enables over
/ three times the amount OF power to he
generated in the same space and at n
very much lower cost.
We therefore see that at least two
great gains have resulted from increased
size nf power stations namely. improved
| efficiency and increased capacity Bu,
this is not all, Improvement in load
factor has also resulted This results
| from the increase in the diversity OF
service, making IL possible to deliver Z
much greater total output with a eiver
peak capacity.
The effect Of Improvement in load
factor is cumulative. for not only the
| improved economy enables rates to he
| reduced but this reduction in rates in.
creases the sale Of power. again better
ing the load and load factor and max
ing still larger generating units possihl
with further increase in economies. &C.
Large stations can handle service
which IL iinrracticable for smaller sta.
tions thus fiuctuating loads too large
for a small station may be entirely prac-
ticahl- when the station capacity Is
amply large. Steel mill electrifications
with their large motor units and more
or less sudden changes in load. may he
and are handled by large power
station.
The growth in size Of ell ctric power
stations results not only in economy in
their operation but also leads to the de.
velopment and use ~ protective and
safeguarding apparatus. Many new
problems in the control Of the enormous
amounts of energy distributed have
arisen. as well as other problems in the
safeguarding and protecting of the gen
Grating, regulating and distributing ap'
paratus used Thus a short circuit or
a 100 900 XIV. pow-r station may brine
about conditions SO severe as to be be
yond the limitations Of any known