THESIS

on

THE ECONOMICS OF THE APPLICATION

OF

ELECTRICITY .TO COUNTRY LIFE

Submitted to the. Faculty

of the

OREGON AGRICULTURAL COLLEGE

for the degree of

Electrical Engineer

by

Approved:

Department of Electrical Engineering

1909 CONTENTS

Introduction 2

Design of a Plant 5

Cost of Operation 13

A Plant Without a Battery 16

A Water Power Plant 19

A Plant for Lights only 22

An Plant 25

Appendix 30 -n-

INTRODUCTION

Farmers and residents of small country towns

have long felt the need of the electric light.

They appreciate the safety, cleanliness, and convenience

of this method of illumination and would gladly adopt

it in their homes and about their farms if possible.

The farmer would like to be able to provide satisfactory

lighting for his barns without the fire hazard which is

inseparably connected with any other form of illumination.

But desirable as electric lights are, it is in

the application of electric power to the driving of various labor saving devices that the great gain comes

in on the farm. This, of course, applies more especially

to the larger and more prosperous ones; but there are

few farmers who would not use the electric light if

they could get current on the same terms as their cousins in the cities, and of those who would make use of it practically all would employ current for other purposes such as the electric flatiron, electric fans, th and small motors for laundry and dairy and to turn the grindstone. Larger farms would be equipped with many other power driven machines such as some of the following: a cream separator, churn, butter worker, and milking machine for the dairy; a pump to furnish the water supply for the house and barns; a washing machine for the laundry; electric fans for the kitchen, dining- -3-

room and perhaps other rooms; a hay cutter, a root cutter, and a mill to grind feed for the cattle; a green bone cutter for the poultry department; a forge blower, a grindstone, an emery grinder and a post drill for the shop; a sheep shearing machine, a fanning mill, etc. The list could be extended almost

indefinitely.

The farmer is surrounded with natural resources which make him a producer but in order to make the most of his advantages he must use numerous machines which means that he must have an abundant supply of some reliable and economical power. Many farms in the hills along the valleys of Oregon and the other Pacific

Coast states are crossed by small streams which if developed would furnish the desired power at an extremely low cost and give the owner a great advantage over his less favored neighbor. However, there are more farms which are not so favorably situated, and for them the only solution seems to be the internal combustion . The water wheel and the gasoline engine will develop the power but it can not be conveniently or economically applied to the various machines except thru the medium of .

The private electric plant has until recently been too expensive and inconvenient for most people.

Dut recent improvements in gasoline , electrical generators, and storage batteries and the development -4-

of the tungsten lamp have opened up new possibilities in the way of private electric light and power plants.

The purpose of this paper is to estimate the probable cost of installation and operation of a private electric light and power plant, estimates for several plants will be given and an effort will be made to indicate the general method of designing to suit a given set of conditions.

-0-0-0-0-0-0- DESIGN OF A PLANT

We will first carry thru the design of a private

electric light and power plant in accordiance with

conditions which we will assume to be as follows.

The house has on the first floor a living room, a dining room, a kitchen,a pantry, a bedroom, a rear porch, a front hall, and a large porch in front.

On the second floor there are a hall, a bath room, a linen closet , and three bedrooms with closets.

There will also be either a basement or a wood house.

There will be several barns and out buildings to be lighted. The water supply for the house and barns will be pumped from a well fifty feet deep and be stored in a steel tank from which it will be delivered by compressed air under a pressure of about fifty pounds to the square inch. About three hundred gallons a day will be required. The well is so situated that the pump oan be driven direct from the engine. In the house there will be a small motor of say one fourth horse power to run the washing machine and the sewing machine, also a flatiron and one or two electric fans so that the kitchen and dining room may be kept comfortable at all times. The dairy will require a small motor of about one half horse power to run the separator and the churn. A portable motor of about three horse power will -6-

be needed to run a grist mill, hay cutter, wood saw,

and other machinery. We wish to be able to operate

from the storage battery not only all of the lights

but also all of our other machinery with the exception

of the three horse power motor.

We will now design the plant to meet these

conditions. The first thing to decide upon is the

to be employed. As we wish to use an electric

flatiron and the new tungsten lamps, the voltage of

the battery is practically limited to 110 volts;

as flatirons are not made for lower and

tungsten lamps are not made for higher. We would not wish to use a higher pressure in any case as that would make the battery much more expensive.

We will therefore use a 110 volt battery and a dynamo of the same pressure. As the voltage of each cell when nearly discharged is only 1.8 volt, we will have to have sixty cells.

Let us now determine the capacity of the battery.

In order to do this we will assume the maximum load which it will probably be expected to carry.

The maximum demand would be on an occasion in the winter when the family were for some reason kept up later than usual and when an extra large amount of current would be used for power. The following is a probable schedule for such a day. -7-

Dining Room

5.00 - 6.30 a.m.

) 2 lamps = 6 lamp hours 5.30 - 7.00 p.m.)

Living Room

7.00 - 10.30 p.m. 3 lamps = 10* ft

Kitchen

5.00 - 7.30 a.m. 2 lamps = 10 n 5.00 - 7.30 p.m.

Front Hall

8.00 - 10.30 p.m. 1 lamp = 2-t- n

Front Porch

7.30 - 9.00 p.m. 1 lamp = lk ft Bedrooms

5.00 - 5.30 a.m. ) 4 lamps =4 ft 10.30 - 11.00 p.m.

Barns

5.30 - 6.00 a.m. 6 lamps =6 ft 5.30 - 6.00 p.m.

30* lamp hours

This makes a total of thirty and one half lamp hours but the lamps in the closets, wood house, and etc. would probably bring the total up to thirty six lamp hours. If the lamps are only eight candle power carbon -8-

and twenty candle power tungsten, each of them will allow one fourth of an ampere to flow thru it.

Therefore the lighting load on the storage battery will be one fourth of thirty six or nine ampere hours.

In addition to the lighting load there will be the

following motor load.

Washing Machine (1/4 H.P. motor)

Two hours 2 amperes = 4 ampere hours

Dairy (1/2 H.P. motor)

Two hours 4 amperes = 8 ampere hours

Electric flatiron

Two hours 5 amperes = 10 ampere hours

This makes a total of only thirty two ampere hours but in order that there may be no possibility of an over- load we will adopt the forty ampere h©ur size.

The voltage required to charge a battery is considerable in excess of the voltage given by the battery on discharge, and as we wish to use a 110 volt dynamo, we will arrange the battery so that,by throwing a , we can divide the divide the battery into two equal parts connected in parallel for charging.

The normal rate of charge for a battery isthe number of amperes which must be passed thru it for eight hours to charge it from an almost discharged -9-

condition. Ours, being a forty ampere hour battery, will take five amperes thru each group of cells or a total of ten amperes to charge it at the normal rate.

The battery should never be charged at less than the normal rate and it may be charged at almost twice this rate or about eighteen amperes in this case. A battery of this size will not require charging oftener than once a day when there is the maximum probable load. There will usually be a much lighter load so that it will not ordinarily require to be charged oftener than once in two days even in the winter, and in the summer when the days are long and lights are required only for a few hours at night, the battery will not require carping oftener than once a week.

The dynamo will next be considered. As we have already specified a 110 volt machine, the capacity alone remains to be considered. The voltage required to charge the battery ranges from 70 to 85 volts, so the dynamo must be capable of delivering 85 x 18 = 1530 watts or a little over one and one half kilo -watt.

We wish to use a portable motor of about three horse power and as a motor of this size requires two kilo -watts, our dynamo will be of two kilo -watt capacity.

To drive the dynamo we will have to have a three horse power gasoline engine of the special electric type, which is made extra heavy and fitted with a special -10-

governor to give close speed regulation. With this

outfit we can use the dynamo to furnish lights direct

or if an extra amount of current is required for some purpose the dynamo may be run in parallel with the

battery making a combined output of nearly four

kilo -watts.

A switchboard and apparatus with which to

control the dynamo and storage battery will be the next in order. A rheostat in the field circuit of the dynamo will be required to regulate the voltage generated.

An ammeter will be required to show the rate of charge or the load on the battery or dynamo. A voltmeter should be provided with arrangements for reading the voltage in two different places; across the dynamo terminals, or the terminals of the battery.

There should be two circuit- breakers. One of these should be so arranged as to open the battery circuit whenever the charging current falls below the normal rate (10 amperes). The ether should open the circuit when either charging or discharging current reaches an abnormal value; in our case nineteen amperes.

It would be well to provide a third one to protect the dynamo circuit when the large motor is being used; this one might be set at twenty one amperes as the dynamo is capable of carrying an overload of twenty five per cent. Any or all of these circuit breakers -11-

may be replaced by fuses, which should be of the inclosed cartridge type to avoid the fire risk.

Fuses are, however, less satisfactory than the circuit -breakers and altho cheaper to install, cost considerable to maintain if they are blown often.

The storage battery when almost discharged gives only one and eight tenths volts percell and then all of the sixty cells are required. Whenfully charged the cells give about two and two tenths volts and thus only fifty cells are required to produce the desired voltage. An end cell switch should therefore be provided with which to matt in the end cells as the voltage falls on discharge. As the battery is divided into two sections which are charged in parallel, it is imperative that the two groups of cells should be evenly ballanoed and in order to effect this result we will arrange five of the end cells at each end of the battery and connect them to an end cell switch which will alternately cut in a cell from either end of the battery.* Three double pole are required, one of them being a double throw switch used to divide the battery for charging.

As the building in which the plant is installed will usually not be fire proof, it will be necessary to bury the in the ground and have the fuel pumped up to the engine as required. A large tank -12-

should be provided so that advantage may be taken of

quantity prices. The building in which the plant is

installed should also house the shop; and many tools

such as a grindstone, emery grinder, post drill, and

etc. may be driven from the line shaft when the battery

is being charged. The water supply pump should also

be located here, otherwise another one fourth horse

power motor will have to be provided to run it.

COST OF INSTALLATION

The wiring of the house and barns will cost (depending on the quantity and quality of fixtures upwards of ------$75.00 A small electric will cost about 20.00 A flatiron can be had for $3.50 to 5.00 A 1/4 H.P. motor 30.00 A 1/2 H.P. motor 50.00 A 3 H.P. motor 115.00 $295.00

A self contained, 3 H.P., 2 K.W., generating unit ( engine dynamo and etc.) - - - - -,- $500.00 Storage battery g $4.65 per cell 280.00 Switch board and instruments 100,00 Fuel tank and piping 25.00 Testing set for battery 25.00 Labor installing plant 20.00

Cost of plant $750.00 Total cost of installation 1045.00

The total cost of instalation will be $1050 or more depending on the cost of fixtures in the house and other buildings -13-

COST OF OPERATION

Assuming that the average load per day thruout

the year is a little over thirteen ampere hours or aboutone and one half kilo -watt hours, the total amount of energy subblied by the battery during the year will be five hundred fifty kilo -watt hours.

As the efficiency of the battery is only seventy five per cent, the dynamo will have to supply seven hundred thirty kilo -watt hours. If the average rate of charge is fourteen amperes or one kilo -watt, the generator will have to run a total of seven hundred thirty hours during the year to keep the battery charged. As the engine is running at approximately half load the cost for fuel will be 3.38 cents an hour or a total of

24.70 for the year. In addition we will assume that the large motor is used at eight tenths of full load for twenty hours each week or a total of 1040 hours.

The energy consumed will be 1.6 x 1040 = 1872 kilo -watt hours. The engine will be running at about eight tenths of full load and the cost for fuel will be

4.6 cents per hour or $42.25 for the year. The maintenance of the battery will amount to about twelve and one half per cent. -14-

The total cost of operation will be as follows

Interest on plant, 5% on $750 $37.50 Depreciation on engine, 10% on 175 - - - 17.50 Maintenance of battery 12*% on 280 - -- 35.00

Depreciation on rest of plant, 3% on $295 -- 8.85 Fuel for charging battery 24.70 Fuel for power 42.25 Lubricating oil and incidentals 4.20 Total operating charges 170.00

The amount of power developed during the year will be 550 + 1872 = 2422 kilo -watt hours at a cost of

17000/2422 = about seven cents per kilo -watt hour.

This compares favorably with the charges made by the companies in the cities. Power generated by steam generally sells for fifteen cents while water power plants sometimes sell their power for ten cents.

The owner of the plant above described not only gets his power for less than the usual city ,prices but he also can run various devices such as the water supply pump, grindstone, etc. at the same time that he is charging the storage battery and there will be no extra charge for fuel, as the engine is more efficient when running near full load.

The owner of this plant could furnish current to a neighbor situated at a reasonable distance, say

1,000 feet, He could afford to sell the power at seven cents a kilo -watt hour provided his customer would take as much as five hundred fifty kilo -watts hours per year, under proper restrictions regarding -15-

maximum demand etc. Should the demand exceed the capacity of the battery, the generator may be run in parallel with the battery and being run at full capacity would be more efficient than the battery.

To produce the extra 550 kilo -watt hours would cost an extra $25 for fuel making the total yearly cost

,$195. The total amount of power produced would be

2970 kilo -watt hours at a cost of 19500/2970 = 6.6 cents a kilo -watt hour. For ten cents he could afford to sell power without making any minimum charge.

ONO OM -0 --o -- -16-

A PLANT WITHOUT A BATTERY

It would be impossible to design a plant which would suit every body. Some people would object to

the plant just described because of the fact that it contains a storage battery. The battery is not only expensive to install but the cost of maintenance is quite high amounting in our case to $35. This together with the interest on the investment amounts to $49 a year. Apart from the expense, there is another objection which some people would urge against the storage battery and that is the trouble of caring for it. Once a week the battery should be over charged and each of the sixty cells should be tested for voltage, density of electrolyte, etc.

For those who do not consider that the ability to run electric fans and the convenience of having current on tap.at all hours of the day and night, is sufficient to warrant the expense and trouble of ah battery, the following design is suggested.

House and barn wiring with carbon lamps instead of tungsten, upwards of - - - - $60.00 !Tlectric flatiron 5.00 1/4 H.P. motor 30.00 1/2 H.P. motor 50.00 $145.00 A self contained, 2 H.P., 1 X.W. outfit engine dynamo belt etc. 250.00 Instruments but no switchboard 50.00 Fuel tank and piping 25.00 labor installing plant 20.00 Cost of plant $345.00 -17-

Allowing ton dollars for incidentals not mentioned the total cost of the instalation will be about $500 and the cost of the plant itself will be about $350.

No electric fan is included in this outfit as it would usually be wanted at hours when the plant would not be running for anything else and it would hardly pay to run a two horse power engine just to keep a 1 /10 horse power fan going. It is supposed that this plant will be installed in a house which will house all of the power driven machinery of the farm excett such as can be. driven by the 1/4 or 1/2 horse power motors.

The approximate cost of operation will be as follows. Lights An average of 4 hours daily = 1460 hrs A 2.25 c = $35.50 Dairy (1/2 H.P. motor)° One hour daily, during summer = 180 hrs ßi'2.1 = 3.80 Laundry 1/4 HIP. motor 2 hrs weekly = 100 hrs $ 1.3 = 1.80 Flatiron 2 hours weekly = 100 hours A 2.25 cts = 2.25 Power 1.5 H.P., ten hrs weekly = 520 hours a 2.7 cts = 14.10 Total for fuel (distillate) 57.25

Lubricating oil and incidentals ------6.00 Fixed Charges Interest on plant 5% on $350 17.50 Depreciation on engine 10% on $125 12.50 Depreciation on rest of plant 3% on $225 6.75 Total fixed charges - 36.75 Total cost of aeration for ear 1.100.00 -- M. r .rrrr MIN!

° During the winter the dairy motor will be used during the hours when the plant is running for lights and there would be no extra charge for fuel. -18-

The amount of power developed will be:

Lights; 1/2 X.W., 1460 hours 730 K.W. hrs. Dairy; 1/2 H.P., 180 hrs = 90 H.P. hrs - - 67 " Laundry; 1/4 H.P., 100 hrs = 25 H.P. hrs - 18 " Flatiron, 1/2 K.W., 100 hrs - - - 50 " Power; 1.5 H.P., 1040 hrs, 1560 H.P. hrs -1165 " 2030

A total of 2030 kilo -watt hours are produced at a cost of 10000 /2030 = 4.93 cents per kilo -watt hour.

No allowance is made for the power to pump the water used about the farm as it is assumed that the pump will be run direct from the engine during the hours when lights are on and therefore the extra power required is much less than the variation in the lighting load.

The power required to pump 300 gallons in)four hours from a well fifty feet deep and store it in a tank under fifty pounds pressure (equal to an elevated tank

115 feet high) is only a little over 1 /10 horse power assuming that one half of the energy is lost as friction in the pump and piping.

The cost of . producing electricity by this outfit, or by any other in fact, depends upon the amount produced and upon the ratio of the average load to the capacity of the plant. If the average load is only a small part say 1/5 of the capacity of the plant the cost of production may become excessive. Care should therefore be taken to select a plant which can run at nearly full load all of the time it is in operation. -19-

A WATER POWER PLANT

Let us assume that our farm is crossed by a small stream in which we may develop power at a point within 1000 feet of the house. We will assume that a fall of twenty feet can be secured and that a storage reservoir of some size may be constructed.

The cost of installation will be approximately as follows:

Wiring of house and barns $75.00 Electric flatiron 5.00 Electric fans, two at $20 40.00 Motor for laundry 1/4 H.P. 30.00 Motor for dairy 1/2 H.P. 50.00 Portable motor, 7-HP; 160.00 $360.00

Sampson turbine, 15.25 inch - - - - $110

Dam and spillway -- - 400 Power house 100 Dynamo, 5 Iii. W. , 250 volt. 160 Switchboard and instruments - - - - 100 Wire, 2000 feet #8 45 Pole line 20 Labor installing plant 25 Cost of plant $1000 Total cost of instalation - - - - $1360

Allowing five per cent interest and another five per cent for depreciation, maintenance, etc the total operating cost for the year is only $100 As the cost of operation is just the same whether much or little power is used, the only limitation on the amount which may be used will be the capacity of the stream. Let us assume the following schedule. -20-

Lights

1 K.W., an average of 5 hours daily = 1825 hours - 1825 K.W. hours Power Laundry motor, 2 hours weekly, 180 hrs = 25 H.P. hrs - - - - - 18 K.W. hours Flatiron, 2 hours weekly, 100 hours 50 K.W. hours Dairy motor; Milking one hour night and morning 730 hrs Separating 1 hour night & morning 730 hrs Churning 1/2 hour daily 180 hrs A total of 1640 hrs = 820 H.P. hrs = - - 615 K.W. hours

7 H.P. motor, 20 hrs weekly , 1040 hours = 7440 H.P. hrs = - - 5550 K.W. hours

8058 K.W. hours

A total of 8058 kilo -watt hours are developed at a cost of 10000/8058 = 1.24 cents per kilo -watt hour.

It might at first glance be supposed that a large stream would be required to furnish so much power but such is not the case. If the minimum flow is .64 cubic feet per second ( thirty eight and one half cubic feet per minute) and there is a reservoir capable of retaining the flow of one or two days there would be ample power available provided the water wheel operates at 85% efficiency. In other words a stream which has an average velocity of one foot per second at low water will only need to be twelve inches wide and eight inches deep. Just think of it; there are numerous streames of this size or larger scattered all up and down the Willamette Valley.

If the owner of a farm crossed by such a stream -21-

does not wish to use so much power he malt install an

instead of the generator.

He can then deliver energy for lights and small motors

to his neighbors anywhere within a radius of four or

five miles. The cost of the installation would be

much higher or account of the higher price of the

alternator and the necessity for , meters,

and a transmission line. The cost of production would

be correspondingly increased and perhaps would be as

high as five cents a kilo -watt hour, but no one would

object to paying ten cents and at that rate the farmer would receive a good return on his investment and would

at the same time be adding to the attractiveness of the

locality and hence increasing the value of real estate.

MM. 4-4- .22-

A PLANT FOR LIGHTS ONLY

The following is a veru inexpensive plant having the advantages of a storage battery and not costing very much to operate.

Wiring of house and barns, including 15 tungsten lamps and an equal number of the carbon filament variety $100.00 Storage battery, 15 cells, 40 amp.hr. - 70.00 Dynamo, 1/2 K.W., 45 volt shunt wound - - - 65.00 Gasoline engine, 2 H.P., 125.00 Switchboard and instruments 100.00 Labor installing plant 50.00 Total cost of installation $500.00

It is assumed that the maximum probable load on time battery for one day will not exceed forty ampere hours or one kilo -watt hour. It is further assumed that the average load thruout the year will be about one third of this or .3 kilo -watt hour. The total.amount of energy required at the lamps will then be .3 x 365 =

110 kilo -watt hours. As the efficiency of the battery is onit 75 %, the generator will have to supply 110/.75=

146 kilo -watt hours. As the average load on the generator when charging the battery is only seven amperes or .315 kilo -watts, the outfit will have to run a total of 146/.315 = 465 hours.

It does not require nearly all of the capacity of the engine to drive the dynamo. We will therefore assume that when the battery is being charged, other machines are driven direct from the engine making the -23-

average load on the engine about .8 of its capacity.

Then the following energy will be developed.

146 K.W.hrs. at dynamo = at lights - - - - 110 K.W.hrs. As power direct, .8 K.W., 465 hrs - - - - 372 K.W.hrs. 482

The cost of running the engine will be about 2.7 cents per hour or $12.60 for the year. The fixed charges including interest on the investment at 5%, depreciation of the plant, and maintenance including lubricating oil and about x$10 for battery renewals; amount to $44.50 a year, making the total cost for the year $57.10

For this amount the equivalent of 482 kilo -watt hours were produced at a cost of 5710/482 = 12 cents a kilowatt hour. If the engine were used for no other purpose than to furnish current for lights, the fuel cost would be only $9 a year, the total cost per year would be $53.50 and the cost per kilo -watt hour would be about forty nine cents.

The annual operating expense of this plant is moderate but as only a small amount of power is developed the cost per kilo -watt hour is quite high.

To offset this difficulty we use the new tungsten lamps which are much more efficient than the old carbon filament variety, giving about three times as much light for the same amount of current. -24-

This plant is adapted to the needs of those who want only a limited amount of current, who want all of the advantages of a storage battery and who can not afford the expense of a larger plant.

Those who want to use current for other purposes than lighting and running small fans, or wh wish to transmit current farther than about 200 or 300 feet; should adopt some other design.

00 00

NOTE

The plant descrided above is essentially the same as one which is described in greater detail in

Bulletin No.25 of the University of Illinois

Engineering Experiment Station, -25-

AN ALTERNATING CURRENT PLANT

There are numerous localities where five or six families living close together could combiné and

install an alternating current plant and secure for

themselves the advantages of electric lights. It is only lately that such plants have been made possible by the advent on the market of small self excited in sixes of 2, 3, and 5 kilo -watts.

Let us assume the following conditions.

There are six families who want electric lights and who are so situated that only three miles of transmission line are required. It is desired that power for lights shall be on from 5.00 a.m. till sun rise and from sunset till 11.00 p.m., making an average of five hours a day or a total of 1825 hours for the year.

By counting up the lights which will be installed in each house and determining the hours when they will burn, we estimate the probable maximum load on the plant and also the probablt average load. We find in this case that the probable maximum load will be about

.3 K.W. for each family of a total of 1.8 K.W.

The average load during these hours figures out about

150 watts per family or .96 kilo -watts for the plant.

A 2 kilo -watt alternator will therefore be sufficient -26-

in this case and a three horse power, special electric gasoline engine will be required to drive it.

Perhaps the most satisfactory plan would be for one of the farmers to put in the plant and sell current to his neighbors. Each family should pay for its individual , meter, and service leads which would cost about forty dollars for each family.

(House wiring will cost about $2 per lamp, not including fixtures)

Under these conditions the cost of installing the plant would be as follows.

Gasoline engine, 3 H.P., special electric - - - $175.00 Alternator, 2 K.W., 110 volt, single phase - - 200.00 Power -house 100.00 Fuel tank and piping 25.00 Switchboard instruments Voltmeter 16.00 Ammeter 16.00 Circuit- breaker 20.00 Switches, fuses, etc. 3.00 Rheostat (furnished with generator) Transformer, step -up, 2 K.W., 110 -2300 volt - - 40.00 Wire, 6 miles, #12 bare copper,

630 pounds at 25 cents ------160.00 Pole line; poles with cross -arms, insulators, etc. in place, 3 miles at $75 225.00 Labor stringing wire at $4 a mile 25.00 Labor installing machinery in power -house - - - 25.00 Incidentals 20.00 $1050.00

.Cost of Operation Interest, 5% on 1050 $52.50 Depreciation on engine, 10% on $175 17.50 Maintenance and depreciation on rest of plant, 3% on $875 26.25

FIXED CHARGES $96.25 -27-

Fuel Cost

For lights, 1825 hours at 3.36 cents $61.20 Flatirons etc., 4 hrs weekly, 208 hrs at 3.36c - - 7.00 Lubricating oil and incidentals 5.55 $73.75

This makes the total annual expense $170.

For this amount there will be developed .96(1825 +208)

= 1920 kilo -watt hours at a cost of 17000/1920 = 8.85 cents per kilo -watt hour. If the engine were used only for driving the generator the price charged would have to be about ten cents a kilo -watt hour and the average cost to each family would be about $2.40 a month.

Usually, however, the owner of the plant would use the engine to drive various machines about the farm pumping his water, sawing his fire -wood, grinding his cow -feed, etc. If he uses the engine at half load for eight hours a week or a total of 416 hours, the additional expense will be about $15,making the total operating expense for the year $185..The extra amount of power developed will be 1.5 x 416 = 624 horse -power hours or the equivalent of 465 kilo -watt hours. The total amount of power developed will then be 1920 + 465 = 2385 K.W. hrs at a cost of 18500/2385 = 7.8 cents per kilo -watt hour.

Under these circumstances the power could be sold for eight or nine cents, which is'very reasonable.

If the lighting load were equally distributed,the cost -28-

to each family would be about $23.60 or an average of

i2.00 a month. Of- course to secure an economical load

on the generator, a minimum charge will have to be made and experience alone can determine what that

charge should be. In the cities it is usually fixed

at from 75 cents to $1.50 a month, but in our case might have to be made higher.

If the plant were used to supply current for

lights only, a flat rate might be mede and flat =rate

controllers be installed instead of the meters.

This would enable the plant to be run at full capacity

all of the time. The cost for distillate would then be

4.5 cents an hour or a total of 4.5 x 1825 = $82.50

The fixed charges would be $85.85 as before and the

total cost for the year would be $170. Thirty two

16 c.p. carbon filament lamps could be burned at a

cost of $170/32 = $5.32 per lamp per year. Or if some wanted to use the more efficient tungsten lamps,

sixty four 20 candle power lamps could be operated'at

a cost per lamp of only 170/64 = $2.85 a year.

A sufficient number of patrons could be connected up

to take the total capacity of the plant and the yearly

cost per family could be made quite low. Under these

conditions carrent could be sold for 90 cents to $1.00

per ampere per month which means that the average cost

of burning an ordinary 16 c.p. lamp one month would

be only fifty cents or for a 20 c.p. tungsten only 25c. -29-

For lighting only, this arrangement would be very good; but as some people would want to use current for other purposes and all might want to do so at some future time, it would probably be the best plan to put in the meters.

If each family is required to make its maximum demand but little higher than its average load, the plant may be operated at nearly lull capacity and hterefore at high efficiency. This ratio of the average

load to the maximum or the "load -factor" as it is

called is one of the most important factors in the

design of a plant; especially if an internal combustion

engine is used as the source of rower. The higher the

load factor the higher the efficiency of the plant,

other things being equal, and the lower the consequent

cost of production.

waaoiffiaga -30-

APPENDI X

The following table gives the cost per hour of operation of gasoline engines at various loads, figured on the basis of gasoline at 20 cents a gallon and distillate at ten cents. These results are computed from a table given by Carpenter & Diedrichs on page

554 of their treatise on the "Internal Combustion

Engines ".

2 Horse Power Engine

Fuel Max 1/10 load .0 .8 .7 .6 .5 .4 .3 .2 Max

Gasoline 5 ots12.4:754.4.2514.03.7513.3.3532.51 Distillate 3 85j2. 70J2.5512.4012.2512.10j1.95J2J1.5

3 Horse Power Engine

Gasoline 7.517.1316.766.3816.013.35.254.874.53.71 1 1 1 51 Distillate 4.514.2814.06113.8313.613.368 3.25 2.93 2.7 2.25

The above table is for the special electric engine which governs by throttling. This is the kind of engine required to drive a dynamo for lighting.

For ordinary power requirements the hit -and -miss engine is eaten ivel$ used, It will do to drive a dynamo to charge a storage battery or to furnish current for power but will not do for lights as it does not give sufficiently close speed regulation.

It is slightly more efficient at part load but has no -31-

advantage at full load.

Energy Consumption and Cost of Domestic Electrical Devices°

Cost during Average Period that period Article watt -hour of at 10 cents consumption per K.W. hour lame operation

Chafing -dish 400 20 minutes $0.0134 Stove, 6 inch 500 15 .0125 Stove, 8 inch S00 15 .02 Curling iron heater 60 15 .0015 Flatiron, 3* lb 250 30 .0125 Flatiron, 6 lb. 500 30 .025 Frying pan, 7" 500 30 .025 Tea kettle 300 20 .01

Glue pofl , 1 qt. 300 20 .01 Soldering iron two lb. 200 30 .01

A one fourth horse -power motor takes nearly two amperes at 110 volts and costs only two cents an hour with energy at ten cents per kilo -watt hour.

The cost of pumping water a vertical distance of 150 feet or against a pressure of sixty five pounds to the square inch, is only a little less than two and one half cents per thousand gallons if electrical power costs ten cents per K.W. hour; assuming that one half of the energy is wasted as friction in the pump

and piping .

° Electrical World Vol. XLVIII, p. 848. -33-

FUEL

The estimated cost of operation of the various plants was made on the basis of distillate at ten cents a gallon. Distillate is a petroleum product slightly heavier than gasoline and having about the same fuel value. It can be had in Portland Oregon at the present time (1909) for nine cents a gallon in fifty gallon lots. Gasoline is scarcely any better and will cost about twenty cents if bought in large quantities.

PRICES

The prices quoted are only approximate and are for new apparatus of standard make f.o.b. Portland

Oregon. Prices vary with changes in market conditions and some companies make lower quotations than others.

The services of an expert should be secured to order supplies and install the plant. He will select the most suitable apparatus and see that it is properly installed. The efficiency and reliability of the plant will usually be better and the first cost probably no more.

WHERE TO ORDER

For the benefit of those who wish to select and order their own supplies direct we will mention

s ^venal prominent firms who deal in electrical supplies. -33-

The two largest manufacturers of electrical machinery are the "General Electric Company" and the

"Westinghouse Electric and Manufacturing Company ".

There are numerous smaller firms whose advertisements may be found in the technical periodicals.

The "Central Laboratory Supply Company "of Lafayette

Indiana, make small alternators as well as other supplies. The "Fairbanks Morse Company" make a special electric gasoline engine in various sizes from two horse power up. They are also able to supply any kind of electrical machinery and will make same to order if other than standard sizes are wanted.

James Leffel & Company are one of the firms who manufacture turbine water -wheels for low and medium heads. The "Pelton Water -Wheel Company" make the

Pelton Wheel which is especially adapted to high heads.