160 SECTIONAL ADDRESSES. 



No doubt the intrinsic load factor is really higher — by which is meant 

 that could all these numerous undertakings be supplied from one common 

 source, the resulting load factor on the generating plant would be found to 

 be higher in value. 



Still the fact remains that the capital expenditure on generating plant 

 is four times what it would be were the load factor 100 per cent. The 

 latter condition is of course not attainable, but something much better 

 than 25 per cent, can certainly be obtained, an improved load factor on 

 his system being the objective of every responsible engineer. 



A small undertaking supplying a district mainly for lighting purposes 

 will have only a low load factor, probably some 15 per cent, or less. If the 

 consumers add other domestic requirements to their demands for lighting, 

 such as heating rooms, cooking, and many small domestic appliances, 

 it is found in practice that there is a great diversity among the times 

 when the maximum loads of individual consumers occur. 



Some observations made on the use of electric ranges, for example, 

 reveal a diversity factor as high as eight, or in other words the maximum 

 coincident load is only one-eighth of what would be recorded if all the 

 apparatus were working fully at the same time. 



A recorder chart which was taken by the Glasgow Corporation and 

 published in Prof. S. Parker Smith's paper read before the Institution 

 of Electrical Engineers in December 1925, shows that the daily load factor 

 is 44 per cent, in the author's all-electric house, taking the maximum load 

 as the continuous half-hourly maximum consumption: In this case 36 per 

 cent, of the total units consumed are used at night for heating water on 

 the storage system, and a general adoption of this arrangement would 

 materially improve the load factor on the distribution system as well as 

 on the generating station. 



A very complete investigation was made a few years ago in a large 

 southern residential district, which revealed the fact that the maximum 

 demand on the power station followed the growth of lighting connections 

 almost directly, and did not increase proportionately to the total connections 

 of heating and lighting. In other words, the connections for heating had 

 not noticeably affected the maximum load on the station. There was, in 

 fact, a high diversity factor. That is material in the economics of electricity 

 supply, for it meant in that particular case that no appreciable addition 

 to the generating plant or capital involved in generation was necessary in 

 order to supply the heating load, though a heavier outlay on distributing 

 mains was necessarily incurred. 



This increased service raised the load factor, which was stated to be 

 15 per cent, or less for lighting alone, to 30 per cent, or more with the 

 comparatively limited application for heating and cooking at the time of 

 the investigation referred to. That improvement refers only to one 

 district. Consider further the combination of this district with another 

 where the customs of the residents are somewhat different, such as their 

 hours for meals, and an improved diversity would then be found. 



If we go further and bring in industrial power loads, large and small, 

 a yet higher load factor will generally be realised, albeit some industries 

 per se have only a small load factor ; but again their maximum require- 

 ments do not coincide. There are industries such as coal-mining where 



