SECTION G.—ENGINEERING. 
SOURCES OF CHEAP ELECTRIG POWER 
ADDRESS BY 
PROF. FRANCIS G. BAILY, M.A., F.R.S.E., 
PRESIDENT OF THE SECTION. 
For many years the extravagant waste of our coal has been the subject 
of criticism. ‘The steam engine, the blast furnace, and the domestic 
fire consumed it recklessly, and thermal efficiency was formerly dis- 
regarded. ‘To-day we are more careful of our fuel, except perhaps in 
the domestic fire, but there is still a considerable and unnecessary waste 
at the very beginning. ‘The amount of combustible material left in the 
mine, dumped at the surface as useless, or burnt at the pit-head to get 
rid of it, has often been pointed out, but its poor quality and large 
proportion of dirt make its transport to a consumer unprofitable, or render 
it unsuitable for use. The latter disability has been largely overcome by 
various devices in the boiler-house, and to-day we see steam raised by stuff 
that would have been scorned by our predecessors. But the material must 
be used on the spot, and the Commission called together by Mr. Lloyd 
George ten years ago advocated a comprehensive if rather shadowy scheme 
for generating electric power at the pit-head. The saving in coal was 
clearly demonstrated, but the financial advantage was not so convincing. 
The last ten years have brought about great changes in the conditions, 
some favourable to the scheme, some diminishing the financial advantage, 
and the question requires reconsideration under present-day conditions, 
with, if possible, a forecast of future developments. 
The general idea of the scheme of production of electric energy here 
proposed takes as its basis the complete linking up of all parts of the 
country by the grid and the subsidiary lines fed from it or from the 
stations directly. All stations are connected to the grid, and as well as 
supplying their local consumers, put the additional power into the grid 
as required. ‘This is the well-known main function of the grid. It is 
here submitted that this leads to a different scheme of generation from that 
now followed, and that sources of cheap power are rendered available that 
previously could not be utilised economically, 
The questions to be considered are : 
(1) The proportion of consumers who are within economic distance 
of a pit-head station. 
(2) The quantity of very cheap coal that is available. 
(3) The relative advantages of widely spaced large stations and more 
numerous small stations. 
(4) The opportunity offered by the grid to bring into economical 
use pit-head stations at small isolated mines, power from factories 
using industrial steam, power from coke-oven and blast-furnace 
gas, and hydro-electric stations. 
