Central station power for coal mines

The use of electricity in the production of anthracite is rapidly increasing, and hence, its ultimate cost per kilowatt-hour is an important factor in cheap production. An analysis of fixed charges and operating costs of small mining stations indicate that the installation of such stations by mine operators is not always the method that results in the cheapest cost for this form of power, particularly when central station service is available There are several reasons that contribute to this. 1. Present methods of producing steam at collieries are comparatively wasteful. 2. Facilities are not always present for the most economical use of steam. 3. Operating costs are usually based on the kilowatt-hour cost at the main station switchboard and transmission cost are not included, whereas in central station service the cost is net at the substation switchboard. 4. The resulting load factors in several small plants are not to be compared to the resulting load factor on one large central station. 5. The operator is apt to lose sight of the large investment per kilowatt required for the mining plant. This expenditure is not present when making use of central station service. 6. Stand-by loses form a large part of the annual operating cost of the mining plant. Careful consideration of each of the above points will indicate to the operator the most economical proposition to adapt.