This post is really my notes from researching the early days of electricity in Hove, it is probable that there will be corrections and revisions. As with the previous post, the source is the log books of the power station of the Hove Electric Light Company from 24-Nov-1892 to 27-Sep-1894. I have yet to find a floor plan of this site or an inventory of the equipment, but the log books give an insight into the nature of operation and it’s economics.
One thing that stands out when the weekly generation data is plotted on a graph is the seasonal variation in the demand for electricity. Whilst the log books make a couple references to small electric motors on customer’s sites, most of the output is used in incandescent lamps (typically 33 watts) and arc lights which might draw 10 amps (roughly 1 unit per hour with a 110 volt supply). In the winter of 93/94 generation amounted to roughly 2,500 units/week and then dropped off as summer approached. So in the summer of 1894, output was falling even though more customers were being signed up.
It is not clear if this seasonality was factored into the economics of operation, but it is possible that a stoker was laid off during the summer. In Sep-1894, wages accounted for just less than one third of the operating expenses. It is not clear in the remarks if the boilers had mechanical stoking or relied on a man with a shovel.
The largest expense was coal and coke. There is an inference in the log books that the preferred type was Welsh Coal (20 – 27 shillings/ton), this has a high calorific value (marine engineers also liked it), but at times, possibly as an economy measure, alternative fuel was used such Northern Steam Coal (19 shillings/ton). In the first few months of operation some coke was used, maybe this came from the local gas works.
The logs don’t say much about the type of machinery, but there is a reference to Davey-Paxman sets. I’m guessing but these steam engines were probably similar to those used in mills and factories, these were relatively slow speed. Often power was distributed around the factory with a system of shafts and each machine was connected to this by a belt drive. There is also a mention of Willans engine, this was probably a high speed engine specially developed for the growing electricity industry, typically the dynamo was directly coupled to the steam engine’s crank shaft. Hopefully, I can find out more.
By modern standards, the boiler pressure was low, initially they operated at 140 p.s.i. and later this was increased 160 p.s.i.. after inspection by the insurance company. Steam locomotives in the 1950’s were often working in the range 200 – 250 p.s.i. and modern steam power stations run at very high temperatures and pressures to maximise efficiency. The steam would have been saturated and there is no reference to condensers. Thus the efficiency was very low, a crude sum suggests that it was in the range 2 – 3%, that of modern coal power stations might be around 40%. The log book states coal consumption as 10 pounds/unit of electricity generated. Leaving the town hall arc-lamps burning all night would create extra work for the stoker and a noticeable increase in operating costs. Maybe, because of the lack of condensers, they were not able to recover water from the exhausted steam as water consumption was several thousand gallons per week.
The station was equipped with storage in the form of some large lead acid batteries, the capacity of these was about 30 units (110 amp hours). These appear to require regular maintenance as sometimes their consumables (plates, soda etc.) show up as a spke in the expenses. The function of these is not given, but it is probable that the storage acted as a buffer for fluctuations in load and also to meet some or all of the overnight demand, this would allow the boiler fires to be banked up to save fuel. During the summer months the average daily demand might be 100 – 200 units which peaked in the evening, thus the 30 units of storage could simplify operations.