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Thursday, 29 May 2014

Energy Management - An Edwardian View

Technology often implies a system with sensors feeding some form of computer running highly developed software tuned to make make the best possible decision which is then relayed to a smartphone.  These things did not exist in 1901 when my house was built and I'm now in the process of renovating, in practice this means peeling back a century of things that seemed a good idea at the time.  Electric lights which  were installed around 1925 were an improvement on the gas lamps they replaced but the benefits of some of the plumbing from the 1970's and 1980s is not obvious.



It seems that there have been two distinct phases of energy management, the first from the time the house was built up to 1970 and from then to 2005.  Around 1970, natural gas, also known as North Sea Gas became available in the UK, as a domestic fuel it was both cheaper and less labour intensive than coal which it rapidly displaced.  Whilst coal was not cheap, consumption was in part limited by the availability of labour to burn it.  In much the same way as the speed of early coal-fired steam ships was determined by the rate at which stokers could shovel coal, the amount of coal a house could burn was limited by the labour available to carry  the stuff to the fireplace and dispose of ash the following day.  Our house had six open fires, a coal -fired range for cooking and hot water and a copper for the weekly wash bringing the number of places where coal could be burnt to a total of eight.  Within a relatively short period coal was displaced by gas central heating which warmed the whole house, the only control being an on/off switch,  those  people who found the operation of switch too demanding, delegated this task to an electrically driven timer.  The standard of insulation of houses built before 1970 (and maybe for the next two decades) was not high and coal fires needed a good supply of air to burn properly, so Victorian houses were drafty by design.  The installers of gas fired central heating systems handled this by simply putting in big boilers, often in the range 20 to 40 kw.



I've used the language of the 21st century to describe a household of 1901.  The first of these is "zoning", in modern day terms, this means controlling the heating in two or more parts of the house, often "upstairs" and "downstairs".  For the Edwardians, this meant only lighting a fire in a room which was in use, so in the case of our house, there would have always been a fire during the day in the kitchen range and a fire in the living room during the evening, maybe one in the dining room if friends were coming round for supper and you would probably have had to have man flu or some other ailment to get a warm bedroom.

For lack of a better description, the next difference was "integrated energy use".  When the house was built, cooking was done on a  coal- fired range, whilst these things were no great joy to clean, they were alight for from dawn to dusk which meant there was always one room which was warm.  An industrious cook could use the range to maintain a supply of meals, bread, cakes, tea and coffee.  Managing a range required some skill, a fast fire which would be ideal for frying eggs might make the oven too hot for bread which should be baked in a cooling oven.  Also, when money was in short supply, the fuel might be nutty slack or green wood which required some patience and not a little skill to produce a loaf of bread.  It was the warmth of a kitchen which drew people in from the rest the house.

The third concept was "waste heat recovery", this is a feature of modern boilers which attempt to recover the latent heat from the water vapour which results from burning methane in air.  This can be offset by kitchen extractor fans which take the nice warm air from the kitchen and use it to heat the garden.  The Victorians had some ingenious devices for recovering heat, one which to the best of my knowledge had no domestic application, consisted or a chain rotating at the base of a factory chimney.  The top of the chain was heated by the flu gases from the firebox of the boiler, the bottom of the chain was in the boiler's feed water.  This shows some enthusiasm for energy management.  Within a home, waste heat recovery could be a back boiler on the range or simply a heating coil placed in the flu as part of a simple "gravity feed" hot water system.

What is now part of the modern day kitchen was once a coal store filled from outside the house via shute sealed off with a manhole cover.  The capacity of the coal store was, maybe, two tons which was enough to keep the house functioning for several weeks. This "energy storage" did two things.  At the national level, it evened out the demand for coal, whilst the demand for coal peaked in winter, the capacity of mines and the transport system were probably close to the "average" for the year.  In contrast, whilst the modern gas distribution does have some storage capacity, like the old "gasometers" which used to rise and fall and the more modern method of pumping gas into depleted gas fields, the system is sized to cope with "peak" demand.



Having energy storage at the household level also ensured that there was an effective local energy market, most towns had at least two coal merchants and prices would be lower in summer than winter.  Whilst the modern day gas consumer can "swap" supplier which does provide a measure of competition, this is far removed from an exchange between the coalman and some hard nosed housewife.

Since 2005, energy prices have risen sharply.  There is no economic incentive to revert to coal as a domestic fuel because in terms of body warmth, gas and coal seem to cost about the same and the "clean air acts" control the use of solid.  These bits of legislation were created to bring to an end the plots of "who dunnits" in which heroes and villains could conceal their activities in thick London fog as did Raffles  in the "Ides of March".  However, history might offer some guidance for the future, even if the mobile phone has made it harder for writers of crime fiction.




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