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Friday 29 July 2016

Energy Alternatives

The electricity industry took shape in the 1880s.  Initially, it was a "luxury" product consumed by high income households.  Large establishments might have had their own generating plant, but rapid growth in the demand for electricity started when companies were formed to supply consumers from a local power station.  Either by choice or circumstance, many of these companies became owned by local councils, with a little stretch of the imagination, they could be described as being owned and controlled by the community they served.  By the start of the 20th century demand for electricity had grown and the original small power stations with reciprocating steam engines located in residential areas were too small and inefficient to meet the demand, these were displaced by large steam turbine plants located close to a coal supply such as a port, railway depot or even the mine itself.  This became the model used by the industry for a century and it worked well, energy will never be cheap, but its rare to flick a light switch and have nothing happen.  Big nuclear power stations fit into this model.


There are big differences between the late 19th and early 21 centuries, for political and environmental reasons it is desirable to reduce dependency on fossil fuels and many people are uncomfortable with nuclear power.  However, the technologies available make it possible to consider alternatives to the big generator model, for the foreseeable future big power stations will have a role, but it may be possible to stem their growth and possibly even displace some of them.

These comments are based on personal observations, but they may have some wider relevance:
  • Energy consumption can be reduced without a drop in living standards.  In our case, we have steadily migrating to LED lighting, 20 watt compact fluorescent lights have are being replaced by 10 watt or smaller LEDs.  As appliances have died of old age, energy consumption has a factor in deciding on the replacement.  The old washing machine consumed 1.5 to 2.0 kwh/wash, the new one typically uses 0.25 to 0.70 kwh.  There maybe environmental benefits, but our electricity bill is £23/month and falling.
  • Storage is a potential game changer in the way the industry works.  Demand for electricity peaks in the early evening when families are home cooking, staring at a screen or doing homework, at present supply and distribution is set up to meet the peaks and troughs of daily life, if every house had even a small amount of storage, maybe as little as 2kwh, it could be possible to run the generators under constant load with each household having a time slot for charging its batteries.  Grocery deliveries have made us familiar with delivery time slots, doing the same thing for electricity is not such a big step.  Back to economics, there is the potential for buying electricity at off-peak rates (7p instead of 15p/kwh), so there is some potential upside for the consumer.  Storage also helps integrate energy from wind farms in to the energy economy.
  • Back in 1900, if you wanted to generate your own electricity the main options were steam or gas engines, water wheels were an option for those living near a river and wind generation was still being explored.  Even under an cloudy English sky, solar panels can make a contribution.  At present, the economics of home generation are geared towards getting a return-on-investment, however, in conjunction with storage, there is the potential to displace some gas fuelled generating capacity.  Peak demand is in the evening when the sun does not shine bright, if energy generated during the day can be stored for use in the evening, then the load on the grid can be smoothed.  This requires some creative economics.  Some rough calculations suggest that our house's grid dependency would be decreased by two solar panel mounted somewhere other than on the roof.
  • Cars and vans contain reliable combined heat and power systems, a 2kw alternator provides electricity some of which is stored in the battery and waste heat from the cooling system is used to keep the cabin warm.  Extracting the appropriate components and packaging them as a consumer product might produce something costing less than £1,000, such an installation could produce heat and power during the winter months. These could be gas fuelled.  In the context of a car, this is established technology.  One of the incentives for the development of petrol and diesel engines was the limitation on consumption of town gas.  Any loss in efficiency in electrical generation could be compensated for by the use of waste heat.
Some of this stuff is fanciful and no doubt others could expand the list but the point is there are alternatives to big power station model.


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