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Wednesday 21 January 2015

Peak or Average

Over the past year I have been taking a cursory look at the relationship between the demand for energy and the ability of wind and solar systems to provide it.  On the supply side, wind energy comes in pulses which are stronger in winter than summer and the sun does not shine at night and is not too bright in winter.  On the demand side, the base load continues overnight, rises overnight as the day workers leave home and peaks in the evening when meals are cooked.  Adding storage to the system improves the relationship between supply and demand, but at a cost.  Whilst there are incentives to generate electricity, there is little to encourage people to be better consumers other than the price which is a crude and sometimes unfair, regulating device.

In general, there are two ways of designing a system.  A system designed for the average load will probably be smaller and cheaper than one designed handle the peaks.  The downside is that there will be times when frustration erupts around the smaller system.  Anyone who has had to specify office equipment such as printers, copiers, coffee machines will be familiar this dilemma.  One take on this is that if communication is better around the coffee machine than in meetings, scrap meetings and get a small coffee machine.
This post was in part, inspired by our washing machine.  I have no in depth knowledge of how this machine works, so I apologize if I have drawn the wrong conclusions.  Sometime back, I place an energy meter between the wall socket and the machine's power plug.  For most of the cycle, the energy consumed was significantly less than 1kw, during the early part of the spin cycle, it rose to around 2.5 kw, something, somewhere had to provide an extra 1.5 kw for a few minutes.  In the context of a washing machine, it might be possible to reduce this peak by increasing the time taken to get the drum up to a speed at which water and socks are separated.  This would not reduce the overall energy consumption and would increase the time taken to complete the wash, but it would make the machine a "better" consumer.  I guess this was what was behind the recent introduction of a maximum power rating for vacuum cleaners.
A lot of the discussion around sustainable energy focuses on technology, but behaviour is also an element.  Price alone is a crude regulator, but tariffs and business models could evolve to get a better outcome.  One possibility is a variant that  does not restrict consumption, but enforces a ceiling on the rate of consumption, this could encourage the development of storage and management solutions.  I've heard several references to tariffs in which the charge increases with consumption which provide an incentive to manage consumption.  These ideas are in conflict with the traditional business model which is based on sales volume and market share, what is needed is a business model which creates viable energy companies, but at lower levels of consumption.

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