Sunday, December 21, 2008

premature optimisation, the root of all sins

James Wimberley has a good post regarding changing the electricity grid to support dynamic demand-response, where things like Dutch cold-stores or your fridge over-cool when electricity is plentiful and cut out when the grid is under strain. It's hugely important in adapting the electrical system to use stuff like gigawatt-size wind farms; essentially, it's a way to store large volumes of electricity, with the added feature that you lose no power in the process. Not using the power is always 100 per cent efficient.

Anything that lets you buck entropy has to be good, but there are some serious problems to get over. James dislikes some versions of this as being too Stalinist - the grid reliability controller reaches out and turns everyone down a notch. It's not Stalinism he's thinking of, though, really, but rather Charlie Stross's third great evil of modernity, high technocracy. Stalinists would have planned your energy requirements in advance.

He suggests instead that what we really need is a device that handles all the appliances behind it according to rules you set up, and that receives a feed of data about electricity prices, marginal CO2 emissions, and loads on the grid. Which presupposes a standard for announcing grid data onto the Web; RSS for power stations.

But I'm sceptical on a few things; as far as I can tell, demand response is much more useful for managing the grid than for shaving down demand overall. Which is great, but it falls foul of one of my beefs with much of the official green movement; the macro-micro issue. You can't open a newspaper without being lectured by the lifestyle pages about fairly marginal changes; you rarely see anything about moving big chunks of the energy budget.

And I think the geekosphere is guilty of this; Wattson, AMEE and friends are cool, but it's all about shaving percentages here and there. Consider this post about the huge economic returns on US Federal energy efficiency R&D; it's all about building components, fridge compressors and the like. There's a management consulting piece of quasiwisdom that says that it's always better to remove empty work (muda) from a process than to optimise it. But who wants to discuss lumps of building material?

On the good side, though, I notice that prices for my favourite pet project are coming down gradually. And I like this quote a lot:
The Roadster is faster then anything on the road, including the young guy in a fuel cell SUV who improbably challenged me to a Saturday night race on Hollywood Blvd.

1 comment:

ajay said...

Interesting piece on the news last night about GSK's headquarters building west of London, which cools itself using the waters of the neighbouring Grand Union Canal and thus saves about 0.4 splodges of wonga per year. The Waterways are making a bit of that in user fees...

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