Re: "for purposes of tariff comparison"
>> Variable charging rates are going to do nothing more for the customer than confuse him; turning hardware on and off depending on the rate requires significant infrastructure changes (and incidentally, I want to run the washer *now* not when the leccy say I can!)
And *THAT* is what all this smart metering is about. It will save very very little in overall consumption (government officials have already admitted as much), it's there pure and simply to allow variable rate pricing - also known as price based rationing.
You see, with all those windmills we are subsidising to be built, power supplies are going to get more and more intermittent. We are already up to 4 1/2GW of metered capacity onto the grid - and output can vary in a matter of an hour or two between "F**k all" and "nearly flat out". Not to mention, that many of our peaks in demand (like December 2010) coincide with extended calm periods when there's no wind.
This means other generators (most notably gas turbine) have to keep turning their output up and down to compensate - so they are having to do a lot more starts and power changes to compensate for variable renewables supplies as well as variations in demand. Of course, the very significant costs of this are external to the windfarms and so are cleverly not included in the cost of wind lecky. The "simple" answer from the pro-wind camp is one of the following depending on who you ask :
1) wave their hands vaguely and insist that the European super grid will deal with it as we can buy any shortfall from abroad. Except that is, when the rest of Europe is short of power because their windmills have stopped too and they've been too short sighted to build some more nuclear plants.
2) wave their hands vaguely and insist that "smart metering" will deal with it. What they really mean is the power will be rationed, and unless you have lots of cash then you will be forced to use power when the wind blows rather than when you want to. So when the wind drops, your lecky will go up in price to suppress demand. Of course, no-one (or very few) will admit this even though it is the only way huge quantities of variable wind (and other intermittent renewable) power can be accommodated with current (or likely medium term) storage technology.
And if that doesn't work, the remote turn off can be used to create rolling blackouts like I recall from the 70s. I know of more than one person thinking in terms of a small diesel genny with exhaust heat recovery ...