Or is it all just a way to beat these customers up until they switch to using a time of use (demand) meter?
|This version shows a large range of the input values, roughly corresponding to what you might expect from most domestic dwellings. Note that TLC's formulae often turn into straight lines once you get above a certain level of consumption.|
|This shows the very large and painful change TLC have imposed (at rather short notice I might add) on accommodation and holiday home customers (top line) as compared to the formula applied to them (and others) last year (lower, red line).|
What is missing from all of this is a complete, detailed, correct description from TLC on how the formula are derived, how (in)accurate they may be, what data was used as the basis for them and so on. The graphs below comes from an earlier version TLC's 2010 methodology but you won't be able to find it on their site any more...
This "shows" how the non-dairy formula TLC used over 2010/2011 was derived. The red data points are 92 day consumption figures versus peak demand (apparently the single highest 3 hour period "while load controlling" - although this was not data that I processed) based on the smallish sample of homes ALL drawn only from the northern region. Count the dots - I get about 110 which is a miserably low sample size to set the rates for the other (roughly) 20,000 customers. Anyway, the black line is "the formula", derived by finding some kind of "best fit" to the red data points and then expressing that mathematically.
In other words, the line in this final graph shows where the formula behind the blue line in the first three graphs above came from. I wonder what they've used to come up with the 2012 formulae? Looking at the very top graph you'll see they top line is remarkably similar in general shape to the next one down (for 2011) so I think we rest assured the same old tired sample from up north is still influencing everything.