Economy 10 meter question

[JACKC]

Peeps,
I have got to give a proposal to a customer about econ 10 system. Has anyone installed this before. I have installed plenty of e7 consumer units and storage heaters before but can not find any useful info on the way the meter works other than the hours for off peak etc for circuit design. Anyone know or have pictures of an e10 meter and best circuit design I would be most grateful. What type of heaters are best installed for e10.
Many thanks
Jack

 

[flameport]

E10 is normally only installed for central heat storage units, such as those horrid Gledhill efforts which heat up a large cylinder of water and then transfer the stored heat to radiators and the incoming cold water supply to provide hot water.

Switching is controlled by the meter, so is very similar to E7, except the cheaper rate is on for 10 hours each day. The times will vary but usually a longer period overnight with one or two extra periods during the day to 'top up' the heat.

For a nomal system (e.g. hot water cylinder and storage heaters), E10 is of little or no use.
For hot water, it would provide a 'top up' during the day, but this is only of benefit if the cylinder is so small that all of the hot water is used up in the morning, leaving nothing for later in the day/evening. In that situation, the problem can be resolved by installing a larger cylinder (or second cylinder). Or if a larger cylinder is impossible, other methods can be used such as fitting flow restrictors to hot taps, or having the hot water heated to a much higher temperature (e.g. 80C) and installing thermostatic blending valves at the sinks & bath.

Storage heaters are designed to take a 7 hour charge. While it might seem like a solution to 'top up' during the day, if storage heaters are cold by the evening, then either they are too small, there aren't enough of them, the property needs better insulation, or all of the above. It is also possible that the persons who live there don't know how to set the controls correctly.

 

[Stoday]

For the same supplier, you should expect the day kWh of E10 to be more expensive than the day kWh of E7. Also the "night" kWh of E10 should be more expensive than the night kWh of E7.

E10's more expensive because E10 day kWh include a greater proportion of expensive peak kWh. And E10 "night" kWh include some day kWh.

 

[JACKC]

Thanks for the replies, they are most helpful as always.
Jack