Hot Water Buffer

[Degs]

Having recently installed a 4 kw solar panel system I have been thinking of ways to best use the spare electricity. As I have a combi boiler I am unable to heat my hot water via an immersion. What I have been thinking is of a way to heat the cold mains feed to the combi by means of a buffer tank of around 20 ltrs ( not sure about size ) and have a 500 watt immersion fed off the spare electricity. If I go with an unvented buffer its expensive, if I use an ordinary immersion tank / system and heat the tank water via the 500 watt immersion to transfer heat to what was the central heating coil (which is now mains cold water). I'm thinking there isn't enough coil surface area to make much difference. Any Ideas please.
Degs

 

[SimonJohns]

You'd be far better off selling it to the grid. Or charging battery's

 

[TTB]

Hi Degs
Couple of things here , if you go for a small seal tank of 20 ltrs its classed an unvented unit as its over 15 ltrs,
correct in also saying if you buy a standard indirect vented cylinder the coil will be inefficient due to the small
heating surface. So in my eye you may have to go for a direct buffer vessel maybe with a 1KW immersion heater or just
or a special vented cylinder with a larger heat extract coil, there are only a few cylinder manufacturers that will accommodate your requirements, and they are in the midlands.

TTB

 

[zzzjim]

Use electricity to run pump on a solar fluid system !
( Heating , water via coil of mentioned cylinder )

 

[Degs]

You'd be far better off selling it to the grid. Or charging battery's

The energy company gives me three pence approx for every unit fed back to the grid. Being unable to calculate this amount they base it on 50% of my total generation. Thanks any way.
Degs