PV panels using reduced wattage immersion

[jimzjazz]

Just about to have PV panels fitted ( 4 KWp) and I want to use the excess power to heat the water in the HWC rather than export it back to the provider and I wonder why a lot of recommendations suggest fitting a smaller rated immersion one (1kw, 700watts etc) plus as this is for Summertime useage could I have two units fitted 3KW 700W as in the winter I will be using the boiler in place of the larger of the 2 immersions ( I THINK??)
Look forward to any suggestions and advice, from out there
JIMZJAZZ

 

[Iggifer]

then I would look into this type of system pronto

http://www.intelligentenergysolutions.com/solar-water-heating-panels_c53.aspx

 

[ricicle]

What excess power ????

 

[flameport]

I wonder why a lot of recommendations suggest fitting a smaller rated immersion one (1kw, 700watts etc)

This is because your 4kWp panels will in reality only produce 4kW when in full sun for a couple of hours in the middle of the day in the height of summer.
Most of the time, the output will be far less, hence the suggestion of a uselessly feeble immersion heater.

Using a normal 3kW heater would mean a fair bit of the power used would be from your paid electricity supply, and therefore be very expensive compared to gas or whatever other fuel your boiler uses.

Now wait for the inevitable mewlings from those who have such panels and claim they generate vast amounts of electricity all the time and are the most splendid things ever invented.

 

[jimzjazz]

I wonder why a lot of recommendations suggest fitting a smaller rated immersion one (1kw, 700watts etc)

This is because your 4kWp panels will in reality only produce 4kW when in full sun for a couple of hours in the middle of the day in the height of summer.
Most of the time, the output will be far less, hence the suggestion of a uselessly feeble immersion heater.

Using a normal 3kW heater would mean a fair bit of the power used would be from your paid electricity supply, and therefore be very expensive compared to gas or whatever other fuel your boiler uses.

Now wait for the inevitable mewlings from those who have such panels and claim they generate vast amounts of electricity all the time and are the most splendid things ever invented.

Thanks, I hear what you are saying and understand re. 4KW peak but as there are only 2 of us, and a' cold water fill' washing machine I anticipated that with monitoring there would be a residue and as the export rate is not brilliant it would be better employed heating the DHW to some extent.
any comment on my thought on having 2 immersions fitted to the HWC? and switching when need be?
JIMZJAZZ

 

[ajstoneservices]

OP have a look at these.
http://www.immersun.co.uk/
http://www.solarcache.co.uk/solarcache

 

[jimzjazz]

OP have a look at these.
http://www.immersun.co.uk/
http://www.solarcache.co.uk/solarcache[/QUOTE][b]

Thanks, Great minds think a like! I have just been looking at some to include the website you listed + http://www.solarimmersionheaters.co.uk looks intersesting ( to include a 'power reducer (3kw to 1.5) couldn't work if there was some kind of 'override switching to allow the 3KW immersion to cut-in or operate on a 'flip flop basis, I should imagine there is? still I can always drop them a line to establish this
JIMZJAZZ