Choice of intelligent switches ?

Well I've purchase the Solar Immersion MKIII switch from solarimmersion.co.uk using the discount code:- dis2204 and we are really impressed and it works really well in conjunction with our SMA based 3KW system :j

Yes, it maynot be as good looking as say the Solic 200 or the Immersun, however we were'nt bothered about what it looks like or the build quality to a certain degree as it has been fitted away from sight in a cupboard - all we were seeking was good functionality at a NO FRILLS price and this is what you get, doing exactly what it was designed to do !!

So if you either heat your hot water via oil, electric or GCH ( condenser ) boiler, you would be foolish not to consider one of these units especially if no-one is at home during the day to use the generated electric which normally would just go to the grid.

Using one of these devices you heat your hot water ( or/and use on another =< 4KW load ) by electric you have already gained revenue on twice;

1. Once via the initial generation - std generation tariff

2. Second via the 50% estimated export tariff

We calculate our return will over 3yrs, replacing £ 80 worth of GAS which would normally be used to heat the hot water cylinder - then pure profit thereafter.

danesol wrote: »

Well I've purchase the Solar Immersion MKIII switch from solarimmersion.co.uk using the discount code:- dis2204 and we are really impressed and it works really well in conjunction with our SMA based 3KW system :j

Yes, it maynot be as good looking as say the Solic 200 or the Immersun, however we were'nt bothered about what it looks like or the build quality to a certain degree as it has been fitted away from sight in a cupboard - all we were seeking was good functionality at a NO FRILLS price and this is what you get, doing exactly what it was designed to do !!

So if you either heat your hot water via oil, electric or GCH ( condenser ) boiler, you would be foolish not to consider one of these units especially if no-one is at home during the day to use the generated electric which normally would just go to the grid.

Using one of these devices you heat your hot water ( or/and use on another =< 4KW load ) by electric you have already gained revenue on twice;

1. Once via the initial generation - std generation tariff

2. Second via the 50% estimated export tariff

We calculate our return will over 3yrs, replacing £ 80 worth of GAS which would normally be used to heat the hot water cylinder - then pure profit thereafter.

Hope you've factored in smart meter rollout from next year.

You will be lucky to get 80% efficiency in the summer, just having the gas boiler cycle to top up the tank every time someone uses some hot water.:eek:

That said you would be lucky to get 20% efficiency from PV panels but at least the "fuel " is free.:D

Must go and switch off the cold fill washing-machine and turn on the immersion.;)

Cardew wrote: »

£80 worth of gas is around 2,000kWh(then take into account boiler efficiency which will lower amount put into tank to, say, 1600kWh if 80% efficient)

Isn't that a little optimistic from a 3kWp system? Especially bearing in mind the HW tank has a limit on the amount of electricity it can 'absorb'.

Hi

I suppose that the answer to the above really relates to the structure of the op's energy supply contract. For example, in our case, having a tiered tariff gas supply, the energy cost offset from our thermal system is calculated at tier1 rates.

Our gas supply tier1 bracket is ~7.5p/kWh for the first 670kWh/Qtr, so considering that our gas use over the past 12 months has been <1100kWh (almost all in winter months) - March totalled ~55kWh, April 5kWh ... £80 would therefore relate to somewhere around 1067kWh of supply(80/0.075), or around 850kWh (01067x80%) of heat, that's the equivalent to ~4.7kWh/day over a 6month summer period (850/180), so not unreasonable from a 3kWp system with an automated control system.

With a solar thermal system the direct heat provision efficiency drops away as the differential between ambient & cylinder temperature rises (a form of automated modulation) whereas direct element-heating wouldn't, however, our system is amply capable of providing double the heat provision calculated above ... if we used more water the average lower storage temperature would cause system efficiency to rise and we could save even more gas and still have enough HW on tap, but using more water in order to show a better payback isn't really consistent with the reason for having the system!! ....

HTH
Z