So now I have a solar PV system how do I make the most of it???

thermomonkey

Morning all. I have a 3.7kw system, with an immersun 2 installed. It is working great, and heats my hot water no problem. I was wondering however if a device exists which will 'pre heat' the water going in to my radiators? There is a consideration however; assuming it will be connected to my immersun and only gaining the excess electricity then it would have to be a 'dumb' element, and may therefore be prone to overheating the water if the radiators were not demanding heat.

I am sure I can not be the only person interested in such a device, but I have googled an can not seem to find anything. Thank you in advance for any replies.

EricMears

thermomonkey wrote: »

Morning all. I have a 3.7kw system, with an immersun 2 installed. It is working great, and heats my hot water no problem. I was wondering however if a device exists which will 'pre heat' the water going in to my radiators? There is a consideration however; assuming it will be connected to my immersun and only gaining the excess electricity then it would have to be a 'dumb' element, and may therefore be prone to overheating the water if the radiators were not demanding heat.

I am sure I can not be the only person interested in such a device, but I have googled an can not seem to find anything. Thank you in advance for any replies.

You'd only be able to do that if your system incorporates a suitable tank. Most domestic systems would feed water direct from the boiler to the radiator circuit(s).

Our house is a bit more sophisticated than that and uses a 'Heatbank' which is heated from an oil boiler OR from a logburner's back boiler OR an immersion heater element. I don't actually have an 'Immersun' (or very similar) but I do have a 3kW immersion element that is downrated to 750W by dropping voltage from 230v to 115v with a 'builders transformer' and fed from an Optiplug.

zeupater

thermomonkey wrote: »

Morning all. I have a 3.7kw system, with an immersun 2 installed. It is working great, and heats my hot water no problem. I was wondering however if a device exists which will 'pre heat' the water going in to my radiators? There is a consideration however; assuming it will be connected to my immersun and only gaining the excess electricity then it would have to be a 'dumb' element, and may therefore be prone to overheating the water if the radiators were not demanding heat.

I am sure I can not be the only person interested in such a device, but I have googled an can not seem to find anything. Thank you in advance for any replies.

Hi

There is .... it's your DHW cylinder's GCH coil. You'd need to work out a control method to open the valves (both - assuming S-plan) and switch on the circulation pump without the boiler firing up and probably incorporate a de-stratification circuit, but it's possible ... it's similar to how some with solar thermal systems dump excess summer heat in order to prevent system high temperature stagnation ...

... but the question is "why ?" as when you really need heat the most you'll have little generation to divert and when you have enough generation to heat your DHW to thermostatic cut-out, there's usually no need to run the heating and electric water heating controlled by proportional diversion doesn't suffer stagnation - the thermostat simply cuts out ....

HTH
Z

1961Nick

Would there be a way of using the surplus energy to run an air to water heat pump? Something along the lines of a swimming pool heater coupled into the DHS.

zeupater

1961Nick wrote: »

Would there be a way of using the surplus energy to run an air to water heat pump? Something along the lines of a swimming pool heater coupled into the DHS.

Hi

Depending on your equipment's external control features and how you envisage the control mechanism working it's certainly possible with some basic relay switching ... some inverters have the ability to control external loads so you could probably use that functionality switching in series with something similar to a certain member's immersion control circuitry would do the job as long as the heat-pump has an external demand switch interface (maybe DF will comment) ... alternatively you're looking at spending on a home automation setup ...

HTH
Z

orrery

1961Nick wrote: »

Would there be a way of using the surplus energy to run an air to water heat pump? Something along the lines of a swimming pool heater coupled into the DHS.

As someone who has tried all sorts of schemes to use as much free solar as possible (buying additional electric radiators, timers, builder's transformers, SolarImmersion diverter, 30" immersion, Electric Car...) I'd have to question the return you might get on this (as well as my own sanity).

If you're going to use a heat pump, then that is probably a good idea but I understand that they have to be left on long-term to be effective, in which case just accept that you'll contributing to it whenever there is solar to use.

ourcornercottage

Hi all, I'm having 3.75kw system installed in 2 weeks. I have also arranged an iSolar to attach to my current tank.

I also have oil heating which heats all radiators except one and heats the water. I also have a woodburner with a back boiler which hears the other radiator and the water too.

I'm having my heating fiddled about with later in the year after my solar is done and the tank will be replaced in the work and all my rads replaced.

I would like to have the option to hear water via the iSolar, oil or woodburner depending on which is available. Is it worth having some rads as storage heaters or electrical heaters where there are 2 rads in a room or in the hall where there is currently nothing.

Any ideas that I can pass on to the plumber, it can't be too crazy expensive ideas. I'd appreciate ideas before I make a decision on how to go. (In laymans terms please!)

Doc_N

e.on are offering to fit a smart meter. They tell me that it won't enable me to gain any information at all about the solar panel output - which surprises me.

Can't see any practical benefit to me at all, really, in having one - reading the meters is no big deal, likewise sending in the readings online from time to time. I know what individual appliances use, and there's no way it will change household behaviour one jot for that reason,

I can see clear benefits for energy suppliers, but nothing much for me. Am I missing something? Are they right in saying that these meters provide no information about output from the panels?

zeupater

ourcornercottage wrote: »

Hi all, I'm having 3.75kw system installed in 2 weeks. I have also arranged an iSolar to attach to my current tank.

I also have oil heating which heats all radiators except one and heats the water. I also have a woodburner with a back boiler which hears the other radiator and the water too.

I'm having my heating fiddled about with later in the year after my solar is done and the tank will be replaced in the work and all my rads replaced.

I would like to have the option to hear water via the iSolar, oil or woodburner depending on which is available. Is it worth having some rads as storage heaters or electrical heaters where there are 2 rads in a room or in the hall where there is currently nothing.

Any ideas that I can pass on to the plumber, it can't be too crazy expensive ideas. I'd appreciate ideas before I make a decision on how to go. (In laymans terms please!)

Hi

If you're already looking at heating the DHW with multiple sources you must have looked at a cylinder with multiple heat exchanger coils, therefore all you'll be doing is adding an immersion to be run via the solar controller ... as for attempting to space heat using pv, you might just about get away with a switchable 400/600/1000 oil-filled plug in radiator (or similar) to provide a little warmth in a small room such as a home office (as a number of members on this forum do), but don't expect to save much using this method, especially so considering that you'll already be diverting to DHW ...

Converting excess power to space heating could be done more efficiently using an Air/Air heat pump, but you're probably talking about ~£1000-£1500(ish) for a system which provides 3x to 4x the heat as opposed to sub £30 for the oil radiator ... but don't forget, you'll already be automatically diverting a good proportion of available power to DHW at the times if year when you need the heat ....

As it stands, you may also have an issue with running proportional pv diversion alongside a log-burner DHW circuit as the log-burner would normally need to be heating the cylinder whenever it's burning, so you may find that the proportional diversion would only really be useful spring through to autumn ... you should talk to your installer on this, but make sure that they have relevant experience in all the technologies.

HTH
Z

zeupater

Doc_N wrote: »

e.on are offering to fit a smart meter. They tell me that it won't enable me to gain any information at all about the solar panel output - which surprises me.

Can't see any practical benefit to me at all, really, in having one - reading the meters is no big deal, likewise sending in the readings online from time to time. I know what individual appliances use, and there's no way it will change household behaviour one jot for that reason,

I can see clear benefits for energy suppliers, but nothing much for me. Am I missing something? Are they right in saying that these meters provide no information about output from the panels?

Hi

I agree. As it stands it's all a con to pull-in about £12billion of extra funding to the energy companies with very little chance of there being any real savings to the customer or national emissions targets above what a simple monitor would do.

I attempted to contact the chair of the Public accounts Committee to point out an error in their report into smart metering which was published last year ... it's not a large error, just about £5billion when extended, but the error is there in a report which has been referenced in parliamentary debates on a number of occasions and I've received absolutely no reply, despite chasing and receiving read-receipts to the e-mails sent ....

To compound issues, if you have one fitted, the best it can currently do is automatically report usage to your energy provider, but the ridiculous thing is that it'll probably not even do that if you were to change provider, so much for shopping around then ... and you'll be paying the best part of £500 for the privilege, even if you don't have one or have one which does no more than an ancient analogue meter ....

£500/household for an energy monitor and meters which should cost well under £50 each to the suppliers and could be fitted within the normal replacement programme ... now how exactly does the maths on that stack-up, perhaps the parliamentary parties should stop squabbling about learning times-tables in schools, pull the energy-sector's wool from over their eyes and review their own mathematical abilities ...

HTH
Z