PV immersion heater proportional control

[jbella]

Just a quick follow on since I made this initial suggestion, I've had a brief look at your PVo and your Sailwider seems to do a fairly good job of utilising your surplus, HOWEVER its lets you down on really sunny days as if you review 25 March - you simply dont utilise all available surplus...... therefore I think you need to findout how immersion systems would interact with your existing Sailwider before moving forward with one of them - that IMO maybe the weak link for you, unless you can do as I suggested previously.

Hi,

exactly as you said I simply can't utilise all available surplus because Sailwider controller monitors via CT total PV generation, total consumption and in the same time it monitors what is the load on the individual remote sockets.
It switches first socket (I've got 400 W heater on it) when there is excess of 400 W, then the second based on the load on that sockets, then third and so on.
So I believe if I connect any proportional controller it will take as much as available (up to immersion rating - let say 3 kW) surplus until water is 60 degree. When immersion switches off Saiwider can use the rest of available surplus again providing there is more that 400 W surplus available.
Another option could be as you mentioned to monitor just secondary replay.

You are right living in Scotland and having 2.85 KW system is not too much :-( but in one year I've exported almost 1000 KWh and on other side I'm looking just for small 50-80 l immersion cylinder since we are just two of us.

One thing I am not sure where can I clip the proportional sensor. Is it OK on the live between meter and solarimmersion as their picture shows?
I just remember when I was first time connecting all my energy monitors (3 of them) it took me a while to understand where to clip them. I could not clip it between meter and fuse box because it could not recognise whether I am exporting or importing. So I've end up with my fuse box full of clip sensors for energy monitors and Sailwider and no space left for anything else :-(

Any chance to answer the firsts part of my previous post about summarising available proportional controllers?

 

[danesol]

snip....................

One thing I am not sure where can I clip the proportional sensor. Is it OK on the live between meter and solarimmersion as their picture shows?
I just remember when I was first time connecting all my energy monitors (3 of them) it took me a while to understand where to clip them. I could not clip it between meter and fuse box because it could not recognise whether I am exporting or importing. So I've end up with my fuse box full of clip sensors for energy monitors and Sailwider and no space left for anything else :-(

Any chance to answer the firsts part of my previous post about summarising available proportional controllers?

The Immersion Device CT sensor will always have to be on the tails just after the DNO electric meter and senses current in both directions, or at least I know the Solar Immersion CT does. This way it picks up all current movement and knows precisely the net surplus available.

Unfortunately I do not have enough product knowledge of each device to give you a summary of each but a few suppliers have offered that information in various posts, some havent !

All I can tell you is in a normal situation - they all work and use surplus, supplied at different purchase costs, if you want to know finer details, you need to speak to both suppliers and some of their existing customers.

hth


ps> Note for all - to a certain degree there is a benefit of these devices in conjunction with OLD DNO meters - it will in the majority of cases stop the meter going backwards in naturally the right conditions - lol

 

[jbella]

Unfortunately I do not have enough product knowledge of each device to give you a summary of each but a few suppliers have offered that information in various posts, some havent !

All I can tell you is in a normal situation - they all work and use surplus, supplied at different purchase costs, if you want to know finer details, you need to speak to both suppliers and some of their existing customers.

hth


ps> Note for all - to a certain degree there is a benefit of these devices in conjunction with OLD DNO meters - it will in the majority of cases stop the meter going backwards in naturally the right conditions - lol

Hi,

Is Solarimmersion phase fired controller? Somehow I can not get this info from manufacturer :-(
I can see that you are using this controller. Is it reliable or any issues?
Thanks,

Juraj

 

[echase]

I'm about to upgrade my old combi boiler for a new condensing boiler and I'm considering to install also immersion heater as a either main source of hot water (summer) or preheat (winter) unit for the combi boiler.
Juraj

The unit in my house is generating too much hot water at this time of year, partly because I also had a solar thermal systems installed some years ago. What is the view on feeding combi boilers off the hot water cylinder?

We have 2 gas boilers in our house and although the main boiler goes off for 6 months in a year the combi one that feeds our granny annex has to stay on because it not possible to feed its taps from the cylinder due to a long pipe run. Problems I can see with feeding the combi are:

1. They are mains fed. Is around 0.5bar from the cylinder enough pressure? It will drop as flow rate goes up. The radiator loop will still be at its usual 1 to 2bar.

1. What happens if the feed water goes up to 70C and the combi is only trying to generate 50C? Hopefully the gas will go off but the water still flows through the combi.

1. Due to long pipe runs, around 4 to 8 litres has to flow before the cylinder water reaches the combi. So for short uses, like washing up, the hot water is never going to get to the combi. As the feed pipe can not be insulated due to its inaccessibility it will often cool down again before the next use.

1. Are they any water regs reasons to not do this?

Anyone tried this?

 

[echase]

If you want to know who will be around in 5 years time to support their warranties look at the companies behind each of the various products, and see how long they have been in business.

A lot of the companies in this field are quite new and so there is indeed a risk that your support lifeline will fail if they do not last. The important thing therefore is to get a reliable product that will last you many years even if the company vanishes. E.g. does it have a fuse to protect itself against load failure as otherwise the unit could be toast with no warrantee cover if your immersion fails, as they often short circuit at end of life?

Apart from a couple of units that blew their easily replaceable fuses because of an immersion failure we have never had an in-service failure, but to be fair to Immersun we have not sold as many units as them so would expect less failures than they. Why has Navitron apparently stopped selling Immersuns if they are the leading product?

I have been in this business for 2 years and with another solar product long before that that I still support although it pays me no money. I would continue support out of interest in the technology and not because of any commercial imperative.

Or you could say that with such good paybacks you will have recovered your money in a short number of years. So if it then fails out of warrantee it’s not the end of the world because by then you can probably buy a replacement at half the price.

 

[Worcester]

echase on solution for you:
Pumped mains pressure (i.e permanently circulating) hot hater is a commion feature in premises with long hot water pipe runs and is used a lot of commerical premises, ideally of course going through a thermal store, that way hot water is always hot instantaneously.You need effectively a 'ring main' of hot water pipes to do this of course.

 

[CBR600]

Anyone had a look at iBoost? Seems competitively priced and communication is wireless so no issues if the immersion is not on it's own circuit.

Solar iBoost - Free Hot Water From Your PV Array

Before you ask, no I don't work for Marlec or have any interest in the product!

 

[danesol]

Anyone had a look at iBoost? Seems competitively priced and communication is wireless so no issues if the immersion is not on it's own circuit.

Solar iBoost - Free Hot Water From Your PV Array

Before you ask, no I don't work for Marlec or have any interest in the product!

When you say "competitively priced".... how much is it as it doesnt seem to state on website ???? :angel_smile:

 

[CBR600]

danesol, has a trade price that is less that Immersun & Solic 200.

The key benefit for me is the wireless connection.

 

[echase]

echase on solution for you:
Pumped mains pressure (i.e permanently circulating) hot water is a commion feature in premises with long hot water pipe runs and is used a lot of commerical premises, ideally of course going through a thermal store, that way hot water is always hot instantaneously.You need effectively a 'ring main' of hot water pipes to do this of course.

My last house had such a pumped system but it had been disconnected, presumably because of the heat losses from constantly circulating it in uninsulated pipes mostly buried in the concrete floor. Running its standard CH type pump all the time to circulate it can’t have been very energy efficient either.

I could do it on this house for the annex only, but would need a small pump and/or a control system to keep the losses down, e.g. turn it off when no occupancy/movement detected. Or detect the pressure drop when tap turned on and then starting the pump like caravans use. If it were a CH pump on full speed it would then pump the hot water to taps pretty quickly. Are there standard ways to control this?

 

[danesol]

danesol, has a trade price that is less that Immersun & Solic 200.

The key benefit for me is the wireless connection.

and how much is that ???

 

[The Solar King]

My last house had such a pumped system but it had been disconnected, presumably because of the heat losses from constantly circulating it in uninsulated pipes mostly buried in the concrete floor. Running its standard CH type pump all the time to circulate it can’t have been very energy efficient either.

I could do it on this house for the annex only, but would need a small pump and/or a control system to keep the losses down, e.g. turn it off when no occupancy/movement detected. Or detect the pressure drop when tap turned on and then starting the pump like caravans use. If it were a CH pump on full speed it would then pump the hot water to taps pretty quickly. Are there standard ways to control this?

Grundfos do a range of secondary circulation pumps starting at around £120.00. I have used a basic one in our own house in conjunction with a Horstmann Channelplus H47XL four channel timer. (CH, HW, UFH, & secondary circulation). It is timed to come on when hot water is mainly used. Every pipe is insulated to within an inch of its life. System monitoring shows we are loosing very little in terms of temperature drop on return to the tank. Absolute bliss to turn on the shower and get straight in.

 

[Worcester]

My last house had such a pumped system but it had been disconnected, presumably because of the heat losses from constantly circulating it in uninsulated pipes mostly buried in the concrete floor. Running its standard CH type pump all the time to circulate it can’t have been very energy efficient either.

I could do it on this house for the annex only, but would need a small pump and/or a control system to keep the losses down, e.g. turn it off when no occupancy/movement detected. Or detect the pressure drop when tap turned on and then starting the pump like caravans use. If it were a CH pump on full speed it would then pump the hot water to taps pretty quickly. Are there standard ways to control this?

Not circulating it would give no benefit of a 'standard' mains pressure combi or unvented system. Yes there are standard pressure drop controllers - think power shower. As for movement sensors triggering a pump, just use a normal PIR linked up to a contactor. Simple inexpensiive Din rail mounted contactors form Chint NO or NC. However see The Solar King's post you do need to insulate well.

We picked this up on a refurb project we visitied the other day that also had pumped hot water - no insulation at all, I pointed it out to the owner who immediately got the plumber back on site

 

[danesol]

danesol, has a trade price that is less that Immersun & Solic 200.

The key benefit for me is the wireless connection.

How much was that again............. :tounge_smile:

 

[provr6]

Has anyone tried one of these? THE RENEWABLE ENERGY SHOP - reuk.co.uk

For 30 boof looks worth a try. Sure it dosen't look as well built as the commercial products but if it works could be worth a punt.

Tempted myself

 

[CBR600]

Danesol, as is often stated on these threads, announcing trade prices is not very helpful; we all need to make a living. However I can see that Immersun is being offered on-line fitted for £495 including VAT and I am sure you could get the iBoost fitted for a similar price.

 

[danesol]

Danesol, as is often stated on these threads, announcing trade prices is not very helpful; we all need to make a living. However I can see that Immersun is being offered on-line fitted for £495 including VAT and I am sure you could get the iBoost fitted for a similar price.

That is very true CBR600 and the way it should be especially for trade only sites, however this is an "open forum" so threads which contain both retail & trade pricing could get confusing for some.

I noticed you only made comparison to the Immersun & Solic 200 as a trade price fit which is fair enough, however when members viewing on, see this in comparison to the supply of devices like the SolarImmersion and i2 at £ 229 and £ 199 delivered respectfully which I may add are just as good if NOT better - to me that can more of a negative effect for good PV Installers & Electricians alike as it shows to propective clientèle they are either been ripped off or the units themselves are way way too dear, as any competent electrician/installer should be able to fit anyone of these devices between 30 to 60mins and at £ 75 p/hr say - that ain't much ontop of £ 229 for Solar Immersion giving a top estimated fitted price of say £ 304, a saving therefore of £ 191 on the likes of the Immersun, Solic200 and the one you are mentioning - iBoost

 

[CBR600]

I am not quite sure how I am being pulled into a discussion about pricing, my original question was about iBoost and if anyone had any experience with it so perhaps we can discuss that. If you have I would be very interested to to hear! Alternatively, if you have experience of fitting another device that communicates wirelessly I would be very interested to hear about that too as this is my primary interest in this device.

 

[danesol]

I am not quite sure how I am being pulled into a discussion about pricing, my original question was about iBoost and if anyone had any experience with it so perhaps we can discuss that. If you have I would be very interested to to hear! Alternatively, if you have experience of fitting another device that communicates wirelessly I would be very interested to hear about that too as this is my primary interest in this device.

The very reason you are been pulled into a discussion on pricing is that is so important to most, there's no point IMO paying more if unit.A can do exactly what unit.B can do for £200 less.............. otherwise you just hope the more expensive item comes with a 25yr warranty

IMO, there is very little difference from the user prospective, in how all these different makes & models undertake their primary task - divert excess electric proportionally to your existing Immersion Heater element. However you may want to pay a little more for say reporting and having a secondary relay as standard or linking into to other products such as the Elios Monitoring system.........

I did want a wifi device initially, but I eventually decided against it due to battery longevity and associated issues and just did the donkey work necessary to pull a cat5 cable through to extend the CT sensor.

However, after all that the iBoost is a nice looking device if you are going to have it on show, unlike me with mine in the airing cupboard .................

 

[Worcester]

Or these 3 Immersuns powering 4 x 4.5kW = 18kW of 3 phase immersion mounted above a 2500 ltr thermal store in the basement of biomass heated and PV powered building