Green Building Forum - Diverting excess microgeneration Wed, 29 Jul 2026 19:54:08 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154783#Comment_154783 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154783#Comment_154783 Thu, 23 Aug 2012 15:09:49 +0100 dbj Came across this site the other day and wondered if anyone has any feedback on the 'Mark 11' (as described),which appears to be a primitive version of the emma sytem at much reduced cost.
Has anyone used one? If so I would be interested in their review.

Site: solarimmersionheaterswitch.co.uk

Thanks]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154787#Comment_154787 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154787#Comment_154787 Thu, 23 Aug 2012 16:32:39 +0100 candlemaker Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154791#Comment_154791 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154791#Comment_154791 Thu, 23 Aug 2012 17:30:48 +0100 jamesw http://www.yougen.co.uk/blog-entry/1737/Auto+control+enables+use+of+solar+PV+for+immersion+heater/]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154792#Comment_154792 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154792#Comment_154792 Thu, 23 Aug 2012 17:32:23 +0100 jamesw
Devices that turn on a fixed load:

1. Intelligent Solar Immersion Heater Switch Mark II, http://solarimmersionheaterswitch.co.uk £229

2. SolarDivert, http://www.solardivert.co.uk/index.html £369

3. Immersion Heater Relay, http://www.rudgerenewables.co.uk/intelligent-power-management/our-immersion-heater-relay-unit £160

4. Variety of home-brew devices, e.g.:
i) Arduino-based at http://openenergymonitor.org/emon/node/217
ii) http://www.navitron.org.uk/forum/index.php/topic,16274.0.html (link from first post of jamesingram below)
iii) Another approach described in the body of the first post of jamesingram below

Devices that vary current according to excess available:

A. EMMA, http://www.coolpowerproducts.com/uk/emma.html >£1000?

B. ImmerSUN, http://www.immersun.co.uk £444

C. S&G Wooldridge Solar PV Controller, http://www.sgwooldridge.co.uk/cms/solarpvswitch £474

D. Sunny Home Manager, http://www.sma-uk.com/en_UK/products/monitoring-systems/sunny-home-manager.html - appears to be a German product allegedly launching in the UK in 2012 but haven't seen a price. And maybe this should go into the first class - haven't looked in detail at the technical capability.

E. [Allegedly forthcoming in late 2012] Add-on to Energeno's Wattson energy monitor, http://blog.diykyoto.com/2012/04/upcoming-products.html

If anyone knows of others, post below and I'll try to edit this post to add them to the list!

Apparently Chris Rudge is going to review some products "in due course", according to the editor's comment at http://www.yougen.co.uk/blog-entry/1955/Can+I+connect+solar+PV+to+my+storage+heaters'3F/

My only interest in all of this is that I'm planning to install a product next year to make use of my excess solar PV. In my view, the second class of products above - i.e. the ones that vary current to make use of all of the available excess (but no more) - is greatly preferable if available at a reasonable cost. My strong inclination at the moment is therefore towards the ImmerSUN.

I'll put a pointer to this thread on a couple of old GBF threads on this issue, to try to keep all new discussion here (those threads are at http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=8653 and http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=8456 ).]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154797#Comment_154797 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154797#Comment_154797 Thu, 23 Aug 2012 18:08:41 +0100 fostertom Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154802#Comment_154802 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154802#Comment_154802 Thu, 23 Aug 2012 19:54:38 +0100 tony Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154809#Comment_154809 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154809#Comment_154809 Thu, 23 Aug 2012 22:25:09 +0100 jamesingram http://www.navitron.org.uk/forum/index.php/topic,16274.0.html

some Helpful fella sent me this super cheap option a while back
"Hi the device consists of two photo electric switches (you can buy these at maplins for £5.99 each) and a s.s.r (solid state relay) you can get them on ebay for 99p +p&p
firstly solder one of the photo cells to a long lead(something like doorbell wire)
then this is placed somewhere in the sunshine so that it's in the sun at the same time as your
solar panels ( i've put mine on the roof next to the panels) run the lead back to the circuit board
this is then set so that when you are producing X amount of power the switch operates.
this alone will turn on and off your heater but to stop it from using imported leccy when you turn something
on like a kettle,the second photo electric switch looks at the red flashing light on
your electric meter (you need to have a digital electric meter with the red flashing light on it)
the photo electric switch that looks at the meter needs to be the one with the delay on it
when the led is flashing you are importing leccy and when it is on all the time you are exporting lecy,
place the photo cell so that it is looking at this light this then triggers the switch when the light comes on the output of the relay is linked to the output of the other switch which then turns on the s.s.r
this then turns on your heater
http://www.maplin.co.uk/light-sensit...itch-kit-28574
http://www.maplin.co.uk/light-activa...tch-kit-528796
http://www.ebay.co.uk/itm/New-SSR-25...item4cf71a1c1f "
also sent wiring diagrams etc. whisper me and I'll send them over

Not tried it, but thought it might be of interst .
I've a sunny 4000tl so can use the internal relay to trigger immersion as discussed elsewhere on GBF , another thing for the to do list when work gets quiet ( if only )
cheers Jim]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154812#Comment_154812 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154812#Comment_154812 Thu, 23 Aug 2012 22:47:50 +0100 GreenPaddy I realise you didn't come up with this, nor have you tried it yourself, but I'm wondering why you need 2 photocells. Presumably if the one looking at the red LED on your meter, only switches 'on' the immersion when the red LED is on continuously, (ie. exporting) then the presence of sun is not relevant? If that works, it's a fantastic solution - worth a shot for a tenner, even if it doesn't quite work.]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154819#Comment_154819 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154819#Comment_154819 Fri, 24 Aug 2012 07:03:39 +0100 jamesingram Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154860#Comment_154860 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154860#Comment_154860 Fri, 24 Aug 2012 17:23:42 +0100 dbj I guess they work like an electronic load controller on a non grid connected water turbine, putting power not currently being 'used' into 'ballast' loads (resistive only).]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154886#Comment_154886 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154886#Comment_154886 Sat, 25 Aug 2012 17:41:14 +0100 GreenPaddy I wonder if when the case you describe occurs (probably quite frequently) that you have export...red light ON...put elect to immersion...draw more power than generating...red light goes off...stop elect to immersion, and let it cycle like that. If you wait till you have enough power for the immersion, @ 3kW, you'd wait long time, and miss out on all the 500W periods.

I'm going to try it on a neighbours system, and see what happens, but any pointers to obvious flaws in the single photocell approach would be great. My guess at the role of the second photocell was for the non-fluctuation load devices - eg washing machine. So you set the sun monitoring photocell to have a switch-on limit which ensures you have a good supply of PV power, and then a latching relay holds the wachine machine in operation (so it doesn't switch off even if the sun disappears - can't have the washer going off and on).

This is where good old "JSH" would have come in handy, but I think he drew stumps from this forum??]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154889#Comment_154889 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=154889#Comment_154889 Sat, 25 Aug 2012 19:17:22 +0100 Gavin_A
There's also a timer option so that you can ensure that the tank is hot at the end of the day via the immersion heater, and / or control a secondary heat source, and each unit has the ability to control 2 immersion heater circuits one after the other.

plus it actually looks like a well built piece of kit rather than something someone's put together in their shed after a visit to maplins.

We've previously used the relay function on the SMA inverters to trigger a contactor, but this is a right pain to install as it needs a 1-2kW Immersion heater fitting, which can be a nightmare to do, plus control cables from the inverter to the consumer unit, and customers just find it confusing to use as they have to leave the immersion switch permanently on (yes, people do seem to have a problem with this idea).

fwiw, we're offering them locally fully installed for £499 inc vat, or less if installed at the same time as a PV system, or other measure such as a voltage optimsation unit.

I do have some issues with the concept of this technology when replacing water heated by a condensing gas boiler, but the first unit at least is going in to a place that already uses the immersion heater only, and tbh we've been having so many problems making conventional solar water heating work financially without the RHI in place that I've come around to this as being a more practical and cost effective solution to that issue for a lot of people.

if we're doing links, I'll put mine up for anyone wanting more info about the unit. I won't be offended if it gets removed though.

http://www.leeds-solar.co.uk/energy-saving/immersun]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=177217#Comment_177217 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=177217#Comment_177217 Sun, 02 Jun 2013 11:08:47 +0100 stones
Nibe, initially advised that there was no way to divert excess solar pv into the EAHP immersion, and that there is no boss available to install a second immersion coil. A ray of light however is that on going through the Nibe EAHP install manual I found a little sentence saying that a remote switch can be fitted to the unit to activate temporary lux, which in english is hot water boost using immersion. Having spoken to the sparky who commissioned my additional PV system, it seems all that is needed is a simple relay switch. Nibe have also confirmed that it would be possible to use this function to activate temporary lux with a device that monitors excess solar pv generation. The downside is that the lowest immersion setting is 2.6kw so it would need a relatively good day to work. That said, in my case, I know have 32 PV panels on my roof, east and south facing, so kick off first thing in the morning rising to peak lunchtime of 6kw generation, then dropping back so there is the capacity there for me to use.

The question is now finding the right solar device to do the job as the majority that seem to be available wire directly into the immersion system and deliver variable load to the immersion coil, whereas I simply want a switching, non load function. The Immersun does in addition to its main function appear to have a non load relay which could be used for this purpose, but it does seem an expensive way to go for just the relay function. Looking at the alternatives, I begin to struggle as my knowledge of electronics is limited to basic stuff from school many, many years ago. Anyone have any thoughts as to which way to go? In addition to this specialised form of diversion into immersion, I am looking to be able to run some additional devices, (dehumidifier, heater) when I have excess generation. The Wattson devices look good for that.]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=177238#Comment_177238 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=177238#Comment_177238 Sun, 02 Jun 2013 18:56:23 +0100 SteamyTea Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=177245#Comment_177245 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=177245#Comment_177245 Sun, 02 Jun 2013 22:43:31 +0100 MartinH Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=177247#Comment_177247 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=177247#Comment_177247 Sun, 02 Jun 2013 23:09:12 +0100 dbj Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=177249#Comment_177249 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=177249#Comment_177249 Sun, 02 Jun 2013 23:30:49 +0100 Ed Davies
Posted By: stonesThe question is now finding the right solar device to do the job as the majority that seem to be available wire directly into the immersion system and deliver variable load to the immersion coil, whereas I simply want a switching, non load function.


It's a pity item 3 from jamesw's list early in this thread is no longer available. Seems the cheapest non-DIY answer to me.]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=177266#Comment_177266 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=177266#Comment_177266 Mon, 03 Jun 2013 12:32:13 +0100 SteveZ
solarimmersion.co.uk - sounds similar to a few others, and looks identical to the solarimmersionheaterswitch product, but it reads as though they have sorted out the flicker problems reported on some of the other switching systems]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180420#Comment_180420 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180420#Comment_180420 Mon, 22 Jul 2013 15:25:20 +0100 Immersion Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180503#Comment_180503 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180503#Comment_180503 Tue, 23 Jul 2013 17:36:01 +0100 borpin Posted By: ImmersionAlso add the Intelligent Immersion model I2 www.intelligent-immersion.co.uk to the list. At £199 it is the cheapest available that offers full proportional control. It is a quality built unit and not a cheap and unreliable PCB in a flimsy box like some. Also no flicker. A blatant commercial plug.]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180509#Comment_180509 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180509#Comment_180509 Tue, 23 Jul 2013 19:36:03 +0100 Ed Davies
http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=10577&page=1#Item_15

Pity to use such silly marketing tactics, really, as it looks like it could be a product worth considering in some cases and depending on the price, etc.]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180562#Comment_180562 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180562#Comment_180562 Wed, 24 Jul 2013 12:25:36 +0100 Immersion Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180563#Comment_180563 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180563#Comment_180563 Wed, 24 Jul 2013 13:06:28 +0100 Ed Davies
http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=584&page=1

First sentence: “Forum members that post adverts disguised as a discussion will be banned from the forum. So save us all some time and don't do it.” Is that overly difficult to understand?]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180573#Comment_180573 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180573#Comment_180573 Wed, 24 Jul 2013 14:38:16 +0100 skyewright Posted By: ImmersionA forum that can not mention/recommend/warn of products is not very useful to the many who trawl these forums looking for such info.
Many products receive such comments here on GBF, but a mention/recommend/warn from an established forum poster reporting on user experience of a product is a very different thing to someone joining the forum and using their initial posts to highlight their own product.

Like Ed Davies, I think you may well have a product worth considering, but if anything your promotion methods are currently more likely to put me off than attract me, sad to say.]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180574#Comment_180574 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180574#Comment_180574 Wed, 24 Jul 2013 14:39:49 +0100 bxman
One that excludes qualifying items can hardly be a representative list.

I understood the list was to correlate products that met the criteria.

or is it only to be a partial list

Jamesw acted in good faith who has the right to stop him I would like to know.]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180575#Comment_180575 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180575#Comment_180575 Wed, 24 Jul 2013 14:44:25 +0100 skyewright Posted By: bxman
Jamesw acted in good faith who has the right to stop him I would like to know.
???
I can't see that anyone has shown any objection to Jamesw's list (posted nearly a year ago). Indeed there's at least one "Thanks".]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180577#Comment_180577 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180577#Comment_180577 Wed, 24 Jul 2013 14:49:06 +0100 bxman
I chose it because at the time I judged it to be the best value for money and I think it probably still is.

If anyone in the Worcester area wants to see it in action bring the sun and send me a PM.]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180579#Comment_180579 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180579#Comment_180579 Wed, 24 Jul 2013 15:34:40 +0100 Ed Davies Forum members that post adverts disguised as a discussion will be banned from the forum.My emphasis.

If Mr Chase had declared his interest/connection more explicitly than just his choice of user name then I don't think anybody would have cared¹. His² subsequent removal of his name from his profile just dug the hole a bit deeper.

¹ Actually, quite the contrary - it would have been an indication of relevant experience.
² I'm assuming he edited his profile himself. If not then apologies.]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180612#Comment_180612 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180612#Comment_180612 Thu, 25 Jul 2013 08:00:21 +0100 Seret
However, there are people with business interests on here who contribute as valued members. Don't feel like we're trying to run you out of our little one horse town. If you have input relevant to the discussions then feel free to contribute your expertise. However, if your only intention is to big up your own product for free people well see right through that and will tire of it exceedingly quickly.]]> Diverting excess microgeneration https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180622#Comment_180622 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=9487&Focus=180622#Comment_180622 Thu, 25 Jul 2013 11:46:12 +0100 Immersion
A PV installer we know bought a couple of other units as they had forgotten to order new stocks of our model from the supplier in time. Both these units had to be removed within weeks, which cost them around £500 each in materials and labour, i.e. most/all of the profit on the whole PV installation job. One unit had failed despite the manufacturer’s 10 year warrantee and the other was not liked by the customer, who demanded a different unit, as he had originally been promised one of ours. After installing our model all was well.

I would mention the model name that was rejected as a warning to others, but you probably will not allow this. Suffice it to say that is quite a well known unit despite not being mentioned above. Unlike many others it does not contain a load fuse, so most shorts/failures of the immersion will blow a vital component in the unit – bad design practice. Even with the warrantee cover the installer is still likely to end up with the bill for 2 site visits, one to remove the failed unit and one to install the replacement.

Do we not therefore need proper assessments/reviews of these units here?

For the sake of those thinking of buying a unit some of the questions you ought to be asking are:-

• Performance – how close to zero export does it get and how quickly does it react to load and generation changes? How much waste heat does it give out?
• Reliability – is it well made in adequately strong box with high MTBF and long warrantee?
• Safety – is it well made to good design practices with proper fusing and does it pass all relevant legal and EMC standards, including flicker?
• What display is provided to indicate the unit is functioning and where the various energy flows in the system are going to?
• Looks and size – will it look OK where I want to place it?
• If the sensor position and unit are not close can the sensor wire be extended?
• Does it control second loads?
• How easy to install and set up? Technical consumers like lots of things to fiddle with, PV installers do not as is slows them down and leads to call backs when controls get mis-set.
• Good installation documentation?
• What technical support is given?

And that is not bigging up us as we can’t fully tick all those things, e.g. we don’t have an LCD display, partly for reliability reason as they are not likely to last the intended life of the PV system.

One final question, how to you arrange notifications for when posts are replied to? Can’t find that tick box.]]>