PV immersion heater proportional control

[brian wright22]

Have a look at this thread also: http://www.electriciansforums.net/s...ral-heating-linked-monitoring.html#post551986

As far as I WAS aware, the only commercially available proportional control system is the EMMA,

I installed a EMMA SP15/30 a couple of weeks ago, simple to install and seems to be working well.

There is the Immersun device that is proportional and the other that I am looking at theAnthony Wooldrridge sola Controla £395 = vat.See my earlier post but I have repeated the attachment here.
http://www.electriciansforums.net/a...olar-pv-heating-switch-s-g-wooldridge-ltd.doc

Brian

 

[legoman]

Re: PV immersion heater switch

Scobo,

Sounds OK and the price(ready to go) is good.
Only thing I noticed after following the link was this:-

The key thing is not to find yourself importing expensive electricity to power the immersion!

Does this mean that if you turn on an appliance (say your kettle) it does not turn off the immersion.
My system uses 2 LDRs. 1 to turn on the immersion/appliance at whatever I set it to, say 1.2kw and the 2nd, that monitors when the red LED in my meter flashes, indicating I am importing power. If this happens the 2nd switch cuts off the power to the immersion

I would be interested to know your set-up performs anyway.

 

[Scobo]

Re: PV immersion heater switch

Scobo,

Sounds OK and the price(ready to go) is good.
Only thing I noticed after following the link was this:-

The key thing is not to find yourself importing expensive electricity to power the immersion!

Does this mean that if you turn on an appliance (say your kettle) it does not turn off the immersion.
My system uses 2 LDRs. 1 to turn on the immersion/appliance at whatever I set it to, say 1.2kw and the 2nd, that monitors when the red LED in my meter flashes, indicating I am importing power. If this happens the 2nd switch cuts off the power to the immersion

I would be interested to know your set-up performs anyway.

No, it only has the one LDR to turn the immersion on and off when the power generated is high enough.
This won't usually be an issue as when we're out we have a base load of around 200 watts so I'll calibrate the controller to kick in around 1.5kw and when we're in I could just disable it if there's not enough power to cover the other appliances.
Your setup sounds pretty nifty !

 

[brian wright22]

Re: PV immersion heater switch

Scobo,

Sounds OK and the price(ready to go) is good.
Only thing I noticed after following the link was this:-

The key thing is not to find yourself importing expensive electricity to power the immersion!

Does this mean that if you turn on an appliance (say your kettle) it does not turn off the immersion.
My system uses 2 LDRs. 1 to turn on the immersion/appliance at whatever I set it to, say 1.2kw and the 2nd, that monitors when the red LED in my meter flashes, indicating I am importing power. If this happens the 2nd switch cuts off the power to the immersion

I would be interested to know your set-up performs anyway.

I have not got this device yet but the statement you have raised is explaining that whatever you have connected the Wooldridge device is totally proportional in that it will not import electrcity to suppliment the appliance that is connected to the output of the Wooldridge idealy (THE IMMERSION HEATER).
The Wooldridge will only supply the surplus exported power to the load connected to the Device(THE IMMERSION HEATER).As soon as you turn on anything in the house that exceeds the exported power then the Wooldridge will import nothing to feed to the Immersion Heater. Obviously there will be imported electricity to feed the shortfall of PV to meet whatever appliance you have switched on.
It is not suitable for White Goods Appliances which always require the full 240v ac to function correctly.
Personally I think these proprtional devices are the ideal method of saving money to capture the spare PV power and the Immersion Heater is the perfect load which is ideal for proprtional voltage feeding.
The other is probably storage heaters but you wont have the same savings as the water heating in the Summer months.

 

[legoman]

Re: PV immersion heater switch

Brian, Thanks for that. I see what you mean now. Am I right then, in thinking that Scobo's device is similar to mine without the 1st switch with no delay?


Scobo, One thing that would concern me is the size of your system(2.88kw) and the setting recommended to use an immersion(2kw). Your system would need to be performing almost at its peak to supply it. This would be possible on nice sunny days but will struggle through Nov-Feb. I would lower it as you say or maybe more.

I think my system(4kw) will struggle too but, I will test it through the winter months and then reassess things. My base load in the daytime is fairly low(fridge freezer + odds and sods) so, in the winter I may try running my immersion when I am generating say 800w, if it works outs cheaper than using my gas boiler. I guess I could turn the f/f off for a short while to help this.

 

[Scobo]

Re: PV immersion heater switch

I don't intend to use the immersion in the winter.
We'll use the boiler as we'll have it on for the heating anyway.
Our base load is around 200 watts and the immersion now runs at around 1kw so I'll have the controller set for around 1.2 to 1.5kw.
There will be dull days when our PV doesn't generate that or not for long enough so the timer will come on to give it a boost.
Our aim is really to save using the boiler during spring/summer to help prolong its lifespan without it costing more.
I realise we won't get completely free hot water with this setup (certainly not this summer) but it should still save a few quid.

 

[Worcester]

By the time you guys have messed around playing with this and that , you could have saved yourselves a lot of time and possibly imported electricity if you get the settings wrong, by simply buying either the Wooldridge or Immersun devices... both of which I guarantee will have out perfomed your home grown solutions with absolute no concerns about possible import, and no need to change your immersion heaters.

The Immersun has a timer and boost switch, the timer allows you to extend the use of the immersion heater in case the water isn't hot enough at certain times of day and also a short boost button, both of which overide the proportional control if needed. You could also programme you exsiting heating system to provided a hot water boost at the end of the day if needed.

Much Much simpler --- read this post in detail http://www.electriciansforums.net/p...-immersion-heater-regulator-2.html#post562074 and you'll see the actuall difference between proportional and non-proportional systems, also an analysis if the available and used power. The proportional system will give you much greater return in the long term.

 

[peterwigan]

I have been using Anthony Woodridge's Sola Controlla for the past month and give it full marks. It appears to divert all available energy produced by my 3.3Kw PV not been used by the house to my 3Kw 27" immersion heater. I turned the immersion heater thermostat to max and now have scalding hot water on sunny days (rare at the moment) and acceptable temperatures on even the dullest days.

 

[thushar]

I just installed the Mark II intelligent version of solar immersion switch from Intelligent Solar Immersion Switch - Use Surplus Solar PV Power to Heat Water and really happy with the performance. It comes with a differential controller that monitors both PV production and house hold consumption. very affordable price too

Had a chat with the customer support and said they were working on a Mark III with proportional controller as well - don't know if it's true

 

[danesol]

..................My current supplier Eon, is targeting 1000000 installations to have Smart Meters fitted by March 2014. This may or may not happen but if it does a lot of people will be out of pocket.

Why ??

export is (currently) calculated at 50% of your generation figure and then only paid at ~3p per kw so will have no impact at all. Infact I would go as far to say that if they did monitor your export and it was nil, as you were utilising either sending back through the inverter or using it all, you would still be in pocket as you import at ~12 per KW and you get paid 44p per kw ( or pre DOS day installs do ).......... :smug:

OP I like the sound of these devices as I would like to do this but for me it has to be the right device as its an impossibility for me to have a device thats hard wired in between the immersion heater and the PV system, so needs to be based on RF and/or sensor in my situation, which this sounds like it would satisfy but its over £ 350 + fitting - it may not be worth it....

 

[brian wright22]

I have been using Anthony Woodridge's Sola Controlla for the past month and give it full marks. It appears to divert all available energy produced by my 3.3Kw PV not been used by the house to my 3Kw 27" immersion heater. I turned the immersion heater thermostat to max and now have scalding hot water on sunny days (rare at the moment) and acceptable temperatures on even the dullest days.

This is what we need Peter, early feedback about this emerging technology. I like this device and am pleased it is performing well.

 

[thushar]

Why ??

export is (currently) calculated at 50% of your generation figure and then only paid at ~3p per kw so will have no impact at all. Infact I would go as far to say that if they did monitor your export and it was nil, as you were utilising either sending back through the inverter or using it all, you would still be in pocket as you import at ~12 per KW and you get paid 44p per kw ( or pre DOS day installs do ).......... :smug:

OP I like the sound of these devices as I would like to do this but for me it has to be the right device as its an impossibility for me to have a device thats wired in between the immersion heater and the PV system, so needs to be based on RF in my situation, which this sounds like it would satisfy but its over £ 350 + fitting - it may not be worth it....

Smart meters are years away - at least 10, as it will cost a fortune for the supplier to replace all the existing meters.

It make sense to use the surplus power flowing back to the grid and why worry when the investment made on the switch is less than 3 months worth of FIT payout (for 4kW).

To me, it's to make the best of the existing situation as I will get the full return of investment in less than 2 years.

Also, it make sense to use the existing immersion wiring from the consumer unit to the immersion itself, as it is stable and solid circut. RF could turn the immersion on, but the question is , can we trust it . After the controller is installed, i could forget it expect it to run for years without any issues. I don't thing a cheap Chinese switching unit will stand a chance for what i want. Also, don't think the Chinese units are CE certified - Not electrical device is suppose to be used in any Europe without CE. Another trouble is a potential patent violation, as they use dual sensors.

Adding to that, the immersion will be switched by a reliable MCB from the consumer unit and the unit my electrician installed does that . Also, the unit from Intelligent Solar Immersion Switch - Use Surplus Solar PV Power to Heat Water looks very simple to install, as it just uses a single sensor to detect and calculate the difference. Also they are CE certified, designed and manufactured in UK and very reasonably priced. Hence the reason I went for it.

 

[brian wright22]

The immersun appears to do the right job, the question is at what price? Don't post trade price here, if you know, pop it on the Sunlounge.

The website is a little light, so can anyone tell me how it works?

Is it proportional?

How does it wire in?

For those that like to know, Immersun is a product fron 4Eco Ltd 3 Church View, Business Centre, Binbrook, Lincolnshire, LN8 6BY (the immersun dot co dot uk website is regsitered to them) 4ecoltd dot co dot uk
From duedil, the people at 4Eco are:
Jodi Huggett (37), Director, Company Director, 1 Sep 2010 – Present
Robin Barrett (36), Director, Company Director, 1 Sep 2010 – Present
and
Lee Robert Sutton (35) Director, Company Director, 26 Jan 2007 – Present

From the MCS Website:

4eco were MCS Certified by elecsa on 01/04/2010 for:
Air Source Heat Pumps
Ground Source Heat Pumps
Solar PV and
Solar Thermal

Hi MickF
Yes the Immersun modulates the supply to the immersion heater based on detecting the exported excess and feeding appropriately to the immersion heater.
I have contacted Immersun and they have given me the following details of an installer.Immersun will not supply directly to individuals quite rightly because they would not be able to police the DIY installation.
THEY WILL SUPPLY ELECTRICIANS WHO OPEN AN ACCOUNT WITH IMMERSUN.

The follwing details is all I have from one of Immersun's Installers
If you want the name and contact details of this installer and their supply & fit price then PM me as it may not go down too well if I advertise the installer here!•Uses existing immersion heater
•Can control power to any resistive load up to 3kW
•Back-lit LCD display shows: energy saved, load power and mode *
•Volt-free relay contact can be set to operate for additional loads *
•Built-in hot water programmer to set times when water needs to be heated *
•Hot water heater boost function
•Maintains settings and time during power outages *
•Can control boiler for water boost function or use immersion heater *
•Cylinder de-stratification pump control option *
•RS485 MODBUS interface *
•Several units can be linked together to control many loads *
•Can be configured to operate two immersion heaters sequentially *
•OEM units available in a wide range of RAL colours
•Non-invasive grid power monitoring using AC current clamp
•Built-in thermal overload protection
•UK manufactured
•3 Year Product Warranty
•Quality all-metal wall mounted enclosure
　
•Features not available with the immerSUN Lite
[FONT=Atlanta,Atlanta][FONT=Atlanta,Atlanta]Electrical specifications
[/FONT][/FONT][FONT=Atlanta,Atlanta][FONT=Atlanta,Atlanta]Supply: 220-240VAC 50Hz
Power Consumption (excluding load): <1W
Maximum Load: 3.3kW @ 220VAC
Maximum Load Current: 15A
[/FONT][/FONT][FONT=Atlanta,Atlanta][FONT=Atlanta,Atlanta]Dimensions
[/FONT][/FONT][FONT=Atlanta,Atlanta][FONT=Atlanta,Atlanta]Width: 155mm
Height: 145mm
Depth: 60mm
Weight: 800g
[/FONT][/FONT]

 

[danesol]

So in this day and age you can buy a gas boiler, an Inverter and a chain saw etc all of which could potentially kill you but this company think they need to police the installation of their product -bah, its just another way to get more money out of you !

 

[brian wright22]

So in this day and age you can buy a gas boiler, an Inverter and a chain saw etc all of which could potentially kill you but this company think they need to police the installation of their product -bah, its just another way to get more money out of you !

I totally Agree,especially as the nearest installer to me is over 40 miles away so the installation adds £250 to the device.