Solar immersion optimiser fitted

[arwooldridge]

Shouldn't do.

They don't interact but each will have a different threshold dictated by the unit they serve. This makes it quite random which one will come on first. I designed the SolaControla and can adjust the threshold . I had to set it to over 500watts to stop it interacting. Unfortunately most other units are not adjustable or configurable. In theory though it would be possible to design a transformer with very low secondary volts, say 1volts feeding a few turns into the CT, say two turns at 1amp would give you the offset you need. It should only consume 1watt continuously at this level. With careful design the output winding resistance could be tailored to give the desired offset current, or use a series load resistor.

 

[Joules]

Just had a look at the EDDI controller.
It reads the same as the spiel that came with the one i have fitted from https://solarimmersion.co.uk/
Quite a difference in price though, i wonder why

I have the Immersun Mk II which was bought back in 2014 and still in use today. Immersun folded but these guys survived to bring out their present Mk V. The topology of both are quite different, the one you bought uses phase control thyristors/triacs to reduce/control the export which creates an enormous amount of RFI and grid third harmonics distortion. Their design effort has largely revolved around RFI suppression and meeting compliance. The reason they survived is that they make them to order one at a time.

The guy who designed the Immersun formed a new company which now makes the EDDI. The Immersun got around the RFI and harmonics problem by using PWM to create an amplitude modulated 50Hz sine wave in phase with the mains. Yes, they are expensive and more complicated about a 100 more than yours but IMHO they are and remain the better product. There are a lot of what you bought out there so I'm sure members will solve your problem for you.

 

[BorisJ]

If you normally use gas to heat the water I don’t understand why you have a solar optimiser at all. The cost of gas is around the same as the electricity export tariff so why bother, just export it and use gas.

 

[Joules]

If you normally use gas to heat the water I don’t understand why you have a solar optimiser at all. The cost of gas is around the same as the electricity export tariff so why bother, just export it and use gas.

With the greatest of respect I disagree, the cost per kWh of gas under the guarantee is around £0.14 and the best SEG tariffs vary between £0.03 to £0.075. The whole thing is is controversial in that solar has nothing to do with the wholesale price of gas. Withstanding the guarantee suppliers will sell your export back to you for around £0.50. They argue the excessive profit is necessary for investment in energy infrastructure. The optimiser could for example preheat the combi- boilers hot water supply pushing its efficiency over 90%. On the grid the best gas generators operate around 48% efficiency because of the higher calorific value of gas compared with coal. Better on principle to heat hot water using solar power than wasteful grid electricity.

 

[torbrowser]

Not interested in arguing over the price of gas.

Some good answers so far chaps thanks, joules, I can follow vaguely what you said, but bring a spanner man my philosophy is what happens inside the black box- stays in the box, I concentrate on getting it to work !

The answers are adding up and pointing towards the solarimmersion beating the inverter and drawing power before it’s directed to the batteries.

There is a setting in the menu called power margin, it’s set at 50w but can be adjusted right up.
I am just waiting on a call back from solarimmersion technical, to describe what this function does - nothing in the booklet about it.

Predictably sky is a dull as dishwater so not much chance of it firing up today anyhow.

I’ll see what they have to say

Jack

 

[binky]

If you normally use gas to heat the water I don’t understand why you have a solar optimiser at all. The cost of gas is around the same as the electricity export tariff so why bother, just export it and use gas.

Depends if you are getting a tariff or not. There's also some joy in not buying anything from the grid, gas or electric, if you can help it. It's good for the planet.

 

[Joules]

Not interested in arguing over the price of gas.

Some good answers so far chaps thanks, joules, I can follow vaguely what you said, but bring a spanner man my philosophy is what happens inside the black box- stays in the box, I concentrate on getting it to work !

The answers are adding up and pointing towards the solarimmersion beating the inverter and drawing power before it’s directed to the batteries.

There is a setting in the menu called power margin, it’s set at 50w but can be adjusted right up.
I am just waiting on a call back from solarimmersion technical, to describe what this function does - nothing in the booklet about it.

Predictably sky is a dull as dishwater so not much chance of it firing up today anyhow.

I’ll see what they have to say

Jack

Yes, my Immersun Mk II has a similar feature that requires a minimum amount of power available before it starts exporting. The user manual says that a 50W (default) setting prevents adverse CT interaction with the grid. There is a catch 22 with the unit you own, because the tech pushes so much rubbish back into the grid the CT is heavily filtered or dampened which means that its response is slower than it might be. As suggested try setting the export threshold up in increments until it starts behaving itself. Did you know that November used to be the start of the Celtic winter?

 

[torbrowser]

Immersun and solarimmersion are all the same lot, the box it came in had immersun written on it.

Anyway the buggers haven’t bothered ringing me back yet so I have altered the power margin up to 500w.
Since weather today is shite, I tested this by flipping the CT clamp so it thinks I’m exporting, turned on a couple hundred watts and it didn’t activate, turned kettle on and she fired up,

So this setting does seem to affect the point where it activates the immersion.

Need some sun now to test properly.

Of course I knew about the Celtic winter, I know everything, I keep it all in my Google memory.

This way I have more room in my skull to figure out why shit never works as it should.

 

[torbrowser]

Depends if you are getting a tariff or not. There's also some joy in not buying anything from the grid, gas or electric, if you can help it. It's good for the planet.

I’m not on a tariff and gas heats water cheaper than electric, but not as cheap as wasted electric, you know around 60% of the worlds produced electric is thrown down the toilet, it’s called stranded energy.
I know you are an environmental chap so might be interesting to you ( you may already know)

The planet will be just fine, we are what’s ******.

 

[Chrisbee]

I had a similar but not identical issue with Solis hybrid and Solic200.

What would happen was this.
Solic would detect a minor overshoot of export as inverter settled after a load change (say kettle clicked off).
Solic would grab this very fast and direct it to immersion.
Next, Inverter sees this as as a new load and ramps up output, using battery if necessary.
Somehow this would slowly spiral and the system would end up with a constant 2.5kw flowing from battery to immersion until battery was exhausted.

My temporary fix which may become permanent is this:

I've taken the "live" out from solic200 and passed the single, double insulated cable, through the inverter's CT clamp. In a direction such that the CT sees current going to the immersion as export. Which from the inverters point of view, it is.

So now the inverter, in effect, ignores anything the solic does and acts just like it did before solic was installed.
While solic grabs any export and directs it to the immersion.

It actually appears to work perfectly, far better than I expected. I appear to have set up a hierarchy. Solar generating to house first, batteries second and immersion only when there's more than the other two can take.

 

[torbrowser]

Great reply, thanks.

Yes it is similar to what i now believe is happening on mine,
I will re read your post a couple of times to soak it in, but threading a single through the inverter CT could be worth trying on my system if nothing else works.
The result is, you get export, the immersion CT picks it up and switches on, that load goes through the inverter CT cancelling itself out.

So as far as the inverter is concerned no extra load is being pulled. May have to draw this out on paper,

Thanks.

 

[Chrisbee]

Yes this took lots of thinking about at strange times of day before I even tried it.

A second opinion would be extremely welcome.

(As would any thoughts of downsides that convince me I really ought to remove it again.)

 

[Joules]

Immersun and solarimmersion are all the same lot, the box it came in had immersun written on it.

Anyway the buggers haven’t bothered ringing me back yet so I have altered the power margin up to 500w.
Since weather today is shite, I tested this by flipping the CT clamp so it thinks I’m exporting, turned on a couple hundred watts and it didn’t activate, turned kettle on and she fired up,

So this setting does seem to affect the point where it activates the immersion.

Need some sun now to test properly.

Of course I knew about the Celtic winter, I know everything, I keep it all in my Google memory.

This way I have more room in my skull to figure out why shit never works as it should.

Let me try and explain. I have a mains powered hammer drill with a speed control wheel in the trigger. Its tech uses a type of rectifier called a thyristor which the wheel uses to control speed. This same tech is used in various makes of product to divert excess solar energy and may be in the one you have even though you say it came in a box marked Immersun.

The tech used in the original Immersun and now its successor called Eddi goes under the trademark name of Varisine which has nothing to do with thyristor control of the exported power.

The inventor of Varisine and patent owner is Lee Sutton who is co-founder and CEO of Myenergi the company that makes the popular Zappi EV charger. There was an article late in 2016 in the Scunthorpe Telegraph that mentioned 4Eco the company that originally sold me my Immersun. The original Immersun product is still available at around £500 and appears not to be the one you have. Lee Sutton may be taking a royalty on his patent and this is partly why it is expensive.

 

[binky]

I had a similar but not identical issue with Solis hybrid and Solic200.

What would happen was this.
Solic would detect a minor overshoot of export as inverter settled after a load change (say kettle clicked off).
Solic would grab this very fast and direct it to immersion.
Next, Inverter sees this as as a new load and ramps up output, using battery if necessary.
Somehow this would slowly spiral and the system would end up with a constant 2.5kw flowing from battery to immersion until battery was exhausted.

My temporary fix which may become permanent is this:

I've taken the "live" out from solic200 and passed the single, double insulated cable, through the inverter's CT clamp. In a direction such that the CT sees current going to the immersion as export. Which from the inverters point of view, it is.

So now the inverter, in effect, ignores anything the solic does and acts just like it did before solic was installed.
While solic grabs any export and directs it to the immersion.

It actually appears to work perfectly, far better than I expected. I appear to have set up a hierarchy. Solar generating to house first, batteries second and immersion only when there's more than the other two can take.

Great idea, simple but effective

 

[stuboy]

I think what is needed is some sort of time delay in the diverter. This would allow variations in battery charging etc and only then divert when it senses that energy has been exported for more time than the battery charger takes to operate. Or a signal from the battery charger to say i'm done for now ;-)
Stu

 

[johnb2713]

This is sounding very complicated for a simple task. Surely an amount of headroom to stop it triggering as the inverter hunts around zero. When export is seen the current to the immersion is increased until the export is back to the small headroom allowance. It the adjusts the immersion current up or down as required when the conditions change.

In Myenergi EDDI it has the following settings, I assume the OP's unit must have similar?

Export Margin: Minimum level of export power which is maintained when eddi is diverting surplus power
Exp Threshold: Level of export which must be seen before the eddi will start diverting power to the heater
Response Delay: Time before the eddi starts diverting after Exp Threshold is exceeded

From a programming perspective, these three parameters are essential to get correct operation of a diverter.

 

[Chrisbee]

My guess is that the simpler diverters were designed before hybrid inverters and batteries were common place and when the "have your cake and eat it" FIT systems were installed.

My Solic200 certainly appears to trigger by small amounts very often. Pretty much every time the inverter is hunting. Not an issue when there's no battery charging to conflict with.

 

[torbrowser]

Here are the settings on my unit

This can be adjusted up and down.

This setting can’t be altered, or rather you can but just goes back to off when you exit the menu.

 

[torbrowser]

Still waiting a sunny day to see what happens.
And still waiting for solarimmersion tech to ring me.
Glad this is mine and not a job, with backup like this they really do leave you in the $hite.

 

[torbrowser]

This is sounding very complicated for a simple task. Surely an amount of headroom to stop it triggering as the inverter hunts around zero. When export is seen the current to the immersion is increased until the export is back to the small headroom allowance. It the adjusts the immersion current up or down as required when the conditions change.

In Myenergi EDDI it has the following settings, I assume the OP's unit must have similar?

Export Margin: Minimum level of export power which is maintained when eddi is diverting surplus power
Exp Threshold: Level of export which must be seen before the eddi will start diverting power to the heater
Response Delay: Time before the eddi starts diverting after Exp Threshold is exceeded

From a programming perspective, these three parameters are essential to get correct operation of a diverter.

I get what you’re saying John, my unit came from the factory set at 50w, and was still triggering.
Have a look at my photos and let me know what you think these settings do.
It only has these two. So probably not as advanced as the EDDI unit.