Exporting with Solic

[canalsiderenovation]

Ok so we have never exported before but are moving onto Cosy with Octopus but how does this work with Solic which allows excess to be diverted to the immersion?

 

We are moving onto the cosy tarrif and we know we have days when our hot water heats well over the 48 degrees because we have ample hot water. How do we stop it diverting any excess and export to the grid?

 

Hopefully before the year is out we will get batteries which will add another layer of complexity to things!

[dpmiller]

do you ever run out of hot water with the tank at 48c? Simple answer is to turn down the thermostat in the immersion heater- when it's sufficiently hot and not taking any power you'll be exporting instead.

[Dillsue]

10 hours ago, canalsiderenovation said:

How do we stop it diverting any excess and export to the grid?

With a typical PV diverter as soon as the thermostat in the immersion opens the diverter cant push any more electricity into the immersion and the excess starts to go to the grid.

 

If you want more export at the expense of hot water then either turn the thermostat down or turn the diverter off. Just be concious of legionella considerations, if that concerns you.

[Nickfromwales]

So, how much does it cost to create more DHW, and how much do you get for each exported unit? The immersion, if you set the thermostat that low ( eg you set it to 48^oC but clearly it is factory set atm (?)), is not going to be on all the time and you'll then revert to exporting the surplus? Simples.

Just tweak the stat, but no lower than 45^oC!! DHW should be the No.1 priority for diversion, so you need to preserve that before considering exporting, however if you can buy electricity back in cheaper than the export then that's a different thing and you then need to add a timer to the immersion to select when you heat the hot water.

Not sure what these tariffs offer, but the principles above can be applied either way.

[Nickfromwales]

That low a temp is only feasible if you have a large / over-sized hot water cylinder, of course. Possibly set to 50oC at the outset and see how you manage with that temp / capacity.

[canalsiderenovation]

I'm a little confused as yes we have the DHW set to 48 degrees on the ASHP, which is what it is heated to without solar but on days where we have good solar it frequently goes above this to say up to and above 56 degrees and this is what I'm confused about. How does the diverter stop diverting when we have excess solar?  We do have a large 400 litre I think it is Gledhill tank as I took advice from here at the time re ASHP installation and oversized it. 

 

[Dillsue]

The ASHP and immersion will likely work separately from each other and it looks like your ASHP set point temp is 48 degrees and the thermostat in the immersion is set to around 55 degrees. If your ASHP heats the tank to 48 degrees the immersion will always try and heat to 55 degrees, if theres power available.

 

If your priority has now changed to export rather than divert then you need to turn the immersion stat down to just under 48 degrees to stop divert into hot water, or bin the solic!

[Nickfromwales]

28 minutes ago, canalsiderenovation said:

How does the diverter stop diverting when we have excess solar?

Simple. The stat in the immersion reaches the set point, and bingo, no more input goes to the immersion and export kicks back in at full wallop.

Shut off the power to the immersion, whip the lid off, and post a pic of the settings on the stat head please.

[canalsiderenovation]

On 22/02/2023 at 11:55, Nickfromwales said:

Simple. The stat in the immersion reaches the set point, and bingo, no more input goes to the immersion and export kicks back in at full wallop.

Shut off the power to the immersion, whip the lid off, and post a pic of the settings on the stat head please.

Ok so our export with Octopus goes live on 11th May so I need to turn down the stat in the immersion so we export as soon as the water is at 55 degrees (or maybe lower as that is plenty hot enough)! How do I stop the Solic from diverting when we have reached this temperature?

 

Do you mean the lid of this big tank? How do I get in this?

 

 

 

[canalsiderenovation]

No way of getting inside here 

[SteamyTea]

Whenever I see an UVC installed, I am so happy that I have a really simple vented cylinder.

[TonyT]

The lid to the immersion heater

[Nickfromwales]

7 minutes ago, TonyT said:

The lid to the immersion heater

The little heater at the bottom with the wire going into it. Isolate the supply at the CU, remove the nut and cover, post a pic of the guts.

[canalsiderenovation]

4 hours ago, Nickfromwales said:

The little heater at the bottom with the wire going into it. Isolate the supply at the CU, remove the nut and cover, post a pic of the guts.

 

Please tell me you mean this? If so I'll look at it tomorrow.... If I unscrew it it's not gonna flood the house is it (I realise this is probably a stupid question)!

[ProDave]

 

This is the immersion heater.  Follow the white cable, it should go to a switch on the wall. Turn that switch off.  Then remove the screw that is visible in the picture, that holds the plastic cover on.  Post a close up picture of the inside and we will tell you what to adjust.  No it won't leak water.

 

Turn the switch back on when done or the immersion heater won't work.

[canalsiderenovation]

56 minutes ago, canalsiderenovation said:

 

Please tell me you mean this? If so I'll look at it tomorrow.... If I unscrew it it's not gonna flood the house is it (I realise this is probably a stupid question)!

 The pic didn't upload but I think it is this @Nickfromwales.

 

@ProDave is this the same as your pic? Think you guys have solved it. I'll tackle it tomorrow.

 

 

[ProDave]

Yes that's it, turn off the electric undo that nut and remove the plastic cover then post a picture of the inside and someone will tell you which is the thermostat.

 

No water will escape doing that.

[canalsiderenovation]

19 minutes ago, ProDave said:

Yes that's it, turn off the electric undo that nut and remove the plastic cover then post a picture of the inside and someone will tell you which is the thermostat.

 

No water will escape doing that.

Thank you! Job for tomorrow.

[JamesPa]

6 hours ago, SteamyTea said:

Whenever I see an UVC installed, I am so happy that I have a really simple vented cylinder.

Funny you should say that as I have the same feeling.  I'm not particularly keen on having 200l of hot water at 3bar in the centre my house either.  But i also must concede that fresh mains pressure hot water is better than stale low pressure water 

 

Before ashps came the scene thermal stores seemed the way to go, at least if you have a loft.   I'm not yet quite convinced that we won't end up back there eventually.  Maybe a thermal store and a small secondary ashp to heat, real time, from the ts temp to the desired dhw temp?  Or some clever stratification like Mixergy are playing with.

Edited May 6, 2023 by JamesPa

[SteamyTea]

14 minutes ago, JamesPa said:

But i also must concede that fresh mains pressure hot water is better than stale low pressure water 

I have a pumped shower.

If I was fitting it again, or installing from scratch, I would place it on something solid and sound proof.

Not really a problem as it is only me at home.

[JamesPa]

11 hours ago, JamesPa said:

Before ashps came the scene thermal stores seemed the way to go, at least if you have a loft.   I'm not yet quite convinced that we won't end up back there eventually.  Maybe a thermal store and a small secondary ashp to heat, real time, from the ts temp to the desired dhw temp?  Or some clever stratification like Mixergy are playing with.

Thinking about it, a TS with a water to water HP drawing its input heat from the TS might be a good way to go.  Heat the TS with the main house ASHP to say 40, pass the incoming mains water through the TS to heat it to say 35, then use a W2W HP mounted above the TS to heat from 35-48.  Needs 20kW to get 20l/min (do we really need 20l/min I ask) which is a lot, but starting with a source of low grade heat from the TS at 35 (and water not air so much more compact), perhaps not unachievable.  The TS could also serve as a buffer tank for the CH if it needs one.

 

Mixergy have probably patented this by now, they seem to be innovating at the boundary between heat pumps and water heating.

[PhilT]

20 hours ago, canalsiderenovation said:

Ok so our export with Octopus goes live on 11th May

Would this be via Fixed Outgoing? What does it pay now - is it still 15p/kWh?

[canalsiderenovation]

On 07/05/2023 at 10:37, PhilT said:

Would this be via Fixed Outgoing? What does it pay now - is it still 15p/kWh?

Yes, I understand flux I understand is a little more at about 22p export but the cheap rates are only 2-5am where with Cosy the times work better for us with the heat pump (more so in winter). If we can get batteries sorted this will sort out any use in the peak times.

[canalsiderenovation]

Ok here are the pics... @ProDave @Nickfromwales

 

 

[canalsiderenovation]

Ah ha, I can see numbers 1-5 under the label which says factory set do not break seal. Question is how do the numbers correspond to temperature of the water. Ideally we don't want the Solic to heat the water beyond 50 degrees (anything that would heat the water beyond this we want to export). And do you have to pic a definite number - can't you have between 3-4 for example. It's between 4 and 5 now which heats to up to 56 degrees.