Ronski's Solar & battery DIY build with whole house backup

b0rn2sk8 said:
The Daikin MMI isn’t accurate at all and I expect hot water efficiency is impacted by how long your run is from outdoor unit to your tank given how little time it takes in practice.
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The total pipe run is about 12m, so 24m return. The DHW cycle generally takes around 30-40 minutes but never uses more than 1.5kWh.

I suspect it's just the Daikin MMI being rubbish. If the assumption is made that the thermostat saying the water is at 32C is in the middle (with warmer water above and cold below), heating the whole 210 litres to 48C takes 3.91kWh of heat. If I'm using about 1.3kWh on average then its a SCOP of about 3.

It's all at 6p/kWh anyway, so no issue. The inaccuracy of the MMI is just annoying though.
 
As above Daikin kWh isn't accurate, it rounds up or down to whole numbers :cry:

190 ltr tank, running at 50c, uses around 2.5 kWh a day, sometimes a little less, sometimes a little more, its not on a schedule, just reheats when it drops in temperature, not sure what the threshold for that is.
 
Once I got mine dialed in, I stopped worrying about it.

I’m using 1.5kwh/day on hot water. So ~10p or £36/year.

My NAS uses about the same amount of energy.
 
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Ron-ski said:
As above Daikin kWh isn't accurate, it rounds up or down to whole numbers :cry:

190 ltr tank, running at 50c, uses around 2.5 kWh a day, sometimes a little less, sometimes a little more, its not on a schedule, just reheats when it drops in temperature, not sure what the threshold for that is.
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I think it just rounds up! It ends up over reading by about 20% going by what I've measured. It's just really annoying more than anything.

It's only used 260kWh on hot water since 23rd April, all at cheap rate (6p/kWh), so about £15. I'm really happy with it, but it just bugs me how crap the MMI is.
 
If it's any consolation I'm not sure that the Valiant is much better, I'm pretty sure it's power usage isn't close to what my Shelley power meter shows, I'll have a look tonight if I remember.

Heating actually came on this morning, it's getting colder.
 
According to the Shelly CT clamp total for the ASHP is 370 kWh, and the unitower 20 kWh.

Vaillant App reports 335 kWh for the pair of them.
 
Interesting. It looks as bad as the Daikin MMI, but about 20% too low instead of 20% too high. Looks like they're all terribly inaccurate.

Ours came on this morning too, using about 3.9kWh to generate 17kWh of heat (according to the MMI). It was ticking along at around 600-800w with a leaving water temp of 36C.
 
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@reef I've just realised after watching Jonathan Tracy's video that my Aerotherm is pretty accurate, my heatpump was replaced in May and I reckon that reset to zero the power used shown in the App. Looking at HA the figures look about right for that to be the case.

Looking at this month's usage Vaillant says 64.7 and HA says 62.91, pretty close.
 
Im hoping once I get the sigenergy gateway it'll be able to monitor the power usage on mine as it will be wired directly into the spare INV port. As it stands I cant monitor it with a shelly as I have no spare ways in the consumer unit.
 
I used the smaller one in the house for the uniTower and induction hob, and the Din rail one in the garage although it's not in the garage consumer unit, to monitor the heat pump and the Zappi.
 
What a busy day I've had, my brother came round this morning and we replaced the optimiser, it was hard work, but its done. We built a platform on the kitchen roof, just using some planks & blocks of wood and a scaffold board.

I went up on the main roof, we slid the first panel down, and that gave me a gap to work from, we had to the slide the next panel lower to be able to remove the optimiser, which was bolted to the rail.

I tested the optimiser and it had no output, it should have been 1v, the panel had just over 34v, the spec sheet shows an open circuit voltage of 34.6v so the panel is good.

Now I just need to get the new optimiser paired, my installer says they've made me site admin, but my SE installer account only has monitoring access, so I've opened a case with SolarEdge support.

Then this afternoon, in return, I had fix my brothers car which failed its Mot yesterday.
 
Ron-ski said:
What a busy day I've had, my brother came round this morning and we replaced the optimiser, it was hard work, but its done. We built a platform on the kitchen roof, just using some planks & blocks of wood and a scaffold board.

I went up on the main roof, we slid the first panel down, and that gave me a gap to work from, we had to the slide the next panel lower to be able to remove the optimiser, which was bolted to the rail.

I tested the optimiser and it had no output, it should have been 1v, the panel had just over 34v, the spec sheet shows an open circuit voltage of 34.6v so the panel is good.

Now I just need to get the new optimiser paired, my installer says they've made me site admin, but my SE installer account only has monitoring access, so I've opened a case with SolarEdge support.

Then this afternoon, in return, I had fix my brothers car which failed its Mot yesterday.
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At least the panel is good. It would be a bit of a nightmare if it was that.

To get to 10 years and only lose a single optimiser is pretty good in my book. A friend of mine has a full SolarEdge setup (three orientations on a 2 string inverter) so will be happy to hear that.
 
Great work, my swapping an unreliable wifi socket (which turned out to be full of water) for another one seems like a easy day at the office in comparison.
 
I'm back to a fully functioning SolarEdge array :D

I had to get SolarEdge support to pair the new optimiser, as I've still not managed to get site admin access, haven't done the correct training course apparently, so that's still a work in progress.
 
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