dnoble

Hi Would the generation meter be part of the smart ,meter? The 2.5 kWh figure comes form looking at the MyEnergi Eddi unit and also the zappi one which gives a readout from the panels whilst they're generating. I don' t have a cumulative one (and this may not be accurate as the panel are switched off on windy wet days to avoid the fusing problem. Regarding shading the panels are I full direct sun facing south with no tree shadows on them when they are generating the 2.4Kwh which is why I don't really agree with the installers tree comments (he just saw some tall trees near the house and assumed/scapegoated them, I suspect) Below are some shots of the inverter I sent the installed July 2019 when I initially tried to explore this. I think it demonstrated that both strings were generating.\

Hi Steamy Tea, It's a; PV-I-SGL-6.0-SP Solis 6.0 Single Phase with DC ( 110AD0183150020 )

There is not any tree shade on the panels except earring in the morning when the Sun is low. Sorry the info provided is inadequate. To be fair my original post was to try and find for an expert who could do a site visit. It's a complicated problem with a few issues and I wasn't expecting folk here to fix it easily.

They might be and I laboriously noted the numbers on the back of each one in anticipation of registering them on an app. They have "tigo optimisers" which were supplosed to correct probs with performance due to shading etc. You can moniter this if you've registered/set it up, though I wasn't led to believe not doing this would adversly affect generation. There was a complication in that they needed some kind of gismo in the loft which needed another electicity supply to run so I elected not to bother with any of that (I tend to avoid unnecessary complication/tech) and I was told it wouldn't make any differnce to performance.

I mechanically installed the panels, (Jinko Tigo 260W Smart Module with Gateway) 2 sets of 12 in series and connected up all the wires and ducted them through the roof. The folk who installed the inverter tested them and said they were fine, both sets generating. This was 2.5 years ago. They should potentially generate capacity of about 6KwH shouldn't they? but in full sun have only ever produced 2.8 (confromed on the inverter, the eddi/harvi/zappi thingy readout) Excess goes into a 9kw sunamp and electric car. It never fuses when the circuit with the solar panels/inverter on it is switched off. I agree it sounds like a water ingress issue which is a bit dispiriting as I was very careful to avoid this when I installed it. I'm not an electrician or a solar installer and I think I need someone experience to get up and "have a look under the bonnett" The original installer did come back and did some calcs and sent me this graph which I think confirmed the output but didn't explain it (it may be my expectations/understandi are wrong). either way the fusing problem persists so I could still do with someone to have a gander.. Hi Dan, Following my site visit, I have now run my measurements through the standard MCS matrix to calculate your overall power generation. Having measured the shading and applied the additional coefficient due to the proximity of the tree to the South East, the following graphic show a realistic generation that can be expected from your system under the current conditions. You should be able to compare the monthly projection against the accumulative figure on the Solar Generation Meter to reassure yourself that the system is working correctly. Kind regards

Can anyone recommend someone in the South West (Bristol) who could review and test my solar PV system and advise on installing storage batteries. 1)I have an allegedly 6Kwh which has never generated more that 2.8Kw/h despite being well situated, shade free etc. Installers couldn’t really explain this and did some tests ultimately fobbing me off, this was over 2 years ago. I may just have unrealistic expectations. 2)There is also an issue that the fuse trips in windy/rainy conditions when the solar circuit is switched on. Never when it’s off so something’s amiss there. I installed the panels but not the inverter etc. 3). I’ve got room to install another 12 panels all if this would be worthwhile, though wouldn’t bother if the existing ones could work at closer to predicted 4) would like advice on battery storage to be coordinated with the Sunamp, electric car Eddi/Harvi thing which should hoover up surplus PV in summer and also be charged up by the cheap Octopus plus 4 hours and then used to supply house the other 20 hours. Hope that make sense? I’ve had a couple of leads but struggling to get anyone to visit!

Update as the original poster System with one Willis pump and a mechanical timer is still working well. What’s changed are energy tariffs. I’m now on Octopus plus which provides 5p/KWh for only 4 hours (12.30-4.30 am), compared to 20-25p rest of the time I have stingily reduced the time it’s on to only four hours which has meant house is a bit cooler and down to 17-18 deg some grey spells (no passive heating from solar gain) Can charge, car and Sunamp also in this brief window. The obvious heating solution I suppose would be to add a second Willis pump (in line?) to double the amount of cheap heat I can dump uni th floor slab in 4 hours? Another expensive solution would be to invest in a bit storage battery (eg Tesla) and charge that up during the 4 hours.

We are currently in our second winter in the house. MBC passive house with MVHR Two of the triple glazed casement windows appear to have significant condensation problems. One is in a bathroom (with good air extraction) and the other in a home office. I've just written to Rationel aftersales support but after previous problem with a faulty door locking mechanism, I'm expecting an initial brushoff. Do folks feel this suggests a particular failing in the window?

I opted to have the UFH pipes installed pre slab pour as an insurance though I had hoped after speaking with Jeremy that I might not need it. It was only 1700 quid extra but very much more expensive to retrofit so I'm glad I didn't scrimp then! have you any idea how much electricity you’re using compared to what phpp predicted? I didn't do a PHPP prediction and the house isn't certified. It should cost about £2.10 per night for the winter months with economy electric if that's any help (7 hours of 10p/kwh with a 3kwh heater) This seems like a parsimonious solution and cost well under a grand. Compared to the 10-15K quotes I was getting install an ASHP (I know cheaper if self installed which I may do one day when they're cheaper and I have more time) it would take a very long time to payback the outlay. Glad I sought the wisdom of this forum! Thanks for all these useful points TerryE. I'm not entirely sure of the point of lowering the flow rate?It isn't really noisy when running. Getting a spare Willis pump really good idea in anticipation. Any recommendations on water softeners? Dan

MBC sorted the sand IIRC but told me what to put down beneath it. Some kind of compacted crushed stone I think (it was 3 years ago now!!) Are you laying the EPS yourself? If not wouldn’t the EPS laying people be the ones to ask?

Thanks for input everyone. I’ve got it up and running with a Willis heater off amazon (labelled “Tesla” rather unexpectedly) and a cheap mechanical timer. The manifold + pump was the main outlay around £400. It took about 3 days continuous running the get the slab up from 18 to 25deg. Now I’m running it only from 12.30 at night till 7.30am when I get cheapo electric. The floor doesn’t feel “warm” but it no longer sucks the heat from your body when you walk on it and everyone’s stopped moaning. The house feels remarkable warmer! Temp is hanging around 20deg. Here’s a pic. All the gubbins is under the counter in the utility room next to the Sunamp

Thanks for the quick replies. I thought so. The obvious next questions is how big. TonyT you say 1 litre per kW heat (which would be 3l with a 3kW willis pump?) I'd assumed you'd calculate it from the volume of water in the system (though I'd need to work out the length of pipe first!) It's about 100m2 of standard-spaced 16mm per pipe. The

I recently posted about running my UFH using a Willis heater. Plumber on board with this in theory but hasn't encountered before. We were wondering if it'll need an small expansion vessel? Shopping list so far is; Manifold Grunfos Pump Willis Heater Timer.

Hi Will. Thanks for this, looks important. Thanks too, Terry. Is this because there’s a risk of overheating or damaging the slab? I assumed this will be a slow, non-reactive system. The house is fairy constant temp between 15-20deg and I was hoping that just warming the slab for a few hours overnight would bring up the background temp by a few degrees. I don’t have any programming skills and want to keep everything as simple/idiot proof as possible. I am also wondering if, using a Willis heater (obv element switched off) would there still be a way of cooling the slab in summer by circulation cold water as someone mentioned previously in this thread?

Thanks for this. I think I might go for this as a short term plan. I already have E7 leccy which tops up the Sunamp. I have a mate who’s a qualified electrician and plumber. Currently there are just a dozen UFH pipes sticking out of the slab. As well as the Willis pump and a suitable manifold, what else would I need to set it all up? I think just a timer so it comes on for 6 hours overnight would be as much control/monitoring I’d need.