DamonHD

The way my system is now set up the heat store is a smalish Thermino (~2 day's DHW in a small unit under the combi) currently heated by PV diversion, but can be boosted from mains at appropriate times. The Intatec Intasol valve automatically draws water direct from the Thermino if hot enough, else via the combi (mixed down to 28C since my combi doesn't like hot input) as preheat. https://www.earth.org.uk/note-on-solar-DHW-for-16WW-UniQ-and-PV-diversion.html#2022-03-09 Gas demand has dropped from 4kWh/d to almost nothing (less than 0.5kWh/d). Rgds Damon

All storage (other than the Thermino heat battery) and inverters are outside the main living space, though the inverters are in the loft which might worry some as a hazard. (I asked the London Fire Brigade to check over the system as I had it at the time and they were content.) On the other hand, my insurers won't ensure anything outside even though I did point out that for (eg) Li batteries this is (a) common and (b) safest... I managed to negotate a compromise, but it's a bit silly... Rgds Damon

#NotAllLithium The bulk Lithium batteries that I have used / am using are LiFePO4 which do not tend to do most of those nasty things: AFAIK the electrolyte is the problem in Lion laptop/phone batteries. Rgds Damon

FWIW I run my router (12V) off-grid (ie from off-grid PV and storage) automatically when possible. https://www.earth.org.uk/expanding-off-grid-PV-system.html Rgds Damon

Interestingly, while the supply meters say my Enphase is doing that job relatively well, my Eddi metering dsiagrees quite substantially, though does its own job reasonably well. (This is the old banking joke about if you don't want to have to do reconcilliation, don't record more than one stream of numbers.) I'm starting to assemble side-by-side streams here to enable better comparisons: https://www.earth.org.uk/energy-series-dataset.html So still can't help you I think, though I am prepared to add sponsored equipment under test in principle! As to battery life, other than abuse (pushing to close to or beyond limits), I basically assume both calendar-life limits AND effective full-cycle limits (whether taken piecemeal or not) for both LA and Li chemistries. But what do I know? Rgds Damon

I definitely know of one unratcheted meter that the FiT administrator has been told about that hasn't been replaced, but the system isn't big and maybe the cost of replacement was considered too high. No, it's not mine! Rgds Damon

@SteamyTea Cascading system would be the right way to do it, but I suspect that many users would fail to distinguish needs from wants well. @markocosicI don't understand your question, or don't know the answer, or both! Rgds Damon

Some mechanical meters do run backwards.* Ofgem is very unkeen on this type of uncontrolled net metering as I understanf things, because in part your PV spill provided to the grid unbidden is not worth anything like retail rates to the grid. Some mechanical meters have a ratchet to prevent running backwards. *Some of the older unratcheted ones catch fire. Another reason not to do it. I have been through both in my installation. I now have an import/export pair, which also means I can work out what I'm actually consuming. Rgds Damon

Why do you believe that a Sunamp wouldn't allow similar overcharge? Rgds Damon

Gas use for the whole of April was just over 1m^3, so ~0.38kWh/day. Thus a 90% reduction in direct gas burn. Result. https://www.earth.org.uk/note-on-solar-DHW-for-16WW-UniQ-and-PV-diversion.html#2022-04-30 Rgds Damon

Yes @SteamyTeaall the ratings in the EU and UK just got reset so that A means 'best' again (rather than A++++++++++++++++). Rgds Damon

The meter may itself be using something getting on for that 6W... Rgds Damon

I'll get a better view at the end of April, but gas use is now about 0.5kWh/day, and will go lower if I can train my family not to whack the hot tap full on for 30s use (where hot water doesn't even get to the tap!)... https://www.earth.org.uk/note-on-solar-DHW-for-16WW-UniQ-and-PV-diversion.html#2022-04-11 Also these may be of interest: https://www.earth.org.uk/eddi-diverter-dataset.html https://www.earth.org.uk/heat-battery-topup-dataset.html Rgds Damon

You are meant to talk to your FiT administration before installing storage, eg to confirm whether you intend to allow exports from storage to the grid. Rgds Damon

Then they are breaking the law, ie not operating VAT correctly. Rgds Damon