AidenL wrote: » I’m still rolling things around in my head. Since I had the NightSaver meter and started turning off non essential items, we are using around 11 daytime units and 5 night units. This is down from 24 overall on the old meter without me making any efforts to save electricity by turning equipment off. So my question is, does our reduced consumption make a PV install less or more sensible?
n97 mini wrote: » What make/model inverter did you buy? Interested in something similar eventually, once DC coupling has finished leading me down a rabbit hole
KCross wrote: » A Solar PV only system is much more eco friendly and is guaranteed to last decades. That, along with a FiT, is what I'm vying for.
GaryCocs wrote: » Can anyone tell me the depth of discharge for the Plyontech batteries? Also I still can't get a definitive answer on what the definition of a cycle is? Every day my battery is charging and discharging several times. e.g. Cloud cover, Oven goes on etc. all swaps from charge to discharge.
unkel wrote: » Lead acid doesn't need a BMS like lithium. I have bought a second hand AC side battery inverter (similar setup as Tesla Powerwall). It has two CT clamps on mains incomer and PV, on which basis it decides to charge / discharge the battery. It checks battery temps alright. Not sure yet about battery costs but not willing to spend much. A basic 4 * 100Ah 12V leisure battery setup would give you 5kWh (only half of that usable), but I am hoping for something a lot bigger than that. Weight could be huge and footprint easily a few sq meters. Will install outdoors. Wouldn't want lead acid inside my house.
wexfordman2 wrote: » So, 10,800 before grant? As was suggested to me when I got a.similar quote, bargain them up to a slightly.larger system up to 6kwp solar. Also, query the usable capacity of the battery, for example your 4.8kwh battery may only provide 90% of that as useable power, so 4.3kwh usable. Post up the make and type.of inverter and battery too
unkel wrote: » I'm still going ahead with battery storage, but with very cheap lead acid batteries. Costs so little that there is virtually no payback time (I should be able to sell my hardware for as much as I paid for it), so very little risk. I can replace the lead acid batteries with lifepo4 in the next few years / if their price has dropped significantly. Or decide not to go for lifepo4 batteries at all if we get a FIT that has higher rewards
KCross wrote: » If the battery paid for itself within, say, 5 years I'd have gone for it and be happy to chance the degradation as I would have had 5 years of "making money".
KCross wrote: » ok, i get 2 3 and 4 dont make sense to me though. They peak at 7kW. I presume your battery cant take 7kW so is it the amount being taken from the grid or is that graph 4? Can you clarify how to interpret 3 and 4
GaryCocs wrote: » Sorry cut wrong 2) Consumption Power 3) Charge Power 4) Buy energy power
GaryCocs wrote: » The best day of the year so far for me. 2019-04-18 3.3kw panels split sw and se with 2.4kwh batteryhttps://www.dropbox.com/s/8qx5ep4njyghzt4/Screenshot%202019-04-26%2010.48.20.png?dl=0
unkel wrote: » I reckon they will last longer than a lot of people today think. They will deteriorate, but with the relatively low C values of charging / discharging (typically around 0.5C max) and the battery management not letting them go to far up or down it could very well be possible they still are usable after 15-20 years with perhaps 60-70% capacity left (provided the lithium batteries are indoors - so at an ideal temp of around 20C most of the time)
unkel wrote: » Shouldn't be. 4kwp costs a touch over €1100 + VAT at trade prices The biggies are the hybrid inverter, the batteries and the install costs...
DrPhilG wrote: » At the end of the day the panels are by far the biggest cost (certainly in my case)
AidenL wrote: » And we will all need new batteries in ten years time, thus pushing out payback further.
DrPhilG wrote: » I have oil heating and that also heats the water. But much of the year we only have it on for 3 hours a day so we don't always have enough.
AidenL wrote: » I haven’t paid my deposit yet, but having read the last few posts, I’m wondering is it dead silly of us all getting into something with a 20 year payback time. And we will all need new batteries in ten years time, thus pushing out payback further. I’m actually having second thoughts.
unkel wrote: » Yes that will save a bit. But only in winter really. If you program your hybrid inverter to charge the battery (all year round) at night rate for use in the morning, there is the risk you will pay 8c/kWh and your solar in the morning has nowhere to go but to your hot water at 4-5c/kWh, so you would actually lose out If you get a full cycle of your battery say 183 days per year, you will save 4.4kWh (usable) * (18c-8c) * 183 = €80 per year. This is very optimistic though and you will lose money on sunny days in winter when you are not using up this storage before PV wants to fill it up again. Take a year off your pay back maybe realistically
niallers1 wrote: » and if you are heating your hot water that could be worth you €80 per year by not having to heat with gas.
niallers1 wrote: » Plus there is also the smug satisfaction with generating your own power and the nerdiness factor of it. That's worth a couple of k.:D
DrPhilG wrote: » PS what about the value of electricity stored to the battery overnight and used during the day? I'm damned if I can find the calculations I did previously but that was definitely a consideration for another €100 a year or so.