No I was really saying that if you do have a (poor connection) grid supply but need solar to guarantee security of supply then cost really isn't an issue. But if you have no grid and the choice of either solar or running big cables for a km or so then a different set of calculations apply. Then, if you want to make lots of the stuff and sell it back and think that you can make a pile of cash then a third set of calculations apply.
I'd suggest that anyone who thinks the 3rd option is viable needs to take an accountancy course.
Of course there is also the impending issue of a levy being charged on ALL generated power - the Lines Companies argue that as more people generate the stuff, their income falls and someone has to continue maintaining the grid. If the Gubbermint's Green Wing gets it's way then NZ will have a diabolical distribution problem on its plate as no-one will be keen to pay for infrastructure that they are not using.
moby,
Mar 19, 2:34pm
This is reminiscent of the old levy charged by NZED back in the 1950s to high country farmers for the power generated from their own microhydro systems on their own streams. The logic was something along the lines of "you have to pay for the availability of electricity which we have to install cables for even if you don't choose to use it" - which was a bit like paying the local brothel even if you never went there.
tegretol,
Mar 19, 3:55pm
Yes well we all know the answer to that prickly one don't we!
budgel,
Mar 19, 7:01pm
Well, I'll be #ucked!
gocontinental,
Mar 20, 7:27am
We are off grid and have old(8yr) lead/acid batteries. Admitidly we are a bit frugal with use ie hot water heating on a different system, no micro-wave, dishwasher, heat pump, e-bike or electric car, use a gas stove, They are still working well, with the generator only kicking in occassionally during crappy mid-winter days, There are still places that are not that remote to civilisation that don't have reticulated power. Sometimes the cost of line installation is prohibitive, other times it isn't even an option, leaving the home-owner with no option but to go Off Grid.
tygertung,
Mar 20, 8:30am
Even if you did have an e-bike, I dar say you'd be alright as the battery holds usually only 750 W h or less
tegretol,
Mar 20, 11:21am
Back in the days of the NZED, it was considered the governments job to get the stuff to our back door. Bloody great idea this privatisation isn't it?
To run a normal fridge and a small freezer you require app. 1.6 K/whr's or electrical units per 24 hrs. == app 170a/h daily solar input @ 12volt. To generate this amount of Amp hours via solar requires app 1kw of solar and about 300 A/hr storage via a Lithium battery and a 2-3 kw inverter.
All works well during summer but even that is suspect if you get 3-4 dull days in a row. During winter a grid connection is needed to top up lower solar input.
These are my observations saving app. $0.70cents a day with good sun.
I believe using a solar hot water heater system is far more cost efficient but most only use about 5 units to heat normally daily unless you have a big family or like 20 minute showers etc. Check your controlled meter readings to see how much your needs are, you will be surprised .
do the maths first as you can buy an awful lot of electricity for the cost of any Gas or Solar installations and don't forget the fixed charges which will go up if you install a grid tied system.
5425,
Mar 24, 7:20pm
for those interested in an owners figures ; It now takes basically until 3pm+ for the battery bank to return to fully charged by 1kw of solar and a load of 1.6kwh or units. during January it was by 10.30 am. Lithium PO4 after 13 weeks from the longest day was Dec.22nd [solar maximum.] summer equinox.
Solar production just goes downhill.
will need some grid input before Solar regains around late November
ps I live in the highest Solar region in NZ. Whakatane.
harm_less,
Mar 25, 9:51am
A bit cryptic there Greg. Am I right in thinking you have just 1kW of PV panels? And what are the details of your battery set-up? Who designed your overall set-up?
Solar generation is reliant on sunlight hours, panel orientation and shading issues. It will always be higher in summer and lower towards winter so no surprises there.
If your battery is failing to gain full charge by sunlight alone then investigate utilising offpeak grid supply to do so more economically. (i.e. charge at night for those times when your PV isn't generating sufficiently.) Or increase the size of your PV array.
trade4us2,
Mar 25, 10:52am
I have maintained a solar hot water heater system for many years. It is excellent and cheap. I have looked at the economics of a solar panel to run my daytime power needs. When the panels are a bit cheaper I will get one, at least to run my waterbed!
reelingmaze,
Mar 25, 1:11pm
They pay us 8 cents per kw. They charge us 0.163 cents per kw. Talk to them about changing your plan to low user rates.
reelingmaze,
Mar 25, 3:40pm
We have 16 Tier 1 panels and 2 x 4.5 kw batteries. 8 panels West and 8 panels East with no shading, 25 yr Warranty. We love love love our Solar System. No problems with filling the batteries even on a cloudy day at this time of year however there will be times over winter we won't be able to. Our power bill has gone from $220 per month to average $40 over the last 5 months we have had installed. We have a timer on the hot water to come on at 11 a.m. to give the day light time to generate. This seems to work as it sucks out of the battery combined with solar generation, on fine days it doesn't pull much from the battery. Our battery charge gets us through the night with on average 40% left in the battery in the morning which sees us through the start of the day. The system cost us $26.5K and we wouldn't change it for the world. We love our very little power bills.
bill1451,
Mar 25, 6:28pm
Hmm you sure you got that right 0.163 cents per Kw 16.3 cents more like it, or put up the name of your service provider and we,ll all put in solar
reelingmaze,
Mar 26, 8:11am
You are correct it is 16.3 cents. Our service provider is Contact for now and I do recommend you put in Solar.
smallwoods,
Mar 26, 9:14am
Are you working there?
tegretol,
Mar 26, 8:07pm
So a few years ago, you spent $21,000 and that resulted in a saving of $50/mth, ie $600/year. Allowing for the loss of interest (@2.5%pa) and the capital depreciation (@ 7.5%pa), you'll have recovered your 'investment' after 76 years. Is that a good investment?
tegretol,
Mar 26, 8:09pm
Some honest calculations say that your payback time is 13.2 years.
5425,
Mar 26, 9:33pm
It was setup as a trial in this area by a Solar Company with the correct orientations , cable size. PO4 battery MPPT controllers This system app. cost was $4,500 installed. It saves app 1.6 units a day at present with the battery full around 3-30pm.
There were suggestions of going to soft start fridges but the costs were unreal.
If you want to spend $20k + on a setup go for it but then after 2-3 days of low solar you will still need a grid backup and some lifestyle changes.
"We’re getting in touch to let you know your electricity pricing will change from 20 April 2021. We are changing your pricing to reflect increases in the costs of providing the electricity you use. This change has been driven by recent increases in wholesale electricity prices and our operating costs.
Network area: Horizon Energy . Nova Energy Charge Type Current Prices (excl. GST) New Prices (excl. GST) Daily – c/day 35.294 35.294 Composite – c/kWh 31.536 32.176 "
5425,
Mar 26, 9:37pm
The Aussie version of no battery and around 90-180 Volt DC into a grid tied large solar system is very popular in certain states . They have the same Electrical standards as NZ .
tegretol,
Apr 2, 4:01pm
Sure but what can run on DC these days without installing a seriously expensive inverter?
5425,
Apr 4, 11:31am
You need some sort of inverter regardless of how the solar system setup works if 230V AC is needed . These are all grid tied anyway and owners found they stopped even with battery backup if the Grid failed, safety for lines company employees.
harm_less,
Aug 5, 1:56pm
Your post is a bit ambiguous in regard to the "battery back-up" of inverters.
If a system has battery storage then it should be configured to instantaneously disconnect from the grid in the event of a power outage but will still be able to provide power from the battery for the home's use, effectively 'islanding' the installation. It will have a 'dead man switch' type of isolation built into it in the same way as a generator back-up set-up does so that presumedly dead transmission lines aren't energised for repair staff's safety as you say.
What you are suggesting is a battery that overrides the grid outage thereby allowing the solar generation to flow unchallenged into the grid which is definitely illegal.
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