Stand alone solar power

[Laava]

As above, looking for opinions from people who have Off the grid installations and comments re Installation cost,ongoing costs, obsolescence etc. Is only for a one bedroom bach.

[TheDemonLord]

As above, looking for opinions from people who have Off the grid installations and comments re Installation cost,ongoing costs, obsolescence etc. Is only for a one bedroom bach.

Obligatory 'Not me'...

However, some dear friends of mine run the above - Setup cost was I think between $25-30K - they run a full-size house (2 people, no kids) However, they don't run many high-drain appliances:

They use Gas for Cooking/Hot water, have a Wood Burner for heating etc.

One of them works from home (a writer), the other doesn't.

Most of the cost for the installation was for the Batteries that are required for the system, I think they have a backup diesel generator if the Batteries get too low and there isn't any Sunshine - I can ping them for full details if you are interested.

Installation was pretty simple as it was entirely a new-build house - the Solar Panels were installed in a static location (no fancy sun-following setup) and a special 'shed' was built to store the Batteries and the Controller etc.

On-Going costs - I think they get the system serviced yearly, but I'd have to check with them - I would imagine that the Batteries have a life-expectancy of somewhere between 10-20 years, they also have to be careful when cleaning the Solar Panels and if there's been any funny weather, then they need to do it, otherwise the efficiency drops off.

They love it, it suits their needs and their outlook on life etc.

[Berries]

How about this field trip for a bit of research?

Remote solar power www.bbc.com/news/science-environment (https://www.bbc.com/news/science-environment-53450688)

[jim.cox]

I know a couple of simple cottages that are off the grid.

In both cases, there's a large(ish) panel and a small deep-cycle battery or two.

That runs lights and battery charging. Being able to flick on a light is great, sure beats Tilley lamps.

Batteries have been a bit of an issue. Started out el-cheapo with 2nd hand ones - no reliability == bad idea.

Even using new good ones, they seem to need replacing at around year 7.

We have also had one controller fail and need replacing.

Set-up costs were around $1k for panel, battery, controller and lights. You can get everything you need at Jaycar.

I need to about triple the size of the battery banks, and maybe add an other panel, to run a small fridge.

[GazzaH]

Solar panels vary in engineering and build quality, performance and longevity. The advertised outputs are under ideal conditions i.e. optimistic. If badly installed e.g. poorly positioned or unmaintained and dirty, or old, output will be less, perhaps much less.

Despite the name, "deep cycle" lead acid batteries can't actually cope with deep discharge very well, apparently. Most batts are damaged by over-charging and overheating. Don't abuse them and they should perform close to spec, provided they are quality products anyway. However, modern lithium batteries, coupled with suitable smart controllers and installed in such a way that they don't get too hot (not in the sun, not enclosed ...), are more reliable, longer life and higher capacity than lead acid types ... but cost more up-front.

Any decent-sized solar system stores a lot of energy in a small space for those long nights. Under-sized or badly installed and unmaintained wiring is a safety as well as performance issue. Gas, diesel or petrol generators can get you through long, dark Winter days and weeks ... but they also have their issues and costs.

"Energy efficient" electrical devices make the most of whatever power is available. Do you need 230V AC (requiring a lossy inverter) or can you make do with 12V systems and LED lighting? How about gas or wood-fired heating and cooling?

Get experienced & competent help to design your system, buy reputable brands from reputable sources, and have them professionally installed ... or wing it, do it on the cheap and suffer the consequences - your choice bro.

[Laava]

Thanks guys, yep a lot to think about. Initially I was going to just have gas hot water/ cooking and led lights and run the whole lot from the inverter in my truck, but also have to factor in the water pump as well and now er indoors want to have a fridge here and running 24/7. So would defo need batteries. Since I posted this thread I spoke to a local sparkie who is coming to have a gander. My neighbour has panels and feeds back into the grid with no batteries and reckons he has made $1400 so far this year...Much as I like the idea of no monthly bills, I also will have to weigh up cost over the expected lifespan of a solar system.

[Black Knight]

I know a guy who does installations,average cost for a full system is ballpark $35K all up.In his opinion you would only install one if the cost of running power line to your house was prohibitive.

[Laava]

Wow, thats a lot! Probably for a full blown family home tho eh Chris?
Actually, my neighbour over the fence put in a huge system for his huge hilltop mansion, cost him well over 250k all up including the shed according to my other neighbour. But he only did that because the council here, Far North, would not let him buy the paper road bordering his 4ha to run his power in. Long story but he is one of those uber wealthy americans who gets angry when his money cant get him what he wants...

[Viking01]

An interesting proposition to explore. I went through the exercise of trying to work out the economics of retro-fitting solar panels on the garage roof, for feeding power to both the house and garage. Explored two options (with and without storage battery). Did this about 2 years ago.

The cheaper option was obviously without storage battery, due to the high cost of the battery.

The first of the two articles pretty much summarises the results that I found from doing the financial analysis.

https://www.stuff.co.nz/business/107335911/solar-power-systems-take-decades-to-pay-for-themselves-consumer-nz-says

I used the University of Canterbury calculator that is embedded within the second link. It is very comprehensive, yet very easy to use.

https://www.canterbury.ac.nz/news/2016/uc-experts-create-solar-cost-benefit-calculator.html

The net result was that with at least 10 panels installed, in order to "break even", simple payback was going to require 20-21 years, and normal payback (taking cost of money into account) over 25 years. And that assumed that I did not have to do any panel (or converter) repairs or replacement within that time frame.

[Edit]

Think the most frustrating (annoying) part of the whole exercise was actually getting the proposed supplier / installer to give me a straight answer to the question: "Do you know of a reasonable online calculator that I could use to try and model the financials? ". I already had an answer to the question, but I just wanted to see what they would say (a small integrity test, you might say).

Well, more twists and turns than the Rimutakas, and a whole range of non-answers. And when the two written proposals arrived in the mail, use of the calculator vindicated that caution.

[Hugo Nougo]

Everyone here is talking about professionally installed latest tech, lots of dollars for labour, inverter and batteries, you can save a lot with a bit of research and shopping around.

As has been stated you need to decide on your particular needs, I just want something to handle power cuts and take over winter heating may be hot water. Stand alone systems are going to be cheaper, higher voltages are more expensive, check out the prices for 100amp+ cabling.

I personally still prefer mono-crystalline panels mounted with a robust tracking system, I just got a 2-axis system out of China for under $300, steel and parts to fit panels another $300 (need to get it galvanised before install). This gives another third of sunshine hours at least, no brainer to make system more efficient.

Instead of 1 big inverter, i've opted for 3 cheap 2000w (4000peak) Chinese made inverters, Checked on oscilloscope and they are punching well above their price tags.

Batteries, they are killers, i picked up 16 2nd hand 150a/hr lead acids weighing 50kg each from a UPS company for the price of moveing them, it's not worth the scrap for them to handle them, they are old, not full deep cycle but have been awesome, by controlling discharge ( dont let them go below 11.7 ) i've only lost 2 in 6 yrs.

PWM controllers, I will upgrade at some time, got the panels brand new cheap from trademe.

Have to go to work now, but there are plenty of helpful sites and people online, as long as you're not in a rush, oh and jaycar and supercheap are way overpriced.

[Laava]

Cool, thanks Hugo. I recently installed a 2000w inverter in my truck from Jaycar, think it was in the $3-400 range. It is good for electronics stuff too but I primarily installed it to run power tools and batt chargers. The cables and fitments cost as much as the inverter as well! To be honest tho, I got the cable for nothing, but I do know what it is worth.
Anyhow, it is not looking to be a good financial decision at this stage...

[Naki Rat]

An interesting proposition to explore. I went through the exercise of trying to work out the economics of retro-fitting solar panels on the garage roof, for feeding power to both the house and garage. Explored two options (with and without storage battery). Did this about 2 years ago.

The cheaper option was obviously without storage battery, due to the high cost of the battery.

The first of the two articles pretty much summarises the results that I found from doing the financial analysis.

https://www.stuff.co.nz/business/107335911/solar-power-systems-take-decades-to-pay-for-themselves-consumer-nz-says

I used the University of Canterbury calculator that is embedded within the second link. It is very comprehensive, yet very easy to use.

https://www.canterbury.ac.nz/news/2016/uc-experts-create-solar-cost-benefit-calculator.html

The net result was that with at least 10 panels installed, in order to "break even", simple payback was going to require 20-21 years, and normal payback (taking cost of money into account) over 25 years. And that assumed that I did not have to do any panel (or converter) repairs or replacement within that time frame.

[Edit]

Think the most frustrating (annoying) part of the whole exercise was actually getting the proposed supplier / installer to give me a straight answer to the question: "Do you know of a reasonable online calculator that I could use to try and model the financials? ". I already had an answer to the question, but I just wanted to see what they would say (a small integrity test, you might say).

Well, more twists and turns than the Rimutakas, and a whole range of non-answers. And when the two written proposals arrived in the mail, use of the calculator vindicated that caution.

I also used the Canterbury Uni/Energywise calculator recently as we're planning on installing PV on our present property. We had a 6kW installation on our last property (https://www.harmlesssolutions.co.nz/index.php?route=module/blog/view&blog_id=7) so learning from our experience there. We struggled to consume more than 50% of our generation from the 6kW despite doing much of the charging of our Nissan Leaf during daylight hours.

The system we're looking at will be around 3.5kW so smaller than previously but the real game-changer looks to be the inclusion of a 'power diverter (http://www.paladin.nz/)'. These gismos monitor the mains to the property and if generation export is detected that power is diverted into the hot water cylinder. We installed a dual element cylinder just after we purchased our current property with such a scenario in mind.

Presently the cylinder is heated by the lower element so behaves like a normal single element but once we install the PV and diverter the top element will be grid fed (for back-up and quick recovery) with the lower element powered by the PV. Obviously the PV heating will raise the temperature at the top of the cylinder first (by convection) so the top element will not be required for the most part thereby reducing our hot water bill significantly. According to the Energywise calculator we should expect 80-90% self consumption of our generation. For those new to PV the key to making a PV system pay is to minimise export of your generation as this typically returns around 25% of what imported power costs. So, in effect we will be using our HWC as a battery to store our generation in the form of heat, offsetting the electricity this would otherwise require.

We're still to receive the quote back on our planned system but based on what I estimate it will cost the payback period is around 10-12 years based on Energywise's calculations. Also we again plan to 'ground mount' our panels for ease of cleaning and maintenance, and because we have the room to do so on our rural property.

[mashman]

If I had some spare $... (http://www.v2h.co.nz/vehicle-2-home/)

[Naki Rat]

If I had some spare $... (http://www.v2h.co.nz/vehicle-2-home/)
V2G is a developing technology. If these guys are accurate Tesla's soon to be announced (https://www.caranddriver.com/news/a32938647/tesla-battery-day-september-15/) "million mile battery" will enable Tesla's entry into this market. Interesting theorising.


https://youtu.be/pP971PYzQJs

[pritch]

Then there's this...

https://www.rechargenews.com/transition/australia-to-fast-track-worlds-largest-solar-battery-project-with-grid-link-to-singapore/2-1-849688

[mashman]

V2G is a developing technology. If these guys are accurate Tesla's soon to be announced (https://www.caranddriver.com/news/a32938647/tesla-battery-day-september-15/) "million mile battery" will enable Tesla's entry into this market. Interesting theorising.

Perfect for an automated fleet.

[MarkH]

As above, looking for opinions from people who have Off the grid installations and comments re Installation cost,ongoing costs, obsolescence etc. Is only for a one bedroom bach.

One source of information about a suitable setup could be from people that use solar panels and batteries for a motor-home. I've been looking at some videos and other sources of information for motor-homes and it seems pretty common to put solar panels on the roof and charge a bank of batteries. They often save power by using gas cylinders for stove/oven and using a very efficient 12V fridge and LED lighting. You can use an inverter to provide 240V AC power for things that need that, but you can charge a phone or tablet with a charger that powers from 12V - better than turning 12V to 240V and then running a mains charger. A laptop may also be able to get a 12V car charger to use instead of the mains charger that came with it.

If you can bring your power usage down enough then it wouldn't have to cost a fortune to have off-grid power.

[SPman]

Geez - payback period is long over there. Our first 1.5Kw system 10 yrs ago took us 2.5 yrs to pay off - but we had a 40c/Kwhr feed in tariff. We added another 3 Kw system 5 yrs ago and that is now paid off, even though the feed in tariff dropped to 8c
/Kwhr. I assume there are no incentives in NZ to install PV. A local we know was quoted $50k to get power in for his new house - 5Kw system, batteries and a wind generator cost him $22k. Solar hw with LPG booster and gas cooking.

[MarkH]

A local we know was quoted $50k to get power in for his new house

Yeah, that would make going solar with batteries a super easy decision. Fifty grand is a huge cost to be hooked up, followed by regular bills. A solar system would be paid back twice over before day 1, you'd have to be a fuckin' idiot to not go solar in this situation.

[Laava]

Well, I had a conservative estimate of $30k for a solar setup and just decided that I could use the money better elsewhere. $30k will pay for my power mains in and then many years of power after.
I also only had 72m of trench to dig so it was not too far and it also gave me a chance to drop in a conduit for future fibre or phone plus a couple of power feed for my little shed and water tank went back up the trench 15-20m each.
Also, as we are with Contact, they do a bach supply that has no charges other than what you actually use which will make it a bit cheaper again.
Will post in again when the bills come for trenching and cables...