Off grid system recommendations

Hi, this is my first post to this forum (I'm also posting it on a few of the larger similar forums) - I'm somewhat new to all this, but I've been doing a lot of research into off grid power setups for the last couple of months, since purchasing a piece of land in New Zealand. My family of four will be moving there from here in the US in 6 - 18 months from now, we'll start building our house shortly after we arrive.

I've been quoted $20,000 to run grid power to the site we'll be building on. I've always wanted to get off the grid as much as possible, so it was a no-brainer to decide not to pay that kind of money to be grid tied!

Seems to me the site is ideal for off grid power - the land is mostly on a north facing side of a hill (Southern Hemisphere, so north facing being best). I have a stream on one boundary, that should give me about 30 feet of head with good enough flow in summer to give me .5 to 1kW (rough estimate). And I have an elevated spot above the building site that would seem to be good place to put a small wind turbine.

Researching the New Zealand prices of the gear I'm looking at purchasing, it didn't take long to see that I'd be much better off sourcing a lot of it here in the US before leaving. We'll be shipping our gear over in a 40 foot container which will have some room to spare, so it's not going to add to the cost of the move.

I have a preliminary list of what I'm planning to purchase, based on a combination of my research and various recommendations I've received. As I have no practical experience, I can see there is a high possibility of making some wrong choices here. So I'd be grateful for any guidance anyone can offer on this proposal, or different approaches, as there are no doubt many oversights I've made:

For panels, I'm looking getting a pallet of 25 Astronergy 255 watt panels. The house we are looking at building is fairly small, but the north facing roof is the perfect size for 24 panels, getting a pallet means I'll have one for a spare. I figure that even though maybe that's a lot of panels, they will help on cloudy days to meet our needs.

For charge controllers for the PV, looks like Midnite Classic's are the way to go. I'm told for that number of panels the best configuration is going to be two Classic 150s, each with 12 panels wired with 4 parallel sets of 3 in series.

Batteries: I like the idea of getting sealed AGMs to avoid maintenance. I've found what seem to be good prices on Rolls Surrette S6-460 sealed AGMs, advertised as 6 volts 415 ah. I'm looking at getting 8 of them for series connection to get a 48 volt bank. If I buy them now (good price and free shipping as part of a package), and make sure I top them up once a month or so with a trickle charger, before using them in the system for a year or so, will they be compromised at all?)

Inverters: I've been recommended Outback, Magnum and Schneider, they all seem to have their pros and cons. As it seems there are more Outback inverters in use in use in New Zealand than the others that I've been recommended, I'm leaning towards the 3.0kW, 48V Outback VFX3048E (the 230V 50 version). I think we could mostly get away with a 3kW inverter if we change our power usage habits accordingly. But I'd like to know I can have a few higher demand appliances running at once without wondering if everything is going to fall over during periods of high demand, so I think I'll get a pair of them running in parallel. I also like the idea of adding redundancy in case one of the inverters fails, I'll at least be able to keep things running with one inverter.

(I'd like to figure out how I can get the second one to sleep as a slave to the primary master, and only kick in when required - I think this is possible. I will phone Outback tech support on Monday. Not sure if this can be configured in such a way that if the master fails, the slave automatically takes over - that would be great).

I think running two or more FX inverters requires a Hub4, and I'd also get a Mate2 for setup/monitoring.

For mounting the inverters, breakers, etc, I initially looked at the Midnite ePanels which I like, but as I'm probably going with Outback for the inverters, if I go that way I think a Flexware 500 enclosure may be a better option.

I don't want to spend too much on a wind turbine, as I'm not sure about my site. I figure if I got a 48V Primus Air 40, and a 45 foot pole kit - that would be a fairly low risk investment, it directly connects to the battery bank and doesn’t use a charge controller, diversion loads etc. I'm not sure how much it would contribute to my production, but it will be interesting to find out.

For a water turbine, the Powerspout looks like a nice piece of gear. It's made in New Zealand so if I go that route, it will be purchased over there.

I was going to use a Midnite Kid for the charge controller for the micro hydro (as it allows a diversion load to be directly connected, as I understand it, and lets you divert the voltage directly from the hydro to the dump load, meaning you can use 115 volt water heater elements). But I was told by Midnite the other day that hydro support for the Kid is now discontinued.

So it looks like another Classic 150 is the way to go here - I could get something less expensive, but seeing as I would already have two for PV, I like the idea of having shared components in the system that I can swap in and out if case of failure. This means I'd require some solid state relays (suggestions?) to control with the Aux2 output of the classic, as I want to use 48 volt water heating elements for my diversion load. This way, I could potentially be heating my water for much of the day in summer once my battery bank is back up to float once the previous day's usage is replaced.

Seeing as I'll have three Classics, I'm thinking I could add a second water heater element for redundancy. The primary element could be set to divert at one threshold voltage on one Classic, and the redundant one could be set to divert at a threshold voltage set to be a fraction higher on one of the other Classics.

The three classics, as I understand it, will let me connect three Whizbang Jrs and shunts, one per Classic on Aux1. If it makes sense, I'd like to add extra shunts/Whizbangs around the system, and switch them in and out manually to monitor currents at different locations (engineer nerd side of brain speaking now). I've asked Midnite what they’d recommend, they are going to have someone call me back.

Someone recommended the Outback FN-DC monitor system, but as the Midnite Classics already come with Whizbangs, and both setups require shunts, I figure I'd get pretty much the same results with the Midnite solution, without the extra expense of the Outback parts? Seems there are more options monitoring remotely when using a Midnite setup.

I'd think the lighting for the house should be LEDs run directly off the 48V battery bank. Not a lot of choice though for that voltage...so maybe a step down transformer to 24V would be the best option. Not sure yet if we should purchase 48v refrigerator/freezer to allow the inverters to be off for longer at night.

I realize that for a system of this size in terms of PV and inverter power output, a larger battery bank may be recommended. With this project I’m mindful of keeping the costs down where possible, without compromising reliability. I'm willing to buy once/cry once, and get a long lasting reliable system that does not end up being overly restrictive. But trying not to use the funds I have unwisely.

I just don't like the idea of tying any more money than is necessary up in batteries just yet, seeing as they seem to be the parts that will be most likely to need replacing, sooner rather than later, compared with the other components in the system. And perhaps the most prone to failure. The bank I'm looking at is $4200, the next step up for a 48V setup seems it has to be double that - not sure I'd be able to swing it just yet, but, I'd like to potentially expand it in future.

I'm hoping that 415 A/h at 48V, nearly 20kW of battery power, may turn out to be enough for now, if we make a few changes to our power consumption habits, e.g. performing most of our power intensive activities during the day when the PV is producing. And not use more than 10% of the battery capacity per day, for up to 3 days, while the PV is not producing, in order to prolong the life of the batteries (of course I'm counting on the combination of wind and hydro to be able to make that happen).

I'm planning on having the system assembled for me, and I'm being recommended the following (with much or all of this going in the Outback Flexware FW500-AC system I guess) - 8 Midnite 15A DC DIN breakers, 2 Midnite MNSPD300 surge suppressors, 2 Outback Flexware FW-DCA DC adapters, 2 Midnite MNEDC-175 DC panel mount breakers, 1 Outback FW-IOB-D-230VAC dual inverter input-output-bypass, 2 Outback Flexware FW-SP-ACA AC adapter w/surge suppressors, 4 Midnite DC panel mount 3/4" MNEDC-100 amp 150VDC breakers, 2 Midnite DC panel mount 3/4" MNEDC-100 amp 150VDC breakers. And a couple of MidNite MNPV-6 6 position combiner boxes. And all the necessary wiring.

I’ve just started looking at generators. Seems I can avoid extra components if I use a generator with 2 wire start (can be controlled from the Outbacks). I like the idea of a diesel because I’ll be experimenting with biodiesel for my vehicles (canola oil cut with gasoline), so the fuel could be shared. And I’d want something fairly small and inexpensive, just for kicking in when/if the batteries get discharged more than 30% or something like that. Any suggestions? If the costs of using a small diesel generator started getting to high, I’d be open to gasoline (but not propane). Might be best to pick this up when I’m over there.

The total cost (apart from the charging generator, and hydro generator / associated piping) comes in about $22k.

About what it would cost to get on-grid :-)