Need upgrade advice

**Mike90250** · 08-12-2021, 05:57 PM

1) I want to go 24v all the way through, is that hefty enough?

Not really, 1500W @ 24V is going to be around 65A. Way too much amps, at 48V, it would be 33A, much easier to handle

2) I'm thinking of a 2000w inverter (the inverter will accommodate the start loads according to the specs) and I think that's big enough given that I'm not going to be running everything at the same time, but am I right?

it will not start the water pump, the Air Cond might be rough, it depends on the individual specs of the unit.

3) Buy 4 x 600Ah 6v batteries. The question here is GEL, AGM or open (for which I'd have to finagle some spot outside the building)?

I would recommend eight 400ah L16 flooded lead acid in a 48V configuration. When they wear out, then consider the AGM. GEL is not a option, they are
generally for standby use only, and trickle recharge. Not suitable for solar

4) I love the EPEVERs. The controller will go up to 1040v at 24v (2 panels max) but I figure I need more panels or more wattage.

5) Go safe and buy a petrol generator

How will your generator hook into your system ? Does your chosen inverter have a Generator input & Transfer switch internally ? does it have capability to Charge your batteries ?

1500w water pump (to be used once or twice a month on a sunny day)

This will need at least a 5KW generator or inverter to start/run it.

**nomadros** · 08-13-2021, 03:54 AM

Many thanks Mike. You've made it easy for me. I'll just go with a free standing generator not plugged into anything else in the meantime. I doubt I'll be allowed open lead acid batteries due to the perceived fire risk. It took over 3 years to get a permit for the panels. I've got so many civil (public) servants from so many different departments, all with different agendas in on this, I need to baby step this all the way through. Goal 1 will be getting water out the hole and get it up the hill. by any means. I've been assured by the water bunch that I can do what I want re panels because i have a permit for water although they changed the pump spec at the last moment to something that wouldn't do the necessary lift and I need assurances in writing before I trust them again. The countryside protection bunch is demanding 4 panels. I'm basically trapped between departments who have been told to do "green" but all the specs still point to fossil fuel options. All I'm trying to do is grow crops. I'll revisit all this when I've got water at the top of the hill. Thanks again.

**Mike90250** · 08-13-2021, 09:56 AM

Flooded lead acid batteries are the least likely to burn, explode or cause issues, just add distilled water monthly. Li and AGM are able to perform "rapid disassembly" under normal conditions.

Before buying the pump, insist on seeing the Pump Curve chart for it, to verify it will provide the water you expect, at the lift and rate needed.

Grundfos_10_SO5-9_pumpCurvesC.jpg

**nomadros** · 08-13-2021, 11:06 AM

Hi again... I've been through all the specs with the installer and the pump chosen is the only one in the govt approved spec list that can do the lift needed. It is bought. We're going to install it this month, use his generator to test and comission. Once that's done i can get the install signed off by 2 govt bodies. The next stage is to excavate a trench up the hill and install pipes and power underground. Then i can get that signed off by another govt body.

In the meantime i need to start the panel install on the roof of my building and get the architect to sign that off which gives me 3 years to complete the works.

At that point I've got head space to figure a power system out.

I'm setting up an experimental crop project with another govt body this fall and we havent even decided on crops yet, so if i can get water up the hill I'm good to go on drip/micro sprinlker irrigation of any type really... even though i really want drought resistant crops and no irrugation.

I've got no allowed space to do a open lead battery install and the architect/council/ecological transition fascists expect the batteries to be inside the building, so I'd probably have to go AGM unless i excavate one of the exterior walls (2 foot thick) and place the batteries in there.

Just let me get water out the hole as a first step.

Thanks for your patience.
Neil

**nomadros** · 08-25-2021, 06:18 AM

I'm back to thinking about this... My options are, get a petrol generator or go "green" and spend a fortune.

My current loads are very small and I use 2 x 12v systems, one with a 300w inverter (lights, tv, laptops ) and the other with a 1000w inverter ( biggest loads are a 500w blender (say 2 mins running time) and an occasional use 850w angle grinder for say an hour)..

My only problems with my current set up are snow, wasps and 10 day fog events. I'd like to double my storage capacity to cover the fog issue. I can ride it 7 days on the 300w and 3.5 days on the 1000w

For what I want to do now Mike90250 advised that I need a 48v system.

My new need needs are...
1500w water pump shifting 1200L per hour which will be used for around 8 hours a month.
300w aircon unit in the summer for say 12 hours a day. Building is well insulated.
850w microwave.

My main problem is panel area as I only have a permit for 5.2m2 which, even with finagling I can probably only muster 400w at 48v max when I want/need to use a min 2000w inverter. According to SunKing's sticky I need more, but I can't.

What I'm thinking of is 400ah 6v batteries x 8, a 2000w inverter that'll only be pushed 1 day a month and a couple of 24v 400w panels in series. How mad/off am I?

**Mike90250** · 08-25-2021, 09:22 AM

Originally posted by nomadros

I'm back to thinking about this... My options are, get a petrol generator or go "green" and spend a fortune.

............

What I'm thinking of is 400ah 6v batteries x 8, a 2000w inverter that'll only be pushed 1 day a month and a couple of 24v 400w panels in series. How mad/off am I?

Until you actually build and use it, you have to rely on your calculations. Since you really only get usable sun for less than 7 hours a day, your Air Con will be running off batteries for several hours, factor that usage into your calculations. When sun comes up, you have to both supply loads AND recharge the batteries

**nomadros** · 08-29-2021, 04:21 AM

I've made my decision about all this. I'm trapped with 4 x 200w panels for the moment so....
My normal loads are (not a lot) all and I'll have high amp short duration loads. I also have long fog events, so I'm thinking...
1) I have to go 48v due to high amps. (Thanks Mike90250 because I'd forgotten the old V=IR thing)
2) Get huge battery power (400ah 6v x 8) AGM (Because I fancy that)
3) 2000w 48v inverter (the smallest I can get away with)
4) Keep the 4 x 200w 12v panels in series (because I have to)
5) Buy a generator, nail it to a trailer for transport and link that to the charge controller (found one) for back up.
6) Hot water (1000w) and aircon (300w) are summer only things (If it's 42c outside, it's only 28c inside the building). Winter I can get hot water off my wood burning stove.

I need a generator anyway for field work. My current elec consumption is only about 0.5v a day in bad weather in the winter, so I'm not going to be deep diving a lot and I figure this "walking on 2 legs" approach might fly. I can then spend the next 3 years getting a new permit for more panels.

Earth bonding I've got covered (as per SunKing's sticky), so my only outstanding problems are wild boar and rats eating cables and lightning (temporary blindness is weird; white and pink swirls).
Thanks for your help.

**Mike90250** · 08-29-2021, 08:20 PM

Wow, if you have lightning, you need to double down on your surge protection on both DC and AC lines. I recommend the Midnight Solar SPD's in the appropriate voltage :

http://www.midnitesolar.com/products.php?menuItem=products&productCat_ID=23&productCatName=Surge%20Protection%20Devices

Also, consider using flooded batteries, instead of expensive AGM batteries.

Generator for battery charging: 40A @ 60V is going to be 2400 watts, plus power factor losses. So you may need a 240V charger. You do not use a generator driving a solar charge controller. You can either use a couple of AC-DC chargers in parallel, or look for a inverter that supports being used as a battery charger when AC power is available from a generator.
( screen shot from my XW a couple years ago)

GeneratorChargingXW.jpg

**nomadros** · 09-02-2021, 04:53 AM

Thanks for the above.. I'll be taking this very slowly. First thing I need is to mount a roof structure for my existing panels so the architect (yes I had to use an architect, to do a project, so I could get a permit) can tick a box to say that the project is underway. The permit is for 5.2m2 of panels to pump water and some electricity for the farmhouse. Once the project is underway I have 3 years to finish it. The water pump installers return soon to put the pump in and will use their generator to test that everything works. Then I get a bulldozer in to create trenches and then buy I'll a generator and that should get me water to the top of the hill. I'll then reapply for more panel space after the ground is replanted and irrigation installed (I'm barred from applying for anything until the ground is irrigated) and then nail down the specs for a proper solar install. I'll have to use indoor AGM batteries as I've no place to store open lead batteries. This is my big project for the next 5 years with new crop growing methods, ancient stone walls repaired, green energy use for everything, wildlife monitoring etc etc. Public servants have been told to want "green" but every department has different rules and ideas about what "green" is. Drives me nuts. Thanks again for your help and info.

Need upgrade advice

Need upgrade advice

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