Is advising off-grid newbies to go cheap the first time a good idea?

[ron_jeremy]

My wife and I live full time in a 'full blown' house (electric fridge, multiple tv's, washer, etc.) on an island in the Pacific Northwest. Our new neighbours have a very small cabin that they use on occasional weekends (typically during nice weather). Currently, their only source of power is a 2000W Honda genset.

Recently they have been procurring quotes from local vendors for a solar/battery setup and I noticed both quotes were in the $12K-$13K USD range. Both quotes offered similar setups: 2.6kW and 3kV PV, 24V lead carbon battery bank (2 x Northstar NSB190FT Blue+ 12V and 4 x SWE6-420 from an unknown (to me) manufacturer), and one offered Conext electronics while the other Victron.

Now, I am far from an expert, but I was not impressed with either offering. Am I wrong to think the Northstar batteries are ****e telecom units? The other batteries look ok but I don't know who makes them. Also, wouldn't a 48V setup make more sense?

And on another completely different line of thinking, I'm tempted to suggest they forgo the PV altogether (for now), go to Costco or any place that sells cheapo lead acid batteries and buy the cheapest ones they can & just charge them with the generator because they will almost surely kill their first set of batteries well before their time so why spend a ton of money???

Thoughts?

[Mike90250]

Depending on the new solar owner's sense of involvement, that decides the expense/complexity of the system. Start with cheap flooded costco golfcart batteries. When they can get them to last 2+ years, then get the expensive batteries

Does it snow/accumulate snow there ?

If I was consulting to the new owner, and knew it was a weekend cabin, I'd strongly lean toward a small, 24V system of 6V 200ah golf cart batteries with about 500W (4) grid tie style panels hooked to a charge controller. if 24v @ 200ah s not enough storage, double it to 48V, but then it's not so much a hobby checking the water in all the batteries.

get a 24V 30A battery charger that can run off the generator, to recharge batteries in case of bad weather. And then hide as much as you can so the tweaker thieves don't steal the whole thing for a quick high.

[chrisski]

With the amount of work that would go into the build, I would think the price is correct if done correctly. There’s something to be said about not putting 12 months of your life into designing a system.

More important to me would be the vendor reviews. If the installers have been using those batteries for years with little complaints, than I would enjoy it.

My guess is that in the Pacific Northwest the system provides provides 2 kwh of power a day in the sunny winter days and perhaps 6kwh on a sunny day in the summer. That’s not a lot of power, but if that will keep the generator off most of the day, than it’s awesome.

My only concern is a 3kw size array might provide more power than the batteries can handle charging on a sunny day in the summer. That could easily be limited by the SCC.

[sidpost]

With no labor or transportation expense, for ~$3K, you can get 16x302Ah LiFeP04 batteries, a BMS, and racking. This will give you ~4.8KW/hr of usable storage since Lithiums can be discharged much lower than lead-acid batteries. You also don't have to monitor water, EQ, etc.

As for weekend 'fair weather' owners, I would be very hesitant to recommend common lead-acid batteries from someplace like Costco or Wal-mart.

The real question is, how much USABLE CAPACITY do the batteries in the quotes provide? Using the Honda genset to top-off the batteries in the Winter months is a great plan.

In terms of too much solar panel capacity in Summer, a good charge controller will just dump the excess power so no worries there. Of course, you are 'throwing away free power'.

[ron_jeremy]

With no labor or transportation expense, for ~$3K, you can get 16x302Ah LiFeP04 batteries, a BMS, and racking. This will give you ~4.8KW/hr of usable storage since Lithiums can be discharged much lower than lead-acid batteries. You also don't have to monitor water, EQ, etc.

LiFePO4 might not be the best choice considering temps can dip below 0C.

[ron_jeremy]

Depending on the new solar owner's sense of involvement, that decides the expense/complexity of the system. Start with cheap flooded costco golfcart batteries. When they can get them to last 2+ years, then get the expensive batteries

Does it snow/accumulate snow there ?

My thoughts, exactly. We don't see much, if any, snow here, but temps can dip down below 0C.

There’s something to be said about not putting 12 months of your life into designing a system.

Yes, they are realizing this now.

[checkthisout]

My wife and I live full time in a 'full blown' house (electric fridge, multiple tv's, washer, etc.) on an island in the Pacific Northwest. Our new neighbours have a very small cabin that they use on occasional weekends (typically during nice weather). Currently, their only source of power is a 2000W Honda genset.

Recently they have been procurring quotes from local vendors for a solar/battery setup and I noticed both quotes were in the $12K-$13K USD range. Both quotes offered similar setups: 2.6kW and 3kV PV, 24V lead carbon battery bank (2 x Northstar NSB190FT Blue+ 12V and 4 x SWE6-420 from an unknown (to me) manufacturer), and one offered Conext electronics while the other Victron.

Now, I am far from an expert, but I was not impressed with either offering. Am I wrong to think the Northstar batteries are ****e telecom units? The other batteries look ok but I don't know who makes them. Also, wouldn't a 48V setup make more sense?

And on another completely different line of thinking, I'm tempted to suggest they forgo the PV altogether (for now), go to Costco or any place that sells cheapo lead acid batteries and buy the cheapest ones they can & just charge them with the generator because they will almost surely kill their first set of batteries well before their time so why spend a ton of money???

Thoughts?

I live in the PNW. Between November last year and about mid Feb this year my 2430w system barely produced .1 to .2 kwh per day. If it rains, you basically get no juice and combine that with a short winter day and you need a gen.

The nice thing is the batteries greatly reduce gen run time and help save fuel, noise, fumes etc.

Inverter 600.00, batteries 800.00, transfer switch 100, solar cc 500, cables, fuses etc 500.00-1000.00. Panels probably $2000.00?

So Minimum 5k and that's using cheap batteries and doing all the labor yourself.

Rule of thumb if youre any kind of contractor is double materials cost to get your total cost so I think 10-13k is in the ballpark to hire someone to do it.

My parts cost is using Amazon stuff, not enterprise grade.