Connecting off grid homestead to the grid--am I crazy?

[zanydroid]

Oh the $500 likely assumes local pickup or sharing a pallet with a friend. I doubt you can get 5-6 panels delivered for $500.

 

[Checkthisout]

I'll be reaching out to the utility company soon asking for quotes for a new service at the road, and I can ask about other options.

Perhaps I don't fully understand, but I don't see how running conduit and having the utility company pull wire through it could possibly be cheaper than a $1200 triplex 2 AWG direct burial for a 30 amp service. I mean, the conduit alone must cost $1/foot at least. But, never hurts to ask I guess.

For reference, my parents were recently quoted $40,000 to run service 1200' down their driveway. They decided to go off grid with a real beefy system for about the same price.

They might do it for free.

Excavation is the biggest part of the deal. If you're allowed to dig your own trench and set conduit, all they have to do is pull wire, set transformer and wire it up to the meter.

This grid connection will up the property value and provide a return on investment should you sell and also be much easier to deal with as you get older.

Solar living requires maintenance, care and awareness. Grid connection does not.

 

[Checkthisout]

Your idea of installing too small of a service and then using the batteries/inverter like a cistern in a low flow well system is fine on a property that already has service and you're maybe trying to do an outbuilding or something but doesn't make financial or end result sense when you can just do a bit more work and get a full grid connection.

 

[Doggydogworld]

.... I think I can do it for $0.50/W, bringing cost of power down to $0.01/kWh (amortized over 20 years.)

Can you share your math? I figure in a good location you get 1.5 kWh per year from each installed 50 cent Wp of capacity. That's 30 kWh of juice over 20 years for a simple cost of 1.67 cents/kWh. When I include cost of money and panel degradation over those 20 years I get 2.5+ cents/kWh.

Lithium batteries are around $0.05/kWh (amortized over cycle life.)

Yes, if you can get 5000 full cycles of usage before they age out. That's 14 years of full daily cycling. If you size them for dark winter days you'll get maybe 100 full cycle equivalents per year. If calendar life is 15 years your simple cost rises to 17 cents/kWh. Well over 20 cents with cost of money.

 

[halfmoonhomestead]

Your idea of installing too small of a service and then using the batteries/inverter like a cistern in a low flow well system is fine on a property that already has service and you're maybe trying to do an outbuilding or something but doesn't make financial or end result sense when you can just do a bit more work and get a full grid connection.

Yep, I see where you're coming from. Always better to oversize and future-proof when possible.

A bit of research shows that the minimum conduit size for 100A service is 2". 2" schedule-40 conduit is $2.70/foot, so $2160 for 800 feet, not including the glue, elbows, etc. Plus... it's a lot more work to lay conduit than to throw a bendable wire into the ground. If I come across a rock while digging my trench, laying that conduit is gonna be a challenge.

I'm also not crazy about having a utility-owned transformer and wire run coming right up to our doorstep.

Resale value has no importance to us, as we plan to live here the rest of our lives. If anything, let's keep that tax assessment as low as possible!

 

[zanydroid]

Yes, if you can get 5000 full cycles of usage before they age out. That's 14 years of full daily cycling. If you size them for dark winter days you'll get maybe 100 full cycle equivalents per year. If calendar life is 15 years your simple cost rises to 17 cents/kWh. Well over 20 cents with cost of money.

I don't think anyone knows if LFP calendar life is going to be a cliff or more gradual. I doubt every cell will die at the same time, though maybe one of the cells will die and the battery is not equipped with cell bypass / inverter not capable of handling flexible input voltages once cells start being bypassed. If ESS are designed properly to eek out the last bit of lifespan out of each cell, or someone is willing to do surgery you could probably get a lot more years out of it, especially lightly cycled.

Now for a very simple, forklift replace, servicing model I think the simple calendar life model makes sense.

 

[Texican]

Wow - how can you come up with a 2kW PV array for $500 let alone less? I'd love to find that kind of deal.

when I get the new 305w panels on backorder I will be selling about 5kw of used 250w and 240w panels for probably about 10 cents/watt, so $500 maybe $600. the new 305w were 28 cents watt I think.
used 250w panels from private parties will end up dirt cheap
I could just make another ground mount but mine are beefy ironridge and cost at least 2k for diy

 

[Checkthisout]

Yep, I see where you're coming from. Always better to oversize and future-proof when possible.

A bit of research shows that the minimum conduit size for 100A service is 2". 2" schedule-40 conduit is $2.70/foot, so $2160 for 800 feet, not including the glue, elbows, etc. Plus... it's a lot more work to lay conduit than to throw a bendable wire into the ground. If I come across a rock while digging my trench, laying that conduit is gonna be a challenge.

I'm also not crazy about having a utility-owned transformer and wire run coming right up to our doorstep.

Resale value has no importance to us, as we plan to live here the rest of our lives. If anything, let's keep that tax assessment as low as possible!

And when the inevitable health problems crop up, who's going to keep the solar system going as well as future battery replacements etc.

You'll want conduit even with the minimal service you're planning on. It's a one-time cost.

I'm just one idiot with an opinion though.

If the cost of conduit is going to kill you then solar will not work for you either.

 

[Checkthisout]

My own personal off-grid system.

3k Multiplus, backup gen, 305 ah 24v battery, 2400 watt array.

All this stuff I got for a steal, used etc.

With wiring etc I'm at $5000.00. That's self-building a battery, self-modified self start generator etc.

I am without question off-grid with grid power as no option but if the grid was close it's a no-brainer.

 

[zanydroid]

when I get the new 305w panels on backorder I will be selling about 5kw of used 250w and 240w panels for probably about 10 cents/watt, so $500 maybe $600. the new 305w were 28 cents watt I think.
used 250w panels from private parties will end up dirt cheap
I could just make another ground mount but mine are beefy ironridge and cost at least 2k for diy

Today it's dirt cheap, tomorrow it's going to be a tsunami of bulk e-waste when all the tryhard DIYers have as many panels as they need :laugh:

At least it's relatively non-toxic.

 

[Hedges]

Can you share your math? I figure in a good location you get 1.5 kWh per year from each installed 50 cent Wp of capacity. That's 30 kWh of juice over 20 years for a simple cost of 1.67 cents/kWh. When I include cost of money and panel degradation over those 20 years I get 2.5+ cents/kWh.

Yes, if you can get 5000 full cycles of usage before they age out. That's 14 years of full daily cycling. If you size them for dark winter days you'll get maybe 100 full cycle equivalents per year. If calendar life is 15 years your simple cost rises to 17 cents/kWh. Well over 20 cents with cost of money.

I agree with both your points and math.

The cheaper kWh is with cheaper PV panels. I just bought pallets of new panels for $0.17/W delivered (maybe that was $0.19 with some fees and taxes.) I said "amortized" to mean I ignored time-value of money (which seemed valid a couple years ago.)

Inverters are going to cost me more now that I need to buy the new Sunny Boy Smart Energy. I had seen Sunny Boys around $0.20/W. I managed to pick up one SB -41 for about $0.04/W. Mostly, it is older models not allowed for new systems that I got cheaper.

Same figures as yours for battery. You only get the $0.05/kWh price if you deeply cycle them every night. You could use a generator for cloudy days, but those cost $1.00/kWh and require maintenance, so I'd favor bigger battery.

I have AGM ($0.50/kWh) sized for one night. Grid-backup, so I don't anticipate exceeding 20% of cycle life during float life, so $2.50/kWh. But that's for the power I use at night during grid outages. Most of my power would be PV-direct, like A/C. That's when the grid is down. Most of the time, it is a net metering system, good so long as NEM 1.0 holds out.