Do you have enough solar to go off grid in winter?

[sunwarriors]

Very expensive to use typical generators. Direct fuel cost is typically 50¢ to $1/kWh. Small generators (propane or gasoline) usually have a useful life of 1,000 to 3,000 hours before uneconomic rebuild or replacement. Oil change every 50-100 hours.

Industrial diesel generators last much longer and are more efficient. Figure over $10 grand.

In some places (not many) wind may be able to supplement solar. Last time I looked residential wind equipment was not reliable or economic. The vast majority of residential wind turbines are merely kinetic sculptures.

YMMV

I live totally off grid and gave up using generators years ago.

Since you're totally off grid currently, what do you do? I don't think I mind the industrial diesel generator neither nor cost if it's at least something that's known/almost guaranteed to reliably work, sorta like the current energy grid as no one with minimal means is expected to be able to do this to begin with.

I'm generally less concerned with cost as this is more of a thought experiment/proof of concept in my mind. It's not about ROI at all since I know having a single fuel source (solar, wind, etc...) is never going to be a solution to this.

I would be curious to know typically how long it takes to run a generator to fully charge batteries if anyone has it working. May have to look for any Enphase installs or ask them.


I don't think vertical solar panels or hanging panels on a fence, wall, backyard is very practical for a non-camping solution in most households. Wiring it all will be a pain and a cable mess everywhere I would imagine.

nwdiver, is your fence bolted panels tied into the rest of your house and did it have to get approved?

 

[nwdiver]

nwdiver, is your fence bolted panels tied into the rest of your house and did it have to get approved?

It's a wall not a fence. A fence might work but a rigid surface would probably be better. It's tied into the house via DC lines.

The system I did last year was inspected just fine. There's no reason this would be any different than a ground mount. In some ways it's better. We had to 'scrim' one ground mount we did to 'protect' the PV wiring, this wouldn't be necessary if the panels are mounted on a wall.

 

[Grayson73]

Not many people have 1:1 net metering anymore or yearly netting. Almost every utility has changed that for their own benefit and if people do have it, it is a legacy grandfathered plan.

Interesting! I hope Maryland doesn't change!

 

[nwdiver]

Swiss consortium switches on 325 kW vertical PV system on retaining wall​

Solar Walls. The new roof-top solar

 

[iPlug]

Swiss consortium switches on 325 kW vertical PV system on retaining wall​

Solar Walls. The new roof-top solar

View attachment 995635

Even better efficiency with the heat sink effect of the retaining wall.

 

[dho112]

Yes, But...

9.6Kw +1 Powerwall+

I have to be a bit stingy in the evenings and monitor the best times to charge the car... My houses' "heartbeat" energy usage is .4-.6Kw and if I am proactive about things like not using the clothes dryer or oven or dishwasher etc after the sun goes down and the house is on battery, I can just make it to morning when the house goes back on solar and starts charging the battery.

Keep in mind that this doesn't mean that I have to go "apocalypse" mode in trying to conserve battery I still can have the majority of the lights on and multiple TVs going and my computers on etc... Just no heavy appliance until solar can start supplementing during the day.

Details of my situation help me though since all my panels are facing south and get sunlight from sunrise to sunset, I'm in California and our deep winter forecasts are typically sunny-partly sunny 60-75 degrees.

During spring/summer/fall it's a cinch, and with just a tiny amount of care I can be off grid for months at a time. I've decided though it's more relaxing to not have to think about usage and then get a small/moderate check back from PG&E every year, then it is to constantly monitor and micromanage everything and get a big check at True-Up. As long as NEM credit is positive (money back) in any amount; I'm good. The near zero electric bill every month compared to the previous $400-500 pre-solar/storage electric bill each represents the HUGE percentage of the savings anyway.

 

[SageBrush]

9.6Kw +1 Powerwall+

The near zero electric bill every month compared to the previous $400-500 pre-solar/storage electric bill each represents the HUGE percentage of the savings anyway

Interesting post, thanks. How much did you pay for the PV + battery (installed) after tax credits ?

 

[Jeremy3292]

I know this is a long thread and many topics have been discussed at length already, but I don't see how anyone could realistically have enough solar and Powerwalls to go off grid in the winter. If you live in an ideal temperate climate with lots of sun, like maybe south Florida, and have spent a lot of money on numerous Powerwalls and lots of solar, then I would think that maybe could work and you could just "ride out" the cloudy days.

But even for me in South Carolina, which is still pretty far south relatively to many others, there's no way I could have enough solar and Powerwalls to go off grid in the winter, unless I was very rich and had plenty of space for a ground mounted solar array. We are almost at the winter solstice now and man there just isn't enough daylight without something asinine like 30 kW+ of solar panels and 7-8+ Powerwalls. Even then with 3 cloudy days in a row your Powerwalls are likely empty, which isn't that crazy as it is pretty cloudy and rainy during the winter.

This is likely why most of this thread has been about using some sort of oil based product or maybe using a wood stove, but that requires A LOT of wood. Using oil based products is the same as just being on the grid IMO and unless you are a lumberjack with a large tract of wooded land, you'll run out of wood eventually too.

Solar + Powerwalls are awesome but like everything in life it has its limits.

 

[bkp_duke]

I know this is a long thread and many topics have been discussed at length already, but I don't see how anyone could realistically have enough solar and Powerwalls to go off grid in the winter. If you live in an ideal temperate climate with lots of sun, like maybe south Florida, and have spent a lot of money on numerous Powerwalls and lots of solar, then I would think that maybe could work and you could just "ride out" the cloudy days.

But even for me in South Carolina, which is still pretty far south relatively to many others, there's no way I could have enough solar and Powerwalls to go off grid in the winter, unless I was very rich and had plenty of space for a ground mounted solar array. We are almost at the winter solstice now and man there just isn't enough daylight without something asinine like 30 kW+ of solar panels and 7-8+ Powerwalls. Even then with 3 cloudy days in a row your Powerwalls are likely empty, which isn't that crazy as it is pretty cloudy and rainy during the winter.

This is likely why most of this thread has been about using some sort of oil based product or maybe using a wood stove, but that requires A LOT of wood. Using oil based products is the same as just being on the grid IMO and unless you are a lumberjack with a large tract of wooded land, you'll run out of wood eventually too.

Solar + Powerwalls are awesome but like everything in life it has its limits.

I was thinking of this just last night, and there is a GAME changer which most of us have not yet considered.

Cybertruck. I has full V2G, a 120+ kWh battery back, and interfaces with the proper V3 wall charger to powerwalls to allow it to work with the Tesla Gateway to dump power into your home.


In my case, that would mean I just got enough backup power supply to more than triple my power reserves (4 x 13.5kWh PW2 = 50 kWh) for a long winter.

And, if the truck battery is running low . . . and only in a pinch mind you . . . run down to the local supercharger and fill that battery up.

With Cybertruck, you now have a VERY large, portable, bi-directional power source.

 

[wwu123]

I know this is a long thread and many topics have been discussed at length already, but I don't see how anyone could realistically have enough solar and Powerwalls to go off grid in the winter. If you live in an ideal temperate climate with lots of sun, like maybe south Florida, and have spent a lot of money on numerous Powerwalls and lots of solar, then I would think that maybe could work and you could just "ride out" the cloudy days.

Outside of the most temperate climate zones, I think it could also be possible if the site and house were designed towards net zero, e.g. things like passive solar, earth berms, insulated foundations, SIPS walls, etc. Those would mitigate heating, cooling, and lighting energy needs substantially, that it could be possible. But you'd need an appropriate site, and also can't retrofit an existing house - so yeah, not realistic for the overwhelming majority.

 

[RKCRLR]

This is likely why most of this thread has been about using some sort of oil based product or maybe using a wood stove, but that requires A LOT of wood. Using oil based products is the same as just being on the grid IMO and unless you are a lumberjack with a large tract of wooded land, you'll run out of wood eventually too.

I have a wood stove that I use when the high is predicted to be below 60F. I have a lot of trees that go down throughout the year (I'm behind cutting them up right now). If I wasn't burning them in my wood stove I'd be burning them in a pile. But even if I completely relied on the wood stove for heat I still wouldn't be able to make it through the winter on just solar.

 

[Jeremy3292]

I was thinking of this just last night, and there is a GAME changer which most of us have not yet considered.

Cybertruck. I has full V2G, a 120+ kWh battery back, and interfaces with the proper V3 wall charger to powerwalls to allow it to work with the Tesla Gateway to dump power into your home.


In my case, that would mean I just got enough backup power supply to more than triple my power reserves (4 x 13.5kWh PW2 = 50 kWh) for a long winter.

And, if the truck battery is running low . . . and only in a pinch mind you . . . run down to the local supercharger and fill that battery up.

With Cybertruck, you now have a VERY large, portable, bi-directional power source.

The base Cybertruck is around $65k all in and not available until 2025 and has a smaller battery pack than 120 kWh I do believe. The premium models are $80k to $100k, so either way I'm not sure that capital outlay makes much sense in attempt to be "off grid" in the winter. I still don't think it will work as you have to drive and use the vehicle, unless your plan is to have it sit as a simple battery brick (lol), which I still don't think that will work either.

Additionally, 9 Powerwalls gives you the same battery capacity as an $80k Cybertruck and costs less than that on a gross and net basis (30% federal tax credit on Powerwalls). So we arrive back at the same question.

The Cybertruck could be a great addition to your arsenal if you want to own one but it doesn't solve any of the winter issues this 11 page thread is about.

Like I said if you have enough money in life you can do anything, but it is not realistic for most people, even those that are upper middle class.

 

[bkp_duke]

The base Cybertruck is around $65k all in and not available until 2025 and has a smaller battery pack than 120 kWh I do believe. The premium models are $80k to $100k, so either way I'm not sure that capital outlay makes much sense in attempt to be "off grid" in the winter. I still don't think it will work as you have to drive and use the vehicle, unless your plan is to have it sit as a simple battery brick (lol), which I still don't think that will work either.

Additionally, 9 Powerwalls gives you the same battery capacity as an $80k Cybertruck and costs less than that on a gross and net basis (30% federal tax credit on Powerwalls). So we arrive back at the same question.

The Cybertruck could be a great addition to your arsenal if you want to own one but it doesn't solve any of the winter issues this 11 page thread is about.

Like I said if you have enough money in life you can do anything, but it is not realistic for most people, even those that are upper middle class.

I think you are missing my point.

CT is most likely the FIRST of many Tesla products to have this functionality. And I'm not saying it should REPLACE Powerwalls. I think it is a kick-ass supplement to them.

I have a Model 3 and Y in my garage, and 4 powerwalls. I would love to be able, in a pinch, plug the 3 or Y into the charger and have them provide house power when the powerwalls are getting low.


It's not to replace powerwalls, it's to supplement them.

With 4 PW2s, I can cover 98% of our usage cases through out the year. The last 2% is a big hurdle, and buying 5 more powerwalls for that use case would not pencil out. But if I already have a car that I could plugin and get us through those 1-2 weeks a year where the powerwalls+solar are not sufficient, then that adds a lot more value to the auto purchase. Especially here in Cali where the utilities are like the mafia and now want to charge you $180/mo just to be connected to their grid (F that).

 

[Jeremy3292]

I think you are missing my point.

CT is most likely the FIRST of many Tesla products to have this functionality. And I'm not saying it should REPLACE Powerwalls. I think it is a kick-ass supplement to them.

I have a Model 3 and Y in my garage, and 4 powerwalls. I would love to be able, in a pinch, plug the 3 or Y into the charger and have them provide house power when the powerwalls are getting low.


It's not to replace powerwalls, it's to supplement them.

With 4 PW2s, I can cover 98% of our usage cases through out the year. The last 2% is a big hurdle, and buying 5 more powerwalls for that use case would not pencil out. But if I already have a car that I could plugin and get us through those 1-2 weeks a year where the powerwalls+solar are not sufficient, then that adds a lot more value to the auto purchase. Especially here in Cali where the utilities are like the mafia and now want to charge you $180/mo just to be connected to their grid (F that).

Gotcha, understood. I agree this is likely something that will be available in the future on all new Tesla vehicles, but current vehicles likely lack the hardware to do it right now. When I am in the market for a new Tesla in 5 years or so, I hope it has V2H/V2L too!

 

[doghousePVD]

I know this is a long thread and many topics have been discussed at length already, but I don't see how anyone could realistically have enough solar and Powerwalls to go off grid in the winter. If you live in an ideal temperate climate with lots of sun, like maybe south Florida, and have spent a lot of money on numerous Powerwalls and lots of solar, then I would think that maybe could work and you could just "ride out" the cloudy days.

But even for me in South Carolina, which is still pretty far south relatively to many others, there's no way I could have enough solar and Powerwalls to go off grid in the winter, unless I was very rich and had plenty of space for a ground mounted solar array. We are almost at the winter solstice now and man there just isn't enough daylight without something asinine like 30 kW+ of solar panels and 7-8+ Powerwalls. Even then with 3 cloudy days in a row your Powerwalls are likely empty, which isn't that crazy as it is pretty cloudy and rainy during the winter.

This is likely why most of this thread has been about using some sort of oil based product or maybe using a wood stove, but that requires A LOT of wood. Using oil based products is the same as just being on the grid IMO and unless you are a lumberjack with a large tract of wooded land, you'll run out of wood eventually too.

Solar + Powerwalls are awesome but like everything in life it has its limits.

I live off grid year round in Maine just off my solar panels. I don’t have a generator. It takes one work, but it is lifestyle we love.

99% of my cooking is electric. Heat is wood and passive solar. Hot water is a combination of electric and wood.

My land has a lot of dead falls. I can’t burn it as fast as it falls.

 

[sunwarriors]

I know this is a long thread and many topics have been discussed at length already, but I don't see how anyone could realistically have enough solar and Powerwalls to go off grid in the winter. If you live in an ideal temperate climate with lots of sun, like maybe south Florida, and have spent a lot of money on numerous Powerwalls and lots of solar, then I would think that maybe could work and you could just "ride out" the cloudy days.

But even for me in South Carolina, which is still pretty far south relatively to many others, there's no way I could have enough solar and Powerwalls to go off grid in the winter, unless I was very rich and had plenty of space for a ground mounted solar array. We are almost at the winter solstice now and man there just isn't enough daylight without something asinine like 30 kW+ of solar panels and 7-8+ Powerwalls. Even then with 3 cloudy days in a row your Powerwalls are likely empty, which isn't that crazy as it is pretty cloudy and rainy during the winter.

This is likely why most of this thread has been about using some sort of oil based product or maybe using a wood stove, but that requires A LOT of wood. Using oil based products is the same as just being on the grid IMO and unless you are a lumberjack with a large tract of wooded land, you'll run out of wood eventually too.

Solar + Powerwalls are awesome but like everything in life it has its limits.

This is why I'm all for the generator solution which already exists. I only have 20kWh batteries, but I consume around 20kWh a day (not counting any solar generation), so with no sun, it's a 1 day and done deal. For most suburban homes with limited roof space, it's not possible to even scale more panels for limited sun/cloudy days. In regular cool, fall/spring days, I think a lot of people can go solar/storage already. One also needs to watch out for fire danger with clouds blocking solar.

Generator already works to recharge batteries now (one can find videos on youtube):

Generator support | Enphase

Seamless resilience during extended grid outages. Enphase generator support and documentation.

enphase.com

I've stated this before on this thread, so the problem is still no solar for multiple days so another energy source is definitely required. I don't know how long a large generator will need to be ran to fully recharge say, 40 kWh of batteries.


V2H/V2G is coming in 2024:

Enphase Bidirectional EV Charger | Enphase

enphase.com

If this works with my existing equipment, I may seriously look into buying their V2G charger/box/whatever is needed. With say a 100kWh car, that's like another 5 days for me so yeah, I can probably do it at that time, but I would still also buy a generator too since energy diversification is a good thing. Bad thing with generators are noise, cost, maintenance (too many moving parts) and it'll probably break, have to be ran regularly.

Overall, my idea is not to even avoid oil based products, but at least make it possible. Of course, all this is not about ANY ROI so toss that out the door. I didn't even get batteries expecting any ROI and wouldn't expect any with these things. Just sorta neat if possible.

 

[Jeremy3292]

I live off grid year round in Maine just off my solar panels. I don’t have a generator. It takes one work, but it is lifestyle we love.

99% of my cooking is electric. Heat is wood and passive solar. Hot water is a combination of electric and wood.

My land has a lot of dead falls. I can’t burn it as fast as it falls.

How much energy do you consume daily? How big is your home?

Lots of variables here but if you're in a small cabin in Maine like I'm picturing then it is possible, but not realistic like I said for most people.

 

[getakey]

I don't think EVs to power house are the answer. First of all, they recommend only charging battery to 80% unless you need the range. And, in my case, I wait until it is down to 40% or 50% to recharge it. So for unexpcted outages, the EV battery is likely well below capacity. I guess you could go fast charge it somewhere if the chargers have power

 

[SageBrush]

but I don't see how anyone could realistically have enough solar and Powerwalls to go off grid in the winter

The internet is chock full of 'off-grid' living experiences that typically but not always have fossil back-up. I think it then becomes a question of how much of their lifestyle is powered by PV/battery, rather than a black or white question

 

[doghousePVD]

How much energy do you consume daily? How big is your home?

Lots of variables here but if you're in a small cabin in Maine like I'm picturing then it is possible, but not realistic like I said for most people.

My home is about 2700 sq ft, 5 bedrooms. The old section is a 100+ year old farmhouse, to which we added sprayed insulation and (in hindsight sub-optimal) double paned windows about 20 years ago. We built a new section built to passifhaus standards for our bedroom and indoor shower, toilet and sauna.