Where is Southern, Vermont?

Andover - specifically on terrible mountain.

I have a roof top solar system and a Tesla powerwall. Sun common installed it. Works great as a back up but it’s not capable of being completely off grid during winter months. I’m not super knowledgeable on what it would take to be totally off grid but probably a lot if you live a modern lifestyle. The main problem being the limited amounts of sun we get in the winter. Like I said depends on your lifestyle, needs and how you heat and cook in your home but you will most likely need a lot of batteries plus a large solar array to be completely off grid during the winter in VT. If you have a small cabin and just want the lights on it would be different. But using your dryer, refrigerator, wifi, tv and lights at the same time on an cloudy December day will require a lot of battery back up because the sun probably won’t provide enough energy to do it.

It usually takes a fuel powered generator to be completely off grid. Even with extra panels and a power wall for storage there are times that a generator is needed to augment what the sun can provide.

I would look carefully at augmenting your system with a wind turbine, and a generator that can operate 24/7 when the wind turbine gets blown off the mountain top.

If possible you probably still want to hook the house to the power grid. I know people with pretty large solar arrays that still don't make enough to power their house in the winter.

Running a house entirely on a generator is just stupid and bad for the environment. Don't do this just because you want to live a specific lifestyle

Makes sense. VT winter sun just isn’t sufficient

My understanding is that being off grid would require a huge amount of battery power and even then would often not provide sufficient power during winter.

That said, you can accumulate credits by selling power back to the grid to offset your winter bill. Friends up in Vergennes do just that—and pay next to nothing for electricity.

Thank you, all! This verifies for me that I have to be connected to the grid in order to have sustained living.

This is very doable if you’re willing to manage your power around the solstice or install a small standby generator. Any hybrid inverter will work, Sol-ark comes to mind first. It will manage your batteries and call on the generator only as a last resort.

Oops, try green mountain solar.

I’d steer clear of sun common and sun run, particularly for this type of installation.

Your best bet might be to get an electrician to do everything except the actual solar panel install.

Thank you! I will look into Sol-Ark just to understand what that can look like :)

As others have pointed out grid tie is the easiest. But it could very well cost more to get power up a mountain than it would to install the entire off grid setup.

Here’s the sol-ark 15kw, they make a 12kw that could work too. https://www.sol-ark.com/sol-ark-15k-all-in-one/

Catamount solar does off grid systems, they have a good reputation but I don’t know how far south they install. I would start there, it’s doable to be off grid on solar with enough battery space but if your goal is just to offset your usage a grid tied system is more practical. However there are arguments for being off grid with the incentives and cost/kW being changed constantly. The utilities have a chokehold on the legislature and they try their hardest to lobby against net metered solar all the time, it makes less and less sense every year.

Highly recommend the team at harvest star. They have the best prices around (unless you DIY) are knowledgeable, and do quality work. We are on the grid for now but when it’s time to add more solar we will use them again.

https://harvestarpower.com

Do you know of a local location company proficient in wind turbines for homes?

As others have said, you would need an intense battery set up and probably a big overkill on the panels themselves to make it through Thanksgiving-Valentine's Day (or maybe more). A backup generator would be a less-eco friendly but more budget friendly solution. If you're only powering maybe a fridge, lights and a television, you're going to get a lot further than if you're also doing laundry, vacuuming, cooking with an electric stove/kettle/microwave, using a hair dryer, dishwasher and electric hot water tank.

I looked into doing a battery backup on my small cabin's solar install but both companies I got quotes from told me 2 Tesla batteries would only keep my 800 square foot place powered for 2-3 days with extremely minimal or no usage of the heat pump and none of the "extras" - keeping it set to 40ish degrees or using the wood stove.

I will say it adds insult to injury that I get charged an "energy efficiency fee" by Green Mountain Power on the total kilowatts I use INCLUDING what I generate :/

Buddy of mine has 2 Tesla power walls and like 25 or 30 solar panels. He is still tied to the grid but that’s because he got the power walls for cheap thru GMP but they are allowed to pull from his power walls during peak times. That said if they were his alone I believe he could be 100% off grid with this setup. But obviously it depends on your exact setup. How much sun does your home get for your panels and how much power do you need on a daily basis.

You will still want to be tied to the grid as well, even if you fully own your power walls. You can sell the surplus power to GMP, but also during winter if your panels cannot produce enough power to charge your power walls,you can pull from the grid and still have power. And it will just consume some of the credit you have with the utility company. The only way to offset this need is to have extra panels, and extra power walls. But that means $$$.

I mean you don’t, but it’s just not cost effective as the required number of battery backups and panels required would be extremely expensive. If money is no object, it is possible.

Yup. 81 panels on our roof and winter makes it impossible to entertain unplugging from the grid.

You don't...but you do need to reconsider what "sustainable" "off-grid" life is going to be like.

As someone who lives off the grid in northern Vermont it is certainly possible even with relatively small number of solar panels and batteries and we only use the generator <5 hours a year if at all. It does require some additional thought both in the design of the house (like having the already highly efficient fridge and freezer in a cold space so it uses less energy in the winter) and procedural such as unplugging internet etc. when not using them. We do have a propane stove.

Though our system certainly works if you have grid power easily accessible I would recommend hooking onto that but still building and living in the house as if you were off grid to save energy.

If you have questions I would be happy to answer them.

residential-scale wind has improved tremendously recently; have you looked into a combination system?

I have not - but let me take a look. Thank you!

It absolutely can be done. I know of several people that do and will be there myself one day.

Using you funds in the smartest way possible means learning to conserve. It's the low hanging fruit. Plug strips/kill switches on everything, Kill-A-Watt meter to see what's the biggest draw, off grid (instead of "high efficiency") appliances, clothesline instead of dryer, etc.

I don't. Personally, I can count the number of people I know with home wind turbines on the fingers of no hands.

This interesting read might be a good place to start: https://www.nrel.gov/docs/fy07osti/41219.pdf

We had the largest array of panels that were legal along with 4 Tesla battery banks installed in our home. This system cost approximately 60k before tax incentives. In the summer we make %200+ the amount of electricity needed. These end up being tax credits later when you don't make enough. In December, January, February and even March there are days where we are only making %10 of what is needed. Having a tank in the ground that feeds a generator is the only way that we found that makes it capable of being completely off grid if we wished. To answer your question with everything available now, there isn't a viable option to be completely self sustaining and live a modern electric hungry life.

I looked at a full off grid solar vs bringing grid to cabin. Costs were roughly equal, I had to out in five poles and trench 100m. Ended up Going grid with intention of adding panels down the road to offset costs.

Costs being equal, ultimately there are a few things that dont do well with solar, hairdryers, toasters and certain powertools, and for me someday I’d like to put in a hot tub which you cant really do on battery power. To truly be off grid you generally will need to make some changes and sacrifices to things most people take for granted.

Having said all that we were fully off grid solar before and ran a generator to run tools and charge batteries when necessary in winter and it was not bad.

What Is the cost of poles?

One thing you may have a hard time getting a mortgage loan with off grid.

I literally JUST got off the phone with GMP and they gave a rough estimate of $5k to get the job done. We are right on Route 100, which makes the project easier from their perspective.

Good point on the mortgage loan!

You would be surprised how efficient it is to use the backup generator to fill batteries only when necessary. Takes less than an hour to top off a power wall from near empty and burns maybe 2 gallons of propane in the process. And it doesn't have to happen all that often.

It would help if you could explain your needs, solar exposure, personal electrical skills/DIY mindset, and financial requirements before anyone can really give you viable solutions.

If you're in anyway handy, I'd suggest watching vids by Will Prowse who wrote a book on this stuff and regularly posts videos about solar setups, inverters, batteries etc and does reviews for them, he goes from newbie level all the way to advanced stuff.

https://www.youtube.com/@WillProwse

I have a 16 panel solar array on the ground with 24 48-volt batteries inside my house . Using a Honda 6500 generator for the darker days and to top off the batteries . My house is not grid tied . I have an overbuilt system because I wanted to run things essentially as a regular, grid tied house would and account for any additional people in my house in the future . That being said I am still aware of what is running in my house at all times and there were a few things the inverter and system didn’t appreciate . ( like when I missed the specs on a new oven that said it was electric convection/fail ) I like the independence of my house but some days off grid life throws some wrenches . I would think about whether you have enough to sink into a system that will deliver the power to meet your needs or if not - what are you willing to sacrifice or adjust ? If your panels can’t deliver to meet your needs you may need a backup generator in the winter . If the panels are accessible you may want to get a long handled brush so you can remove the snow all winter . I would strongly recommend a high quality generator as it will need to run and you will likely hear it . The loudest generators known to man would ruin my quality of life in the woods but the Honda runs pretty quiet . Take in mind all the maintenance of these interconnected systems ; the inverter settings were a little complex initially to me, batteries such as the ones I have require regular watering . If inside - the battery array will need to be vented to the outdoors . If using a generator - it needs maintenance, oil changes, etc. also you will have to be hauling gas up ( unless it’s propane) Our system has worked flawlessly for the most part but it’s needed repairs and maintenance . In one case , we could not find anyone to do the repair. A fan blew on the inverter and the unit was overheating . Had to learn how to remove the tan and replace it myself . It was crazy but I managed to do it . I would say consider these issues and the cost and occasional difficulty in getting people to service the system . But hey if I could learn all this stuff I think anyone could . I appreciate people like you on the move to go solar and so does the earth.Good luck with your project .

Good to know! A decent solution if you're far from a grid tie in (especially now when running wire is so expensive - maybe even a good temporary solution while we hope and wait for the price of that to go down).

OP, the biggest issue you may run into with this build is almost every lender will require you to be on grid. I believe some people on this sub before have listed some smaller local banks that may fund a project like this.