Resource guidance

[brianm1007]

My wife and I are building an off grid retirement homestead. We're building in eastern Tennessee. I'm looking for the best resources of reference material to help me with the project. I have a pretty good grasp on home electrical systems but no real experience with solar. I'm slowly learning the lingo but would like to do a deeper dive before making my first and hopefully last large purchase. I know there will always be things that either break or will need to be added. But for the most part, I don't want a starter system that I will outgrow before components age out.
Since I don't have the home built yet, I'm not sure how to tackle my energy needs. I may use my current electrical usage as a baseline. This should give me a way overbuilt system. I currently live in NJ, in a 100 year old home without very many efficient appliances or an efficient structure. My new home will be built with very efficient materials along with new appliances. I feel like this approach will accommodate the needs for our homestead. Deeper well, larger auxiliary buildings, and distance around the property to send electric and water. I plan on doing ground mount tracking arrays mixed with some stationary.
I've been watching a lot of Will's videos and I see that technology in this field changes at the speed of light. Which also means, there will always be something better coming out. I feel like I'm entering this arena at a pivotal time with the new solar panel technologies, battery designs and chemistry, and inverter abilities.
Long story long. What resources are the best to give me a leg up in this venture?

 

[DIYrich]

Plan for an expandable system. Then you can start small, and easily add more later. Ground mount makes expansion much easier. Waiting for the 12000xp would be a good start. Add two Powerpro batteries. I'm guessing start with 10kW of panels.

It may be big for a small house, or small for a big house. But, you need to oversize for off-grid. 3 days of batteries is the rule of thumb, and ability to recharge in one day.

28kWh of batteries is 9kWh per day, which is small. But easy to expand.

10kwh is oversize for 28kWh, but I'm guessing in the winter, not so much.

 

[stromy]

If you dont find anything else, here are some very rough rules of thumb as a start:
Estimate your yearly consumption. For this example i use 5000kWh.
There are various online "solar return calculators". You put in your location and panel orientations, and they give you some yearly return in kWh.
On an average location, with optimal angles, this might be 5000kWh per year for 5kWp panels. If you situation is different, adjust the following with a factor.

The first third of your needs can be had with solar only. Typical sizing would be 5kWp of panels for this example.
The second third of your needs can be had by adding a battery. Typical 5kWh battery, and another 5kWp of solar panels for this example.
The problem is with the last third: Typically, the most cost effective solution is to use a diesel generator. If you do not want that, you will have to "oversize" your panels by 10-20x, to have enough solar even in very cloudy winter conditions.

Tracking panels are a waste of money. Panels are so cheap, that it is usually more cost effective to just add more fixed mount panels.

Also note that building your own homestead grid requires a lot more thought than just connecting to the public grid. You will have to provide all the redundancy/reliability and electrical safety mechanisms yourself, that otherwise the grid would provide.

 

[Mattb4]

...
Long story long. What resources are the best to give me a leg up in this venture?

There are many online sources as well as books available for those getting a start. I would suggest reading the Forum here for real world perspective.

Many folks simply ask for a solution and spend no time in trying to understand the underlying fundamentals. They don't want to design their car they simply want to drive it. All well and fine if the car they buy meets their needs. However if they need to pull a 30 ft travel trailer the Prius was not a good choice. Ultimately you need to know the loads you intend to power before you can work out the supply.

One advantage to those that start off with a hobby solar setup is they get a feel for how it all works. This helps a great deal when it comes to building a more robust setup. As the saying goes, "it is hard to know what you do not know".

 

[brianm1007]

Plan for an expandable system. Then you can start small, and easily add more later. Ground mount makes expansion much easier. Waiting for the 12000xp would be a good start. Add two Powerpro batteries. I'm guessing start with 10kW of panels.

It may be big for a small house, or small for a big house. But, you need to oversize for off-grid. 3 days of batteries is the rule of thumb, and ability to recharge in one day.

28kWh of batteries is 9kWh per day, which is small. But easy to expand.

10kwh is oversize for 28kWh, but I'm guessing in the winter, not so much.

I was going back and forth with the 12kpv or the 18kpv. Last night I saw a video showing the 12xp. Seems like my timing is working out. The technology is advancing and becoming available just ahead of my build.

 

[brianm1007]

Plan for an expandable system. Then you can start small, and easily add more later. Ground mount makes expansion much easier. Waiting for the 12000xp would be a good start. Add two Powerpro batteries. I'm guessing start with 10kW of panels.

It may be big for a small house, or small for a big house. But, you need to oversize for off-grid. 3 days of batteries is the rule of thumb, and ability to recharge in one day.

28kWh of batteries is 9kWh per day, which is small. But easy to expand.

10kwh is oversize for 28kWh, but I'm guessing in the winter, not so much.

I don't mind adding on. My main concern was buying something and finding out that I have to replace the whole system. I believe in buy once, cry once. I figured that I'd over-build from the beginning since I know the property will develop and eventually use the full potential. The electric company wanted $35k just to run wire to my land. That didn't include poles or conduit. So dropping $20-30k on an overbuilt system is still a savings.

 

[DIYrich]

So dropping $20-30k on an overbuilt system is still a savings.

If you DIY, you might be able to get a small off grid system for that price, after tax credits.

Let's say 10kw of panels at $1.50 / watt, that is $15,000.
45 kwh of batteries is another $10,000.
Add inverter, backup generator, solar shed, ....

"Small" in that it provides 3 days of power with 1 day of production. But then power is free.

 

[Mattb4]

I don't mind adding on. My main concern was buying something and finding out that I have to replace the whole system. I believe in buy once, cry once. ...

Panels and batteries generally do not need to be replaced and can be added to. While it is a nice nickle philosophy to say, " buy once, cry once", in practical sense it really comes down to what you want to power and how much money you have to accomplish it.

 

[50ShadesOfDirt]

Actually, this forum has dozens of threads with the outlines of what you should think about for off-grid scenarios. Just search for off-grid, and poke through all the threads that come up.

I'll do some of the homework for you, and point at one of my own answers (shameless plug) to this common question:

Post in thread 'Your Ideal Offgrid New Construction Setup'

Jul 9, 2024

I'd go completely off-grid, and build in the redundancy ... everything ties into every stage of construction (plus, you have $30k to burn through, along with possible tax credit amount):

0. finish site planning ... where everything goes (roads, house, solar utility shed, septic, other desired structures)

1. put in roads (roadbase for now), get clearing done (firewise protection, fire road around perimeter of 10 acres) ... one bulldozer effort, done
- fire departments exist, but won't get to you quickly, so plan on your own response to things, until they get there

2. put in site propane...

• 50ShadesOfDirt

• 

But, there are many threads with useful info for you!

 

[brianm1007]

Panels and batteries generally do not need to be replaced and can be added to. While it is a nice nickle philosophy to say, " buy once, cry once", in practical sense it really comes down to what you want to power and how much money you have to accomplish it.

My point in that quote is that I don't want to buy a starter system. I expect to grow it eventually but I don't want to replace it before it ages out.