Off Grid residential Living

[wulfraat]

We have an airstream which we have configured with Victron systems and solar - a bit of a prototype for small scale off grid living. We have 8.1kw (nominal) of lithium energy storage (600ah @ 13.5v) and 800w (0.8kw) of solar power generation in our 30'.

Ultimately the goal is to build our next residential home 100% off grid, fully self-sustaining energy-wise but will full residential amenities.

This could be a great solution for energy storage and delivery: Off Grid Power Container with Victron energy management components:

https://www.youtube.com/watch?time_c...&v=2Nfw_vDdpHc

• 120kw nominal lithium battery bank (15x what we have in the airstream - equates to 9,000ah @ 13.5v for comparison purposes - feels about right)
• 45kw inverter/charge leveraging multiple Quattros! (spot on power output capacity-wise - equivalent of 200A / 240v service residential = 48kw..... )
• 60kw solar inverters capacity (that's 60,000 watts of solar input capable - would be a nice sized array for sure)
• Grid Tie, off grid or hybrid configurable
• Grid or Genset bypass
• LTE mobile network enabled for remote monitoring (like my airstream)
• Fully packaged / drop shipped in a 10' insulated shipping container
• 2kw high efficiency air conditioner to keep equipment cool under loads / exterior heat

Any guess on the price tag for this big battery box?

I love this tech - what a clean install.

[GMFL]

I’ve thought about the possibility of taking an Airstream shell and building a portable power source for events. Pack the shell full of lithium batteries and and a huge inverter. Then build a roof rack that would allow for 2000 watts of solar on the roof.

No idea on the price of your planned system.....

[wulfraat]

I like it!.... as the $/kwh for lithium storage comes down every year, these solutions become more and more attractive!

[uncle_bob]

Hi

Had a friend who went pretty heavily (for the era) into low energy consumption design for a house outside Santa Fe NM. He did a very nice job and it worked pretty well. Ultimately employment forced a move and the house went up on the market. Recovering anything close to what it had cost to do turned out to be essentially impossible. After three years on the market (her in the house and him on the new job) they made a deal and moved out .....

Bob

[Daquenzer]

Ok. So the problem with off grid living is resale. I’m a professional real estate appraiser and do hundreds of lending appraisals a year. The issue is that most lenders want public hookups to at least electricity.

Below is the link to Fannie Mae standards. And remember they buy a lot of loans. And most lenders pretty much stick to these standards

https://www.fanniemae.com/content/gu...g/b2/3/01.html

You will note: “served by utilities that meet community standards.” That’s the key.

So if I was appraising your house and it was completely “off grid” the following problems would result:
1). They would require me to have a sale of a similar house that is off grid.
2). They would want me to show that an off grid house is not atypical in the market.

So all that money you put into being off grid, even though it’s cool and efficient, could be a major downer when you get to resale UNLESS someone came along and paid cash OR a bank would hold the loan in house and not try to sell on the secondary market.

Now things like solar energy etc has enough market acceptance in southern and sunny states that there is data out there. But most are still hooked up to public utilities as well. So before you get too far I would recommend to research your area to see if anyone has ever done it and has resold their property. Because in the appraisal world it’s all about the hard data.

But it’s a cool idea. Good luck. Hope it works for you.

And may I say I see people do lots of interesting things in the housing market. Lots of them get really burned however. The old adage that cost does not equal market value must be constantly remembered.

[PKI]

As with a trailer, the key to off grid power is conservation first and $s second. Spend your time researching how to eliminate energy use. Insulation, passive heat/cooling and similar design elements. University Prof built his house imbedded in a hill with south facing windows for passive winter heat. That was in the late 70s. Much better options now. Pat

Edit - The investment in clean and efficient off grid energy needs to represent a reasonable pay back. No difference from any residential specification. It all has to work.

[wulfraat]

Good info Daquenzer - appreciate the perspective for sure.

We are about 7yrs out perhaps. I am totally not opposed to being connected to the grid and your input definitely highlights advantages.

I think a grid tie system could be advantageous in that:

1. There is permanente and always on redundancy

2. We can live energy neutral and even sell energy back to the opco during periods of over production

3. With a system like the above with grid tie - we could (in theory) sell the building as-is (with grid connectivity) and take our 8x10 energy container with us to the next property or sell the asset separately on the secondary market. Solar panels too, maybe.

I’m just dreaming a bit - but it’s good to dream right? Less dependency on the grid means less pollution and a more sustainable planet perhaps.

[uncle_bob]

Originally Posted by wulfraat

Good info Daquenzer - appreciate the perspective for sure.

We are about 7yrs out perhaps. I am totally not opposed to being connected to the grid and your input definitely highlights advantages.

I think a grid tie system could be advantageous in that:

1. There is permanente and always on redundancy

2. We can live energy neutral and even sell energy back to the opco during periods of over production

3. With a system like the above with grid tie - we could (in theory) sell the building as-is (with grid connectivity) and take our 8x10 energy container with us to the next property or sell the asset separately on the secondary market. Solar panels too, maybe.

I’m just dreaming a bit - but it’s good to dream right? Less dependency on the grid means less pollution and a more sustainable planet perhaps.

Hi

Take a look at the rules on sell back with your utility. Some are getting pretty aggressive about how much they will accept. PA is not all that sunny. I have friends around here who have been told "can't do that" in terms of solar. I see a lot of windmills sitting idle, likely for the same sort of reasons.

Next gotcha is the charges for a rural electric line. If you have never put one in before, be ready for a shock. There are install fees and monthly upkeep fees that tack on to your bill. They are a very compelling reason to go off grid if you are far enough out. (yes, you have a resale problem ....).

Lots of twists and turns.

Bob

[pdavitt]

Originally Posted by wulfraat

We have an airstream which we have configured with Victron systems and solar - a bit of a prototype for small scale off grid living. We have 8.1kw (nominal) of lithium energy storage (600ah @ 13.5v) and 800w (0.8kw) of solar power generation in our 30'.

Ultimately the goal is to build our next residential home 100% off grid, fully self-sustaining energy-wise but will full residential amenities.

This could be a great solution for energy storage and delivery: Off Grid Power Container with Victron energy management components:

https://www.youtube.com/watch?time_c...&v=2Nfw_vDdpHc

• 120kw nominal lithium battery bank (15x what we have in the airstream - equates to 9,000ah @ 13.5v for comparison purposes - feels about right)
• 45kw inverter/charge leveraging multiple Quattros! (spot on power output capacity-wise - equivalent of 200A / 240v service residential = 48kw..... )
• 60kw solar inverters capacity (that's 60,000 watts of solar input capable - would be a nice sized array for sure)
• Grid Tie, off grid or hybrid configurable
• Grid or Genset bypass
• LTE mobile network enabled for remote monitoring (like my airstream)
• Fully packaged / drop shipped in a 10' insulated shipping container
• 2kw high efficiency air conditioner to keep equipment cool under loads / exterior heat

Any guess on the price tag for this big battery box?

I love this tech - what a clean install.

I live in an off grid house in West Texas, but I did not start out looking to go "alternative energy". Until, as some one else mentioned, I got the estimate from the power company to run service to my new house.
At that point I decided to look into Solar Power, not from a "Tree Hugger" standpoint, but from an Economic one. After crunching the numbers, it was more economical to go Solar, especially with the 30% tax credit.

Though I would share some thoughts:

1. For a large system, hire an "Independent" Solar Engineer to design and supervise the installation. They are out there and will save you money, time, and disappointments.
2. If you are going "Grid Tied", let the Engineer consult with the power company and regulators to design a system that meets their requirements.
3. Consider using propane for your heavy power needs (Water Heater, Clothes Dryer, Furnace, Stove, etc.), I have a 500 gallon tank.
4. Air Conditioning is the 500lb. gorilla in the room. I would have had to at least double my Solar system to provide power for air conditioning. Which I chose not to do. Been it the house for over seven years and have not regretted the decision.
5. I hate to say it, but Victron does not have a heavy presence in the US for large, home systems. I love their equipment, but in the US, especially if you are going "grid tied", I would consider Outback Power, Magnum, or other US manufacturers. Not from a quality standpoint, but from a regulatory compliance standpoint.
6. Consider Flooded Lead Acid batteries for a fixed home installation. I have two 48V 1,000Ah "Fork Lift" batteries that weigh 3,300lbs. apiece but only cost $16K USD for the two of them. Mine have been in service for seven years and show no signs of wearing out. The cells are balanced and show near new specific gravity. Plus you can refresh the sulfuric acid if needed.

Just wanted to share,

Pat

[uncle_bob]

Hi

If you *do* run into the A/C "gorilla" looking at full off grid - there are a lot of very interesting (and efficient) single room systems out there. They originally were targeted at "the rest of the world" that does not do A/C the "whole house" way we do in the US. Might be useful for those nights when the low is 85 degrees and the humidity is also 85 . Yes, it depends a *lot* on exactly where you are.

Bob

[wulfraat]

Lots of great insights here - my wheels are starting to turn and I appreciate everyone’s experience and perspective.

[OTRA15]

Great thread, thanks for starting!

Peter

[youngpeck]

Of course, for air conditioning in dry climates there is the old-fashioned "swamp cooler" or evaporative cooler. Sadly, not seen so much anymore on new installations. We loved ours in Salt Lake City to cool a 4000 square-foot, intelligently designed house and loved also having the windows open. It used less than 1 amp of electricity to run the fan as opposed to over 20 for a comparable compressor-based refrigerative system. It doesn't work as well, of course, when the humidity is over 50%. But we would use one again when living in the western U.S.