Need Design Advice! Building a brand new 2300sq ft 100% off grid

[evotech]

I am in the design phase of a 100% off grid home to be built in San Diego. I am a DIY guy to my core. Building this home will be my first project in retirement. I spent the last month teaching myself autocad to design the home. So far so good. Now come the choices for energy. This is not a cabin and I am not looking to rough it. AC is a must. I was thinking split units. I designed in a giant south facing roof with room for all the solar I want. Heat should not be too much of a concern due to the temperate climate. Looking for any advice I can get from those who have gone before me. Should I consider propane for stove, dryer, and heat to relieve some of the solar requirements? Any advice is appreciated.

 

[Craig]

I would use propane for dryer I think that if you have enough power for AC the stove would not be a problem. Have you calculated your watt hour needs running your AC and other essential Items.

I like your project. Getting enough solar power will not be a problem however storing all that energy is what is going to cost a few bucks.

 

[evotech]

I would use propane for dryer I think that if you have enough power for AC the stove would not be a problem. Have you calculated your watt hour needs running your AC and other essential Items.

I like your project. Getting enough solar power will not be a problem however storing all that energy is what is going to cost a few bucks.

I am currently using about 30KWH a month but that is with old inefficient appliances in a 100-year-old home in New York. So it is hard to estimate what it will be like in a new energy-efficient home in San Diego with energy star appliances. I am prepared to spend what I need to get the job done albeit from a DIY perspective not a Tesla one. Although, I can't lie ....the 30% reduction in price on the V3 tesla roof option does make it appealing and for some unexplained reason, the calculator on the website shows the cost of 2 tesla powerwalls at 9K installed after incentives and 11K for three! That can't be right.

 

[Steve_S]

Interesting. I just updated my profile which includes info about my hyper efficient build , links to info and more...
If your interested have a peak here: https://diysolarforum.com/index.php?members/steve_s.1720/#about

 

[Craig]

I am currently using about 30KWH a month but that is with old inefficient appliances in a 100-year-old home in New York. So it is hard to estimate what it will be like in a new energy-efficient home in San Diego with energy star appliances. I am prepared to spend what I need to get the job done albeit from a DIY perspective not a Tesla one. Although, I can't lie ....the 30% reduction in price on the V3 tesla roof option does make it appealing and for some unexplained reason, the calculator on the website shows the cost of 2 tesla powerwalls at 9K installed after incentives and 11K for three! That can't be right.

I have been told there are no rebates if you are 100% off grid. But that was by an electrician friend of mine so it's just hearsay. I bet if you are willing to do some testing and wait a month for delivery you can build your battery 12kw bank with lifepo4 for about $4.5k or even less. If you are ok with DIY which it seems like you are then this should be a rewarding experience. Are you sure about only using 30kw that seems low my computer alone runs 30kw a month.

 

[Steve_S]

I have been told there are no rebates if you are 100% off grid. But that was by an electrician friend of mine so it's just hearsay. I bet if you are willing to do some testing and wait a month for delivery you can build your battery 12kw bank with lifepo4 for about $4.5k or even less. If you are ok with DIY which it seems like you are then this should be a rewarding experience. Are you sure about only using 30kw that seems low my computer alone runs 30kw a month.

I know that here in my Province, you get no rebates etc if off-grid. Rebates are only qualified to grid connected systems, whether they have their own batteries or not. You will have to check with your local governments & see what is available in your are and what conditions they have.

 

[Stiffmeister]

I'm also doing 100% off grid in Cabo San Lucas. Starting with a garage for storage/hurricane protection. Regarding Tesla, I recommend calling them directly when you are ready. Installers up here tried to rip my parents off with their installation fees (they know you get rebates). I think Tesla/solar grid tied would be best for you unless your're in BFE. PG&E has time of use now and jacks up their rates from 3-8pm. Using battery during those times (up here) is how you get your money back plus our blackouts now

If you're hell bent on 100% off grid, there are a few of us rolling the dice on extremely cheap LiFePO4 batteries. I have 2 80 amp charge controllers, 30 300watt panels and a 7.2k Outback inverter. Energy storage is the key here and I don't want to have to worry about running out of power. It's not uncommon for people to get a $1k-$2k power bill in Cabo due to AC. Not sure why you would retire in CA now but good luck. I'm outta this state (PG&E burned my town down and I lost everything but my truck...which is melted).

 

[Craig]

I'm also doing 100% off grid in Cabo San Lucas. Starting with a garage for storage/hurricane protection. Regarding Tesla, I recommend calling them directly when you are ready. Installers up here tried to rip my parents off with their installation fees (they know you get rebates). I think Tesla/solar grid tied would be best for you unless your're in BFE. PG&E has time of use now and jacks up their rates from 3-8pm. Using battery during those times (up here) is how you get your money back plus our blackouts now

If you're hell bent on 100% off grid, there are a few of us rolling the dice on extremely cheap LiFePO4 batteries. I have 2 80 amp charge controllers, 30 300watt panels and a 7.2k Outback inverter. Energy storage is the key here and I don't want to have to worry about running out of power. It's not uncommon for people to get a $1k-$2k power bill in Cabo due to AC. Not sure why you would retire in CA now but good luck. I'm outta this state (PG&E burned my town down and I lost everything but my truck...which is melted).

EFF the power companies. they burnt me out as well in Idaho.

 

[evotech]

I have been told there are no rebates if you are 100% off grid. But that was by an electrician friend of mine so it's just hearsay. I bet if you are willing to do some testing and wait a month for delivery you can build your battery 12kw bank with lifepo4 for about $4.5k or even less. If you are ok with DIY which it seems like you are then this should be a rewarding experience. Are you sure about only using 30kw that seems low my computer alone runs 30kw a month.

Sorry that 30KWH was a daily average. So 900 KWH monthly. I have a gas stove and clothes dryer. I have plenty of time and motivation, so building my own battery system is definitly in the cards, unless that powerwall price is accurate. Being new construction, the tesla solar roof and powerwall almost actually makes sense with the hefty rebates. Doing a traditional roof will yield me no rebate on the roofing itself, just the solar, but going the tesla route I earn the rebate for the entire roofing of my new home. I know they are not designed for off grid, but it seems just a software update away or hopefully integrated into a V3 powerwall whenever that comes. I am probably 12 months out from roofing the house. I don't even have permits yet.

 

[evotech]

So as far as the rebates are concerned as they relate to off grid......This is a federal rebate, so it is not state specific. I know some states have their own rebates including California and No I will not qualify for those since all energy rebates at the state and local level filter through the utilities which only proves that they are not really interested in promoting independence but rather looking for purchase cheap energy from us!

Quick Facts About the Investment Tax Credit
The following solar electric systems will qualify for a 30% federal tax credit:

All grid-connected residential and commercial solar electric systems to include all materials, components, and installation.
All off-grid residential and commercial solar electric systems to include all materials, components, and installation.
All RV solar electric systems for RVs and boats that are established for tax purposes by the IRS as a second home.
All expansion to existing grid-connected or off-grid solar electric systems where at least one solar panel is included.
All emergency backup battery systems where at least one solar panel is included.

 

[newbostonconst]

Here is a great washer/dryer for you. This is a 120vac unit that washes and dries. The efficiency comes in when drying that it heats the cloth then uses a small amount of cold tap water to condense the water out of the air to dry the cloths. It is really a genious design. It is a washer so it has the water present to do it.

LG WM3997HWA: Front Load Washer / Dryer Combo | LG USA

Get information on the LG WM3997HWA. Find pictures, reviews, and technical specifications for this LG front load washer dryer combo.

www.lg.com

I have found it to use 1300 watts during the dry cycle and little the rest of the cycle. I have played with it the last 3 years and found the energy to wash/dry is directly related to amount of cloths. We like doing a small load every night that is done by morning, so I am saying to 2 smaller loads instead of one full load doesn't use anymore energy, the large load just takes longer.

Caveats of the unit:
It doesn't get the cloths super hot so you can't fluff them back up if needed from letting them sit in the unit.
The machine likes the water outlet low in the wall because it has to pump out the water.
It is a long cycle (usually around 3 hours) so that is why we run it over night, can't do a quick wash/dry.
No Hole For Dryer Venting Needed......big plus to me....We got .79 ACH for a tight house and this was one reason.
Only need room for one unit space.

 

[evotech]

Here is a great washer/dryer for you.

Thank you. I came across that unit in my interweb research. I was very skeptical, but it is great hearing from someone with real-world experience with the machine. I can live with the small sacrifices that you described. I will put it on the list. It also saves a little space which is nice. If the unit takes up 9 sq. feet and my construction costs come in at 170 a sq. foot, you just saved me $1530 which I can use to put towards my new $2000 Washer/Dryer.

 

[eddie1261]

I am in the design phase of a 100% off grid home to be built in San Diego. I am a DIY guy to my core. Building this home will be my first project in retirement. I spent the last month teaching myself autocad to design the home. So far so good. Now come the choices for energy. This is not a cabin and I am not looking to rough it. AC is a must. I was thinking split units. I designed in a giant south facing roof with room for all the solar I want. Heat should not be too much of a concern due to the temperate climate. Looking for any advice I can get from those who have gone before me. Should I consider propane for stove, dryer, and heat to relieve some of the solar requirements? Any advice is appreciated.



View attachment 1735View attachment 1736

That is the most ambitious thing I have ever seen! Bless you for having the skills to do it. You lost me at the big retaining wall around the pool..... I was in San Diego once in my life, in the mid 70s. I went in February and it was over 60 degrees AT NIGHT!!! What does it rain there, like 5 times a year? One guy I met there laughed that he knows it's time to sell a car when the windshield wipers are worn out because of how seldom it rains. Be great to see pictures when it's done to compare the end product to your rendering!

 

[BoloMKXXVIII]

Efficiency is the key. Insulation, efficient appliances, lights, pumps, etc. are incredibly important. You don't need to purchase equipment to make power you don't use. Propane isn't the only way to go. Check out heat pumps for water heaters too. Try to schedule your biggest power draws during sunny hours. Solar panels almost never put out the power they are rated for. Skies are almost never completely clear all day. You have fewer solar hours during winter. Inverters have losses. Be sure it is easy to get to the panels for cleaning. So many things to keep in mind...

 

[evotech]

That is the most ambitious thing I have ever seen! Bless you for having the skills to do it. You lost me at the big retaining wall around the pool..... I was in Sand Diego once in my life, in the mid 70s. I went in February and it was 60 degrees AT NIGHT!!! What does it rain there, like 5 times a year? One guy I met there laughed that he knows it's time to sell a car when the windshield wipers are worn out because of how seldom it rains. Be great to see pictures when it's done to compare the end product to your rendering!

Some say ambitious other obsessive and those who know me more accurately simply say insane. Off topic, but I stared at those retaining walls and that pool on and off for 12 hours trying to figure out how to both keep it while cutting the costs of said walls by 90%. They are 100% non negotiable items as the view and the slope absolutely make them a necessity. The background photo in the rendering is an actual picture that I took from the actual spot that the home will be placed. The slope is also accurate. I imported the satellite data from Google earth and overlayed that rendering on top of it for topogrraphy that will be pretty close to the real thing. Anyway back to the pool and walls. At 2 AM the following morning a solution came between snores. If I did a self supporting above ground pool and butted it up to the slab, there would be no need for any retaining walls. I could simply build faux retaining walls that support no weight thus saving a year's salary. The end result will look exactly the same minus a totally unnecessary deep end. Below is the pool that I choose. I can customize it to any size that I want and even have built in custom stairs with a top step wide enough to place two chaise lounges on it keep cool as the playboy bunnies serve me something with an umbrella in it. My dreamy solution will cost a grand total of about $15-20K which is about 80% reduction of what the real thing would have cost. This was one of my all-time best cheapskate ideas. Can't wait to see it in technicolor. Sorry for the long digression. I am just a little excited about building this house. I have been planning my retirment from the 1st day I started working. I skrimped, saved, worked multiple jobs, drove shitty cars, and otherwise compromised for 25 years so I could retire early (48) and build my dream house in my dream location. I bought 10 acres 7 years ago when the market was in the crapper and raw land was dirt cheap because the only construction happening at the time was flipping foreclosures. Almost no one was building new homes at that time. As a result I stole 10 acres on top of a mountain with views to the pacific ocean, downtown San Diego and Tecate Mexico to the south. Here I will milk goats, grow green things, Here is the pool naked before I wrap the faux walls around it.

 

[evotech]

Interesting. I just updated my profile which includes info about my hyper efficient build , links to info and more...
If your interested have a peak here: https://diysolarforum.com/index.php?members/steve_s.1720/#about

Great post. I am learning a lot reading it all. Thank you. Do you or anyone else have any opinions or experience with The Hot Point Heat Pump Water Heater/ AC Combo unit. It looks very interesting to me.




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[PatBlack]

At risk of stating the obvious here, but the ultimate off-grid clothes dryer is a clothes line and a bag of clothespins. 0kWh. With 10 acres I think you have enough room!

 

[Luc]

I am currently using about 30KWH a month but that is with old inefficient appliances in a 100-year-old home in New York.

30kWh a month... I use 300-350kWh a month powering LED lights, a refrigerator, wall warts, and a computer.

 

[Fred]

I have been 100% off grid for a few years. I made a lot of mistakes but one great decision was for backup generator power consisting of a winco LPG 12kw genset and an underground 1000 gal propane tank. The gen has a honda motor and very well made with quality parts. It has a 2 wire start capability which makes it easy to automate turning it on as needed. I use propane appliances where possible.

 

[erik.calco]

30kWh a month... I use 300-350kWh a month powering LED lights, a refrigerator, wall warts, and a computer.

My 12 month average is 1,020KWH/month. Nearly half (456) is just from a handful of computers that are on 24/7:



These are just my "critical load" computers. I rarely use A/C and have gas heat, hot water and oven. Electric dryer.

Since I use 87% more than my neighbors, I plan to send them my old power hungry computers to bring that metric down.

You want to conserve? Go fishing. ;p