BajaNomad

Baja Off Grid Living

JDCanuck - 7-24-2022 at 09:08 AM

As this seems to be a pretty common discussion topic, I wondered if we might get issues related to power, air conditioning, water and gas supply all in one spot. Might be helpful for those considering making this move. Edible and or medicinal plants that do well? If there was a section devoted to this, I couldn't find it.

JDCanuck - 7-24-2022 at 09:25 AM

My remaining question would be this: We have built on the Pacific Coast west of La Paz. What kind of edible plantings that produce fruit pretty consistently do you think might survive well in our area given the very arid conditions and strong winds?
We are planning on some edibles as well as fragrant and evergreen shade trees within a wind protected courtyard. Any suggestions? Neem has been suggested for shade. Maybe an orange tree for fruit, blossoms and fragrance? Unable at this point to locate an edible berry bush.


[Edited on 7-24-2022 by JDCanuck]

larryC - 7-24-2022 at 09:32 AM

To help get this section started off I would suggest to anyone thinking of building a new solar system to use a higher voltage battery bank as in 48v, but 24v is good also. The advantages are numerous, ie smaller wires, less charge controllers, etc. The new LifePo4 batteries are a game changer since you can use 80% of the rated amp hours of the battery and not do any harm to them.
If you have an existing solar system it makes sense to upgrade but you won't save as much.
As far as batteries, the relatively new LifePo4 batteries are great. There is also a growing number of people out there building their own batteries with great success. I have built 4 so far and it is a fun project which can save you 40 to 50% of the cost of a store bought battery. For instance I built a 300ah 48v LifePo4 battery for about $2300. The same size store bought battery was $4500.

JDCanuck - 7-24-2022 at 09:44 AM

Quote: Originally posted by larryC  
To help get this section started off I would suggest to anyone thinking of building a new solar system to use a higher voltage battery bank as in 48v, but 24v is good also. The advantages are numerous, ie smaller wires, less charge controllers, etc. The new LifePo4 batteries are a game changer since you can use 80% of the rated amp hours of the battery and not do any harm to them.
If you have an existing solar system it makes sense to upgrade but you won't save as much.
As far as batteries, the relatively new LifePo4 batteries are great. There is also a growing number of people out there building their own batteries with great success. I have built 4 so far and it is a fun project which can save you 40 to 50% of the cost of a store bought battery. For instance I built a 300ah 48v LifePo4 battery for about $2300. The same size store bought battery was $4500.


Thanks Larry: Could I ask how much you think a person should budget as a percentage of full cost to put in an initial Solar system? Your house size, and what Air Conditioning you find adequate? Mine has come in at about 12% to date, but I suspect it goes down significantly as we enlarged the size of the house.

SFandH - 7-24-2022 at 09:44 AM

Fruit trees?

Lots of citrus in the Mulege area. Date palms in San Ignacio. Mangos around Todos Santos. These areas all have fresh water supplies.

JDCanuck - 7-24-2022 at 09:49 AM

Quote: Originally posted by SFandH  
Fruit trees?

Lots of citrus in the Mulege area. Date palms in San Ignacio. Mangos around Todos Santos. These areas all have fresh water supplies.

Mangos sounds great, we will have to look at when they produce and whether the size fits, thanks.

AKgringo - 7-24-2022 at 10:02 AM

I have seen some old, well established pomegranate trees in central Baja. There were some yellow ones at a church courtyard in the Comondus that were small, but very tasty!

Key lime trees seem to do well, and maybe some variety of orange will thrive, but I don't have any personal experience.

For a berry crop, I would investigate whether a Kiwi would do well in a Baja climate. They do very well in the Northern CA foothills, but again, that's not Baja.

I am sure that a date palm would do well, but that is a whole different kind of landscaping.

JDCanuck - 7-24-2022 at 10:17 AM

Quote: Originally posted by AKgringo  
I have seen some old, well established pomegranate trees in central Baja. There were some yellow ones at a church courtyard in the Comondus that were small, but very tasty!

Key lime trees seem to do well, and maybe some variety of orange will thrive, but I don't have any personal experience.

For a berry crop, I would investigate whether a Kiwi would do well in a Baja climate. They do very well in the Northern CA foothills, but again, that's not Baja.

I am sure that a date palm would do well, but that is a whole different kind of landscaping.


We were considering Pomegranate as well. I think Date Palms might survive outside the protected courtyard, and maybe the flowering cactus with medicinal qualities Udo had mentioned (Ocotillos?) in another thread as well if i try to get them growing where we presently discharge our captured rainwater. Thanks all, you have given us some very interesting ideas.

larryC - 7-24-2022 at 05:22 PM

Quote: Originally posted by JDCanuck  
Quote: Originally posted by larryC  
To help get this section started off I would suggest to anyone thinking of building a new solar system to use a higher voltage battery bank as in 48v, but 24v is good also. The advantages are numerous, ie smaller wires, less charge controllers, etc. The new LifePo4 batteries are a game changer since you can use 80% of the rated amp hours of the battery and not do any harm to them.
If you have an existing solar system it makes sense to upgrade but you won't save as much.
As far as batteries, the relatively new LifePo4 batteries are great. There is also a growing number of people out there building their own batteries with great success. I have built 4 so far and it is a fun project which can save you 40 to 50% of the cost of a store bought battery. For instance I built a 300ah 48v LifePo4 battery for about $2300. The same size store bought battery was $4500.


Thanks Larry: Could I ask how much you think a person should budget as a percentage of full cost to put in an initial Solar system? Your house size, and what Air Conditioning you find adequate? Mine has come in at about 12% to date, but I suspect it goes down significantly as we enlarged the size of the house.



That is not as easy a question as it should be. Every house is different and everyone's needs are different. I've been off grid in Baja since '98 and my solar system has grown slowly over the years. I've seen lots of solar systems everything from 2 car batteries and a 350 watt harbor freight inverter to some newer ones with more than 10kw in panels and 13kw inverters.
Your needs will be different than mine for sure and trying to budget a percentage of the cost to build a house plus the solar system would drive me crazy. Basically you need to sit down and figure out if you need air conditioning, refrigeration, are you going to be running welders in the garage, etc. and come up with a preliminary plan and then at least double if not triple it. The instant your wife finds out there is electricity in the out let she will plug a coffee maker into and a microwave oven and more. You gotta love 'em and I do.

I have a small house at about 900sf. I have 2- 1 ton mini splits and run them both if I need to cool the house quickly and then run only 1 the rest of the night. That will bring one of my 300ah batteries down to about 10% SoC and in the morning I fire up the generator for 2 hours and get a charge back into the batteries and then turn off the gen set and let the sun top off the batteries the rest of the day. I used to run the gen set all night before I got the lifepo4 batteries but that used a lot of fuel, 2 hours I can afford.

I'm really not good at the technical stuff so I just build a system and add to it if I need to.

Alm - 7-24-2022 at 05:49 PM

With solar it's easier doing it right from the beginning than building a percentage of full system and expanding it later. You need to do your energy audit - how much Kwh a day with whatever you think to run. This will give you approximate size of solar array. Winter or summer, there is a big difference. Less sun in winter but you don't need A/C. Then budget the battery bank, inverter etc. Then multiply solar size by 1.5 because like Larry said once your wife finds out that there is electricity in the outlet she'll want to plug in - well, a lot. There are offgrid alt-energy forums that you might want to start with, here is one https://forum.solar-electric.com/.

Propane is a separate topic.

JDCanuck - 7-24-2022 at 06:05 PM

Larry; That is a lot of info thanks. I have a 2600 sq ft house with a separate guest wing with its own kitchen and fridge/stove, 2 car garage and run pretty much all the same loads I run up here. This meant a significantly larger solar system than you require, I agree. I have not had to run the backup generator yet, but it's there in case of system failures. Propane is for the extra stove, bbq and if we do run hot water to soaker tubs and of course the generator. So our solar is designed to carry a fully electric home, including the hot water tanks.
We have 24 panels, each 445 w, and two Inverters supplying 6 racked lithium 48v 3.455kwh batteries. Most would find this excessive, and it is at present but we hope to have excess to charge a future EV late in afternoons.
I purposely oversized the panels and undersized the batteries for our full future anticipated use for present cost reasons.

A\C: 2 1/2 tons mini split inverter heat pumps (2) and one 1 ton cooling only in the main bedroom which I find more than meet either winter heating or summer cooling needs.


[Edited on 7-25-2022 by JDCanuck]

RFClark - 7-25-2022 at 07:45 AM

Yes, there should be a new category for “Living Off the Grid”!

RFClark - 7-25-2022 at 09:12 AM

We live in a gated community plus we have security cameras that notify us when something or someone shows up. The community well is up next to the highway and has been burglarized several times in the last year.

JDCanuck - 7-25-2022 at 11:01 AM

Locked gates, signage and confrontation by residents....some people respect the signs and locked gates. Others believe anything in Baja is free game to travel and inspect at will. More security will be forthcoming, no doubt. I would really hate to get to the point of Nuevo Vallarta Fortress where visitors are met by armed security guards and given pre-approved time restricted "passes" to enter and visit friends. At that point it gets to be a self-inflicted prison.



[Edited on 7-25-2022 by JDCanuck]

Alm - 7-25-2022 at 06:45 PM

11kw solar will keep you afloat in daytime. With solar it's all or nothing, on a good day you get "all" and want a big bank to store it for rainy day, literally. With that much solar that would be at least 40 kwh bank, this is 12*3.455 kwh.

RFClark - 7-25-2022 at 07:09 PM

Alm,

With flat mounted high voltage (250VDC) solar arrays (6 panels in series) you still get 20% of the normal output even on overcast days. With Lithium batteries you can charge at high rates so 2-3 hours of generator in the evening will carry you. 10 - 20 KW of batteries should be enough. What you need depends on your base load.

JDCanuck - 7-25-2022 at 07:42 PM

Alm: With ours all we have needed overnite is the 20 kwh storage. In a bit over a year, we have never needed more, even during cloudy periods. Night loads are very much reduced compared to the daytime use of 3 hot water tanks, laundry, dishwasher and Induction stove. LP Generator is there just in case, but so far not needed. AC loads to maintain 23 degree temps throughout are pretty minimal with inverter mini splits.
Lithium batteries generally still have about 30-40% left in morning.
The choice for the remaining 20KWH batteries installed was $10,000 plus, or a backup Cummins 17kw generator at $6,000. Zero LP gas used so far, so seems to have been the right decision at this point. Batteries will get cheaper and that may change in future.



[Edited on 7-26-2022 by JDCanuck]

larryC - 7-26-2022 at 06:47 AM

JD, Your system sounds pretty robust. What inverters are you using?

JDCanuck - 7-26-2022 at 11:28 AM

Quote: Originally posted by larryC  
JD, Your system sounds pretty robust. What inverters are you using?

My installer supplied Victron Inverters, controllers and Pylontech batteries
I had asked for Schneider inverters and Canadian Solar panels with Simplifi batteries,, he overruled me and I'm very glad he did. Pays to have an expert do the installation and keep out of his way.

[Edited on 7-26-2022 by JDCanuck]

Alm - 7-26-2022 at 11:29 PM

Quote: Originally posted by RFClark  
Alm,

With flat mounted high voltage (250VDC) solar arrays (6 panels in series) you still get 20% of the normal output even on overcast days.

Output drops when solar irradiation drops, regardless of total array voltage or whether it's flat or tilted. They are usually titled anyway, minimum few degrees to shed rainwater and dust. Higher voltage reduces wire losses, thinner cables, easier for contractor to work with. In overcast the output drops, in rain it could drop to mere few percent. I remember last winter there was a wet spell lasting more than a week, it was raining every day, though not all day, this is still Baja.

I doubt that panel brand matters. This is just a commodity, the more - the better.

[Edited on 7-27-2022 by Alm]

RFClark - 7-27-2022 at 04:12 PM

Alm,

Flat mounted panels are about 71% efficient. Panels angled for where you live are about 75% efficient. The correct angle is 15 minus your latitude which for Cerritos is about 8 degrees of elevation on your panels. If you run your panels parallel and loose 80% of your solar you get nothing. If you run series you get at least 20% or more of your output. Flatter panels output more on cloudy days as the lighting coms from overhead.

Alm - 7-28-2022 at 06:47 PM

RFClark, JDCanuck was talking about 20% of "normal output" in overcast. Normal, meaning full-sun output. Yes, panel is not 100% efficient but under ideal conditions it does produce close to 100% of what it says on the label. Less when it's hot, less when cloudy. If you lose 80% on a cloudy day, this is still 20% of "normal" - or 10%, or 5%, depends on how cloudy.

With array of that size, series-parallel is the only way to go. The reason is monstrous 200-something amp current and 5-inch thick cable to controller, if it were all-parallel :).

Yes, optimal tilt in summer is latitude minus 15 degrees. In winter it's latitude + 15. Optimal year-round tilt is close to latitude, about 20-21 degrees for La Paz. Canadians mostly stay there in winter, for reasons not related to weather.

RFClark - 7-28-2022 at 10:29 PM

Today in San Felipe it was partly cloudy. Solar radiation was down to 500W/Sq Meter from a 1100W/Sq Meter normal high. Our fixed array was outputting 2KW which is 2/3rds of it’s normal mid-day output.

larryC - 7-29-2022 at 08:24 AM

Quote: Originally posted by Alm  
RFClark, JDCanuck was talking about 20% of "normal output" in overcast. Normal, meaning full-sun output. Yes, panel is not 100% efficient but under ideal conditions it does produce close to 100% of what it says on the label. Less when it's hot, less when cloudy. If you lose 80% on a cloudy day, this is still 20% of "normal" - or 10%, or 5%, depends on how cloudy.

With array of that size, series-parallel is the only way to go. The reason is monstrous 200-something amp current and 5-inch thick cable to controller, if it were all-parallel :).

Yes, optimal tilt in summer is latitude minus 15 degrees. In winter it's latitude + 15. Optimal year-round tilt is close to latitude, about 20-21 degrees for La Paz. Canadians mostly stay there in winter, for reasons not related to weather.


In my experience a solar panel will put out about 77% of its rated capacity in the real world and bright sun light. So a 100 watt panel will generally produce 77 watts of power. Using an mppt controller will help a little, maybe 10% if you are lucky. If we were up north in cold country and bright sunlight then panels will do better but almost never anywhere near 100%.

If you look at the output rating of a solar panel they almost always list the rating as "STC". That stands for "standard test conditions" which is where a batch of panels are mounted in a large room and connected to test equipment and a large strobe light is flashed on them and the current is measured and recorded.
A lot different than the real world usage but the only way they can control the test.

[Edited on 7-29-2022 by larryC]

Alm - 7-29-2022 at 07:34 PM

Quote: Originally posted by larryC  
If we were up north in cold country and bright sunlight then panels will do better but almost never anywhere near 100%.

If you look at the output rating of a solar panel they almost always list the rating as "STC". That stands for "standard test conditions" which is where a batch of panels are mounted in a large room and connected to test equipment and a large strobe light is flashed on them

Finally :). Yes, temperature matters. So does the tilt. Ideal conditions in real world would be early summer with panel tilted "just right" - not at the fixed summer or winter angle, with cold wind so that the panel doesn't get hot, and then at 1 pm you get 90-92% of the rated power.

MPPT - of course. With large array using PWM is impractical. MPPT could boost the total system output - not the panel output, it's still 90-something of the nominal power at best. Panel temperature and high input voltage affect MPPT conversion.

RFClark - 8-16-2022 at 09:46 AM

After a few weeks of operating our solar electric system I’ve made the following observations.

Flat mounted solar panels have a higher output on overcast days. Todays output at about 1/3 normal solar is about 1/3 of normal. They also have a higher output (100% in 87 degree weather) while the sun is overhead or north of our location in BCS as it is about 6 months of the year. As the sun moves south I’ll keep track of the output and back report here.

[Edited on 8-16-2022 by RFClark]

JDCanuck - 8-16-2022 at 01:51 PM

Quoted: In my experience a solar panel will put out about 77% of its rated capacity in the real world and bright sun light. So a 100 watt panel will generally produce 77 watts of power. Using an mppt controller will help a little, maybe 10% if you are lucky. If we were up north in cold country and bright sunlight then panels will do better but almost never anywhere near 100%. end quote



We've been testing ours for about 3 months now. While we are having voltage issues on the one array, we are getting between 95 to 100% of rated power on the fully operable array at peak period during the day (in our case 1:45 pm as they are not oriented perfectly for the 1:15 solar peak). At our location the best we have had on a slightly cloudy full day was 5.5 times of full rating total power yield. Recently washed and still not using all the power available as we have programmed the controllers for maximum battery life and they drop down 1 full volt to 51 volts in float mode from peak of just over 52 volts when they go into absorption mode.

My rough estimate is there will be between 60-65 KWH power per day for our use on days like today once both arrays are fully remediated. so far we have been limited to 58 kwh
Panels are these : https://energy.dmm.com/en/product/%e5%8d%98%e7%b5%90%e6%99%b...
and both arrays total to 10,920 full rating. We are running very close to 100% peaks on slightly cloudy days with 24 panels installed.



[Edited on 8-16-2022 by JDCanuck]