BajaNomad - Off Grid Construction: Advice Needed

Hi All,

I have 12 330W new Solar Panels sitting at my place south of San Felipe l will sell all or part for $2 per watt. Contact me at rclark@intervideo24.com for details.

We’re there now.

Richard

Hi Richard, $2/watt ($660/panel?) sounds awfully high. New 330 watt panels are substantially less in San Felipe. Are you sure about that price?

DBaja - 2-16-2020 at 10:20 AM

Thanks for the offer Clark

Pacifico - 2-16-2020 at 10:55 AM

Looking forward to seeing some pics!

BobbyC - 2-16-2020 at 11:21 AM

Here's a good group to ask:

https://web.facebook.com/groups/BajaOffGrid/

BajaBlanca - 2-18-2020 at 04:20 AM

Your build sounds fantastic! We are in La Bocana, on the Pacific side about half way down Baja. One of our neighbors is literally just starting a build, this week, of a 3000 square foot home. Builder from Santa Rosalia but using local helpers...he gave himself a year to put it all together. Going to be a beautiful home!

Welcome to all the newcomers!

I think it is hysterical that you read God and Mr. Gomez before starting construction. Since husband Les has done lots of construction here, trust me, the difficulty is REAL. My recommendation is to be there for every minute they are building to make sure it is up to snuff. Wish you luck and many great moments in your new home.

DBaja - 2-18-2020 at 06:20 PM

Thanks, more than anything the books just feed my excitement! Going down in just a few days for more progress :bounce:

gnukid - 2-19-2020 at 05:42 AM

We live in a solar powered community in Baja at the moment, the designer uses "inverter motor" appliances, fridge, pool pump, fans, etc which are apparently much more efficient in that they ramp up and down and continue at low rpm when power exists, versus step up/down, on/off. We run the lights, AC, charge electric vehicles etc without a worry and pay no electricity bill! Reduces our stress with visitors or kids who may inadvertently leave lights and fans on and doors open which would otherwise cost a fortune, running AC and fans also reduces humidity.

gnukid - 2-20-2020 at 02:38 AM

SMA makes inverters to use your solar and power the house without a battery bank, so, instead of having a massive bank, you can have power for either emergency situations when you are grid tie and the power goes out, or when you only use a little power at night but a lot in the day, apparently you can reduce your bank bank size for an application like yours. https://www.sma-america.com

[Edited on 2-20-2020 by gnukid]

capitolkat - 2-20-2020 at 01:12 PM

WE built in Centenario (suburb of La Paz) 9 years ago. My only comment is about the tankless water heaters. WE had three installed as it would have been a long run from one end of the house to the other. Good brand Bosch. Because the water pressure fluctuates depending on the pump from the cistern, one minute you could be doing fine in the shower and when the pump turned on you had to jump to avoid being frozen or scalded. The Bosch service came and examined the systems to make sure they were properly installed etc. The pressure tank fluctuates between 40-60 lbs from off to on and the Bosch guy says ok. But, the problem was never solved on any of the three heaters. We replaced with propane heaters and never looked back. The tankless heaters sat outside our gate for three weeks as I thought someone would take them. Finally the trash men took them.

Get the biggest propane tank you can afford particularly if you get a propane generator. They are thirsty if you run them a few hours a day and that cuts down on propane deliveries. You will develop a relationship with the propane guy and if so they come when you ask. Otherwise it's Mexico and sometimes manana means maybe tomorrow.

Like others said-- insulate, insulate. A stove or fireplace is very nice as no matter if it is Mexico some nights are cold.

Seeking Off Grid Advice

JDCanuck - 2-23-2020 at 12:04 PM

Thanks for all the responses in here! We too are building an off grid home on the Pacific coast west of La Paz (Conquista Agraria). As we presently live in Canada, we have very little knowledge almost everything we will need to consider. Presently we are seeking info on sizing a complete solar system for this area. We will have a 2400 sq ft home, with 4 bedrooms and 3 full bathrooms and kitchen fridge, freezer and most all the appliances we use up here in Canada, including microwave and 2 burner induction stove top (110v). In addition we hope to charge at least one, perhaps 2 electric vehicles eventually. We are planning on a 5kw solar panel system to begin and anticipate 12kw eventually. The 5kw is sized for a partial build at around 1400 sq ft 2 bedrooms and 1 bathroom with 2 car garage.

With that in mind and the need for an engineered septic system, are we in the ballpark on sizing the solar system? How many AGM batteries at 48 v would we need given 351 days of solar per year? We have a small 2kw gasoline generator but could enlarge that to 4kw and have looked for Inverters with backup generator supplies.

Any input from experienced off grid owners would be greatly appreciated.
Thanks

JDCanuck - 2-23-2020 at 12:31 PM

Hi again: My second issue is choosing an appropriate water heating system as we have exceptionally hard water supplied at about 300 ppm Calcium Carbonate equivalent. I really would like to use tankless propane heaters to reduce water wastage in warming, but understand they scale up very quickly. Not wishing to use ion exchange softeners due to water use and salt output, has anyone come up with alternative softening? I am considering using a black painted hot water supply tank to warm hot water followed by sediment filters, a small propane hot water tank to boost to 120 degrees f and blowdown taps perhaps automatically controlled at both mentioned tanks. Local hot water appliances seem to need replacing very often, at about 3 times the rate we experience up here. Any comments appreciated.

[Edited on 2-25-2020 by JDCanuck]

[Edited on 8-19-2021 by JDCanuck]

mtgoat666 - 2-23-2020 at 01:19 PM

Hi again: My second issue is choosing an appropriate water heating system as we have exceptionally hard water supplied at about 500 gpg Calcium Carbonate equivalent.

That is really, really hard water!

mjs - 2-23-2020 at 04:33 PM

Thanks for all the responses in here! We too are building an off grid home on the Pacific coast west of La Paz (Conquista Agraria). As we presently live in Canada, we have very little knowledge almost everything we will need to consider. Presently we are seeking info on sizing a complete solar system for this area. We will have a 2400 sq ft home, with 4 bedrooms and 3 full bathrooms and kitchen fridge, freezer and most all the appliances we use up here in Canada, including microwave and 2 burner induction stove top (110v). In addition we hope to charge at least one, perhaps 2 electric vehicles eventually. We are planning on a 5kw solar panel system to begin and anticipate 12kw eventually. The 5kw is sized for a partial build at around 1400 sq ft 2 bedrooms and 1 bathroom with 2 car garage.

With that in mind and the need for an engineered septic system, are we in the ballpark on sizing the solar system? How many AGM batteries at 48 v would we need given 351 days of solar per year? We have a small 2kw gasoline generator but could enlarge that to 4kw and have looked for Inverters with backup generator supplies.

Any input from experienced off grid owners would be greatly appreciated.
Thanks

You need one 48-volt battery. The question is: How big (amp-hours or kW-hours)? and How will it be configured? You said AGM so you could create your 48-volt battery using 24 individual 2-volt cells (batteries). Or four 12-volt batteries (which each consist of six small 2-volt cells. You need to determine your electrical needs to determine the appropriate battery size for your system.

BWOE, our 48-volt battery consists of 24 2-volt, 1200-amp/hr batteries wired in series. My goal in normal use is to limit discharge to 20% to achieve maximum life (over 3500 cycles according to the mfg.) We have a 9kW solar array to quickly recharge the batteries and run the AC in the summer. It also provides for enough output to recharge the batteries even on a cloudy day. The result is we usually only run the generator to exercise it.

But our use and needs may not match yours. I suggest you call a solar supplier who has a lot of off-grid experience and discuss your needs with them.

JDCanuck - 2-24-2020 at 01:01 PM

Thanks for that response, the main question we will face is how much load overnight, and we were planning on a 48 volt system. Batteries being the most expensive single part of our system and considering all the work being done on better storage at present, I am trying to avoid oversizing there, while at the same time avoiding running the small generator overnight.
I see you use a very well sized battery system, do you run pumps and electric fridge/freezer overnight? We wish to hold the drawdown rates overnight to less than 50% at the worst times. So far we have received very high prices on all components in La Paz, so are trying to avoid retailers there and considering importing directly.
Thanks again

[Edited on 2-24-2020 by JDCanuck]

mjs - 2-24-2020 at 03:55 PM

Thanks for that response, the main question we will face is how much load overnight, and we were planning on a 48 volt system. Batteries being the most expensive single part of our system and considering all the work being done on better storage at present, I am trying to avoid oversizing there, while at the same time avoiding running the small generator overnight.
I see you use a very well sized battery system, do you run pumps and electric fridge/freezer overnight? We wish to hold the drawdown rates overnight to less than 50% at the worst times. So far we have received very high prices on all components in La Paz, so are trying to avoid retailers there and considering importing directly.
Thanks again

[Edited on 2-24-2020 by JDCanuck]

We live just as we did up north. TV, lights, 2 fridge/freezer, pressure pump, etc. We had friends over for dinner last night. A lot more lights than usual (although they're all LED), in an out of fridge, etc. Battery was at 89% SOC at daybreak this morning. So I'd say the battery is oversized for our normal needs except, in summer it runs the AC overnight so we can sleep. I also have MIG and TIG inverter welders I run of my system.

You have to consider your worse case load and what compromises you are willing to make. Batteries are expensive but look around. My neighbor(s) ordered some Leoch LPS2-1350 2-volt AGM batteries for approx <$350 ea IIRC. Haven't arrived yet so I'm reserving judgement until I install them. I paid less than $500 each for my AGM batteries.

Forklift batteries are an option but most will be wet cell although there are some AGM units. Dealing with the weight of those is usually the issue but if ordered new they can be constructed with individual removable cells to make moving them easier.

Send me U2U if you want the names of some vendors. (Note: I'm not in the business or connected to any business, just have a background in electrical and mechanical construction including custom designed equipment and controls.)

BajaTed - 2-24-2020 at 04:13 PM

Place the Batteries in an underground vault if possible, harder then to steal, they like steady temps too.

JDCanuck - 2-25-2020 at 09:48 AM

Thanks for that additional info. While we don't have underground storage we will attempt to locate our storage in as cool a spot as possible.
Jerry

JDCanuck - 7-18-2021 at 02:59 PM

Just checking back in in case anyone is still interested. System has been designed and almost completely installed now, except the backup generator. As this developed and we kept increasing the load, we went with a much larger system than originally planned. Now have the following for our fully electric home west of La Paz:

24 - 445 watt panels (10.6kw total) mounted on roof $11262,
2 - 8kw Victron inverter/chargers with associated controllers and cabling $12660
6 Pylontech 3.55 kwh lithium batteries in racks totalling 21kwh at 100% or 17.5 kwh at 80% $12288
misc. cabling, labor switching and load centers and IVA $4966

Hope others looking into solar systems can find this a bit helpful. I should point out very early this spring solar systems in general jumped rapidly due to covid supply and high demand issues and was suddenly up in price overall by about 10% within one month.

Terry28 - 7-18-2021 at 05:32 PM

If my math is close.....you spent over 40K just for solar...wow

RFClark - 7-18-2021 at 09:23 PM

JD,

We have very hard water too. We run a tankless propane water heater with a softener in front of it. We’ve had it for 6 or 7 years now. Also gas refers don't do well when it’s hot. We run a cheap Best Buy AC refer. Which is very efficient!

PaulW - 7-19-2021 at 08:22 AM

These newest AC refers are for sure efficient.
Any comparison on efficiency for various unit's?
Price probably would be the determining factor?

pacificobob - 7-19-2021 at 08:51 AM

for septic check out a bio digester made by
rotoplas. widely available, and very effective.
or, just do what most in san juanico do...rely on the super sandy soils to transport to the sewage to the beach.

JDCanuck - 7-19-2021 at 10:21 AM

Quote: Originally posted by Terry28

If my math is close.....you spent over 40K just for solar...wow

Yes Terry, seems like a lot to spend, but the alternatives were far more expensive over a 10 year period. Solar power came in at about 12% of total building costs, but petroleum based alternatives have risen far faster than we anticipated as well. Natural gas here where we are is costing us 50% more than just one year ago, and governments globally promise to keep taxing it more and more into the future. Running a power line into the property would have cost more yet, and then we would also be looking at ongoing power costs that would also be constantly rising. A reliable water supply will be the next big issue, especially in the La Paz area.

JDCanuck - 7-19-2021 at 10:29 AM

JD,

We have very hard water too. We run a tankless propane water heater with a softener in front of it. We’ve had it for 6 or 7 years now. Also gas refers don't do well when it’s hot. We run a cheap Best Buy AC refer. Which is very efficient!

Thanks RF, I decided to go with electric tank type hot water heaters to both reduce replacing fouled tankless heaters and keep everything as solar based as possible. Other owners there reported tankless heaters needing replacing within 3 years, while the electric elements are far cheaper and easier to replace when they foul up. No salt based softeners allowed as is becoming more and more common, both because of excessive water use and salt going into the septic system. We are installing a whole house TAC conditioner to attempt to reduce scaling as much as possible, so far studies show good improvements with them.

JDCanuck - 7-19-2021 at 10:35 AM

Quote: Originally posted by pacificobob

for septic check out a bio digester made by
rotoplas. widely available, and very effective.
or, just do what most in san juanico do...rely on the super sandy soils to transport to the sewage to the beach.

Bob:We have an engineered septic system with air pump to double process (both aerobic and anaerobic) the septic and expect to reuse the effluent from it for irrigation purposes reducing our water consumption as much as possible. This system is required by local codes.

El Jefe - 7-19-2021 at 11:19 AM

Quote: Originally posted by Terry28

If my math is close.....you spent over 40K just for solar...wow

Yep, 40 grand seems about right for a solar system designed to run a modern house with modern appliances. We spent nearly that in 2005 on our off grid system. There have been additions over the years and a full battery replacement after 12 years. At that time the new tech was too expensive so we spent about 10 k on lead acid batteries which are still going strong four years later. Still, I have battery envy for some of my neighbors that have recently gone with LI batteries. My understanding is that they charge faster and can be drawn down much further than mine.

We are on the east cape so it gets a bit hotter than over on the west side. We use AC in late spring and summer, but mostly just in our bedroom. The new mini splits are so efficient that we can run our bedroom unit 24/7. Nothing like having to pull up a little blankie on your afternoon nap! We call the bedroom ICE STATION ZEBRA.

All lights have been converted to LED and other energy saving measures like the smart pool pump have been game changers. Getting better all the time.

Propane is used for cooking and water heating as well as backup generator. Instant on water heaters lasted about 6 months until we got so frustrated with them than we changed out to old fashioned tanks and never looked back.

There is no heat in the house. Never needed it. Tri-D panel construction insulates pretty well. The pila under the garage holds 6,000+ gallons, two truckloads of water. When I get just over half way down I call for a load. Never ran out.

There is some great info on this thread. I think the main takeaway for some might be that it is going to cost more than you expect. But hey, in the long run you will be the one living the dream.

pacificobob - 7-19-2021 at 12:28 PM

In Mexico?

What entity has such codes?

if SJ has such codes regarding septic treatment, a quick trip to the beach will make it clear that those codes are not enforced.

Solar System Costs

JDCanuck - 7-19-2021 at 01:10 PM

Thanks El Jefe for that extra info. We have kept our battery sizing at the minimum as we expect this is the one area that will continue to improve costwise. As we have no LP gas except for the backup generator and alternate cooking if needed, I am pretty sure we have sized correctly. Lithium batteries did become the better choice a while back, as lead acids continued to rise in price while Lithium continued to fall and become more reliable as well. Tech advances seem to be focused mainly on this area. Recent shortages of panel constituents has driven panel pricing up, hopefully temporarily.

JDCanuck - 7-19-2021 at 01:18 PM

El Jefe: I am impressed with the life you got out of your lead acid batteries, you must have done well with the maintenance. As i calculate now, we are paying 1.5 to 2 times the price of equivalent usable storage size deep cycle lead acid or AGM, so we will be hoping to get the full rated 6000 cycles out of them to justify the extra cost. I am really hoping the environmentally superior Aquion saltwater batteries or something similar is available before we need to buy any more.

El Jefe - 7-19-2021 at 01:40 PM

Our original batteries were 12, 4 volt Rolls top of the line 300 pounders. They cost over a grand each. The problem with running a 48 volt system like this is that if you end up needing more energy storage you have to get 48 volts more. One of my neighbors had 24 of those suckers! You can't just add another couple of batteries because it throws off the voltage.

According to my limited understanding, if you buy say, three 48 volt LI batteries and you find that you need more power you can add a forth battery no problem (except to the hit to your check book). But my neighbor just bought a single battery about the size of a back yard barbeque that is rated 48 volts for the whole thing. I don't know if he could add a smaller 48 volt battery to boost it if needed???

When we replaced I switched out to 8, 6 volt Rolls monsters and saved some money by having a bit shallower well so to speak. Hasn't been a problem.

[Edited on 7-19-2021 by El Jefe]

RFClark - 7-19-2021 at 07:03 PM

What you shouldn't do with “Li batteries” is mix different types of Li chemistry. 48V is a relative value and the actual voltage can vary depending on the battery you buy. Li batteries don't like to be overcharged. The best Li batteries have battery monitoring systems to prevent over charging and over discharging.

A major difference and advantage is Li batteries reach full charge much faster than Lead acid batteries. They also are far less effected by Baja temperatures.

4x4abc - 7-19-2021 at 11:05 PM

now that you mention Baja temperatures
the winters are cold
I knew that long before i built the house
so I got myself heated floors
with solar hot water
so comfy in the winter

Mean Baja Temperatures

JDCanuck - 7-20-2021 at 07:21 AM

We found the temperature range where we are building (Pacific coast north of Punta Marquez) almost perfect for our tastes, along with about the best solar gain available anyplace in North America. Temp ranges from a low of 53 in winter to highs right around 95. I can live with a 72-74 degree interior temperature quite comfortably. We have chosen 1/3 heating capable heat pump minis along with cooling only in 2/3 of the minis installed. Total AC for a 2600 sq ft area would produce 5.5 tons cooling if every area was fully air conditioned at the same time, which we expect will never be the case. Expectations are a maximum of 3 tons cooling at any one time.

Passive cooling home design

JDCanuck - 7-20-2021 at 07:36 AM

If anyone out there has some info on newer cost effective passive cooling designs for the Baja, I'd be interested in seeing them. This is one area we were unable to research before building and I suspect could have reduced our power needs significantly.

Udo - 7-20-2021 at 09:18 AM

In Ensenada, 450-watt panels for $185.00 USD.

Solar Batteries

JDCanuck - 7-20-2021 at 09:53 AM

Attempting to add picture of batteries and inverters. We found the cost of Pylontech US3000C batteries for the storage the best value compared to Tesla Power Wall or BYD banks when we looked this spring despite that pricing bump that occurred just then.

JDCanuck - 7-20-2021 at 10:00 AM

Quote: Originally posted by Udo

In Ensenada, 450-watt panels for $185.00 USD.

Thats an exceptionally good price! Perhaps you could provide the supplier for others on the thread?

JDCanuck - 7-20-2021 at 01:02 PM

Quote: Originally posted by Udo

In Ensenada, 450-watt panels for $185.00 USD.

Exciting to see how prices have dropped.

Anyone have opinions on the Chinese-made panels vs others ( assuming there are panels made anywhere else

From my investigations almost all solar panels are made in China or other Asian countries where labor is even cheaper. I think the major concern would be the supplier and how well they back up warranties. Same applies to the installer, does he have a history of backing up his installations, how quickly would he respond to failures, etc.

My personal preference would be Canadian Solar as they have a long history of backing up and pretty much all their panels are manufactured in China. US buyers would be subject to very large tariffs on Canadian Solar panels, while anyone buying them outside the US would find their prices very competitive.

SFandH - 7-20-2021 at 01:17 PM

Quote: Originally posted by Udo

In Ensenada, 450-watt panels for $185.00 USD.

Here's a TJ store that sells 100w panels for $99.

https://solshop.solenergy.mx/3-paneles-solares-tijuana-ensen...

[Edited on 7-20-2021 by SFandH]

JDCanuck - 8-18-2021 at 11:09 PM

Quote: Originally posted by Terry28

If my math is close.....you spent over 40K just for solar...wow

Yes, I know it seems to be a lot. The plan was to get to zero hydrocarbon use if possible. We may be there and at present it's cost about 13 percent of the total building costs. Payback in investment terms will take about 10 to 12 years, no subsidies.
Another way of looking at it is we get a return on invested monies at a rate of 6 to 7 percent averaged throughout the payback period. Beats putting the cash in a bank account realizing 1 percent.

RFClark - 8-20-2021 at 05:02 PM

My experience has been that the price of solar panels has gone down from a few dollars a watt to a few cents per watt in 15 years! That added to the availability of Li batteries has made solar cheaper than Edison and way cheaper than CFE!

JDCanuck - 8-21-2021 at 05:59 AM

Thats the same as I've found. Baja especially and Mexico and the lower US States now have an opportunity to drastically improve the environment by capitalizing on this ongoing resource with or without subsidies. Power Utilities are moving at an increasingly rapid direction to accomplish this. But it's not free. And in our case the big challenge is how to use all this excess while the demand is not there. I am hoping for increased storage over long periods at a much lower cost to resolve that issue in the future.

[Edited on 8-21-2021 by JDCanuck]

JDCanuck - 8-21-2021 at 07:41 AM

...cheaper than Edison and way cheaper than CFE!

Cheaper? Depends on your lifestyle.

With subsidized lower tier rates, I've rarely paid over US$30/month in CFE bills, at which rate it would take quite a while to pay off a solar installation; if a grid connection is easily available, not much economic incentive to go solar.

I'm curious, how much gas do you use per month, and how many air conditioning units do you have installed? I had heard the lowest tier on electricity in Mexico was quite low, but once that was passed it ramped up in cost very quickly. Our home is designed for maximum occupancy of 10 people, no gas use and some additional power to charge electric vehicle(s). As we have no available supplied power, CFE was not an option.

[Edited on 8-21-2021 by JDCanuck]

mtgoat666 - 8-21-2021 at 08:15 AM

[
With subsidized lower tier rates, I've rarely paid over US$30/month in CFE bills,

Subsidized?
So who is paying cost of what you consume?

JDCanuck - 8-21-2021 at 10:32 AM

The most difficulty I had equipping my home was locating an induction top/convection oven electric stove. Induction is becoming the big thing up here for it's efficiency, although somewhat more expensive and has issues with maintaining a slow boil. In order to get one out of Cabo I had to have it imported at close to 50% higher cost than it was available for up here.
All the other appliances were either equivalent or cheaper in La Paz than up here.

4x4abc - 8-21-2021 at 10:33 AM

like in all socially oriented countries - the government (your taxes)

BajaTed - 8-21-2021 at 10:43 AM

If anyone out there has some info on newer cost effective passive cooling designs for the Baja, I'd be interested in seeing them. This is one area we were unable to research before building and I suspect could have reduced our power needs significantly.

A hillside home can have a passive cooling vault and tunnel under the home.
The longer the tunnel the cooler the air. House on one side of hilltop with tunnel thru hilltop facing prevailing wind. whole house fan to create negative pressure to draw from below thru floor vents. Common desert design in times of past.

RFClark - 8-21-2021 at 10:59 AM

Our home in the states has passive geothermal, it’s built into a south facing hillside. The entire ground floor is dug into the hill. It has south facing windows that let in the sun in the Winter with an overhang that shades it in the Summer. We are at 4200’, so it gets cold and snows. I feel that the geothermal saves about 40% on energy as we use about 300 gal of propane for heat and hot water plus a cord of wood. We have about 1/2 the Heat pump tonnage that would be normally required for our Sq Footage!

Hillside home

RFClark - 8-21-2021 at 11:04 AM

06F748C3-34DA-45A6-8B2C-86D65AF8AB8C.jpeg - 101kB

JDCanuck - 8-21-2021 at 11:06 AM

Quote: Originally posted by BajaTed

Thanks Ted: That seems to be an excellent idea. Retrospectively, I had looked at something similar using buried conduits, the negative seemed to be controlling the biological growth in the supply air channels due to high humidity. As it is, I have induced air flows using high volume low power rooftop ventilators and hope to draw cool air through bedrooms when possible to avoid some AC use. Will not know how this works out til we can spend sufficient time there. If it's worthwhile I intend to install automated controls to control them.

RFClark - 8-21-2021 at 11:36 AM

Our Baja experience in passive cooling is different. There we built on top of a 30’ bluff behind the beach. The house is on the 2nd floor. Summer ground temperatures in our area 6’ down are about the same as the water temps so no cooling there.

What we did that works is use eves that shade the house in summer, paint the roof with heat reflective white paint backed up by R30 insulation and take advantage of the onshore breeze to keep the house cool. This works until the breeze stops, usually sometime in July. At night we get a reverse flow out to sea that keeps temperatures overnight in the 70s. It is known from sailing days that it’s much cooler in warm climates, 50’ - 100’ above deck!

JDCanuck - 8-21-2021 at 11:50 AM

Our Baja experience in passive cooling is different. There we built on top of a 30’ bluff behind the beach. The house is on the 2nd floor. Summer ground temperatures in our area 6’ down are about the same as the water temps so no cooling there.

What we did that works is use eves that shade the house in summer, paint the roof with heat reflective white paint backed up by R30 insulation and take advantage of the onshore breeze to keep the house cool. This works until the breeze stops, usually sometime in July. At night we get a reverse flow out to sea that keeps temperatures overnight in the 70s. It is known from sailing days that it’s much cooler in warm climates, 50’ - 100’ above deck!

Thanks. Too late in construction for most of that now, but all sound eminently wise. I am told in our area onshore/offshore patterns have been disrupted and the breeze flows parallel to the beach almost all of the time. House layout originally took advantage of onshore/offshore reversals for natural airflow through the common areas, but as is, it seems the main wall including the garage will block most breezes. And so the high flow exhausting fans to draw from whichever side of the house is the coolest.
Am I correct in thinking you are in Todos Santos?

[Edited on 8-21-2021 by JDCanuck]

RFClark - 8-21-2021 at 12:10 PM

The house I described is south of San Felipe, we built it 2003 - 2006 so we have good data on temps and electrical (solar) usage.

Where we are building now south of Cerritos there is cold water off shore through July. There is an on shore cool breeze with overnight temps in the 60s. As soon as the warm water arrives August - September the temps go into the 80s and the humidity goes up.

The white reflective roof makes a big difference in Mexico as does low thermal mass construction. The other thing that works is drawing in air from the center of that flat white roof as it’s usually colder than the surrounding air because of radiation to the sky if it’s clear.

JDCanuck - 8-21-2021 at 12:36 PM

Roof is white...contractor did that on his own. Solar panels are up there tho. Traditional brick construction throughout, no insulation. SentriGlas triple ply windows...lots of em, and front and rear sundecks with overhangs, one across front facing ocean and one in narrowed courtyard entrance way. I think the 40 by 40 courtyard will yield coolest temps for induced drafting, and this is where we will be planting the bushes (ciruela and bouganvillea and whatever will grow)lemon, banana, orange trees? Wife is big on edible plants

[Edited on 8-21-2021 by JDCanuck]

[Edited on 8-21-2021 by JDCanuck]

JDCanuck - 8-21-2021 at 01:24 PM

Quote: Originally posted by mtgoat666

Subsidized?
So who is paying cost of what you consume?

Tax pesos or the higher-tier consumers, have never investigated.

Before you jump on your judgemental high horse as usual, it's hardwired into the rate schedule, not some special individual subsidy.

I'm all for subsidized rates. I think I read someplace the average American uses 10 times the power that the average Mexican does. Gives the lower wage earners some basic power cheap and the power hogs can subsidize them with escalating use costs.

Lencho: I am amazed at your low power costs. Sounds great if you are willing to give up all those luxuries we are used to. Our combined power/gas bill up here for 4 people is costing us 250 USD per month, and is rising at about 15% per year recently. Water availability I think will be our big worry in BCS.

[Edited on 8-21-2021 by JDCanuck]

[Edited on 8-21-2021 by JDCanuck]

JDCanuck - 8-21-2021 at 02:30 PM

I think I read someplace the average American uses 10 times the power that the average Mexican does. Gives the lower wage earners some basic power cheap and the power hogs can subsidize them with escalating use costs.

All that, and no less important if we're concerned about what we hand to future generations, it encourages energy conservation by rewarding low consumers directly where they care: their pocketbook.

I've lived in places where per-unit prices on limited resources DROP as use increases, a model which seems counter-productive in today's world.

Yeah, that's the model we have based our society on. Charge any poorer customers more to subsidize the high volume user. Financials, commodities, even food. Am i sounding like a socialist here?

Don Pisto - 8-21-2021 at 02:43 PM

I really believe the typical mexican family could save a bunch of much needed peso's if they just switched to LED's and turned off some appliances, it's not hard.

for years my CFE bill has been under five bucks a month.

[Edited on 8-21-2021 by Don Pisto]

[Edited on 8-21-2021 by Don Pisto]

Don Pisto - 8-21-2021 at 09:37 PM

Quote: Originally posted by Don Pisto

That's pretty low; do you run air conditioning at all? That's the big consumer for most Baja customers. Probably followed by their refrigerator.

That's assuming they cook and heat water with gas.

no AC.....just ease over to the left side;

JDCanuck - 8-21-2021 at 10:11 PM

Quote: Originally posted by Don Pisto