Building new Off Grid Home in Panama

Panamretiree · April 2013

Afternoon All

New to the forum, and just moved/retired (December past) to the Las Uvas area in the Republic of Panama. Lts of people from up north, but anyone from down here?

Having a house built and wiring it for off-grid solar - wind augmentation.

What forum topic should I go to as I know I'm not in the right place.

Thanks in advance.

BB. · April 2013

Re: Bulding new Off Grid Home in Panama

Welcome to the forum Panamaretiree!

I have moved this to its own thread--So you can continue your Q&A session here.

For creating new threads, you go to the sub forum that meets your overall subject and hit the "Post New Thread" button (some are close--i.e, newbie building an off grid system)--We are not big sticklers for exact sub forum/subjects... Just sort of close is good enough.

As the "creator of the thread"--you control the course of the discussion. (modified by niel to better reflect op and thread relationship as ownership is of naws.)

I suggest asking a few overall questions, then devlving into one or two details at a time. If you ask 10 detailed questions at once, you probably will get ten different detailed responses--and get confused how to respond/continue down which path.

-Bill

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

Thanks for the welcome.

I think a bit of background is wise to start.

Marine Engineer by trade. Understand solar system requirements as I installed a 700 amp-hour system with 2-100 watt solar panels on our 31 foot Uniflite in the 1000 Islands of Ontario. Mother wouldn't let me have a generator so I went a bit big on the system for what I was operating. Figured at least 7 days without starting an engine to charge the battery bank. Great fan of amp-hours, but realize I need to address the watt-hour issue. Also lived on a 40 foot Bayliner Bodega in Victoria, BC for 5 Years.

Now we are in Panama where we get 12 hours of daylight each day. The latest paper on renewable energy here details that in our area (60 miles west of Panama City) we get approximately 5.5 to 6.5 kWhs/m2/day, with an annual average of 3 kWhs/m2/day.

Our house is an octagon design and there is significant roof area to follow the sun as it goes from east to west. The octagon design lets the front left corner capitalize on the morning sun. The left side for the middle day sun and the rear corner to get the late afternoon sun.

We are having as much window area installed to maximize natural air flow.

In the process of determining the loads that I will see, and yes, we are into conservation at all levels (read a lot of your posts).

The house appliances are all new and with energy star ratings where possible. We will have:

1. Samsung side-by-side fridge with the drink access in the door (don't have to open fridge door and dump all the cold when getting a drink - nice feature)
2. Stacked washer and gas dryer - so far have not hooked up dryer and nature does a great job.
3. Gas stove top
4. 12 VDC fans
5. 12 VDC lighting
6. New Panasonic Inverter microwave
7. Required kitchen appliances - coffee perk, toaster, etc.
8. On-demand gas water heater - battery operated igniter
9. Have the requisite electronics that come from living up north - TV, DVD, printer, iPad speaker system, alarm clock, cell phones (pretty much the standard here)
10. Using a Kill-A-Watt meter to determine my loads. Nice piece of kit I've had since our first boat.
11. Big loads such as dishwasher, split AC units (more on this later)

Having the house wired to accommodate the 12 VDC and 120 VAC appliances as the build is cinder block and everything is in the walls. the adage that it's ensconced in concrete is very true here.

Reading the 2013 Solar Electricity Handbook, and perusing these forums and others.

During the day in the house we have rented until ours is finished (in the same complex), we operate three ceiling fans, and the main fridge (the one described above - it comes with us when we move). No need for lighting during the day, or AC (we close up windows and drapes during mid-day time because of the way the house faces). We do put the AC on at night as we are not quite acclimated, but we are using it less and less (we expect to be AC free when we move into our house as it is in a slightly different location). We do leave outside lights on at night for security reasons. We will also have decorative security grates on the windows and doors so we can leave the windows open 24/7, and doors during the day for natural air ventilation.

We do laundry every 3-4 days of 1 to 3 average loads. Have the Kill-A-Watt meter on the washer to determine its power requirement.

Had the Kill-A-Watt on the fridge for almost 3 days. The readings were 19.49 kWh in 68.6 hours - 6.81 kWh/day.

The Power center will be in the middle of the house with a louvered door and exhaust fan for circulation.

We will still have a hook-up to the grid, but it is fast being outpaced by new construction, and electricity cost is not going down. Even though we can be on the grid, when the hydro goes out, we get concerned as time goes on because of the fridge. It's like the Mastercard commercials - piece of mind - priceless.

Starting to look for sources here in Panama for the parts and pieces I will need for the system. Logistics and supply are a real challenge here.

This has been a long rant so I will leave now and get back to thinking about what I am doing. I have some questions already, but need to formulate how to ask them.

Cheers

westbranch · April 2013

Re: Bulding new Off Grid Home in Panama

with those heavy loads you will probably end up with a 48V (or 24v) system so you may have to re-think through on the 12 v appliances etc

niel · April 2013

Re: Bulding new Off Grid Home in Panama

westbranch wrote: »

with those heavy loads you will probably end up with a 48V (or 24v) system so you may have to re-think through on the 12 v appliances etc

maybe not as he can run separate solar setups and this could minimize things like the lights going out if there's trouble in the bigger system for heavier electrical appliances. i do think your requirements will be far larger than you realize and you may wish to have more pvs than just what can fit on your roof. always start with your load requirements in watt hours over the course of a day. if you're going to use more than 1 solar system then figure it for each system individually. also you need to know that there will be times due to weather that at least one other source of power should be on hand such as a generator.

Ralph Day · April 2013

Re: Bulding new Off Grid Home in Panama

A neighbour of mine has a seasonal house (6 months of the year) in Panama and is just tickled by the utility costs down there. He says its about 11 cents per kwhr on just what you use with no rediculous charges like at home...debt retirement, cost to deliver power (not what's used, that's extra) and such like. Are you sure you want to off grid it, or could you grid tie. And take the wife to see/hear an inverter type generator. They're not your father's generator anymore.

Ralph

niel · April 2013

Re: Bulding new Off Grid Home in Panama

ralph,
if what you say is true, then i have a hard time believing our local utilities excuses when a small 3rd world country with few resources can generate and deliver cheap power to their customers. i do have to ask if it was reliable though?

Dave Angelini · April 2013

Re: Bulding new Off Grid Home in Panama

Panamretiree wrote: »

Afternoon All

New to the forum, and just moved/retired (December past) to the Las Uvas area in the Republic of Panama. Lts of people from up north, but anyone from down here?

Having a house built and wiring it for off-grid solar - wind augmentation.

What forum topic should I go to as I know I'm not in the right place.

Thanks in advance.

I lived in Panama for 2 years and I would use a 24V battery as there are many quality fans, pumps, motors,freezers,LED lights, and the loss is less. I seem to remember very little wind except when there was too much. Good Luck!

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

I am wiring the house so that the fridge, dishwasher, washer/dryer and AC units are on individual circuits. I am pondering having a second 120 VAC power panel and put the AC units on it and wire it directly into the grid. The units that I have installed in another house down here draw 4 amps each on 220 VAC when operating.

The dishwasher is also an unknown and will be off at the start of commissioning the house. The fridge and washer dryer will be the only two items that will need to be on the system. I'm of the mind that laundry is to be done early morning to allow the system to play catch up during the day.

I have contemplated sourcing an ABT that would transfer us back to the grid when the batteries need charging due to loads.

I have estimated the 12 VDC amp-hours/day loads at approximately 150 amp-hours/day. These are:

ceiling fans - qty 3 - 12 VDC - 0.4 amps*24 hours - 28.8 amp-hours
lights - qty 12 - 12 VDC - 0.6 amps*12 hours - 86.4 amp-hours
lights/additional fans - at other times - an additional 35 amp-hours

My DC kwh loads are approximately 1406 watt-hours/day or 1.5 (let's round up).

Adding this to the fridge estimate of (rounding up) 7 kWhs/day I have 8.5 kWhs/day. Starting to add up.

I have looked at solar panel size. For a 245 Watt panel, the size is .951 * 1.7 M2. For a 12 panel array system this would give me a surface area that would give me approximately 20 M2. Using the annual average of 3 kWhs/m2/day, this array could produce 60 kWhs/day. If I discount at 20 percent, the array could produce 48 kWhs/day. So far the array may be able to handle it.

Going further, if I were to take the DC loads off the main system and operate them separately, One 245 Watt solar panel should do the job with a battery bank sized at approximately 450 amp-hours - 4 batteries of 225 amp each (battery selection down here is not as plentiful - Trojan T-105 are approximately $260.00 each). Operate this system as a 12 VDC system with a single charge controller. Possibly have two solar panels to ensure redundancy.

Looked at batteries for the first time in this area, and found Trojan T-105s, and a battery put out by Vision battery, a CG6-225 amp hour. Cost is about $330.00. I have also read that gel batteries are more sensitive to charging rates than lead-acid and AGM (both I have used).

So having stated this, possibly a 2.9 kW solar system at 48 Volts could be used. Still doing the math.

Now I would need 14-245 Watt panels, and 12 batteries. 8 would be used for the 48 VDC system, 4 for the 12 VDC system. Both systems would be tied into the grid as back-up. Would probably need a good marine style battery charger for the 12 VDC system - Charles makes a good one.

Hope my math is correct.

Cheers

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

Will look at 24 VDC as well. Once the numbers are in, and they are not that far away, I will have a better sense of what I have to get. Thanks.

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

The hydro costs down here are not cheap if you want to continue the same lifestyle as up north. A good hydro bill down here, using heavy loads such as AC audaciously is approximately $50.00/month. There are those who come down here and rack up $200.00 and more for a hydro bill. Even still, a low annual cost is still around $600.00 or so a year. In Victoria, living on a boat, our annual hydro cost was approximately $800.00 per year at $0.15 per kWh - this is with using electric heat in a floating heat sink. People in houses and condos did not pay as much.

There are hydro-electric projects ongoing in this Republic, but these are a few years out. The other issue is that requirements always seem to stay ahead of the infrastructure so it is expected that costs will go up.

I would surmise that the hydro down here is heavily subsidized because of the effective economy. A good wage outside Panama City is approximately $400.00 (US) while in the city it is approximately $1200.00 (US). Minimum wage here is approximately $2.50 in Panama City and gets less the farther away from Panama city you are.

An example of government subsidizing is the LNG here (it is actually butane). a 30 pound size tank for Panamanians is around $5.00, for us expats it is $30.00. It is illegal for stores to sell to us at the reduced prices (won't get into the reality of the situation). You can also take a ride from Coronado into Panama city for $2.50 one way in a highway bus. These are examples of the subsidies.

It is still reasonable to live/retire here, but the cost of living will go up as supply and demand for products and services continues to grow, not just because expats are coming here, but there is a middle class quickly being developed because of the economy.

Cheers

inetdog · April 2013

Re: Bulding new Off Grid Home in Panama

Panamretiree wrote: »

I am wiring the house so that the fridge, dishwasher, washer/dryer and AC units are on individual circuits. I am pondering having a second 120 VAC power panel and put the AC units on it and wire it directly into the grid. The units that I have installed in another house down here draw 4 amps each on 220 VAC when operating.
...
The dishwasher is also an unknown and will be off at the start of commissioning the house. The fridge and washer dryer will be the only two items that will need to be on the system. I'm of the mind that laundry is to be done early morning to allow the system to play catch up during the day.
...
Looked at batteries for the first time in this area, and found Trojan T-105s, and a battery put out by Vision battery, a CG6-225 amp hour. Cost is about $330.00. I have also read that gel batteries are more sensitive to charging rates than lead-acid and AGM (both I have used).

Free advice, and worth every penny:
1. Consider using a load-by-load transfer option where instead of having the A/C in one panel or the other you can switch it from one breaker to another so that you have the option of running it off battery power if necessary. Certainly routine use should be from grid.
2. Don't use the heated dry on the dishwasher. If your normal water heating is electric, then using the point of use water heating in the dishwasher to get to the sanitizing temperature you need will not cost you any more. But if normal electric water heat is from grid, try to avoid using the heater in the dishwasher off battery. Is the dryer all electric, or does it use gas heat? The solar clothes dryer (a line in the sun) is far preferable to drying clothes with electric heat. Even if the line has to be under a covered porch to stay out of the rain.
3. With a few possible exceptions (and those only by manufacturer claim rather than user experience reported here), GEL batteries can be irreversibly damaged by the same sort of currents that you need to charge the battery bank during a limited number of sun hours. Avoid them if at all possible. They can handle pretty high discharge currents, but still less than an AGM.

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

Thanks much.

Don't understand load-by-load transfer option. Could you elaborate a bit.

Dishwasher not installed or bought yet. Arlene wants the drawer type and yes, the heated dry option will not be used. Open the door here and 30 minutes later everything will be dry. I'm hoping the drawer type will be more efficient.

We will have a hot water on demand system, no storage tank, runs off gas.

The dryer is as, but we use clothes horses and lines. Clothes dry in about a half hour. Don't believe that we ail use it very much, if ever.

Hear you on the gel batteries now that I have done my research. Don't know if and where to get agm batteries here, may very well go with the old standby, flooded. The batteries will be shaded at all times. Shouldn't see more than 75 to 80 degrees F. Had batteries in Victoria that came with a solution in each cell that minimized/eliminated evaporation due to heat. Have to look into this again.

Again, thanks for the information.

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

Question for the thread. Have specified 10 gauge wiring for the 12 VDC runs. Even though this may be overkill on some, I've considered line loss, etc. Have been discussing this further with my Contractor and we have bantered around the idea of using 14 gauge for all 12 VDC runs. Two reasons, expense, but also at the start use 120 VAC then convert to 12 VDC. The hot will be the same, use the neutral as the 12 VDC ground and disconnect the 120 VAC ground (green wire from the fixture). I know the length of a run can add up quickly. For those of you already living the off-grid life, any comments/suggestions?

Cheers

Cariboocoot · April 2013

Re: Bulding new Off Grid Home in Panama

Avoid using 12 VDC all together would be my suggestion.
The Voltage drop is terrible for full-size home wiring (longer than 10 foot runs) and any sizable load (more than 5 Amps). If you must do it, wire the circuit in a returning loop around the place. That way you get essentially double the wire size to any given circuit and more even Voltage distribution throughout. Since you have to 'hit all the points' anyway, running back to the source from the last load should not add that much more wire.

Avoid doing anything where you have wires that were 120 VAC and are now 12 VDC as it is easy to get confused along the way and mix them up. If you must do this, black/hot becomes (+) and white/neutral becomes (-) and the ground wire stays in place (it will be bonded to negative and Earth ground instead of neutral and Earth ground).

vtmaps · April 2013

Re: Bulding new Off Grid Home in Panama

Cariboocoot wrote: »

Avoid using 12 VDC all together would be my suggestion.

I agree! Also, you will have a much better selection (and cheaper) of bulbs, fans, etc.

Curiously, some of the most efficient fans have DC motors but run on AC. They use little "wall wart" type power supplies which are now very efficient. It actually makes sense to create your DC from AC at the point of use. The line loss of a long DC run is greater than the loss in the power supply.

In the event of a catastrophic failure of your system you can just hook up the whole house to a generator without worrying about your DC appliances.

--vtMaps

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

So, the issue then becomes using 120 VAC lighting and fans.

Will do a bit more research on lighting, but for the fans, estimates that I have found are between 0.5 and 0.9 amps, and 30 to 50 watts.

Doing some numbers:

At the bottom end of 30 watts per fan: 0.030*24*3=2.16 kWh/day
At the top end of 50 watts per fan: 0.050*24*3=3.6 kWh/day

At the bottom end 0.5 amps per fan: 0.5*24*3=36 amps/day on 120 VAC or 360 amps/day on 12 VDC
At the top end 0.9 amps per fan: 0.9*24*3=64.8 amps/day on 120 VAC or 648 amps/day on 12 VDC

From these type of numbers, I don't think it's feasible to use 120 VAC fans, might also find that 120 VAC lights also become unrealistic.
I am also seeing that the solar array is the easy sizing part, batteries are going to be a bit more challenging.

Thanks for the input

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

More homework. Will look into this. Agree with the selection, was looking at some 12 VDC halogen in the store yesterday. I think I should buy one and hook it up and see what the numbers really are. They were less than $10.00 for a pot light halogen.

Cheers

BB. · April 2013

Re: Bulding new Off Grid Home in Panama

There are now LED versions of those Halogen track lights. If you need focused light with and can use lower CRI (color rendering index) light--They can save a lot of energy (and reduce heat into your home and reduce A/C costs).

The Led lights are not cheap, but getting there where they can be cost effective for off grid use (and to reduce heat load into the home).

-Bill

Surfpath · April 2013

Re: Bulding new Off Grid Home in Panama

Hi Panamaretiree,
Congrats on the move. I am also a 'remote' off-gridder (albeit only 4 months now). Since you set up and used a system on a boat I am sure you are aware of many of the issues related to off-gridding, but I thought I'd add a few thoughts in bold below that may be helpful.

Panamretiree wrote: »

Now we are in Panama where we get 12 hours of daylight each day. We are having as much window area installed to maximize natural air flow.
Isn't May through December is usually rainly and frequently cloudy in Panama? When you pick out how many panels you need think about this. I almost made the mistake of getting too few panels. In fact I wish I bought more. They are one of the best-values in solar power these days. Dont skimp.Keep your batteries happy

4. 12 VDC fans
5. 12 VDC lighting
If you are gettingan inverter based system anyway, are you sure you want to bother with 12v as well? I realize that it's sometimes more efficient if your batteries directly power appliances, but having 2 banks will be a pain (keeping one bank at 100% is enough as it is). Since you will have an inverter already operating inefficiencies are already in play. Let it do the work. 120v fans are probably cheaper and easier to find and replace.

6. New Panasonic Inverter microwave
Cool, an inverter microwave 8)(I looked it up - seems to do a pretty good job. Will still goble up power if used a lot though).

7. Required kitchen appliances - coffee perk, toaster, etc.
Maybe you can save here. How about French press coffee and gas grilled toast. Cost you zero Kwh.

8. On-demand gas water heater - battery operated igniter
Excellent choice. We use one of those little eccotemps L-5 (2 persons) and it works well (it also fits nicely in a suitcase if you need to fly it in). I can imagine the L-10 model would be better for a bigger house.

11. Big loads such as dishwasher, split AC units (more on this later)
Yikes, these are some of the big ones. Try to avoid.

Had the Kill-A-Watt on the fridge for almost 3 days. The readings were 19.49 kWh in 68.6 hours - 6.81 kWh/day.
6.81 Kw/day is a LOT for a fridge. Methinks a good energy saving fridge for a family of 4 should pull 0.8 to 1.6 Kwh/day. There are others on this forum who do even better.

The Power center will be in the middle of the house with a louvered door and exhaust fan for circulation.
Can you install the powercenter in a room that gets natural ventilation. That exhaust fan is another draw.

Starting to look for sources here in Panama for the parts and pieces I will need for the system. Logistics and supply are a real challenge here.

Importing stuff anywhere is a royal pain. You only want to do it once. This forum is a great place to hash out your ideas and to share your thoughts, before you make your final purchases. A system that keeps your batteries long-lived (so that you dont have to import them too often), one that allows you to monitor your system whenever you travel, and one that others can understand and operate while you are away may be a good thing. Best wishes on the off grid journey!

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

Thanks for the notes. Had some finger problems with the fridge numbers, will review my data and do again.

Going to revisit the 12 VDC lighting and fans. Always open to suggestions until the work has to be done.

Like the idea of a French press.

The Panasonic micro wave also broils, haven't tried it yet but it is supposed to. I can see us cooking outside more often than not, and using a small portable 2 burner gas top and the BBQ.

The exhaust fan for the power center will be using the 12 VDC computer fans that draw a 1/4 amp.

Like your thoughts on panels.

Lots of work to do as we go forward.

Thanks again. Cheers

Surfpath · April 2013

Re: Bulding new Off Grid Home in Panama

Panamretiree wrote: »

Thanks for the notes. Had some finger problems with the fridge numbers, will review my data and do again.

Going to revisit the 12 VDC lighting and fans. Always open to suggestions until the work has to be done.

Like the idea of a French press.

The Panasonic micro wave also broils, haven't tried it yet but it is supposed to. I can see us cooking outside more often than not, and using a small portable 2 burner gas top and the BBQ.

The exhaust fan for the power center will be using the 12 VDC computer fans that draw a 1/4 amp.

Like your thoughts on panels.

Lots of work to do as we go forward.

Thanks again. Cheers

My wife and I lived without power for 7 months while we were purchasing and shipping our solar gear. It taught us where/when we really needed electricity. There are some items you can do without (like inefficient old fridges), some that you can compromise on (like a more efficient microwave), and some that you must have (like ice cold beer).

A big part of that process is hashing out the details with your partner. If they see conservation as a 'fun' game (ie. "how low can we go"), you are on the right track.

I presume where you are located in Panama it can get pretty hot. Ideally, you want to keep your bank at/below 27 degrees (C) to avoid shortened battery life. Like you say, if you have large enough windows, you might be ok (not only for heat but also for battery hydrogen ventilation).

BTW I would guess that a computer fan will do little to cool down a 'solar room' that is located in a central place within a house. Many inverters and controllers come with their own internal computer-like fans already.

Currently my ambient temps might be as high as 29c-31c during the day (with a low of 23c at night). However because I have my batteries close to the cooler earth directly on a large concrete slab on the 1st floor of my house, they only ever experience small shifts in temp (from 25c-27c). Also my solar room was built with extensive cross room ventilation. In comparison, my friend 20 minutes drive away had his batts on a wooden pallet in a stuffy room - guess what his bank temp are during the day: 29-31c. So you see, similar ambient conditions, however sig. higher bank temps in his case.

I'd also advise getting a system that uses Remote Temp Sensing (RTS) to monitor battery temps. Also a cheap useful gadget I got was a Min/Max digital thermometer like this one. It provided a rough measurement regarding the temp/humidity of each room in my house, before I confirmed the location of my solar gear.

High heat is your batteries enemy. Humidity can be rough on electronics. Bugs can be another foe (maybe screen that room).

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

My wife and I are on the same page and we both agree that we have habits that need to be addressed.

The batteries are located outside and the cable run will be less than 15 feet. The batteries will be shaded at all times on a concrete slab with significant ventilation. Have never used a temperature monitor before, but living in Canada did not really need it (my opinion).

The electronic room will be in the middle of the house, it's only one floor. Did this to simplify where power came in, both 120 VAC and 12 VDC, and to hopefully simplify wire runs. The use of the computer fans is to draw air into the room and exhaust it out. Want to put four-4 inch fans in an enclosure much like a bathroom vent fan. I expect this will provide adequate flow, if not, go to plan "B". The door will be louvered.

Getting more data on the fridge. Seems to draw 0.1 amp on 120 VAC. More to follow.

Found some 120 VAC LED lights. 1.5 Watt and 4 Watt. Going to do a test to determine the actual draw. More to follow.

Will be taking some pictures starting tomorrow. Have scanned the house diagram showing the location of the battery bank and interior power center. Hope I can do this.

The wife and I are very excited about this endeavor, but still keeping it in check.

Until later, Cheers.

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Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

More shopping today and happened on 120 VAC led lights. Didn't expect to see them here, but was pleasantly surprised. Panama is not like our fair countries up north with an abundance of supply and diversity.

Have done some number crunching on the LED lights I saw today. They were 120 VAC 1.5 and 4 watt bulbs. There are also LED lights with the GU-10 base. Will be buying some LED lights to do a test run for actuals.

For my outside under the eaves perimeter lighting I intend to install 12 spotlights. They will be on for 12 hours each day - dusk to dawn. There is a good reason for this and will be done. With this in mind and the recommendations from this thread and others I have looked at, my numbers are:

4W LED 120 VAC

amps 0.038 on 120 VAC - 0.38 on 12 VAC
12 lights for 12 hours - 54.72 amp-hrs
12 lights for 12 hours - 0.6 kWhs/day

1.5W LED 120 VAC

amps 0.014 on 120 VAC - 0.14 on 12 VDC
12 lights for 12 hours - 20.16 amp-hrs
12 lights for 12 hours - 0.216 kWhs/day

This lighting string could also be a combination of the two, so I have a good range to work with (trust my math is close). If these numbers are correct, the inside lighting should be easier to account for.

We have also started to discuss the different 120 VAC appliances we use such as the George Foreman, and a small rice cooker.

The rice cooker is a 325 W unit and does rice to perfection in some 20 minutes. We use it maybe once per week so I put it on with the Kill-A-Watt and it used .24 kWh to cook the rice in 0.33 (20 minutes) of an hour. My amp usage should be approximately 0.102 amps on 120 VAC or 1.02 amps on 12 VDC. Should get another chance soon to redo the data.

The "George" is another story at 1000W-120 VAC. We find it to be a great way to not use an oven, and it does a great job. Unfortunately it is just too power hungry and I think we have agreed that it has to go.

Have also sourced some AC ceiling fans that have the look we need. Going to try and find information on the power consumption of these specific units via the internet. Might have to drop back in and see the store as well.

As an aside, since my wife and I have started this, there seems to be all sorts of people interested, or who say they wanted to undertake this type of venture for whatever reason. More on this as it unfolds - always interesting to see who is in for the trip or not.

Cheers

BB. · April 2013

Re: Bulding new Off Grid Home in Panama

I understand that many folks want outside security lighting...

My suggestion is to connect up motion sensor lights (or get a few separate motion detectors to wire into your lighting).

I believe that the lights turning on attract a lot more attention than a a fixed light (which tends to make it easier to see what to "lift").

Of course, you could go farther and use motion detectors for driveway alarms and such. My one concern is that many detectors are built pretty cheaply and may not last too many months (or year) in high humidity.

-Bill

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

Thanks Bill. We have a personal issue that precludes us from changing our requirement at this time. Down here lighting is a deterrent. As always we will be reviewing our requirements as we go.

I am going to upload some pictures of the house.

Cheers

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

Some pictures of the house and work site for your viewing pleasure.

Work site, nicely located. Gives shade in the back almost all the time.

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Couple of pics of the water and wiring runs. They do this on the tamped sand floor then put in a cross hatch of rebar on top, then pour the floor.

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Wiring and water runs in the walls. Again, not too pretty at the start, once parted, not bad.

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Here is the power center in the middle of the house. It will be a 2' by 2' by 8' high room/closet with a louvre door and exhausting out the top.

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More to follow in next post.

Cheers

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

Here are some other pics.

Here is the foundation for my work shed. About 10' by 10', only one in the compound, and may very well be the only one.

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This is the location for the battery bank at the back of the house. There will be a counter running the entire length of the back wall for an outside kitchen area. We initially had it so that it was a short counter, but in discussing the best place for the batteries, behind the shed or here, we picked here because it will be very close to the power center, but far enough away from the outside kitchen area.

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This is the trench for the water and grid lines. Hand dug, pick and shovel, cheaper than bringing in a backhoe.

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This picture shows the roof line that we will have. I'm estimating it at 15 to 20 degrees. The shape is octagon so it follows the path of the sun. Our house is oriented north-south. I imagine some tweaking may be required as we go forward.

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We have also been discussing where to install a wind turbine. We get wind here and it will allow for the solar side of the system to be kept to a dull roar. Found a 48 VDC - 2000 Watt turbine on-line after looking at another poster's web site. As with everything, more research required.

Hope everyone enjoys the pics.

Cheers

Surfpath · April 2013

Re: Bulding new Off Grid Home in Panama

Panamretiree wrote: »

The batteries are located outside and the cable run will be less than 15 feet. The batteries will be shaded at all times on a concrete slab with significant ventilation. Have never used a temperature monitor before, but living in Canada did not really need it (my opinion).
Some constructive thoughts:

* In a warm climate like Panama I highly recommend an RTS. You do not want to cook those batteries. This is a cheap investment and excellent insurance. In a hot climate I believe it's important for your system to know the temperature state of your batteries.

* 15 feet is a long run for thick battery cables ($$ and potential for excessive voltage drop depending on the rest of your system). Also, I saw your house plan. No scale, but it looks like maybe 15 linear feet to the battery bank, however, have you taken into consideration conduit runs & bends? ie. are you really sure you are looking at 15'?

* Will your concrete battery box be exposed to any sun? If so, be prepared for higher temps unless you have some excellent thermal insulation (ie. better than just the blocks). Also think about the times when it's raining torrentially and you need to go outside to take 30 minutes of SG's. Also, you seem to have a pretty long walk between equipment to bank. Not the end of the world, but a pain if you need to make this trip several times

The electronic room will be in the middle of the house, it's only one floor. Did this to simplify where power came in, both 120 VAC and 12 VDC, and to hopefully simplify wire runs. The use of the computer fans is to draw air into the room and exhaust it out. Want to put four-4 inch fans in an enclosure much like a bathroom vent fan. I expect this will provide adequate flow, if not, go to plan "B". The door will be louvered.

* In warm locations: Tiny rooms = moldy + humid + warm/hot = not so good for electronics. Yes, 4 fans running all of the time may help to alleviate some of this, but any constant power draw like this will just add to your import bill.

*I realize that you have the conduit and block going up for your power room, so it may be a done deal, however, perhaps think about no door and maybe some louvered blocks built into (some of?) the other 3 walls. The latter would provide natural ventilation, and maybe avoid the use of fans.

Here's a slightly more extreme thought, but perhaps a good one to consider: Why not put your battery bank and your inverter/controller in your 10 x 10 work shed? It would not add too much to your panel run, everything would be in one location, it would be a fire safety measure, you would not hear all those inverter and controller fans, you could mount a 'mate' (or equivalent) in the house to keep an eye on things, and you can incorporate ventilation (using the same breeze block) on all 4 walls, so no need for all those exhaust fans.

My solar room is also my work room (it's also exactly 10 x 10) and the two can get along quite fine. In fact they seem to be symbiotic:roll:

ps. where are you going to locate your generator?

Again,please see these as constructive thoughts. I am new to solar but I do have experience with design in these conditions.

ps. Good job with the photos. Looks to be a quiet, pretty location!

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

No offense ever taken. This is the most ambitious project I have undertaken in this venue. I know it will not be bullet proof, but there can be changes later on. I don't know of any project where there has never been a better way to do things as you go forward.

A lot of discussion went into the location. We originally were going to put the guts of the system in the work shed. They do things differently here and I had to have individual runs for certain items. This layout and installation was the compromise we came up with.

I will be monitoring things closely and if a change is required, we will be discussing the options.

There's a lot to consider.

Cheers

Panamretiree · April 2013

Re: Bulding new Off Grid Home in Panama

Is there a thread about 48 VDC, or a primer that I can read to understand the differences between 48-24-12 VDC.

Cheers

Building new Off Grid Home in Panama

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