Living offgrid with small solar system(s)

[George Harmony]

For examples and specs of the electrical wok i posted indeed picts from our good friend google. I did use a an electrical wok when i was living in holland.

About fla batteries storage i ment outside=outside in a shed, thus not in my house where i live.

For cooling a housr i started a thread about eveporate coolers and specialists there said its not wise in a humid area.

Our friend google says there are aircons with power consumption of only 260watt. I wonder if such aircons can cool down a 4x4m room.

LG S-05LPBX-R2:

[Crossy]

My imagination is trying very hard to picture living in a condo on the tenth floor with a Honda generator running. I guess the neighbours didn't object to the noise and you probably had it on the balcony to deal with the fumes? But well done for the improvisation. As you say, it's surprising how little power you need to live a reasonable life.

Big balcony, neighbours had all moved out. Actually four units remained occupied one being next door, shared the power with her, no complaints

Main problem was showering with the limited water available, we gravity fed from the fire tank on the roof but had to ration because, even after the flood went down, there was no way to re-fill it.

@George. 4,500 BTU would certainly take the hot edge off a 4x4 room, much depends how cool you actually need to be.

[George Harmony]

My imagination is trying very hard to picture living in a condo on the tenth floor with a Honda generator running. I guess the neighbours didn't object to the noise and you probably had it on the balcony to deal with the fumes? But well done for the improvisation. As you say, it's surprising how little power you need to live a reasonable life.

Big balcony, neighbours had all moved out. Actually four units remained occupied one being next door, shared the power with her, no complaints

Main problem was showering with the limited water available, we gravity fed from the fire tank on the roof but had to ration because, even after the flood went down, there was no way to re-fill it.

@George. 4,500 BTU would certainly take the hot edge off a 4x4 room, much depends how cool you actually need to be.

One more remark about my posted pictures in this thread... If the picts are bad quality pics these are picts i made myself in my current situation hahahahahha

My living room temp at noon is usually 29-30c when outside is 32-35c. In the evening i dont need to cool down as 26+ is for me acceptable. Im happy if i can reach constant temp of 25-26c.

Added:

IS IT INDEED ONLY 260WATT power consumption???

Edited February 25, 2016 by George Harmony

[IMHO]

About the cooking with an electric Wok. Its just an idea for the future. Perhaps@Muhendis can predict the lifetime of the battery if I draw daily 200-400 watt hour using for example 125Ah battery. Also an inverter of lets say 2000 watt will not last forever. Financially speaking, is it then worth to cook like this.

Ok George I'm going to start with the basics. Please humour with me if you already know this.

125Ahr........ What this means is that you can take 125 Amps from the battery for 1 hr. At the end of that time the battery would be discharged and close to death. It would ideally need to be fully recharged to minimise sulfation before you use it again. That is a cycle. Deep cycle batteries are good at this type of cycling due to the construction of the plates etc. You may be able to get up to 500 cycles like this but 300 is more likely. Generally it is preferred to keep the depth of discharge to somewhere between 20% to 50% This will extend the life of the battery but at the cost of only using part of its capacity.

Your 125Ahr 12v battery according to Ohms Law will drive a 1.5KW load for one hour (12v x 125Ahr) so by reducing the maximum discharge to 50% you would reduce either the time for a 1.5KW load to 1/2 hour or drive a 750 watt load for one hour. this will add many useful cycles to the life of your battery but unfortunately it is not a proportional relationship. As time goes by the plates will degenerate, internal resistance will increase and the dreaded sulfation will occur. This can be minimised by regular maintenance. If the battery is FLA (That's the one with screw caps to allow topping up of the acid with distilled water and to allow readings of the SG to be made) then you can keep an eye on the acid level and apply a desulfation cycle ever so often.

If you draw 500 Watt/hr per day then that would be the same as 41.7 Amps/hr (500W/12V). Using your 125 Ahr battery and limiting yourself to 50% capacity then you would be able to use the battery for 1.5 hrs before recharging. I'm sure you can now work out a few other scenarios from this.

Your idea that a 2KW inverter not lasting for ever is possibly true but if it is designed and built to a reasonable standard then the likelihood is that it will be replaced due to better things becoming available rather than old age or component failure.

If you are interested in further reading about batteries you might like to google "Battery University".

Good post, and I realize you kept this as simple/basic as possible, but there's still a couple of points I'd like to clarify for the readers:

1. There's no way you can discharge a lead acid battery 100% even more than a few times before it's kaput - and ech time you discharge it fully, you won't get the same amount of charge back into it again. Anything more than about 80% DOD is going to reduce it's cyclic life very, very fast. The lower the DOD, the more cycles you'll get though, as you noted.

2. The amp-hour rating on a battery is generally specified as it's 20 hour rate, not a 1 hour rate - i.e. that 125Ah battery is actually rated to supply 6.25 amps for 20 hours. If you pulled all it's capacity in just an hour, you're not going to get anywhere near 125 amps out of it, and you'd probably also shorten it's lifespan to an amount of cycles you could count on your fingers Read about Peukert's Law for more info on this: https://en.wikipedia.org/wiki/Peukert%27s_law

Edited February 25, 2016 by IMHO

[Muhendis]

My imagination is trying very hard to picture living in a condo on the tenth floor with a Honda generator running. I guess the neighbours didn't object to the noise and you probably had it on the balcony to deal with the fumes? But well done for the improvisation. As you say, it's surprising how little power you need to live a reasonable life.

Big balcony, neighbours had all moved out. Actually four units remained occupied one being next door, shared the power with her, no complaints

Main problem was showering with the limited water available, we gravity fed from the fire tank on the roof but had to ration because, even after the flood went down, there was no way to re-fill it.

@George. 4,500 BTU would certainly take the hot edge off a 4x4 room, much depends how cool you actually need to be.

One more remark about my posted pictures in this thread... If the picts are bad quality pics these are picts i made myself in my current situation hahahahahha

My living room temp at noon is usually 29-30c when outside is 32-35c. In the evening i dont need to cool down as 26+ is for me acceptable. Im happy if i can reach constant temp of 25-26c.

Added:

IS IT INDEED ONLY 260WATT power consumption???

I had a quick look at the air con and the quoted input power is indeed 260 Watt. I've been looking for something like this for ages I had a look to see where I could get one but Lazada.th don't do them. Only Lazada in Indonesia

[George Harmony]

I think its not worth that i send it to you if the courier costs is too high.

Blessed Indonesia

[Naam]

LG S-05LPBX-R2 / 260 Watt

product discontinued

https://translate.google.co.uk/translate?hl=en&sl=id&u=http://www.lg.com/id/split-air-conditioning/lg-S-05LPBX-R2-split-ac&prev=search

[George Harmony]

@naam, there are also other models with power cons up to max 500watt only.

@jingjoe,i agree with your KISS principle. For me its a challange to be not depending on the grid, gas and other fuels.

Lets say i need a system of 300wp. Already have 80wp which i will use for my lighting and waterpump. The planned extras is for electric cooking and also to be on the safe side when i use other appliances in the evening. Lets take an example of the extra investmen needed as i am still living in thailand and buy at amornsolar (.com).

Roughly prices

2 x panels 120wp 9.000 bht

1 x charge controller 2.000 bht

1 x expensive inverter 9.000 bht

2 x batteries 12.000

With roughly total 32.000 baht investment only i can be offgrid with the same comforts as i were ongrid and also not depending on gas/fuel. If i only use the inverter for cooking max 30min per day i in fact dont need an expensive inverter. Can be half of the above price. I think i keep it simple this way

Ive seen grid-tie and offgrid examples and i think WOW....why so much???

Pict with the current real amorn prices.

[Naam]

@naam, there are also other models with power cons up to max 500watt only.

now you are talking George! when i asked whether you are willing to increase your solar capacity you dodged. but with 500 Watts one can do "a lot of DIY". e.g. rigging a system consisting of automotive aircon parts, main part a car a/c compressor belt-driven by a 12V DC motor for those who hate inverters.

[BKKdreaming]

trying to pull 50 amps for very long is like a dead short , even the cables will get hot ,

I know the numbers might work , but has anyone actually done it ?

I think you need to think more about solar cooking , and a little solar water heating (easy in the tropics)

it would be interesting to see a 12v Air conditioning set-up with auto parts for a room , again has anyone done it ?

and how much temperature drop do you get and does it cut the humidity too

the 12v cookers work but are best when you are driving down the road charging the batteries ,

the 12v microwaves get very bad reviews on Amazon ,

I am always looking for 12v cooking things to use in my Camper van , but most of them pull too much power to use unless the motor is running ,

they are made for large motorhomes with large back-up batteries......

Anyway please report back on what works and more important what does not work

[IMHO]

@naam, there are also other models with power cons up to max 500watt only.

@jingjoe,i agree with your KISS principle. For me its a challange to be not depending on the grid, gas and other fuels.

Lets say i need a system of 300wp. Already have 80wp which i will use for my lighting and waterpump. The planned extras is for electric cooking and also to be on the safe side when i use other appliances in the evening. Lets take an example of the extra investmen needed as i am still living in thailand and buy at amornsolar (.com).

Roughly prices

2 x panels 120wp 9.000 bht

1 x charge controller 2.000 bht

1 x expensive inverter 9.000 bht

2 x batteries 12.000

With roughly total 32.000 baht investment only i can be offgrid with the same comforts as i were ongrid and also not depending on gas/fuel. If i only use the inverter for cooking max 30min per day i in fact dont need an expensive inverter. Can be half of the above price. I think i keep it simple this way

Ive seen grid-tie and offgrid examples and i think WOW....why so much???

Pict with the current real amorn prices.

2x 120Ah batteries gives you a total of 2880Wh, which means about 1400Wh of safely usable capacity - or 1000-1200Wh after you factor in some losses. Can you really get by on just 1 unit/day? That's offsetting just 150 Baht/month of electricity usage.

Edited February 26, 2016 by IMHO

[Muhendis]

I think the savings are not so important as actually having fun doing it. My system would take ten years to payback during which time I will have gone from the temporary supply to a normal tariff supply (mine is a hybrid system). Also electricity prices will not stay the same during that time. There is also the feelgood factor of knowing that you are helping the world in your own small way.

[Naam]

1. it would be interesting to see a 12v Air conditioning set-up with auto parts for a room ,

2. again has anyone done it ?

3. how much temperature drop do you get

4. and does it cut the humidity too

1. the principle and the required parts are the same like a conventional split unit except that the compressor is belt driven by an electric motor,

2. yes i did many rainy seasons ago in the African bush,

3. depending on compressor size and power supply the same like a conventional unit,

4. of course!

[George Harmony]

Im wondering why they dont invent a fridgr/freezer which is also an aircon....

About the solar system how small or big it is, in my case i decided to go offgrid due to the regular outages in the (big) city where i am now. How do you feel if you have power outage during world cup footbal finals and then the outage is more than 3 hours....hehehehsheee

Besides its ofcourse a challenge and indeed fun to be offgrid.

With my current 80wp i am already satisfied. Intended to get only one 50 or 100wp panel extra and a bigger battery capacity. With above plan for cooking i think its more than enough cause i will cook during peak hours also and using only +/-450watt hour.

@naam,i still not plan for an aircon but am orientating in alternatives.

After my housr is completely finished it will be also a challenge to have a solar powered vehicle

[BKKdreaming]

just found this website

http://ac2015.net/posts/portable-air-conditioner-for-car-12-volt/

lots of info and may help you make something to use with your solar set-up

[George Harmony]

bkkdreaming wrote: I think you need to think more about solar cooking , and a little solar water heating (easy in the tropics)

I tried a simple selfmade solaroven. It works but the weather here is too unreliable to have a steady (daily) cook method.

Solar water heating is not so difficult to make. I will make one soon and store the heated water in an insulated tank.

And, to be honest in my current situation its more cheaper to buy (take away) food in a restaurant rather than cook myself. In the weekends though its fun to cook at home and hopefully soon with an electric wok

[Naam]

Im wondering why they dont invent a fridgr/freezer which is also an aircon....

for the same reason that a small dog can't be used to do the ploughing job of a water buffalo.

...indeed fun to be offgrid

[George Harmony]

My simplistic thoughts of a fridge with attached an independent compartment which will also be cooled by the freezer. Insulated freezer space will not be effected if there is blower in that extra attached space. Or am i talking rubbish...???

[IMHO]

I think the savings are not so important as actually having fun doing it. My system would take ten years to payback during which time I will have gone from the temporary supply to a normal tariff supply (mine is a hybrid system). Also electricity prices will not stay the same during that time. There is also the feelgood factor of knowing that you are helping the world in your own small way.

I hear you, I'm just trying to imagine what I'd be able to run off such a system.. And I'm still thinking

My first thought was my outdoor garden lights - I have 20x 7 watt LEDs for that, so for 12 hours runtime (overnight) that's 1,680Wh - still significantly more than such a system could support. TV? nope, the combined usage with media players and hi-fi would mean only 2-3 hours/day. Computers? nope, they need to run for much, much longer. Small fridge? also nope. Pump? no chance with the amount of water used at my house.

None of my loads are small enough

I suppose it could be used to power phone/tablet chargers, but for that it'd be overkill

[Naam]

My simplistic thoughts of a fridge with attached an independent compartment which will also be cooled by the freezer. Insulated freezer space will not be effected if there is blower in that extra attached space. Or am i talking rubbish...???

you are talking enigmas. define "independent compartment / extra attached space" and the function of the blower.

may i assume the blower is meant for blowjobs moving air from point a to b? if yes, please define points a and b.

[George Harmony]

@imho,

Till now i did talk abt indoor supply of solar electricity.

I was thinking of 2-3 lanterns for my backyard later like attached pict from someone in indonesia. He uses 5watt led bulbs. Per piece about +/- 2650 baht incl 7ah battery and wires but excluding the steel pipe.

About your other needs,its the choices you made. I am happy what i have and also if i can realise my plan to cook using solar power

[Muhendis]

I think the savings are not so important as actually having fun doing it. My system would take ten years to payback during which time I will have gone from the temporary supply to a normal tariff supply (mine is a hybrid system). Also electricity prices will not stay the same during that time. There is also the feelgood factor of knowing that you are helping the world in your own small way.

I hear you, I'm just trying to imagine what I'd be able to run off such a system.. And I'm still thinking

My first thought was my outdoor garden lights - I have 20x 7 watt LEDs for that, so for 12 hours runtime (overnight) that's 1,680Wh - still significantly more than such a system could support. TV? nope, the combined usage with media players and hi-fi would mean only 2-3 hours/day. Computers? nope, they need to run for much, much longer. Small fridge? also nope. Pump? no chance with the amount of water used at my house.

None of my loads are small enough

I suppose it could be used to power phone/tablet chargers, but for that it'd be overkill

I run rather a lot off my system including my woodworking power tools several pumps and a house full of all sorts of gadgets. One of the fewer mentioned problems is the startup current for ac motors. The capability of the inverters needs to cover this. I dread to think what my utility supply would be like if I tried to use it for my purposes.

My utility supply meter (temporary) is about a kilometre from my house hence my desire for an independent supply.

In addition to the electrical bits I also have a flat panel hot water heater which is scolding hot by the afternoon and is good still for an almost warm shower the following morning if I can get in there quick enough (before her indoors).

[George Harmony]

@naam,

Many households have a combi fridge/freezer. If for example above the freezer an extra compartment will be buildin and one way or another also cools that compartment is it possible without extra wattage. The freezer and fridge inner space will not be effected if that extra compartment have an outside hole. In that extra compartment is a fan that blows cool air out. To where? Up to you. You can use insulated flexible pipes.

Also imaginable for only a freezer.

Just a thought......

[Naam]

is it possible without extra wattage

no it is not!

[IMHO]

@naam,

Many households have a combi fridge/freezer. If for example above the freezer an extra compartment will be buildin and one way or another also cools that compartment is it possible without extra wattage. The freezer and fridge inner space will not be effected if that extra compartment have an outside hole. In that extra compartment is a fan that blows cool air out. To where? Up to you. You can use insulated flexible pipes.

Also imaginable for only a freezer.

Just a thought......

Every refrigerator has a maximum amount of cooling power (BTU), and that doesn't include very much overhead - just enough to keep temps stable on extra hot days, or for those who like their beer extra cold. Not the kind of reserve capacity you'd need to keep another enclosed space cold as well.

And even if you did plumb in another insulated box small enough that the refrigerator could actually keep it cool too, it's not happening for free... it will use more power.

Compared to AC's, refrigerators have tiny cooling capacity - like 500-1000 BTU (maybe 1200/1300 for a really big fridge) - typical household AC's are 9,000 to 35,000 BTU.

The other thing to remember with fridges is, they put out more BTU as waste heat than they do BTU as cooing. The harder you make them work, the hotter they're making the room they're in.

Edited February 26, 2016 by IMHO

[Jing Joe]

1. it would be interesting to see a 12v Air conditioning set-up with auto parts for a room ,

2. again has anyone done it ?

3. how much temperature drop do you get

4. and does it cut the humidity too

1. the principle and the required parts are the same like a conventional split unit except that the compressor is belt driven by an electric motor,

2. yes i did many rainy seasons ago in the African bush,

3. depending on compressor size and power supply the same like a conventional unit,

4. of course!

When you guys get an A/C going, don't dismiss the potential to use the condensate derived from the humidity in bold above.

I've measured the TDS Total Dissolved solids as near zero and its drinkable in that respect.

No hormones or pesticides from rivers or dams that aren't filtered out with reverse osmosis filters as with in-home or vending machines.

It's the same principle as natures dew and just need to keep the A/C clean and free from dust.

No mozzie fogging nearby lately?

Cover the bucket with a lid with a hole for the tube for extra cleanliness.

At the very least is good for car battery water and car radiators.

Here in Oz they were selling machines to produce pure drinking water using exactly the same refrigerant principle.

Not real good in dry climate.

Is there cheap water-quality lab testing for bacteria near you? Probably not applicable anyway.

Free solar power, free hot water, free pure water. Good luck.

[IMHO]

1. it would be interesting to see a 12v Air conditioning set-up with auto parts for a room ,

2. again has anyone done it ?

3. how much temperature drop do you get

4. and does it cut the humidity too

1. the principle and the required parts are the same like a conventional split unit except that the compressor is belt driven by an electric motor,

2. yes i did many rainy seasons ago in the African bush,

3. depending on compressor size and power supply the same like a conventional unit,

4. of course!

When you guys get an A/C going, don't dismiss the potential to use the condensate derived from the humidity in bold above.

I've measured the TDS Total Dissolved solids as near zero and its drinkable in that respect.

No hormones or pesticides from rivers or dams that aren't filtered out with reverse osmosis filters as with in-home or vending machines.

It's the same principle as natures dew and just need to keep the A/C clean and free from dust.

No mozzie fogging nearby lately?

Cover the bucket with a lid with a hole for the tube for extra cleanliness.

At the very least is good for car battery water and car radiators.

Here in Oz they were selling machines to produce pure drinking water using exactly the same refrigerant principle.

Not real good in dry climate.

Is there cheap water-quality lab testing for bacteria near you? Probably not applicable anyway.

Free solar power, free hot water, free pure water. Good luck.

I think I'd probably want to give it a very big dose of UV irradiation before I drank it

[IMHO]

@imho,

Till now i did talk abt indoor supply of solar electricity.

I was thinking of 2-3 lanterns for my backyard later like attached pict from someone in indonesia. He uses 5watt led bulbs. Per piece about +/- 2650 baht incl 7ah battery and wires but excluding the steel pipe.

About your other needs,its the choices you made. I am happy what i have and also if i can realise my plan to cook using solar power

Got a link to a vendor that sells what's in your pictures for under 3K Baht? Doesn't have to be Thai...

[George Harmony]

In indonesia:

https://m.tokopedia.com/ecolife/paket-lampu-pju-solar-sel-mini-cocok-ut-jalan-lingkungan-perumahan

This one is all buildin and cheaper:

https://m.tokopedia.com/utashop/lampu-tenaga-surya-penerangan-jalan-umum-pju-12-led-solar-panel

[IMHO]

In indonesia:

https://m.tokopedia.com/ecolife/paket-lampu-pju-solar-sel-mini-cocok-ut-jalan-lingkungan-perumahan

This one is all buildin and cheaper:

https://m.tokopedia.com/utashop/lampu-tenaga-surya-penerangan-jalan-umum-pju-12-led-solar-panel

OK not quite was I was expecting... with 2x 6V 4Ah cells, and using a 10W panel + 7W LED, it has only ~5 hours runtime/night - and even that's running the batteries to > 70% DOD, so they'll probably only last a year.