Living offgrid with small solar system(s)

[Jing Joe]

Startup current for a motor under normal load can be anything from x5 to x9 you will need to calculate your own wattage from that.

i concur having always believed about x 6. But everything is relative in that it is only till the rotor is gets going so that the field's back EMF just about equals the applied voltage. Wow that came from the dim distant past of A.C motor theory!! Hope it was right guys?

This should be all over in about 1 or 2 seconds? (but longer proportional to the driven mass. ) But the inverter's inbuilt over-current drop-out safeguards might trip quicker even for a fridge.

I made a suggestion of a super cap across the inverter DC input as one place to start just for input voltage sag. Did anyone think anymore about this?

There is always the chance in (compressor) refrigeration that if by chance the motor is required to start again before most of the liquefied refrigerant has slowly been released into the evaporator, the compressor has some head of pressure and the re-start current could well be M's figure of x 9 or more?

That's why in domestic fridges there's that current overload that trips/times out for x minutes after a short power dropout IF the compressor was running at the time. A clever concept actually.

[Jing Joe]

not to mention propane powered refrigerators that many RVs have.

Propane absorbs a lot.

My old kerosene fridge was converted to gas and used one four foot high bottle about every 6 weeks. Figures will be available for more modern absorption fridges, and hopefully better than that. But they still might still only be about 50% energy conversion efficient regardless of insulation.

The latent heat of evaporation in compressor refrigeration is a winner and from memory has a C.O.P coefficient of performance of at least 2.4.

Some heat exchanger hot water systems quote much higher. Great way to go as I have enthused before.

[George Harmony]

I will wait till i can get such a fridge as above and will temporarely use a small peltier fridge which i will run only during peakhours. Also 12v microwave is difficult to buy here.

Ref attached pict, all the other appliances i already run with my small solar system. Why using an inverter if its not needed?? Perhaps i need one for my planned electric wok cooking. If a 12volt electric cooking plate is available suitable for wok cooking ill prefer that.

[George Harmony]

Someone did compare ac and dc of the same size (140ltr)

My target temperature for inside the fridges was 5 degrees Celsius (second bottom shelf), this was adjusted and set during the 24 hours run up time prior to the test period for each fridge.

The room temperature ranged from 26-29 deg throughout the test (air-conditioned).

The results:

Current consumed during the 24 hour test period.

LG 240 volt fridge.99.6Ah TOTAL, with a 7Amp average whilst in the 'on' cycle and 42.2Amp peak on start up.

WAECO 12 volt fridge..42.2Ah TOTAL, with a 4.5Amp average whilst in the 'on' cycle.

http://www.fridge-and-solar.net/fridgetest1.htm

Its obvious that if you use solar panels the 12v compressor types are most suitable fridges to use.

[IMHO]

Someone did compare ac and dc of the same size (140ltr)

My target temperature for inside the fridges was 5 degrees Celsius (second bottom shelf), this was adjusted and set during the 24 hours run up time prior to the test period for each fridge.

The room temperature ranged from 26-29 deg throughout the test (air-conditioned).

The results:

Current consumed during the 24 hour test period.

LG 240 volt fridge.99.6Ah TOTAL, with a 7Amp average whilst in the 'on' cycle and 42.2Amp peak on start up.

WAECO 12 volt fridge..42.2Ah TOTAL, with a 4.5Amp average whilst in the 'on' cycle.

http://www.fridge-and-solar.net/fridgetest1.htm

Its obvious that if you use solar panels the 12v compressor types are most suitable fridges to use.

That test is just not scientific enough - was the LG fridge an old thing from the 90's? What was his inverter efficiency? Was the inverter output waveform or frequency so bad it resulted in wasted energy? How do they perform when putting an identical hot mass inside to cool down?

The fact is there's no general answer on what's more efficient. There can be a huge variance in energy performance in fridges of the exact same size. The only generalization I think is possible is that seeing as 12DVC fridges are so rare / such a small market, it's highly likely the AC powered ones get a lot more R&D put into them.

Have a look around this website and you'll see what I mean:

http://labelno5.opr.egat.co.th/appdata/labelno5/en

[Jing Joe]

To George (especially) ; would you have guessed since your first post that in less than one month and 274 posts later there would have been so much that so many guys wanted to help you? I've learnt quite a bit too. Quote;- "You can learn something new every day and if you don't, well you're not paying enough attention".

I'm not real intuitive but it could be that not much more now might happen in these posts other than your keeping us up how you sorted it all out.??

Also to tell us how much you are enjoying that free "fuel" that travels/delivers at the speed of light; to you, and you, and you, your neighbour and me.

You are now helping that neighbour like I have helped and encouraged others over the last 38? years and may he in turn help others with the transference of enthusiasm you've shown.

If this topic starts to dwindle down to no more posts, and if I lose track of it, I'm glad to be emailing with you.

Wondering how many other subjects have gone 11 pages on Thaivisa.com with such consistent insightful gentlemanly accord? It's been a positive delight.

"Solar power" --- Go George. Good luck.

Ooops, its into 12 pages now.

Edited March 13, 2016 by Jing Joe

[George Harmony]

@Jingjoe,

Few years ago i already knew that i want to go offgrid when i build my own house on the land i bought 20 years ago. When i was in Udon i asked people there online about solar power.

If i see attached pict of a (small)house in holland with solar gridsystem im wondering what the hell they are doing there. 10 panels x 260wp and only achieving 50% reducement of their monthly bills. They are only 2 people living in that house and 1 have a full time job.

Do you think that you can live offgrid with 2600wp panels????

My answer: Sure, including aircon calculated by @muhendis in one of the previous posts.

Edited March 13, 2016 by George Harmony

[Muhendis]

I know some people who live in Groesbeek and they have an enjoyable amount of computer electronics and electric kitchen gadgets. I think they have gas central heating and cooking but I somehow suspect they could easily live without utility power if they could afford the installation. Does the Netherlands have feed in tariff?

Looking at the pitch angle of the roof in the photograph, I would think they are not getting the optimum annual power from the panels. Also maybe the sun only shines 50% of the daylight hours/year where they are.

[Jing Joe]

hi Guys can you please advise me how do I put a picture in the text box please?

Not just a jpg but a Pdf thats stored for example on my desktop

Edited March 13, 2016 by Jing Joe

[Jing Joe]

Hi Guys. This is a particularly hard item to find but I found and ordered one and sorry not two.

Essential for the steam/air release in Solar Hot Water where the solar collecting plate is higher than the storage tank.

Its only the size of a child's clenched fist.

Air Release Valve / Air Vent (Solar)
Caleffi Brand. All Valve industries Pty Ltd. Aus·
·
[email protected]
Standard Automatic AIR VENT
CODE 250032 10mm

I now understand about "not allowed to use image extension" so just look for the item on their solar section

Edited March 13, 2016 by Jing Joe

[George Harmony]

I know some people who live in Groesbeek and they have an enjoyable amount of computer electronics and electric kitchen gadgets. I think they have gas central heating and cooking but I somehow suspect they could easily live without utility power if they could afford the installation. Does the Netherlands have feed in tariff?

Looking at the pitch angle of the roof in the photograph, I would think they are not getting the optimum annual power from the panels. Also maybe the sun only shines 50% of the daylight hours/year where they are.

Thought the same re the angle.....

Feed in tariff?? I dony know what you mean by this.

Above setup was a subsidised package, soft loan and tax deductable. Does not mind they have a grid system but they could easily achieve a 0 meter situation or even sell it to the grid company, negative result. Lets say 3hours watt peak average is a lot of watts. I presume that they did not adjust their loads, e.g. Still using old model lamps.

@jingjoe,

Dont know if you can upload such files here. You can make a screeprint and adjust the pict with paint and save it as jpg, then upload here. Just open the file and press screeprint. Then open paint and paste it.

[Naam]

Hi Guys. This is a particularly hard item to find but I found and ordered one and sorry not two.

Essential for the steam/air release in Solar Hot Water where the solar collecting plate is higher than the storage tank.

Its only the size of a child's clenched fist.

Air Release Valve / Air Vent (Solar)

Caleffi Brand. All Valve industries Pty Ltd. Aus·

·

[email protected]

Standard Automatic AIR VENT

CODE 250032 10mm

I now understand about "not allowed to use image extension" so just look for the item on their solar section

any small check valve can be rigged for this purpose by adjusting the spring strength. been there and done it recently again.

[Jing Joe]

@Naam Hi. Not sure of your application. Were you referring to a non return valve? = "check valve" ?

I have 8psi header tank and when steam/air accumulates in the head of the solar plates, the float in the air release device at that head, sinks to release air via a needle valve till it floats and seals when refilled.

There is no pressure buildup in my case needing to force against an adjustable spring, its always at 8psi.

Have and open mind to use your method if possible because they cost about AUD$70.

Edited March 13, 2016 by Jing Joe

[Muhendis]

Jing Joe. There's millions of the things here.

https://www.google.co.th/search?q=air+vent+valve+for+solar+water+heater&espv=2&biw=1920&bih=965&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwj5gJqx1L3LAhWSco4KHaw1DbEQsAQIOg

I brought one with me from UK. Sorry I didn't know you were looking for one.

Lurkio. How do you make a check valve do that job?

George. In the UK the Electricity co. pay's you for any excess power you produce. This is the feed in tariff and usually you can get your installation costs back within five years. It is purely a solar thing so you would have a grid tie inverter and no batteries. There is occasionally talk of this happening in Thailand but since the electricity company belongs to the govt. and they are making money from it, it is unlikely that such a scheme will become law. What about Indonesia?

Edited March 13, 2016 by Muhendis

[Naam]

Lurkio. How do you make a check valve do that job?

by adjusting the spring strength (piece of cake) that the valve stays open to release air and closes with the pressure when water reaches the valve. for water temps up to 65ºC a blue PVC ½" valve for 50 Baht will do a perfect job (it does with my pool heating system). as the system is not closed i have no potential pressure problems but the high temp caused by not draining the water when heating is not required would hurt the panels.

talking of pools. how does @George H@rmony he@ts his @pool and runs his @pool pump with an @12V syst@m?

[Naam]

@Naam Hi. Not sure of your application. Were you referring to a non return valve? = "check valve" ?

I have 8psi header tank and when steam/air accumulates in the head of the solar plates, the float in the air release device at that head, sinks to release air via a needle valve till it floats and seals when refilled.

There is no pressure buildup in my case needing to force against an adjustable spring, its always at 8psi.

Have and open mind to use your method if possible because they cost about AUD$70.

non return valve? = "check valve" ?

yes! any additional explanation on top what i wrote required? the continous pressure in your system should be sufficient to relase air only and close when water rises to the valve.

what you have to make sure is that the valve is mounted at the highest piping point. if your storage water temp is 80ºC or more then a green coloured check valve should be used. they are slightly more expensive.

i also experimented with tiny vacbreaker-valves (another penny item) used in Germany to evacuate air from hot water radiators. but the amount of released air was by far too small.

[George Harmony]

@muhendis,i think in holland its the same systrm as in the uk. In indonesia you may connect to your meter but you can not sell any extras.

@naam, how do you know that im also planning for a small swimming pool at my back yard?? I was thinking of such a pump/filter system : https://m.youtube.com/watch?v=trDnJCXJU_g

[George Harmony]

Many near future solar powered plans @naam.

Also aquaphonics with just a 2.1amp 12v circulation pump.

Like this idea. Water will be filtered by the aquaphonics and undernneath a fishpond

[Naam]

Many near future solar powered plans @naam.

Also aquaphonics with just a 2.1amp 12v circulation pump.

Like this idea. Water will be filtered by the aquaphonics and undernneath a fishpond

yeah right @George! the picture you posted looks like properly filtered green pe@ soup. i don't think too m@ny people would like to dip even an @toe into this @brew.

just looking and thinking of it makes my pecker shrivel

[George Harmony]

Fishpond @naam

[George Harmony]

The pict i made a screenprint of this video : https://m.youtube.com/watch?v=b1tBe2vH02Y. ... In indonesian language.

Perhaps indonesian professors are not so bright in aquaphonics as you are @naam

[Naam]

The pict i made a screenprint of this video : https://m.youtube.com/watch?v=b1tBe2vH02Y. ... In indonesian language.

Perhaps indonesian professors are not so bright in aquaphonics as you are @naam

i find your idea fascinating @George as i always wanted to swim in a pool with water that is filtered, enhanced and clarified by shit feces from fish. however, i have not yet consulted the Mrs to hear her opinion. actually i don't dare to ask her because i fear her repercussions.

joke aside, it's time for you to stop hallucinating especially because that stuff you ingest is quite obviously illegal in any country.

needless to mention that my knowledge of aquaponics (not phonics) is rather limited.

[Naam]

just now i realised that you mix pools with ponds.

[IMHO]

Lorentz make some PV-direct powered pool pumps - no mains, no batteries required: https://www.lorentz.de/en/applications/responsible-leisure.html

Unlike that floating toy in the YT video posted earlier, these will turn over your pool water at normal rates so it has a chance of actually staying clean

There are some problems though... Last time I asked, the smaller pump was still well over 100K Baht (not inc. PV - i.e. 8-10x the price of a regular pump), and these are also really only useful in pools where you're manually dosing chlorine. If using a chlorinator and/or UV irradiation they still need to be powered by some other means, and you'd need to work out how to make their runtimes sync with the highly variable runtime of the pump.

[IMHO]

Jing Joe. There's millions of the things here.

https://www.google.co.th/search?q=air+vent+valve+for+solar+water+heater&espv=2&biw=1920&bih=965&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwj5gJqx1L3LAhWSco4KHaw1DbEQsAQIOg

I brought one with me from UK. Sorry I didn't know you were looking for one.

Lurkio. How do you make a check valve do that job?

George. In the UK the Electricity co. pay's you for any excess power you produce. This is the feed in tariff and usually you can get your installation costs back within five years. It is purely a solar thing so you would have a grid tie inverter and no batteries. There is occasionally talk of this happening in Thailand but since the electricity company belongs to the govt. and they are making money from it, it is unlikely that such a scheme will become law. What about Indonesia?

These must be available in Thailand - both of my (Thai) solar hot water systems have them... They sound like a woodpecker when operating.

Edited March 13, 2016 by IMHO

[Naam]

Lorentz make some PV-direct powered pool pumps - no mains, no batteries required: https://www.lorentz.de/en/applications/responsible-leisure.html

Unlike that floating toy in the YT video posted earlier, these will turn over your pool water at normal rates so it has a chance of actually staying clean

There are some problems though... Last time I asked, the smaller pump was still well over 100K Baht (not inc. PV - i.e. 8-10x the price of a regular pump), and these are also really only useful in pools where you're manually dosing chlorine. If using a chlorinator and/or UV irradiation they still need to be powered by some other means, and you'd need to work out how to make their runtimes sync with the highly variable runtime of the pump.

both, the toy George presented and the direct PV-powered pump, are nothing but ridiculous jokes. one can't do the job, the other one is for people who like to throw money out of the window.

[George Harmony]

just now i realised that you mix pools with ponds.

I did not mix it up. Ive said thaT i plan to make a swimming pool and also a fishpond. In fact i already have a natural fishpond which i will also do aquaponics.

Its still mess but as per attached pict perhaps you can imagine a situation like the video. Workers started already deviding the pond. Already made a (pvc pipe) well in case long time no rain. But, still have to finish my house first.

Indeed the pump and filter of the swimming pool in the video is like a toy. Just an example. A stronger pump and pipes build in can be realised, all solar powered.

So its all solar powered and as the title of this thead says im trying to be off grid as much as possible also with fish and aquaponics....hehehehe

[IMHO]

Lorentz make some PV-direct powered pool pumps - no mains, no batteries required: https://www.lorentz.de/en/applications/responsible-leisure.html

Unlike that floating toy in the YT video posted earlier, these will turn over your pool water at normal rates so it has a chance of actually staying clean

There are some problems though... Last time I asked, the smaller pump was still well over 100K Baht (not inc. PV - i.e. 8-10x the price of a regular pump), and these are also really only useful in pools where you're manually dosing chlorine. If using a chlorinator and/or UV irradiation they still need to be powered by some other means, and you'd need to work out how to make their runtimes sync with the highly variable runtime of the pump.

both, the toy George presented and the direct PV-powered pump, are nothing but ridiculous jokes. one can't do the job, the other one is for people who like to throw money out of the window.

Yep. For less than the cost of the Lorentz pump& MPPT controller, you could buy the batteries, accessories and inverter+charger needed to make a pump and a chlorinator completely off-grid. You'd spend a little more in PV to support the longer pump runtime needed for chlorination, and the chlorinator itself - but even then, the total cost of an off-grid solar power supply would still be close to just the Lorentz pump + the PV panels it needs.

[Jing Joe]

Jing Joe. There's millions of the things here.

https://www.google.co.th/search?q=air+vent+valve+for+solar+water+heater&espv=2&biw=1920&bih=965&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwj5gJqx1L3LAhWSco4KHaw1DbEQsAQIOg

I brought one with me from UK. Sorry I didn't know you were looking for one.

Lurkio. How do you make a check valve do that job?

These must be available in Thailand - both of my (Thai) solar hot water systems have them... They sound like a woodpecker when operating.

M thanks re the "millions" Thai web site. The Caleffi Solar one on the second line is what I used. Kind to suggest but I can get here thanks.

Naam. This float device lets the air out by a lower water level alone, not higher pressure. There is no higher pressure involved. Yes it is positioned at a higher point than the solar plate top manifold to ensure any air travels up the 10 inch long 1/2 inch copper pipe and released from there.

Like M above I'm trying to understand how a spring-adjusted pressure relief valve would differentiate between air and water with the 8psi constant pressure open-system involved. You wrote a great explanation but why should just/only water push the valve closed? Does it involve the relative densities so only water will push it closed somehow? A micro hole of the right size would allow the compressible air out but not the virtually non-compressible water to escape but I don't think you are inferring this?

IMHO. The model I use isn't a like woodpecker. If I drain the solar plate then refill, the air just rushes out till the device is full then a few drops hit the roof.

Edited March 14, 2016 by Jing Joe

[Naam]

You wrote a great explanation but why should just/only water push the valve closed? Does it involve the relative densities so only water will push it closed somehow? A micro hole of the right size would allow the compressible air out but not the virtually non-compressible water to escape but I don't think you are inferring this?

whatever i mentioned works and that on a solar water heating system as well on two dozen radiators in my home in Germany, different design but same principle (differentiating between water and air).

here the gaget for radiators which should also work for the hot water supply but not for something like my pool heating system.

\

http://www.ebay.de/itm/automatischer-Heizkoerperentluefter-1-2-Entluefter-Heizkoerperentlueftung-/300667247566

https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcSPA-hkJ6l3puRzjCFVPpFI16IibCV6Z830k6QCAocA-IkAeXN7