Solar and wind energy in thailand

[KevinN]

I have tried batt operated reefers and they draw to many amps to be economically feasable,I have lived in places where grid is not availabel.lights and 12 volt fans are OK,but reefers should be either kerosene or propane fired absorbshion systems.

as fot figuring the wire sizes and mathmatics of the systems,,no sweat.

http://www.cetsolar.com/wiring.htm

That link will get you what you need, But with the cost per KAH in Thailand,if available,you are spinning your wheels,,no one can save the planet without about 500 M people going along with you.

[simon43]

In response to the various comments that you cannot get photo-voltaic solar panels that generate AC, the answer is you can!

When I lived in the UK a few years ago I built a new house in the countryside. Although this was connected to the mains electricity supply, I also wanted to use solar energy to power the house, for environmental reasons. I investigated this and found that several companies manufacture large PV panels that include a built-in DC/AC convertor. The solar cells are internally wired so that each panel delivers 220v AC. And each panel was about 90cm x 35cm (I seem to recall).

So, the idea is that you cover your house roof with these panels and wire them in parallel so you still have your 220v AC, but with a decent current capability.

Now, this is all fine, but what happens when the sun goes down at night? These 'AC' panels no longer deliver any power and the AC configuration also means that they cannot easily be used to charge DC battery packs. This is because these PV panels are intended to be used in association with a mains electricity supply. During the day the PV panels provide the majority (if not more), of the house electricity requirements. At night, the mains electricy takes over.

In the UK, recent laws allows one to connect such PV panels in tandem with the mains power supply. So, you can actually run the mains electricity 'backwards' during the day when your PV panels are working at their most efficient! And the electricy company will also pay you a reasonable rate for the power that your mini-power station generates.

That all sounds great, but from the comments on this posting about the rules of the Thai electricity companies, I simply cannot see the use of such panels being feasible in Thailand. Can you imagine telling the local electricity company that you want to run your meter backwards and will be sending them a bill for the surplus electricity that you have generated!?

All in all, it sounds very much as if Thailand is totally ignorant of the great benefits to the environment that such sustainable energy resources can provide.

[KevinN]

SIMON; Those must have been massive panels to gen. 220 V with any current capabilities. As a solar cell only produces 1.5 V max and current in the milamp.

So for each panel at 220V you would have 147 cells and then you would need to series additional cells to make your required current. and then parallel them to your panel for dist.

I had a set of ARCO panels about 15 years ago when I set up my first low voltage home,each panel was 24X62 inches and produced 3 amps at 12 V. and the only thing we could run was a small pump,13 in. color TV and lights,,we used a bank of trojan deep cycle batterys with 600 amp hr rating. I trried a 2 cu.ft. reefer and it drew 10 amps and ran almost continuously,so that was out.

I found that propane fired reefer, propane or wood cook stove and water heater and space heater is the real way to do it is you have no access to the power grid.

But then again,if you live in the mountains,Pelton wheels will produce all the juice you can use if you can get a 2 inch stream of water with a 50'+ head. a $1500 hydro system will out produce a $50,000 solar system. and I have used both systems.for anything but lights with a solar system,you are just spinning your wheels,unless you got more money than TOXIN and a lot of area to put it up.

[simon43]

These PV panels were (I think), about 1 metre by 60cm in size. I can't recall the typical energy generated per panel, but if you covered the roof of a typical house then you would be able to generate sufficient energy to power that house (eg heating, lights, all appliances etc).

But the downside was that the cost was about £25 - £30k. To recover this cost would take about 20-30 years, so it was certainly a long-term commitment.

The only reason why I did not go ahead with this idea in the UK was that the local planners decided that they did not want my new house to have a blue roof (the colour of these PV panels)

[KevinN]

Yes,Solar is very possible,,But like you say,It is very expensive to set up and with anything but a low voltage setup,You would need a very large bank of batterys or grid for night time.

about the only home generated power that is really possible for the average guy is hydro, In the USA I do have some friends in both California and Idaho that have the facilities for hydro,one generates for his own use,and is miles from the grid,has a water supply high enough to gen 220V ac power, The other is in Calif. and they gen. 220V-150KVA for their farm use and sell the surplus back thru their meter to PPL. But they have 250 ft. head of 24" penstocks.and I have myself and have a number of friends that gen. low voltage[35 amp/12V] from small pelton wheels to keep batts. at max. charge.

And at one time I had a large pelton wheel that we used for low voltage gen. and also ran an air compressor for use in a mine for some drilling,worked well for this,but was a constant fight to maintain the ditches and to keep the forebay cleaned.as deer,cattle,elk and moose raise ###### with ditches.

[dragonmasterzip]

If you are in Thailand, you do not need to use glycol in a water heater. You only need this in area where there is a freeze. Far simpler and inefficient method, but given sizes of a roof still cheap in gravity feed.

Using a small panel and a European continous flow fuel pump for a car pump water to the peak of your roof and allow it to flow down to the bottom. You can collect it in a standard rain gutter and downspout. Roof is covered with plateglass.

This has two advantages. First the heat going into your roof gets whisked away in the water. You can store enormous amounts of hot water in a large containment (dry stacked cinderblock coated with concrete is the cheapest and strongest. depending on the size, you may need to band it.)

You may need a few pumps to get to the roof. Advantage of auto parts is the are much cheaper than the "Solar" pumps. And solar pumps tend to last 3 to 5 years while a good fuelpump is desinged to last 15 to 20.

Simple system, pump when roof is hotter than tank, using a simple bimetal thermacouple switch.

While glass potted batteries are clearly the way to go, one cheap way to get batteries is to get them from Golf courses. most are rated for 5 years and have 7 years of life but usually get swapped out every 3 years. Last thing any golf course wants is a rich guy forced to walk! because the cart's batteries died.

I used to get the old batteries for scrap value and often got 5 years or more out of them.

For lighting again look to car parts. All those tensor lamps years ago had step down transformers to take them from 110/220 to 12 v.

For frigs again cars campers frigs are small add eatra insulation to them and buy 4. 4 camper frigs will give you more space than a single "12v solar frig"

Super insulating your house is the way to go for cooling.

In Florida they did an experiment where 4 identical houses were built with the only difference being the roofing material. White metal roofs reflect 80% of the heat back off.

In California, they super insulated a house and took it from an annual heating cooling bill of $12,000USD (9,000 square foot house) to $271 using passive solar gain in winter and super insulation and passive soalr rejection (awnings etc.) in summer.

Expanded foam along roofs and in attic spaces cuts down heat infiltration.

Houses built using "expanded concrete" (this is concrete which is whipped and fills with air bubbles then cut into blocks 18" thick with notches and grooves so the blocks are dry stacked and coated. They have an R30~40 value.

I can go on. but let me stop here.