[skippy]

Certainly I'm in a good place to do it as there's plenty of sun here and I do have a flat roof to place any sort of gizmo that I feel like putting up there. Thanks for the help guys!

[martinw]

Certainly I'm in a good place to do it as there's plenty of sun here and I do have a flat roof to place any sort of gizmo that I feel like putting up there. Thanks for the help guys!

Dear skippy,

Dig a big hole in your back yard. Put a big bucket in the middle of the hole.

Put a sheet of clear polythene over the top of the excavated hole, and weight the sheet round the edges with more stones so that the sheet has no tendency to fall into the hole.

Place a small stone on top of the sheet directly above the centre of the bucket below. The sheet will form some kind of inverted cone.

The general idea is that ground moisture will be heated inside the hole (due to in-coming solar radiation trapped by the polythene sheet), and will condense on the underside of the sheet. It will then drip into the bucket awaiting your collection.

If you are feeling brave, you could attempt to augment the ground moisture with "grey water" from your house, but I'm not sure about the possibility of bacteria making the the leap into your bucket.

Ah well, just a thought....

Best wishes

Martin

[martinw]

BTW, that idea came from a "Boys Own" comic a long time ago.

Might just work though..

Best wishes

Martin

[Geof]

The Mother Earth News design is practically identical except the plastic forms a concave vee on a sloping roof and the condensed water runs down the inverted ridge of the vee and is collected at the bottom. The "ground" is black fabric; I thick landscape cloth or something like that would work. The water is intorduced at the top and percolates down. If the sun is intense and the flow is small all the water evaporates before reaching the bottom. Occasionally the fabric has to be replaced becasue it tends to get a build up of salt and dirt when the water is taken to complete evaporation.

Grey water is a no no because the still makes a perfect incubator for nasty bugs. Sometimes depending on the source water the incoming supply needs to be disinfected with bleach.

[martinw]

The Mother Earth News design is practically identical except the plastic forms a concave vee on a sloping roof and the condensed water runs down the inverted ridge of the vee and is collected at the bottom. The "ground" is black fabric; .

Dear Geof,

Mother Earth News !!!!!!

Lorks, it all comes flooding back.

Best wishes

Martin

[Geof]

Dear Geof,

Mother Earth News !!!!!!

Lorks, it all comes flooding back.

Best wishes

Martin

Macrame and candle making , long hair, bell bottom jeans, tie dye shirts.

[martinw]

Macrame and candle making , long hair, bell bottom jeans, tie dye shirts.

Dear Geof,

Please stop right now!

Given my advanced years, it is cruel to remind me of the folly of youth.

BTW, my attempts at tie-dye T-shirts were, frankly, pathetic.

Best wishes

Martin

[skippy]

Martin, I can't do the hole in the ground thing. This picture of my back yard might explain why.
Phil

[Geof]

Martin, I can't do the hole in the ground thing. This picture of my back yard might explain why.
Phil

Life is so tough isn't it?

[martinw]

Martin, I can't do the hole in the ground thing. This picture of my back yard might explain why.
Phil

Dear Phil,

I "feel your pain" but help is at hand in the form of "PLAN B"... a fully functioning , energy gobbling de-salination plant right on your back-doorstep.

Bring it on guys...

Best wishes

Martin

[martinw]

Martin, I can't do the hole in the ground thing. This picture of my back yard might explain why.
Phil

Dear Phil,

Maybe the de-salination idea was not a good one.

It is hard to tell from your photo how far above the sea your back yard might be. Rising sea levels may still get you.

IMVVHO, build an Ark.

Best wishes,

Martin

[mcmxl22]

Global warming is a BIG LIE. Here are a few questions to consider. Where did all that ice come from on the poles? Scientists use greenlands ice to see when a volcano erupted. They found one that erupted 2500yrs ago. If 2500yrs of ice melted from greenland how far would ocean levels rise? Greenlands ice, glaciers, and all this other ice that is/has been melting all came from precipitation. Thus it all started in the ocean and is all returning to the ocean...the water cycle. So will the ocean rise 200ft?

[skippy]

Martin,
we've got a good rise in height if the sea level rises. Global warming would be a good thing for me as I might be able to fish from the chairs in the picture.

On seeing your post about the desalination plant I wondered if maybe you had read about these things in the UK because that's the way things are going here. I can't tell you how many of these huge plants (the size of a very large factory) they have installed and are planning to install here. No one ever reads about the energy requirements of these plants and regarding the output back to the sea, all they say is that it is toxic. By how much no one ever says....
Hey, one has to love that British humour...

[martinw]

On seeing your post about the desalination plant I wondered if maybe you had read about these things in the UK because that's the way things are going here. I can't tell you how many of these huge plants (the size of a very large factory) they have installed and are planning to install here. ...

Dear skippy,

As a back-up system in case of drought, a reverse osmosis desalination plant is going to be built near the site of the 2012 London Olympics. This should be capable of supplying 140 million litres of water per day to the London water network. The plan is to take the water from the Thames Estuary because this has only 30% of the the salinity compared to sea water ( I think). Critics of the scheme say the energy consumption will be double that of a conventional treatment plant. You may be amused to hear that leaks of purified water from the London water mains run at about 915 million litres per day.

Best wishes

Martin

[Geof]

......You may be amused to hear that leaks of purified water from the London water mains run at about 915 million litres per day.

Best wishes

Martin

It is not really very amusing is it? Typical kind of short sighted attitude that I think is dropping us into a lot of future problems. Maintaining existing infrastructure is not 'sexy' so it doesn't get done. But there always seems to be a will to embark on grandiose projects...which will then be allowed to decay for lack of maintenance.

[martinw]

. Maintaining existing infrastructure is not 'sexy' so it doesn't get done. But there always seems to be a will to embark on grandiose projects...which will then be allowed to decay for lack of maintenance.

Dear Geof and Skippy

Geof

Wisdom... but the behaviour of Thames Water isn't really that different from that of most human beings, is it?. Routine maintenance is utterly boring compared to the excitement of a new project. That is just human nature.
I'm guilty in spades, so maybe I should not point the finger at my water company.

Skippy

I could well be wrong, but I think that the main by-product of an RO desalination plant is just brine. If that salt can be pumped out into the sea without creating local high saline concentrations, IMVVHO, no harm done. The salinity of the oceans will not be compromised because the purified water from the plant will find its way back, over time, to the seas, either by drainage or rainfall.


Best wishes

Martin

[Geof]

It is my understanding that an RO desalination plant does not produce a very concentrated brine. RO has a high flow through, which is what Skippy observed in his system. You have to have a high flow through to keep the osmotic pressure difference low enough that you can pump against it.

On the other hand evaporative desalination can have an effluent that makes the Dead Sea look like rain water; this effluent is toxic and needs a large dilution factor before marine life can tolerate it.

[martinw]

It is my understanding that an RO desalination plant does not produce a very concentrated brine. RO has a high flow through, which is what Skippy observed in his system. You have to have a high flow through to keep the osmotic pressure difference low enough that you can pump against it.

On the other hand evaporative desalination can have an effluent that makes the Dead Sea look like rain water; this effluent is toxic and needs a large dilution factor before marine life can tolerate it.

Dear Geof,

I agree to disagree about nothing.

http://www.oas.org/dsd/publications/...ea59e/ch20.htm

Salt pans used for evaporative desalination obviously leave (pretty much) pure salt which might be difficult to dispose of ( add to my fish and chips?).

My understanding (limited) is that small commercial and domestic post-treatment RO units are for purifying water that is in no way salinated to any great degree. They might be used to take away a nasty taste in the Skippy household by , typically, a five stage filtration process, or to produce purified water for an electronics assembly facility.

I believe that in that kind of "non-desalination" application, the throughput efficiency is about 75% in terms of what volume of water goes in and what "pure" product comes out.

Best wishes

Martin

[tmaker]

I live in on a hill in Indiana and am looking forward to having beach front property when the golf of Mexico comes up the Mississippi river.

[Madclicker]

I live in on a hill in Indiana and am looking forward to having beach front property when the golf of Mexico comes up the Mississippi river.

I wouldn't hold my breath waiting for that to happen. In spite of all the doomsayer's shrill screams, I think you'll turn blue first.