An object that converts sunlight into useful heat is usually called a Solar Collector. A Corrugated Iron roof is such an object. A Solar Panel is usually said to convert sunlight into electric power. Both are solar collectors.
Here we want to use solar energy to help produce safe household water.
1. In this example, the Corrugated Iron roof of an house is used directly as the solar collector.
A. Reason: A Corrugated Iron roof that has been painted black can reach temperatures of up to 70 degrees centigrade = 158 degrees fahrenheit. That temperature is the one that rids any type of food or liquid of living organisms.
B. For this example and in order to reach a practical goal, we will specify that exposure to 70 degrees for 1 minute, exposure to 60 degrees for 2 minutes and exposure to 50 degrees for 4 minutes will do the job.
C. Unless you want to do the job by hand, some valve switching will be required. Bimetal thermostats for setting and switching at the above temperatures will be required. There are other types of thermostats and switching possibilities.
D. Moving through those temperature ranges and associated times may require some kind of intelligent control electronics and that is a good reason to see, if your government can attract that type of industry to your country or a country near by so that every thing will be in a price range that you and your population can afford.
2. The idea here is to "braze" water pipes into the Corrugated Iron roof so that maximum surface contact between the roof and the pipes will be achieved.
3. By painting the whole construction black with a none toxic paint the conversion efficiency can be further increased.
4. Unless you can get ready made that is cheaper than your local workman, the above suggestion would appear to be the most basic and cheapest variation.
5. By placing a transparent none toxic material over the Corrugated Iron roof that contains the water pipes, significant heat loss can be reduced. That means that at times the surface temperature of the Corrugated Iron that contains the water pipes will be able to reach temperatures above 70 degrees centigrade in the midday sun, just when the amount of electrical energy coming from the solar panels is more than that which is required by the batteries. See Solar Electric Power.
6. Placing a suitable insulating material that is not the ceiling, directly under the Corrugated Iron roof will complete an efficient sandwich construction.
7. Iron and steel works on your continent can be a viable proposition. Do not use charcoal made from your trees, you will need that for the water filter. Heat from an iron and steel work can be used to drive electric generators, but that is another subject for another time.
How It Works:
1. Rain water is said to be the cleanest water, but it will still pick up things from the atmosphere.
2. Rain water runs off the transparent none toxic material that is on top of the Corrugated Iron roof or simply directly off the roof and on through the Filter. That water is already good enough to drink. If another type of water is being used, the Filter will be connected to that source.
3. When the time is right, water is pumped back up to the pipes that are embedded in the Corrugated Iron.
4. After that water has reached a satisfactory temperature, it is released back down into the collector that is called the HEATER, because it can also have an heater coil embedded into it.
5. The Pump that pumps the water up onto the roof gets its energy from that which was collected by the Solar Panel (SP1). In fact, at midday on the Equator, the system will be able to allow any water to be pumped anywhere within it's power range, even onto fields and or around fish farms.
6. In order to simplify the drawing, only one 4 way valve (V1) is shown in the example drawing. In the practical realization, the constructor will use as many individual valve as their designs require.
7. One could cool down some of the hot water and use it as drinking water.
8. A few simple water quality measuring instruments may be required, but in any case the persons who have this kind of construction will be have very much cleaner waters than others in the same area that do not have a solar roof.
9. If you decide that you want to have perfect drinking water and want to use some of the pasteurized output for that purpose, it can be cooled in shallow ground surrounded by soil, sand and small stones. Water can then be poured on the ground around the tank and that will cause the heat to dissipate quickly, without having any unnecessary land marks around the building.
10. Even with the insulating material under the Corrugated Iron, some persons who are living in arid countries may find it necessary to cool the roof at night by pumping water up to it. An extra water tank will do the job.
11. The water heater can be a specially designed Microwave Water Heater. Extra design work will be required before a Microwave Water Heater can be produced. One of the advantages of a microwave water heater is that it does not use heat conduction in order to reach the water that is to be heated. It will just keep on increasing the temperature of the water at the power level that is applied to it.
ONE SAFETY STATEMENT:
Corrugated Iron within human reach should have all corners rounded and all edges folded in.
In fact folded edges can enable more secure joints between each sheet, because the folds can be designed so that the sheets fit into each other.
If you are also interested in hurricane proofing.
Braze along the full length of the joints would be good.
Nails along the outer edges will not be sufficient.
The same is valid for air inlets along those edges.
You do not want any toxic metals on the roof where you get your water.
The water filter contains:
Sand - Has no effect on the water, filters out larger particles.
Ash - Has no effect on the water, filters out very small particles.
Charcoal - Has no effect on the water, filters out microscopic particles.
Membrane - In this particular drawing, the black separating lines that mark the regions of the water filter represent separators that prevent mixing. For a cheaper solution, you can try using only one membrane at the output of the filter.
Self Cleaning Overflow - The filter was drawn as shown, because self cleaning over flow can be implemented in the construction, whereby the overflow outputs will be at the top of the filter. Decontamination of the filter is done by allowing it's temperature to rise using sunlight. All filters get clogged up at some time or another.
The advantage of this filter is that no matter how far away from civilization you live, once you have a suitable container, you can find all the ingredients that you need to make a good filter right at your finger tips.
For small size and mobile use, you just funnel some water through it right into a small container.
The components used in the filter will not remove dissolved minerals, but there is hardly likely to be very much dissolved minerals in rain water.
Removing dissolved minerals is not classified as being relevant to drinking water.
If you want to build a large pharaoh type OASIS that can funnel large amounts of water into deep underground storage (old mines etc.), chalk can be used instead of ash. There will not be enough charcoal from wood available, but there are other types of coal.
Further Application of Solar Electricity
One of the first things that comes to mind is a fish farm. Carp, Tilapia, Mullet etc. Use types that your government department suggest, so that you can also get advice there. Fish is interesting, because they seem to mostly eat water plants, plankton and the things that fishermen use to catch them on a rod and line.
Here is a point. The majority of water in large natural lakes come in through rain fall, therefore in areas where there is likely to be drought, one could funnel some rain water through a filter to underground storage and use it for any thing, because you have solar power.
As far as fish farms with reusable water are concerned, maybe one should blow in any air that is required in the water, before the water enters the fish ponds, because fish do not normally swim around in air.
A plankton production, a few shrimps and certain types of fishes at the output of your fish farm can help to clean out most organic waste, before water is put back into rivers. Another alternative is to just run that water out onto your banana or other crop field.
Example: If you keep fishes that can digest mud and other types of livestock waste, de-contaminate the livestock waste on corrugated iron plates, before throwing it the fishes, rather than just tying animals on walk ways above the fishes.
Because you have electric power, your government could also bring in small electric farming tools and you setup a small LOW NOISE thing around or near your house that will make you a little independent and keep you busy in your old age.
Example: If you want a day off, apply for one or take one. Do not use any special reasons for it.
Except that the body is weak.
FINAL NOTE: If you are using rain water and you want to reduce the acidity caused by industrial pollution, calcium and magnesium can be used.
Consult your local water board about supply sources and amounts (90% calcium, 10% magnesium in order to get the pH values between 6.5 and 5.5), because it is hardly likely that you will be able to recognize such substances while they are lying in the ground. Some industrial pollutants can wander very long distances.
After all has been said and done, you do not want any elephants to be running you out of your house, because you are the only one in the area with water.
Using a roof as base for solar energy collection