by Brian White
Hydropower is used around the world and provides lots of electricity to many people. However, there is a problem. Small sites and sites where the water falls less than 2 meters are usually not economical to develop. By that, I mean that if you borrow money to develop the site, the interest payments on the money will be greater per year than the value of the electricity produced!
Economically, it is a no brainer ... You DON'T develop a site that puts you in debt forever.
BUT, there are millions of these types of hydro sites ... unused ... around the world. Many of the sites were used up to a hundred years ago or so with waterwheels to grind corn, etc. and indeed to run whole factories of machines.
Along came the internal combustion engine and electricity from oil and coal and it was no contest. The choice was simple ... replace the huge slow moving water wheel and all its cogs and wheels with engines OR electric motors.
And they did.
Now for some lateral thinking!
The entire mindset of the hydropower community is bent on converting that low grade power into electricity and feeding it into the grid.
Please Please PLEASE, drop that idea!
It cannot be done. (economically).
You cannot use the electricity to pay back the money you borrow EVER! The machinery and connector is simply too big and too expensive.
BUT, (lateral thinking!) you don't have to convert hydropower to electricity! (or any type of rotational device!)
You need a really cheap device to use that power AND obeys the pervasive first law of economics!
Enter stage left, the PULSER PUMP
- It is cheap!
- It has no moving parts
- You can make one completely DIY if necessary
In my part of the world, every part needed to make one can be bought in my local hardware store.
Many people find the working of a pulser pump quite difficult to understand but they are actually based on widely used science. If you have ever used a vacuum cleaner, you have used a flow of air to pump solids or liquid! The flow of air is provided by the same basic principle that sucks air down the sink or bath plughole when you pull the plug. Just as that air gets sucked down the pipe, air gets sucked into a pulser pump too! It is that simple.
When a pulser pump pumps water up an inclined pipe another principle is used. However it is readily seen in nature. It is the wave! Air traveling over the ocean makes waves as it moves over the water. Exactly the same thing happens in a 3/4 inch pipe or 1 or 2 inch pipe. And when the wave is high enough, it blocks the pipe and becomes plug flow. So, pulser pumps are based on simple principles found throughout nature. It just happens that they are mathematically difficult to describe. And so people back off! BUT experimentally, it is a piece of cake to make a pulser pump or a model that shows how it works.
I have made pulser pumps which work on a half meter head and about 250 liters per minute of flow to power them. (these use 4 inch diameter pipes for the power flow) but I recommend a minimum flow for a commercial pulser pump to be about 600 liters per minute of water.
Details of how to make a pulser pump are available on the internet at http://members.tripod.com/~nxtwave/gaiatech/pulser/index.htm
I noticed the pulser effect and made my first pulser pump in 1987. In 1988, I made a few more larger ones and cannibalized the parts for one that still runs today. It pumps water for sheep and cattle that are housed in a shed for the worst months of winter. In the summer, my brother sometimes uses the pump to fill several barrels of water that he transports to sheep in waterless fields. He also uses the pump to fill his sprayer with water.
This saves his tractor and pto powered pump the 15 minutes of diesel, and machine life that it takes to fill the sprayer or the barrels.
That's fossil fuel substitution by the way! And reduced CO2 too.
Because my pulser pump is really small, I have only been able to make proof of concept devices for other uses for the pump.
I have used it to agitate animal slurry. (this makes it rot faster and removes the deadly threat of hydrogen sulfide gas buildup). I do not know how efficient it is at that job but it definitely works.
I have used a pulser pump to wash sand for use as building material. (This could be a really important use). I am a stone mason and the sand I washed was an excellent product.
Rivers carry a whole lot of sediment and it would be natural to collect and use some of it.
I have also used the pump to water my vegetable garden, to extract heat from a chimney, to produce a partial vacuum, to dry vegetables (an attempt at vacuum drying that was only partially successful), to produce a fine spray (hothouse applications), and to make a geyser and a fountain. (Leisure and park applications).
I have not had peer review of the pump. Institutional science largely ignores it. Even dislikes the ideas behind it.
Anyway, it is there, it works and has done for a decade and a half.
Pulser pumps obey all the principles of E F Schumachers book Small is Beautiful. They foster independence and can help develop local pride and local infrastructure. They do not need outside tech support if they break down. General maintenance involves cleaning the inlet sieve and that's about it!
Pulser pumps are patent free so feel free to make and sell them! But please tell me of your work.
The pulser pump came from my experiments with a coffee jar pump! I made a hydropowered suction pump to water my garden in the summer of 1987. It was made of about 20 coffee jars and pipes and tubes connecting them.
It pumped to 6 feet high.