Ram Pump Hydro

Steven Lake

Well, it seems that, per the grapevine, our very own local mad scientist is back at it again. This time he's got something that seems like a rather interesting design. Apparently he's got an experimental hydro system that he built that runs a single hydro generator (I don't know the wattage, only that it's micro hydro) from a water tower using ram pumps. According to what I understand, and again this is just grapevine, so I haven't seen it myself and can't verify this, he's taken a whole chorus line of old ramp pumps and mounted them on a river with about four feet of fall at the delivery point, and is pushing, as per the claim, almost 50 GPM of flow to the top.

Now yes, I'm taking this with a grain of salt given the numbers offered, but if true, and he's actually pushing about 50gpm of water to the top (ie, the same amount in as he's using) with a set of ram pumps (probably big ones to get that kinda volume) he would have, in theory, likely one of the best micro hydro systems for small, low fall streams. So if you consider the following numbers, 100ft of fall * 50gpm x 0.09 (turbine efficiency) he would in theory be producing about 450 watts with this system.

Do I believe this is true and he really built it? Probably not. Well, I correct that. Yes, he probably built it, but no, he's not likely getting the numbers claimed. Especially since "embellishment" is a common trait among some people in my area. *rolls eyes* Anyhow, real or not, if such a design were possible, it does present one with a very interesting scenario for power generation from low head streams. Even if it's not, it is still an interesting theoretically "what if".

mike95490

Re: Ram Pump Hydro

considering a RAM type pump may be about 10% efficient, stacked pumps producing more than a couple teaspoons would be amazing, and would solve my problem of only 10' head.

Steven Lake

Re: Ram Pump Hydro

Well, I've seen some really big industrial ones that can do 50 gallons a minute, but at a 10% efficiency they have to suck in some 500 gallons a minute to do that. With a river flow rate that high you may as well do low head hydro, such as a water wheel. If you only have 10' of fall, and a way to put one in, I'd suggest a nice 8' overshot water wheel. Depending on your flow you could get a couple HP out of it, which is enough to give you a decent wattage, since 1hp = 768watts, minus losses to friction and such. The basic math is "# of gallons per minute x .000253 x height in feet x efficiency = horsepower". So if you have 700gpm, and a typical efficiency of 0.55, you should get this: 700 x .000253 x 8 x .55 = .779 horsepower.

It may not seem like a lot, but 0.779 minus losses for other things is more around the area of 0.700 usable, which is a little over 500 watts usable. Heck, 500w * 24hrs = 12kw every day. Heck, I use that much mains power per day. So if you have 10' of fall, heck, build your own 8' overshot water wheel and soak up the power it'll generate. As for the story I related above, I agree that it's probably embellished quite a bit. Even so the idea was interesting enough to mention, even if it's not possible. Now an 8' water wheel for you, that's possible.