The HighDro Power system converts falling wastewater into energy

[txlibdem]

Here's an innovative idea to eke a little power out of your shower. (*see what I did there?) The inventor, Tom Broadbent, has already build a prototype. All systems are "go."

"HighDro Power works by using the water discharged from appliances such as showers, toilets and sinks in high-rise apartments. The water goes down the pipe and hits four turbine blades that drive one generator.

The device, which Broadbent hopes will be picked up for commercial production, would be able to provide energy directly to the building or could be sold back to the national grid."

http://planetgreen.discovery.com/tech-transport/plumbing-device-brings-new-meaning-to-waste-to-energy.html

I hope this guy can find a company willing to commercialize this technology. It seems like a no-brainer that we should be able to snip out a section of pipe, put one of these little babies in and start crankin' out the electrons! Every tall building should have these installed in their wastewater pipes.

I'll go ya one better: install rainwater collection pipes and install these there as well! I can't tell you how many buildings here in Dallas have water just gushing off the roof during a rain. Certain parts of the year, when it rains, IT RAINS. Why not use that rain to get free power! PS, then collect the rainwater to flush the toilets...

[Dead_Parrot]

1. It doesn't quite add up for rainwater, sadly

Water is quite a diffuse energy carrier - hydro needs either a lot of water, or a lot of height, or preferably both to generate usable amounts of power: The sum is Head x Flow x Gravity x Efficiency. Taking some typical values:

Head: Say 5m for a two storey house, but whatever the height of the guttering is.
Flow: The amount of water. Usually you'd use litres per second to calculate the output in Watts, but we can use total litres to calculate total Joules. If you have a 2500ft² (232.25m²) house area, and Dallas gets 33.3 inches (845.8 mm) of rain - Gospel according to St. Wiki - that's about 196,500 litres.
Gravity: 9.81 m/s/s
Efficiency: Depends, obviously. I'll go with 75%, but you can play with values.

So, you'd get 5 x 196,500 x 9.81 x 0.75 = 7,228,743.75 Joules, or about 2kWh over the year. Hrmm.

If you're getting a constant half an inch of rain per hour (pretty wet) you'd just about be able to run a CFL.

[txlibdem]

3. I don't think it's targeted for the residential market at all

You're right that 5m (18 ft?) is not enough height to overcome the inertia of the turbine, plus the amount of water flow (unless you have teenage daughters) is far too light to generate meaningful power.

The HighDro Power is targeted at high rise apartment buildings, multi-storey office towers, and the like. As to the idea of using the HighDro device on down spouts, the buildings I described here in Dallas are commercial buildings, 4+ storeys tall with a roof area in the tens of thousands of square feet. There is a calculation that for every 1000 sq ft of roof area you can channel 500 gallons of water in a good rain (I got this from a rainwater collection video). I just thought it might be worth looking into for all large buildings.

And my lament was that all that rainwater is just going down the drain without being collected and used (at the very least to water the landscaping). And to get a little extra power out of the deal, I thought, would be a double win.

At the risk of being accused of hijacking the topic, please see this video about a simple, cheap solar water heater. It's kinda funny and I love the guy in the videos. He's a hoot and has some really good ideas.
http://www.youtube.com/watch?v=UXGlB1kGO5E&feature=grec_index

and part 2:
http://www.youtube.com/watch?v=sBAi_TVNaiM&feature=channel

Ok. Now that you're done looking at Dan's hot wife, here is a video that shows some potential (even though it looks to me like the building is just a one or two storey).
http://www.youtube.com/watch?v=__eOMzfqtQk

-------------------------
Oh, I was wrong about being able to collect 500 gallons per 1000 sq ft of roof space:

If you have 1,000 square feet of roof on your house, and it rains just 1 inch, you can collect 600 gallons of water to be used in your garden, for washing your car, or just for drop irrigation around your property. That's 600 less gallons you have to pay for and use from your town water supply! So how can you do the math for your own roof? Just multiple the square footage of roof space you have available X 0.6 gallons per square foot per inch of rain, and you can see how much water you can collect from each inch of rain that falls.

So if you have 2,500 square feet of roof available for water catchment, and a single inch of rain falls one day, we see that:

2,500 X 0.6 = 1,500 gallons of water can be harvested for future use…from only one inch of rainfall!

http://www.thegoodhuman.com/2008/08/25/just-how-much-rainwater-can-you-collect-off-your-roof/

That's just what I'd get from my roof (my house is 2400 sq ft, roof is a bit bigger than foundation...). So I guess you can use that calculation to figure how much water we're talking about for the big buildings. Just food for thought at this point, maybe.

[OnlinePoker]

4. It sounds like the idea is only for apartment buildings

I could see major power spikes in the morning and in the late afternoon as people get ready for work or clean up after. I wonder how durable the system will be with the fecal matter passing over the blades; I would think it might gum up the works over time.

[txlibdem]

5. Sooner or later the s&*t is going to hit the fan?

That's a good question. I wonder if the inventor has done much testing. My guess is that a corkscrew shape may be more forgiving than a fan blade type or paddle wheel shape.

Perhaps it could be made out of a material that is oleophobic or lipophobic.

[Dead_Parrot]

8. Looks like he has a bypass system on it, presumably for that reason

(see http://www.creativeboom.co.uk/news/waste-not-want-not-with-dmu-students-electric-idea/ for the pic). As to how well it works IRL, I guess that's the next step.

[Dead_Parrot]

7. It is good to find a use for rainwater if possible...

One of the things on my list of "stuff to do if I ever get the time and money but admit I probably never will" if set up a rainwater system for filling the toilet: It a nice easy target if you can figure the plumbing.

IIRC, The water laws in some US states are so draconian you can't even do that, but that's another kettle of fish.

Cool videos, BTW. :)

[applegrove]

2. Sounds like a great idea. Would work likely in cities on hills like San francisco.

[txlibdem]

6. It should work in every tall building in the world.

The force of water falling down the wastewater pipes has got to be measurable. The taller the building, the more occupants. The more occupants, the more water and therefore more potential energy that we (collectively) are just throwing away right now. It's the force of the water falling from that height that can be harnessed.

How tall are buildings in cities? 10, 20, 50 storeys? Some even more.