The Power of Rain: Alternative Energy
by Tim McGee, Helena, MT, USA on 01.24.08
We have seen wave power, wind power, and solar power, but rain power?
“We thought of raindrops because they are one of the still- unexploited energy sources in nature,” says Jean-Jacques Chaillout of the atomic energy commission in Grenoble, France.
Chaillout and his colleagues realized that every time a drop impacts on a surface it is an opportunity missed. Each raindrop has an impact energy that is highly dependent on the size of the drop; from a small drizzle drop that has 2 microjoules on impact, to a downpour size drop that carries 1 millijoule of impact energy.
The team identified that a piezoelectric material might be able to capture that energy. Piezoelectric materials generate an electrical potential when acted on by an outside physical force- say a raindrop. The opposite is conveniently true as well, an electrical charge will change the materials shape, which is how many speakers turn electric signals into vibrations we can hear.
At any rate, in this case the team used a 25-micrometer thick, 10 centimeter long (~4 inch) strip of polyvinylidene fluoride to do the trick. They were able to capture between 1 nanojoule and 25 microjoules of energy per drop (again depending on the size of the drop). The total power will vary incredibly depending on the conditions, but the device produces about one microwatt of power in a light drizzle.
What can you do with this tiny power plant? The authors suggest that this type of device might work quite well for sensors, especially if the sensor is detecting rain, or in a rainy environment. Imagine a weather sensor that would only send a signal of how hard it is raining, when it is in fact raining. Or how about sensors that will automatically close your house windows when a storm suddenly appears?
I imagine this technology will not likely make up a large portion of our energy matrix, but capturing the available energy all around us is certainly a good idea, and presents an elegant solution for remote sensor technologies.
::Eureka Alert
Via :: New Scientist (Jan. 26. 2008 Edition)
The real power of rain is flooding anywhere it hits..
and also help or sometims hurt the farming industry
DNA Records
Except for generating energy in amounts, all the other applications are available since a long time, reliable and cheap. So if you can get some energy of it, fine, if it is just µW, well done you did a proof of concept there...
i like the idea of this being used to power a device that closes windows when it rains. it's a beautifully simple concept.
I hate to be a skeptic...but I have 3 points:
1) Harnessing rain is not novel. This is what hydro-electric plants use. It's true, the actually impact energy in not used, but...
2) If the impact energy were substantial (or detectable), then that energy would largely be disbursed into heat. For rain hitting bodies of water, you would think the overall water temperature would increase after rain.
3) For the people that complain about solar and wind being intermittent, rain will be far worse; at least in non-tropical regions.
Interesting concept.. what about making a roofing material that covers your abode that can conduct and capture electricity when it rains?
Get a steady rainstorm for an afternoon and you can alleviate some of your power needs.
Wouldn't it be better for the device to power something other than an action that a human is perfectly capable of doing? Shutting windows is not an arduous task.
what about using less energy in general so we don't have to "exploit" the energy potential of things such as rain?!?
Liam,
1) Harnessing rain is not novel. This is what hydro-electric plants use. It's true, the actually impact energy in not used, but...
True, but hydro plants must be built on rivers and are thus geographically limited.
2) If the impact energy were substantial (or detectable), then that energy would largely be disbursed into heat. For rain hitting bodies of water, you would think the overall water temperature would increase after rain.
I believe they do, but you also have to take into account heat radiation from the surface of the water.
3) For the people that complain about solar and wind being intermittent, rain will be far worse; at least in non-tropical regions.
Absolutely true. This is akin to "lighting harvesting" which is another interesting concept I would like to see implemented in a proof-of-concept plant, but is probably highly impractical.
My main concern is that the piezoelectric material they used is "polyvinylidene". I'm not familiar with the material, but it I wonder if it as environmentally noxious a other vinyl-based products such as polyvinylchloride (PVC)?
Luc
This sounds like an idea I had to install gutter systems on buildings in a large, dense urban center which all funnel rain water runoff into a hydroelectric turbine. The rain water could then flow into an underground storage tank and be used for flushing toilets and irrigation for that same urban center.
Luc
Good point glen.
I'd be surprised if the net gain is positive. But I'm intrigued. Perhaps an application to illuminate the roads at night? Weren't the Brits working on something like that with the energy of passing cars?
If they could combine this type of technology into photovoltaic panels then you could have a single panel that generates electricity when it's sunny and when it's raining.
Its a good idea to capture the rain energy or droplets energy by installing piezoelectric that can convert the striking raindrops on our roof. we can at least get some of its wasted energy.
Its a good idea to capture the rain energy or droplets energy by installing piezoelectric that can convert the striking raindrops on our roof. we can at least get some of its wasted energy.
Those of you talking about powering home appliances with this technology need to read the article through to the end. This would more likely be used to power a few LEDs like an audio meter that you could use to see how hard it's raining. 1 LED = drizzle, 2 LEDs = sprinkles ...5 LEDs = hail.
It's a rain sensor technology, not a home power source.
Go forth and multiply my children..
If we start with our 10cm * 10 cm strip generating 1 micro watt ( 10 to the power of -6 ) in Irish drizzle, what we'd call a lovely soft day, which is lets say 0.25mm/hour (see wikipedia).
So we scale up to 100m squared of rooftop during a heavy Irish thunderstorm, i.e. 25mm/hour and we see that we're generating , wooh hooh, 1W.
I agree that there may be some application for powering remote sensors but lets face it its totally irrelevant to the rest of the planet.
The running-a-turbine to generate electricity from the downpipe is a nice-but-no idea as well. For the same roof with a horrible 2000mm/metre-squared/year (don't live in that part of Ireland) you'd generate a theoretical maximum of 1.8 units of electricity PER YEAR. Ah no, thats not the planet saver yet.
Remember, the founding fathers of this marvel work for the atomic energy commission in France. Then again, they didn't force someone to post this to treehugger, shame on someone.
/ Colm
It's a great concept so that when solar panels are unable to capture a lot of sunlight when it rains, we could hypothetically harvest the energy from water as well as the wind.
The actual concept is genius for places like the rainforest where there is non stop rain for months, and it could output enough power for many people.
I worked with a group of missionaries that lived in the rain forest. I tried to develop a rain drop generator that charged the rain with an electrical charge and used it to move the charge to a collection grid to build up electrical current. The project was unsucessful, never got it to work! But in a rain forest something like it could be very usefull for electrical power.
Has anyone out there heard about WideCircles.com. It seems like a way better service then wasting money on PPC.
Apparently they are using referring websites ( forums, blogs, wiki, etc. ) and have a viral word of mouth distributed approach to it.
My friend told me he got around 100 visits from single post which cost him $0.40c.
I am going to give them a try today .
In case you are interested here is it. http://widecircles.com?s=imt1
Here is a thought.
Can we consider Hydro electric on smaller scales, perhaps in the rain gutters that line our homes. why not collect the rain runoff from our roofs into a sistern (reservoir) local to our homes roof system and use gravity to run a turbine generator....Generate power, decrease errosion in our yards by absorbing the engery and perhaps meter the flow for drier times or peak energy times so that we do not have to waste water in the warmer summer months or require storage of the electricity.
rain panels for energy is just for me... I have a small house at my village, at east black sea cost of Turkey, at Rize City and It rains 270-280 days a year top of my house. This rain we must get benefit as a heating, electricty and as water too. I ll welcome if anyone tries to test the system at my house.... All the best