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A simple system to harness the potential energy of falling rain and collect fresh water at the same time.

This idea is a mechanical system that collects rain water at a height and uses this to turn a dynamo and recharge large batteries as it comes down to ground level. Here it is emptied into storage tanks or wells for later use. The system provides free renewable energy and clean water to remote areas with high rainfall anywhere in the world. The key points are that: - it can be reasonably cheap to make and easy for local communities to construct themselves. - Useful in areas that are often cloudy and solar is not particularly effective - Each tower can generate enough electricity to power lighting at a recharge station and recharge radio equipment or mobile phones for locals.

Photo of Nathan Gaydhani
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This idea employs a pivoting shallow trough at the top a fairly tall tower that fills with rainwater when it rains. Once full (perhaps a few inches), it tips slightly and empties into a large bucket on a pully. Once full, the trough levels to start collecting more water and the bucket travels down to the ground pulling a line that turns a Dynamo.

At the same time a second empty bucket at the bottom is raised to the top of the tower.

At the bottom the bucket empties into a tank and the other empty bucket (now at the top) is ready to wait for the trough to empty again.

The water in the tank passes through a simple filter system to remove airbourne impurities and then passes out through a tap for people to collect.

At the bottom of the tower is also a Recharge Station with lighting and sockets for recharging radio equipment and mobile phones for locals.

Sockets and phones could be housed within lockers which you pay for the time you need.

What community does this idea benefit and who are the main players?

The biggest places that will benefit are those in high rainfall/monsoon regions where a lot of rain can fall for many days. During the rainy season heavy cloud cover can mean very little sunlight for effective solar panel use. Areas that have no electricity supply at all will benefit the most.

What skills, input or guidance are you keen to connect with from the OpenIDEO community to help you build out or refine your idea further?

We need to be able to use mathematical/physics models to see how much rain water needs to be collected to generate certain amounts of electricity. What size of trough is needed, how may towers are needed to have a constant supply of electricity while it rains?

Please indicate which type of energy is most relevant to this post:

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This idea emerged from:

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Photo of Nathan Lucy

Great idea, Nathan! You mentioned building a model to prototype your idea. How will you construct it? Also, what might you measure to evaluate it?

Photo of Nathan Gaydhani

To be honest while I would like to build a scale model, I do not currently have the space or resources. I may build a 3D model in the computer though which will help me to understand and pin down structural details.

This is very new idea not one I have been working on for a long time so much still needs to be done. If there are people out there that can help then that would be wonderful.

I really want to measure/calculate the current a given size of bucket can induce in a dynamo and the height the tower would need to be and the kind of gearing possible to slow down the bucket and increase the rotation of the dynamo flywheel. This will give me a better idea of the amount of electricity that can be stored from each bucket descent.

By having gears on the dynamo it could be possible to match the descent of the bucket to the rate of rainfall. In light rain you could slow the descent with higher gearing to create more electricity over a longer period. In heavy rain you might want a quicker descent in order to be ready for the next trough-full.

Photo of Meena Kadri

Exciting stuff, Nathan. We're always keen to frame technology in a human-centered way. If you're keen to have a go you could try creating a User Experience Map and upload it here to your idea post: Looking forward to seeing more of you on OpenIDEO...

Photo of Nathan Gaydhani

Looks really fun, I am familiar with user journeys already when building websites so will have a go.

Photo of Natalie Lake

Hi Nathan,

Neat idea. I'd love to hear more about how you will pilot this idea. Are you able to construct a model of this in an area with rainfall?

For technical inspiration, you might want to take a look at gravity light. It is a solar operated lamp that uses gravity to power itself.

Another great design, gravity powered floor lamps

Hope these prove useful and I look forward to hearing about your piloting ideas :)

Photo of Nathan Gaydhani

Thanks for Gravitylight link, that really is a bright idea! It makes me think that the bucket could take some time to descend as it would be very heavy so need a lot of gearing on the dynamo.
I do not have the resources to build a full scale model but a working scale model may be possible. I first want to get some help doing some mathematical/physics simulation modelling though to see what kind of quantities of water to electricity are possible.

Photo of Natalie Lake

Hi Nathan,

I think that even a scalable model would be great for a pilot. I think a lot of your calculations will depend on the area in which you build. For example, trough size will depend on average rainfall. You might be interested in reaching out to the Jake and the Sunsaluter team. While their idea is a bit different from yours, they also use water and gravity in their design (to rotate the panels) and might be able to offer some insight into the calculations you are looking to do.

Again, looking forward to your pilot