$25,000 to save the planet?

I had an interesting through today whilst having a shower after coming back from the beach. Well, I was thinking about the energy the shower uses to turn water in to hot water for you to have your shower (we have one of these electric showers that heats the water jut before it comes out of the shower). The colder the water, the more energy is needed to heat the water up to the proper temperature. Once the water is hot enough, it comes out of the shower head, but what happens to it? Well, after running down your body is makes its way down the drain, wasting any heat energy it might have.

Now here’s the thought that struck me. If you could transfer some of the heat from the waste water into the water that’s heading into the electric shower, then you would need less energy to heat it up, and therefore save some energy in the process. What I’m talking is some sort of heat exchanger that could even be fitted into the shower base. It doesn’t have to be extremely efficient, but even just running the waste water side-by-side with the incoming water, I’m sure it would have a positive impact on your power consumption. Here’s what I have in mind:

The shower drain would be fed into “Tube-side fluid in” and proceed through the exchanged before coming out from the other end to continue on it’s way down the drain. The fresh supply of water to the electric shower would be fed into the “shell-side in” before actually getting to the shower. Even if the shower didn’t use an electric shower, but used an ordinary mixer, piping the cold water through this system could remove the chill from the water requiring less hot water to bring it to the required temperature.

Anyway, I wondered what I could do with the idea and, while reading the FuelMyBlog newsletter, I got introduced to a company called Perpetuity Direct who are offering loans of up to $25,000 which could be starting capital to actually taking the idea to fruition. If I could borrow the money, I would use it to do some proper engineering as well as market research to find out if the idea is a viable one to take to market.

I don’t think I have the time to take up another project at the moment, but if this idea had to come to market, would you consider changing your shower to be more energy efficient?


  1. Actually, there’s plenty of scope in the average home to take this aspect of recovering wasted heat energy further. E.g. the average home throws energy away with every washing up process; what about washing clothes (either manually or by machine); even the simple boiling of water for tea/coffee making usually involves heating too much water and letting it cool down; ditto ovens used for baking/roasting etc.
    My main lounge has large windows and has sunlight from dawn to dusk; result? without heating in winter the temperatre has never dropped below 15C. Clearly,solar pre-heated water used for showering etc would make sense, but efficient storage is needed.
    All these technoligies will be used when fuel costs rise high enough to make economic sense… good luck Owen!

  2. Great idea, many new energy efficient homes use this method already for waste water from the washing machine, dish washer, shower and taps. It would not cost anywhere near your loan amount, perhaps a few $1000s at most.

  3. That’s a great idea! I think there is a good chance that if it is efficient and works well a big company might want to take it up – if you get a contract with one of the big housing companies and gain the publicity that the idea should get, you could be massive! Providing it didn’t cost too much I’d be interested and I’m sure many others would too!

  4. The problem is with the water consumption, we can all shower with cold water, but what if there isn’t enough of it? We may run into that by 2525

  5. The problem is with the water consumption, we can all shower with cold water, but what if there isn’t enough of it?

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