Home > Advice, cultural commentary > Birthday, mud, and thoughts about electricity

Birthday, mud, and thoughts about electricity

mud clock

Mud Clock

It was my birthday recently, and one of the presents I got was a mud-powered clock.

Yes, you read that right: a clock powered by mud (not supplied as part of the kit).

Sorry about the pic, it was done on my mobile phone which seems to have a few problems focusing (ok, I know, so it’s like me in that regard. Heard that one before).

It’s actually not a recent idea. Mud is slightly acidic, so that if you have two metal strips a short distance apart, one copper and one zinc, you’ll get a small electrical charge between them. It’s a variant of a novelty item that was sold quite a few years ago, a lemon-powered clock (lemon juice is of course rather more acidic).

The pic of the clock shows two small containers of mud, each about two inches high and generating half a volt. Two of them in series create one volt which is enough to power the clock.

I didn’t set it up for a couple of days because I was lazy and the garden was frozen. Some friends offered to send me some of their mud instead, but I declined. It’s working now, though, and sits on top of the fish tank. And it set me thinking.

Bigger metal strips and/or more strips in series, in the garden or even a window box, would generate more current. So in theory, it would be possible to power a 12-volt electrical system by this means.

In fact, add in a solar trickle charger, some control equipment and a battery – the kind you use in campervans (RVs if you’re in the States) and you could have yourself a complete 12 volt household system. And the significance of this is that 90% of the stuff you plug in to your regular mains supply runs off 12 volts or thereabouts, with a transformer either in the equipment casing or as part of a ‘wall wart’ style plug.

Think about it this way: the majority of electrical products you use at home, you can alo buy in-car chargers for and they run off a 12-volt car battery.

The things that would still require mains voltage: some lights, electric cooker, washing machine, dishwasher, big aircons. Not all lighting, though, because a lot of those little halogen bulb spotlight type systems you see run off 12 volts with a transformer. And that’s about it, since you can get all kinds of household equipment – fridge-freezers, TVs and DVD players for example – that work off car batteries.

Imagine, though: once you have the system set up, your electricity bill would be massively decreased because you’re generating electricity literally out of the earth in your garden, window box, or even pot plants. (NB: this is not an excuse to set up a cannabis farm – ‘Your honour, I was only growing the plants to see if the pots could generate enough electricity for the lights they require and then use the excess to power my TV’ – that’s not going to work, is it…)

I started investigating whether this – the 12-volt system, I mean, not the cannabis farm – was actually feasible and came across a number of websites by people who have done this kind of thing. A guy called Nev Sweeney, in Australia, has done it in his house and details are on the Selfsufficientish website.

He even runs most of his house lighting off it, though in his case he runs the system off car batteries and charges them primarily from the mains. And there are other, quite specific, plans at the Halfbakery website, which lists a whole load of ideas that seem half-baked but could actually work. A 12-volt system, they note, does tend to lose some power through the wiring itself, but ‘Power losses from the wiring are more than made up for by eliminating step-down transformer losses’.

One problem with a mud-powered electrical system would be a drought. The mud needs to have some water content to remain electrically conductive, and it does need to be acidic. My clock instructions suggest that a small quantity of vinegar added to the mud periodically will increase the available voltage. On a medical website, though, I came across this piece of information: ‘During sleep, decreased pulmonary ventilation causes respiratory acidosis. As a result, a first waking urine specimen is usually highly acidic.’

See where I’m going with this?

That probably means it’s time to end this post, apart from noting that if you use ‘12 volt home’ as a Google search it brings up some quite amusing sponsored ads – such as ‘Buy 12 Volt Home
up to 50% cheaper’. Huh?


  1. Gwen
    February 1, 2011 at 1:29 pm

    Happy Belated birthday…so if I pee in the mud first thing in the morning my clock will run…got it! 🙂

  2. February 1, 2011 at 1:31 pm

    LOL – Yes, but only if the clock’s wired into the mud!

  3. February 1, 2011 at 2:21 pm

    I’ve heard of ‘dry’ wit, but this is the first time I’ve seen ‘whizzle’ wit.

    Last summer, I did set up one of those solar cookers. Ta-da. Worked surprisingly well. This summer, I’m going to build a water purifier. I’ll try your battery thing, too.

    Also, I’ve decided that grass–the green stuff in my yard that I have mow once a week–not the stuff for smoking–is completely useless. However, getting rid of it is harder than you think.

    And what kind of friends want to send you mud???

  4. February 1, 2011 at 2:38 pm

    Solar cookers – very neat. Have yet to try it myself, but maybe this summer. Good luck with the water purifier! Grass is ok if you have kids who want to run around, etc., but most of our garden is divided into vegetable plots these days. And you’re right, grass is hardy stuff and any broken-off roots left in the soil will keep coming back.

    As to my friends – all I can say is they and I have the same offbeat sense of humour, which is why we’re friends!

  1. February 12, 2011 at 11:47 pm

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