jesperlang 5 years ago

As a high-tech (electrical tech?) geek, i love low-tech magazine. One thing that this article (and many of their other ones) does is to highlight how incredibly wasteful our lifestyle is energy wise. Sure we can be impressed by 95% efficiency motors of new electric cars, it is still +150'000 watt used to transport 70 kg of human flesh. Compare that to 75 watt of pedal powering your transport. Not saying we are going to replace cars with bikes, but it's good to remind ourselves how much energy we actually use in real numbers.

It's like we all have our own army of personal slaves by the thousands that run on ancient sun light to power our excessive needs..

Theodores 5 years ago

75w - 1hup sounds good to me. I could power a computer, a light and monitor with it going into sleep mode when I stop pedalling. This is the level of power I like to use most of the time anyway.

I might not be able to power a kettle, keep the fridge on and all those things that take 10-20 x 1hup but, most of the time I don't need those things.

What I would like on the bicycle is a general purpose recharegeable battery that works off a dynamo and powers the lights on the bike. If it can charge for free on re-gen braking and give a feeble power assist if need be then that would be helpful. But not something actually heavy.

The problem with batteries is they always come in boxes that need other containers that need housings and brackets and even more mounting hardware.

I would like a battery to be practically structural, so, in the bicycle implementation the battery would use the frame tubes, to be more like an internal layer of paint than something big and heavy.

Anyway, it would be great if a bicycle could harvest electricity and store it in a way the EV cars are talking about, but to return electricity to one's personal grid of USB powered devices so, even if you did not have mains power you could always get everything charged.

  • masklinn 5 years ago

    > 75w - 1hup sounds good to me. I could power a computer, a light and monitor with it going into sleep mode when I stop pedalling. This is the level of power I like to use most of the time anyway.

    There's a pair of issues with that plan:

    * 75w is mechanical, factor in the converter and you end up with quite a bit less.

    * 75w is what you can produce doing nothing else, you're not really able to use that computer while you're doing that. It's not strenuous exercise, but it's continuous work.

    > I might not be able to power a kettle, keep the fridge on and all those things that take 10-20 x 1hup but, most of the time I don't need those things.

    OTOH you can't really need a fridge only some of the time. At that point you're better off with some sort of evaporating cooler or (dry-)ice box.

    > What I would like on the bicycle is a general purpose recharegeable battery that works off a dynamo and powers the lights on the bike.

    … buy one? Get a dynamo-charged buffer battery and plug a USB headlight in it or whatever.

    > I would like a battery to be practically structural, so, in the bicycle implementation the battery would use the frame tubes, to be more like an internal layer of paint than something big and heavy.

    A battery is big and heavy by definition. And will remain thus until we get an absolute breakthrough.

    > to be more like an internal layer of paint than something big and heavy.

    Magic, got it.

    • Theodores 5 years ago

      No need to be so cheerful!

  • jotm 5 years ago

    You are not getting over ~500W continuously for more than half an hour, an hour maybe if you're really fit.

    An alternator gets surprisingly hard to turn when it actually has a full load connected to it. I'd compare it to biking uphill.

    Still useful for getting a laptop and two smartphones fully charged when you exercise, though.

    • _Wintermute 5 years ago

      As a keen cyclist that trains with a powermeter, there are very few people on the planet that can produce 500W for an hour, more like 1 minute for mere mortals.

      I think 150W for an hour would be more reasonable for a typical person, even then you're going to get pretty sweaty.

tty2300 5 years ago

This isn't even an efficient way of doing things since muscles are less efficient than electric motors. Just stick a solar panel array on your factory and be done with it.

  • masklinn 5 years ago

    > This isn't even an efficient way of doing things since muscles are less efficient than electric motors.

    Even more so if you factor in the entire human biological system. Humans are pretty shit at converting food to mechanical energy, to say nothing of considering the entire chain from sunlight on. And our average power output is nothing worth speaking about either.

    A pedal-powered work bench of some sort (where the pedalling is an ancillary activity to the primary work e.g. pottery wheel or loom or whatever) can make sense, the mechanical energy requirement are limited and most of the work is relevant to human skills. But for primary power production it makes limited sense, at least in developed countries.

    > Just stick a solar panel array on your factory and be done with it.

    For factories sure but there is a huge advantage to pedal-powered prime movers: they're very easy to slap together and maintain. Solar panels are not always easy to have in low-infrastructure / developing country environments, slapping belts and rods onto a bicycle frame is much more accessible.

stareatgoats 5 years ago

A lot of these suggestions bear the hallmark of that endearing village crank (pun intended). But at least two things are worth considering:

1. The tendency to have electric appliances for every thinkable mundane task does our bodies no good (nor the environment). While we can go to the gym once in a while to alleviate some of the ill effects, it is much better to incorporate some physical exercise into our daily routines.

2. To be totally dependent on a centralized grid is a recipe for disaster. Many million can be put at risk by a single hacker in a basement as it stands, not to mention when state actors are involved. Electricity should really be supplied by local semi-independent grids fed by local renewable energy sources that are resilient to a collapse of the centralized system. Pedal power could play one (minor) part in such resiliency.

  • masklinn 5 years ago

    > Pedal power could play one (minor) part in such resiliency.

    It's less "minor" and more "insignificant". A healthy and motivated laborer can sustain ~75W mechanical over a continuous work day, that's an entry mat worth of solar cells, or a small turbine / windmill.

    You can derive some productivity from your exercise, but humans as power source is inane unless you have literally no infrastructure worth speaking of and no other options (e.g. no wind or water streams).

  • oblio 5 years ago

    I'm not saying that disasters aren't possible, but we've using centralized grids for over a century. They've held up decently.

    And they're pretty good at scaling human activity since they can route/draw power from other places.

    About pedal power, it's nice to look for alternatives but if there's one thing I learned, convenience trumps everything else. We literally die for convenience (drugs, alcohol, being overweight, not exercising, etc.).

m-i-l 5 years ago

I love the concept of this. Not so much to capture energy from individuals who are using the devices purely to produce energy, but to capture the energy produced from large groups doing something that they would be doing anyway, e.g. people using exercise bikes and treadmills at a gym, or prisoners exercising in a prison exercise yard.

But, unfortunately, some quick sums suggest this might not be particularly economically viable:

- 75W sustainable energy output per person, i.e. 0.075kWh

- 33% efficiency of energy conversion, i.e. 0.025kWh

- GBP0.05 per kWh to sell back to grid, i.e. GBP0.00125 per person per hour

- 8 hour day = GBP0.01 (i.e. 1p) per person per day

- 100 people in a gym, or prison, or whatever = GBP1 per group per day

i.e. unlikely to cover the cost of lighting and heating. Even if you could improve to 100% efficiency, and offset against electricity purchased rather than reselling back to the grid, you'd still only be looking at increasing that by a factor of 10.

  • antisthenes 5 years ago

    > i.e. unlikely to cover the cost of lighting and heating.

    You forgot the most important factor in this - extra food.

    Those people will burn a lot of calories, and surely enough compensate for it with a snack or maybe an extra meal. That alone makes any sort of human electricity generation scheme generally not viable.

    • sopooneo 5 years ago

      We're assuming the people would have been doing the biking regardless.

      • m-i-l 5 years ago

        Yes, they would be doing something they would be doing anyway, e.g. exercising at a gym, with the electricity generation just a useful byproduct. Wasn't thinking along the lines of something like a Matrix-style human power plant.

        • antisthenes 5 years ago

          Ah, my bad then. I remember Top Gear or some-such show attempting this experiment and having stationary gym bikers charge their EV.

          It didn't do too well.

soperj 5 years ago

Always thought it would be pretty awesome to have a massive compost bin that could flip from side to side via pedal power. It would be easier to let air in, and make it so that it composted by aerobic bacteria instead of anaerobic, which results in a much fast composting process(and higher temperatures).

  • fian 5 years ago

    Do you mean a compost tumbler? Something like:

    https://www.gardeners.com/buy/extra-large-compost-tumbler/36...

    These are easy enough to hand crank and you don't need to tumble them a great deal each time.

    Maybe if you had a hobby farm and many such tumblers, adding some sort of pedal drive you could temporarily attach to each tumbler might make sense.

    • soperj 5 years ago

      You can't fit enough waste material in a tumbler for it to get hot enough to really break stuff down. You need about 4 cubic feet of material.

jotm 5 years ago

Now replace the human with an animal and we're back to pre-industrial times - but this time, it's environmentally friendly, not necessary!

Only half joking, because bulls and donkeys were used to power a lot of machinery and still are, and even dogs were used on hamster wheels to power rotisseries (their depictions were sad, indeed).

But I would like, and have thought about, a treadmill or stationary bike to exercise and recharge a power bank or two, for example. It wouldn't be much, but it's not hard to implement and I'd rather have several smartphone charges than just excess motion/heat.

On that note, it would probably be more efficient to grow crops, distill alcohol, quit drinking and use that to power a generator... That or compost it to gas, biofuel :D

oconnore 5 years ago

> Cranks and pedals are not a solution at all if we decide to cling to an energy-intensive lifestyle - but then, neither is any other renewable (or even non-renewable) energy source. The main problem with our approach to pedal powered machines is that we compare them to fossil fuel powered machines and not to the inefficient human powered tools and machines that went before them.

I’d prefer to take my renewable energy with no quality of living sacrifice, thanks.

  • icebraining 5 years ago

    Let's hope that's possible.

    • adrianN 5 years ago

      It is possible, it just takes political will and a lot of money.

      • reallydontask 5 years ago

        I think renewable energy with no quality of living sacrifice and a lot of money means that this will not be possible for a lot of people without other changes.

        I'm fortunate enough to be able to afford to pay twice as much for the electricity we consume and not have to sacrifice anything. I'd guess, based on your comment, you are on the same, privileged, boat. Others are not so lucky, which means that they will need some sort of help, which might not be politically palatable because, mainly shortsightedness.

        • adrianN 5 years ago

          Adding wind or solar is currently cheaper than adding coal. The marginal costs of renewable energy are pretty low. The investment costs are also lower than the damage climate change will cause. If we really wanted to we could switch to 100% renewables, for example by printing more money. But just stopping subsidies for fossil fuels or setting up a carbon tax would be good steps.

          • reallydontask 5 years ago

            I was hardly advocating adding more coal.

            Removing fossil fuel subsidies and setting up meaningful carbon taxes are steps in the right direction, but this means that the price the consumer pays will, ultimately, be higher, which is the point I was trying to make.

            FWIW, it's something that I strongly believe we should be doing but through a combination of circumstances will only very slowly happen.

scotty79 5 years ago

I was looking for something that looks comfortable to sit on while pedalling. I found none.