Put two beer stores a hundred metres apart but separate them with a plurality of turnstiles which generate energy when customers push through them. On Store "A" put a large sign guaranteeing the Cheapest Prices on Beer in town. Store "B" similarly guarantees to undercut any competitor's beer prices. (Limit 1 dozen per customer per day)
Customer goes to Store A and gets a written price on beer which he must then take to Store B who then slightly undercuts Store A in writing. Customer then goes back to Store A with B's written price where the guarantee is honoured by another price cut. Thinking he is onto a good thing, the customer goes back and forth incessantly until the beer is practically free or so cheap he can't be bothered any more.
The customer goes away happy with his ' shrewd bargaining prowess' unaware that the two stores have generated more dollars' worth of energy from their customer-powered turnstiles than the beer was ever worth in the first place. What's more, the customer has worked up a raging thirst so goes through his beer in short order only to come back again the next day to restock. Everyone wins.-- AusCan531, Feb 07 2013 Have you actually figured out how much energy this will generate?
Tip: About enough to run a keylight for 15 seconds a day.-- UnaBubba, Feb 07 2013 It depends upon how highly geared the turnstiles are and how many Queenslanders are in town.-- AusCan531, Feb 07 2013 Good point. However, gearing can still only convert the amount of work introduced to the system (it can't multiply it). My experience of Queenslanders is... not that much.-- UnaBubba, Feb 07 2013 Two points:
Many turnstiles
FREE BEER!-- AusCan531, Feb 07 2013 All beer has the appearance and odour of something that has passed through a dog, in my view. I don't get the fascination.-- UnaBubba, Feb 07 2013 ^ that's only when the beer is on the outside.-- FlyingToaster, Feb 07 2013 Sorry. Beer is fucking disgusting and a waste of perfectly good water.-- UnaBubba, Feb 07 2013 ditto UB.
Minor variation, they get beer tokens, the actual beer is in a drinking room (and toilet) on the 3rd floor, piezo electric pads on each stair and a small water-wheel in the outflow of the loo.-- not_morrison_rm, Feb 07 2013 A kilowatt hour is worth ~10 cents.
equipment exists for a human can generate up to 400 watts.
So, it would take 2.5 hours to earn a 10-cent discount, unless I am off on my math. And that's if the turnstiles were equivalent to instense exercise.
Sounds about right. the direct conversion is 860 food calories = 1 kWh. A human can burn 600 calories an hour, which means you lose half to heat over the course of 2 hours.-- Madai, Feb 07 2013 How much energy does it take to keep the store warm in winter as the doors open?-- RayfordSteele, Feb 07 2013 random, halfbakery