Not much. A typical adult can comfortably sustain about 75–100 watts on a bike for an hour. Turned into electricity, an hour of steady pedalling at 100 watts makes 0.1 kWh, worth about 2.6p at the October–December 2026 price cap. A footstep on an energy-harvesting floor tile yields only a few joules.
That does not make human powered energy useless. It is genuinely valuable where the load is tiny or there is no other power: a wind-up radio in a disaster zone, a phone top-up off the grid, a sensor that never needs a new battery. What it cannot do is power homes or make a measurable dent in the UK’s carbon emissions. The numbers below show why.
How human powered energy works
The body turns food into movement, and a human-powered generator turns that movement into electricity. The usual routes are:
- Rotation: pedals, cranks or hand-wound springs driving a small electric generator, as in exercise-bike generators and wind-up radios.
- Pressure: floor tiles that flex slightly underfoot and turn that movement into electricity, as Pavegen’s tiles do. Some systems use piezoelectric materials, which produce a voltage when squeezed (see our article on piezoelectric dance floors).
- Body motion: wearable devices that harvest energy from walking or other movement.
Each step loses energy. Generators, gearing and electronics all waste some of it, so the electricity that comes out is always less than the work the person puts in, and the work put in is in turn a fraction of the food energy burned.
How much power can a person make?
An average untrained adult can hold roughly 75–100 watts for an hour or more. Elite cyclists can sustain 300–400 watts or more for over an hour, about four times as much. Those are figures for mechanical power at the pedals; the electrical output of a pedal generator will be lower.
To put that in context with electricity prices (Ofgem’s cap of 26.32p per kWh for 1 October–31 December 2026, Direct Debit average for England, Scotland and Wales; your own rate depends on your region and tariff):
| Activity | Energy | Value or equivalent |
|---|---|---|
| One hour of pedalling at 100 W | 0.1 kWh | About 2.6p |
| Boiling a 3 kW kettle for 3 minutes | 0.15 kWh | An hour and a half of steady pedalling |
| A typical home’s electricity for a year (Ofgem’s medium value, 2,500 kWh) | 2,500 kWh | 25,000 hours of pedalling, nearly three years non-stop |
| 10,000 steps on Pavegen tiles at about 4 J each | About 11 Wh | Roughly one phone charge at most |
Real-world examples
Footsteps: Pavegen
Pavegen, a London company founded by Laurence Kemball-Cook, makes floor tiles that generate electricity when people walk on them. It is the best-known example of energy from footsteps.
The company is candid about the output. In its own words, every footstep generates 3–5 joules, so Pavegen “is not a stand-alone renewable energy solution”. In January 2026 a Pavegen executive described the technology as “micro-energy”, 2–5 joules per step, not enough to power a building but suitable for LED lighting and USB phone charging.
Older marketing quoted “up to 7 watts” or 8 watts per step. That is a brief peak during the moment of the step, not continuous output; the energy per step, in joules, is what matters. Pavegen describes its installations at stations, shopping centres and events mainly in terms of engagement and footfall data, which is where the value lies.
Gyms that generate electricity
The Great Outdoor Gym Company (TGO) opened its “Green Heart” generating outdoor gym in Hull, reported in 2012. It had a cross trainer, hand bike, fitness bike and recumbent bike, each rated at 50–400 watts depending on effort, and the electricity ran the gym’s own lighting. The company said a gym serving about 5,000 people could make “a kilowatt hour per day”, which at today’s cap would be worth about 26p.
Generating gym kit makes sense for lighting the equipment itself and for motivation, letting users see what their effort produces. It does not supply meaningful power to the grid. The same is true of energy-generating playgrounds.
Wind-up radios
The strongest case for human power is the wind-up radio. British inventor Trevor Baylis began work on a spring-powered radio in 1991, after hearing that people in parts of Africa needed health information but could not easily get batteries. His prototype ran for 14 minutes and was shown on the BBC’s Tomorrow’s World in 1994.
The production BayGen Freeplay radio needed about 60 turns, roughly 20 seconds of winding, for about 30 minutes of play, according to a 1996 review, and a later model was reported to run for up to an hour per wind. It works because a radio needs well under a watt, so a few seconds of effort go a long way. Baylis died in 2018, aged 80.
The knee-brace generator
In February 2008 a team from the University of Michigan, Simon Fraser University and the University of Pittsburgh reported in Science on a knee brace that generated electricity as people walked. It used “generative braking”: it collected energy at the end of each leg swing, when the muscles would normally be slowing the leg anyway. Tested on six men walking at 2.2 mph, generating only during braking cost about one-eighth of the extra effort of generating continuously.
The prototype produced a few watts, but it weighed 1.6 kg (3.5 lb) and the researchers described it as bulky and heavy. As of 2026 we found no mass-market body-powered phone charger; most wearables still run on batteries. Self-winding (kinetic) watches remain the long-established niche.
Vibration harvesting: a UK success story
The best example of energy harvesting working commercially is not strictly human-powered. Perpetuum, a University of Southampton spin-out, makes devices that harvest vibration from moving trains to power wireless sensors on wheel bearings. Early trials produced tens of milliwatts, enough for condition monitoring.
According to the university’s 2021 impact case study, the sensors have been used on fleets in nine countries, by operators including Network Rail, Eurostar, Virgin Trains and SJ, with a company-linked figure of over 11 billion miles monitored. Hitachi Rail bought the company in August 2020. The lesson is that tiny amounts of power can be very valuable when they remove the need to change batteries in awkward places. A similar logic applies to thermoelectric generators that run sensors from waste heat.
Limitations
The scale is small. Even a professional cyclist produces a few hundred watts. A single 3 kW kettle draws more than seven elite riders could supply. There is no realistic number of people pedalling that adds up to a power station.
Losses are unavoidable. Generators, gearing, wiring and batteries all lose energy, so the electricity delivered is less than the effort put in.
The kit costs more than the energy is worth. Tiles, generator bikes and their electronics have to be bought, installed and maintained, while the electricity they make is worth pennies. Projects are justified by engagement, education or off-grid convenience, not by energy savings.
The climate benefit is negligible. A person pedalling burns food, and growing that food has its own footprint. Making the generators and tiles has one too. Human power is not a meaningful tool against climate change. Real cuts come from sources such as solar energy and wind.
Where it does make sense: emergencies and off-grid use (wind-up radios and torches, pedal or hand-crank chargers for lights and phones), tiny sensors, and public installations designed to get people thinking about energy.
The UK angle
Britain has an outsized role in this small field. Trevor Baylis’s wind-up radio is a British invention, Pavegen is a London company, TGO’s generating gym opened in Hull, and Perpetuum’s rail sensors came out of the University of Southampton.
For households, though, human power is not a route to lower bills. A home using Ofgem’s typical 2,500 kWh of electricity a year would need around 25,000 hours of pedalling at 100 watts to cover it. If you are interested in cutting your bills with home generation, solar panels are the established option; check current scheme rules on GOV.UK or with an MCS-certified installer.
Frequently asked questions
How much electricity can a human generate?
An untrained adult can sustain about 75–100 watts for an hour; an elite cyclist about four times that. An hour at 100 watts makes 0.1 kWh, worth about 2.6p at the October–December 2026 price cap, and some of that is lost in the generator.
How much energy does a footstep generate?
About 2–5 joules on a Pavegen tile, according to the company. Ten thousand steps would make about 11 watt-hours, roughly one phone charge at most.
Can a human-powered generator run a house?
No. A typical UK home uses about 2,500 kWh of electricity a year, which would take around 25,000 hours of pedalling at 100 watts. Pedal and hand-crank generators suit lights and phone charging, not whole homes.
Can a gym generate enough electricity to be useful?
Enough to light its own equipment. TGO’s Hull gym used bikes and cross trainers rated at 50–400 watts each to run its lighting. It does not supply meaningful power to the grid.
What is the best use of human power?
Devices with very small loads and no other power source. The wind-up radio is the classic example: about 20 seconds of winding gave around 30 minutes of listening on the 1990s Freeplay model.
What is vibration energy harvesting?
Capturing small amounts of energy from vibrating machinery. Perpetuum’s harvesters, from the University of Southampton, use train vibration to power wheel-bearing sensors, saving the need to change batteries.