High voltage DC lines lose about 3% per 1000km, so this project with 4300km of lines could theoretically be set up to lose 12% in losses. There’s also some experimentation with ultra high voltages that would be more efficient, but probably more complex to engineer.
So even with those ultra unrealistic assumptions (100kg people, 1 step per second, 100% efficient energy capture), 9.8 watts just isn’t enough.
Lighting needs about 0.6 watts per square foot (6.46 watts per square meter) in an office. That means you need someone like that generating 9.8 watts every 16.3 square feet or 1.5 square meters.
There’s an inherent tension there, where sufficient density to make that work would require people to take fewer, shorter steps.
A basketball court is 4700 sq feet (436.6 sq meters). That means you’d need 288 big people stepping that fast, jammed into a single basketball court sized space, just to keep the lights on in that space. If any of the people stop moving even for a second, the system fails to keep up.
The numbers don’t make any sense.
A 100kg (220 lb) person whose steps compress the tiles by 1cm (0.01m) per step would be transferring 100 kg x 9.8 m/s^2 x 0.01m = 9.8 joules, or 0.00272 watt hours. That assumes 100% perfect efficiency in capturing that energy.
A watt is a joule per second, so someone who steps 1 step per second is generating 9.8 watts. That’s not enough to light the station, much less run the computers and signs and the fare gates and escalators and elevators.
And of course it wouldn’t come anywhere close to running the trains. After all, if it were easy to take people’s biomechanical power to run trains, that would mean that humans could push the trains effectively.
So they’re trying to put 2GW of dispatchable (can be dialed up and down on demand), carbon-free electricity by 2028. If you include the last year and a half of the exploratory drilling work they’ve done on site, that’s about 5 and a half years.
They’re also saying that each well is about $5 million, have about 30 wells planned for the 400MW project. Not sure how much going up to 2 GW would increase the cost, but that’s $0.33 per watt for the 400 MW plan.
In comparison, Vogtle added 2 nuclear reactors for 2 GW of capacity in Georgia, and it cost $35 billion and took 16 years. That’s $17.50 per watt.
Solar is somewhere between $1 to $1.20 per watt, but isn’t dispatchable.
Ongoing operational costs might be different between all of the different types of generation, but the up front costs are important enough to where they should be a significant part of the discussion.
So if they can pull this off in a few places, this will go a long way towards actually going to zero carbon on the grid.
You’re not missing anything. Nuclear is looking more and more like it won’t be economically feasible going forward. If modern geothermal provides a cheaper way to feed dispatchable electricity into the grid, in more places, then that might very well be the last link in making a zero-carbon grid possible.
He just turned off the switch in the breaker, right behind the meter. The meter itself is still hooked up, so from the power company’s perspective, he has an account and everything.
At least that’s how I read the article he wrote last year: