New ways of dealing with micro-payments are emerging, such as by deduction from a prepaid account with a computer company, Internet-service provider or mobile-phone company.
His not-for-profit organization, Carbon Manna Unlimited, has developed a system of direct micro-payments to rural people who offset their carbon production through the use of high-efficiency stoves.
As if that wasn't enough, the whole thing also promises to be funded entirely by micro-payments from the public (which would also determine its final size), and be completely self-powered, with it relying on a combination of solar power and regenerative braking from the lifts in the towers.