Complementary currencies like the Bristol Pound act as vouchers for national currency. You swap one Bristol Pound for a Bank of England pound at a 1:1 or 1:0,9 rate. The benefit of a currency like that is that it encourages money to stay in the local economy (jobs with it). The Bristol Pound is valid only locally.
The question is, can complementary currencies take a next step, towards keeping money locally AND stimulating the green economy – an economy where nutrients recycle instead of being brought from outside (entailing a large expenditure of fossil fuel) and an economy where wind, biomass and sun provide the energy.
A recent updated version of a report from Stephen Hinton Consulting demonstrates one way that might be achieved.
The vouchers are not swapped for national currency but for sorted biomass, and for promises to sequester carbon in the soil.
Learn more about this proposal in the white paper.