> Isn't the whole point of renewable energy to have a perpetually renewing "closed system"?
Nope. Renewable just means the energy source can be replenished. Technically, charcoal would fall in this category, even though it has a pretty hefty C02 output.
That's exactly my point. The process of growing the trees that produce the charcoal should remove as much co2 as is released when the charcoal is burned, thus a closed system.
Much of the charcoal used in tropical regions is made by slash-and-charring rain forests. These forests aren't replanted. So, since the carbon output is high, and there is no offset, it has a huge carbon footprint.
You don't get to count the initial carbon sequestration as the carbon offset. If you could, then coal and oil would have carbon footprints of zero.
If you develop a closed loop system, like much charcoal production in North America, then yeah, your carbon footprint is low.
So, when they say "The carbon footprint is 50% cleaner than the grid and 100% renewable" they mean it produces half the carbon output per amount of energy generated (they claim to be more efficient than many power plants), and has the possibility of using renewable energy such as biomass gas (which is not currently produced in large quantities).
Nope. Renewable just means the energy source can be replenished. Technically, charcoal would fall in this category, even though it has a pretty hefty C02 output.