Kick the Habit: A UN Guide to Climate Neutrality

Solar thermal

Solar (photovoltaic)

Introducing the main renewable energies

A semiconductor cell (usually made from silicon) converts sunlight directly into electricity.

A surface absorbs and transfers heat and light rad- iated from the sun to a fluid.

Electricity production Applications: Industrial process Heating or cooling buildings Warming water

Minimal maintenance Minimal maintenance Currently attractive for investors Energy bill reduction

n o G H G e m i s s i o n s *

n o G H G e m i s s i o n s *

* Needs large panel surface * Used cells are hazardous waste * Visual impact

* Needs large panel surface * Used cells are hazardous waste * Visual impact

Transport

Depends on length of daily sunlight and intensity

Depends on length of daily sunlight and intensity

On-site use mostly

Biomass

Wood

Waste

Biofuels (ethanol and biodiesel)

n o G H G e m i s s i o n s * * Uses waste as a resource * Reduces methane emissions Methane from waste decomposition is harnessed to produce heat or run a turbine. Biogas needs to be “cleaned” of corrosive hydrogen sulfide

Either alcohol (from sugar, starch or cellulose crops fermentation) or oil is used to fuel engines.

The steam from wood burning runs a turbine or is used directly for the building.

Feedstock can be wastewood

Replace fossil fuel burning from transport

GHG emissions from land use change * Surface competition with food crops, monoculture * Deforestation, fertilizers Availability of agricultural lands is critical Problematic at industrial scale:

GHG emissions from land use change Distance to wood production areas is critical Problematic at industrial scale (planting fast-growing trees, monoculture)

Distance to landfill / manure production areas is critical

* If you except indirect emissions from building the plants, dams, turbines, solar panels, etc.