what is the difference between green energy, sustainable energy, and renewable energy?
green energy is energy that can be captured with a minimal impact to the environment, such as wind power or solar power. examples of green energy sources include wind power, hydro power (small scale), solar energy, biomass, bio fuel, and geothermal energy.
renewable energy is energy that can be naturally replenished. renewable energies include wind power, hydro power, solar energy, biomass, bio fuel, and geothermal energy. examples of non-renewable energy are fossil fuels and coal.
sustainable energy is energy that meets present energy demands without compromising the ability to meet future energy demands. energy efficiency and renewable energy are said to be the twin pillars of sustainable energy, in the sense that energy efficiency and energy supply (renewable energy) must both increase to meet future energy demands.
green vs renewable: renewable energy is not always green, green energy is always renewable. green energy's primary concern is the environment, while renewable energy's primary concern is long-term feasibility. for example, hydro power is renewable, but some large-scale hydro power projects take a such a significant toll on the environment (carbon emissions, displacement of people) that they are not considered to be green.
sustainable vs renewable (green): sustainable energy includes supply and demand into the equation while renewable energy deals only with supply. an energy source may be naturally replenishing (renewable) it might not be able to meet human demands (unsustainable).