The Future Of Renewable Fuels?
One advantage unique to renewable energy but not fully appreciated is the phenonemon of community renewable power project.
Community renewables projects can be a great force for social cohesion, and they can create a wide range of social benefits that transcend the economics of a particular project. These advantages include decreased dependence on foreign natural gas and oil, a power infrastructure that is far less subject to large-scale disruption or terrorism because of its distributed and diverse nature, local control of generation facilities, creation of much needed high-quality jobs in rural areas, and a supplemental revenue stream for agricultural community members that allows them to maintain their rural lifestyle.
These projects include projects as diverse as willow coppicing and gasifying the wood chip produced, using power plants built mostly on farms, learning how to make biodiesel to community anaerobic digesters processing the food and organic waste of a community feeding electric power into the local power grid and hot water via CHP schemes into their homes for low cost heating.
However this form of energy can be implemented badly, and if it is it can be inefficient and destructive. One example is if biomass is burnt but the forests are not replanted. To power a large proportion of the United States by biomass, vast areas would need to be taken from food production and harvested annually to feed our energy cravings while food prices would still rise higher and higher.
Biodiesel use is small now, but its use in diesel engines and for heating is increasing. Biodiesel and bioethanol do produce carbon dioxide when they are combusted in a car engine.
Geothermal energy uses hot water deep within the earth's crust to spin turbines and produce power 24 hours a day, seven days a week. It produces few carbon emissions and can re-inject used-water back into the earth to be used again, making it fully sustainable.
Solar power is generated when utilities are in highest demand – in the middle of the day. In terms of the energy to make these solar cells, it is said that in about the same time it takes to pay them off – four to five years – the cells provide back the energy that was required to make them in the first place. One place in which solar energy is being heavily used is Hong Kong.
