There is a threat to the very existence of the world today. Years of indiscriminate use of fossil fuels have brought the stocks of the remaining fuel to almost naught. In the meanwhile, primarily due to the pollution levels from burning fossil fuels, the greenhouse effects are threatening the world by their twin effects of rising sea levels and rising temperatures. The answer is on the walls. We have to shift immediately to renewable energy sources or perish.
The options in renewable energy sources are wind power and hydropower besides solar energy, biomass, biofuels and geothermal energy. All these sources of renewable energy have their own share of pros and cons. The well known author Brad Linscott has written a well researched book on Renewable Energy. A Common Sense Energy Plan. In this book, the author has stated that the US has invested more than $200 billion during the last five decades in energy research and development. Today, despite such large investments, the current renewable energy sources provide but a small fraction of energy needs. While wind and solar derived energy costs vary from between two to eight times the current cost of energy the biofuels books affirm that the conclusions from that source is also not so heartening.
The biofuels books state that biofuels are a range of fuels derived from biomass. There are countries such as Brazil that have made bioethanol from sugarcane. Brazil today sells ethanol from biofuels separately in dual fuel service stations that also sell gasoline. While one can use biofuel such as ethanol in its pure form, it is normally used as an additive of gasoline so that octane value can be increased and emissions improved upon. Although biofuel is used widely in the US, the author feels that enough is not being done to find rational answers to renewable energy sources.