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IN WONKISH circles, energy efficiency used to be known as “the fifth fuel”: it can help to satisfy growing demand for energy just as surely as coal, gas, oil or uranium can. But in these environmentally conscious times it has been climbing the rankings. Whereas the burning of fossil fuels releases greenhouse gases, which contribute to global warming, and nuclear plants generate life-threatening waste, the only by-product of energy efficiency is wealth, in the form of lower fuel bills and less spending on power stations, pipelines and so forth. No wonder that wonks now tend to prefer “negawatts” to megawatts as the best method of slaking the world's growing thirst for energy.

Remember when you were a kid and your parents made a big fuss about turning off the light when you left a room? Who knew that, besides adding to the monthly electric bill, keeping a single 60-watt lightbulb lit for 12 hours uses as much as 60 liters of water? According to researchers at the Virginia Water Resources Research Center, in Blacksburg, Va., fossil-fuel-fired thermoelectric power plants consume more than 500 billion L of fresh water per day in the United States alone.

Photovoltaic (PV) technologies have shown remarkable progress recently in terms of annual production capacity and life cycle environmental performances, which necessitate timely updates of environmental indicators. Based on PV production data of 2004–2006, this study presents the life-cycle greenhouse gas emissions, criteria pollutant emissions, and heavy metal emissions from four types of major commercial PV systems: multicrystalline silicon, monocrystalline silicon, ribbon silicon, and thin-film cadmium telluride. Life-cycle emissions were determined by employing average electricity mixtures in Europe and the United States during the materials and module production for each PV system. Among the current vintage of PV technologies, thin-film cadmium telluride (CdTe) PV emits the least amount of harmful air emissions as it requires the least amount of energy during the module production. However, the differences in the emissions between different PV technologies are very small in comparison to the emissions from conventional energy technologies that PV could displace. As a part of prospective analysis, the effect of PV breeder was investigated. Overall, all PV technologies generate far less life-cycle air emissions per GWh than conventional fossil-fuel-based electricity generation technologies. At least 89% of air emissions associated with electricity generation could be prevented if electricity from photovoltaics displaces electricity from the grid.

A brief general picture of the world, european and italian energy situations is made, analyzing several different energy sources and paying attention to the relations energy-quality of life, energy-environment and energy-health. Then will be discussed fossil fuels, renewable energies, the role of electric energy, nuclear energy, energy savings, the greenhouse effect, a possible sustainable development, the hydrogen economy and the risk and its perception. Then follow the conclusions and perspectives.

The future of biofuels is not in corn, says a new report released today by Food & Water Watch, the Network for New Energy Choices, and the Vermont Law School Institute for Energy and the Environment. The corn ethanol refinery industry, the beneficiary of new renewable fuel targets in the proposed energy legislation as well as proposed loan guarantee subsidies in the 2007 Farm Bill, will not significantly offset U.S. fossil fuel consumption without unacceptable environmental and economic consequences.

The island of Barbados is 99% dependent on fossil fuel imports to satisfy its energy needs, which is unsustainable. This study proposes a 10 MW distributed wind energy scheme using micro wind turbines (WT) of horizontal (HAWT) and vertical axis (VAWT) configurations. These units are rated less than 500 W, and the scheme is hereafter referred to as mWT10. mWT10 is compared to the proposed 10 MW medium WT farm by the Barbados Light & Power Company (BL&P). The economic bottom line is the levelized cost of electricity (LCOE). The results highlight the BL&P proposal as the best economic option at BDS$0.19 per kWh, while that of both mWT10 configurations exceeds the conventional cost of BDS$0.25 by two to nine times. This is attributed to significantly higher relative installation and operational costs. However, the financial gap between mWT10 LCOE and the retail price of electricity is much smaller due to a large fuel surcharge passed on to each customer. Annual additional benefits of using wind energy include: greenhouse gas emissions savings of 6–23 kt of carbon dioxide; and anavoided fuel costs of BDS$1.5–5.3 million.

Launch a space-based climate change initiative to combat global warming. Create a $50-billion strategic energy fund to research ways to boost energy efficiency and reduce reliance on fossil fuels.