Up to around 1980, hydropower research and development (R&D) efforts focused mainly on improving turbine efficiency, reducing cavitations, and increasing generation. Whereas older units had efficiency ratings as low as 60%, the new units have efficiency ratings of approximately 90%. The U.S. Department of Energy (DOE) also looked at new technologies for developing low-head, ultra low-head, and small hydropower projects. These technologies included the following: (more…)
Hydropower, also known as hydroelectric power, is the use of water to produce power. Harnessing water to perform work has been ...
The World Commission on Dams (WCD) was formed in 1998 by a joint initiative of the World Conservation Union (IUCN) and the Worl ...
The winners in hydropower and other large dam projects are those who gain electricity, domestic water supplies, sanitation, dro ...
The water levels of most of the world’s rivers fluctuate with seasonal rains, melting snows, or droughts, and in the arid zones ...
Hydraulic turbines have two main classifications: impulse and reaction. The impulse turbine generally uses the velocity of the wate ...
Addressing global warming, however, is a highly complex and daunting endeavor. Many climate experts have urged the world to stabilize greenhouse gas concentrations in the atmosphere around 450 to 550 parts per million (ppm)—that is, no more than 450 to 550 units of greenhouse gases for every million units of air in the earth’s atmosphere. This approach, experts say, could keep average global temperatures at no more than 3.6° Fahrenheit (2° Celsius) above preindustrial levels, which could avoid some of the worst, irreversible consequences of climate change. (more…)
Although some scientists and critics still dispute that human caused greenhouse gases are causing climate change, the majority of s ...
Climate change caused by the enhanced greenhouse effect is one of the most significant global environmental issues. Increased emiss ...
Options for dealing with the threats of climate change include both adaptation to inevitable changes and mitigation, or lessening, ...
Scientists study Earth’s climate not just from observation but also from a theoretical perspective. Modern-day climate models succe ...
Earth’s climate is a complex system of interacting natural components. These components include the atmosphere, the ocean, and the ...
In Europe, modern renewable energy sources technologies were explored thoroughly for the first time after the oil embargo/ price crisis of 1973. Notably, market introduction of renewable energy technology started in about 1985, but the renewable energy sources industry has become vital only during the past decade. Accordingly, relevant statistical renewable energy sources data have been systematically compiled only over the past decade, although reliable and consistent statistical renewable energy sources data, collected since 1989, exist for all 15 countries of the European Union and for Western Europe (defined here as the EU-15 plus Switzerland, Norway, and Iceland). (more…)
There are various and somewhat complementary reasons to foster the growth of renewable energy sources in Europe. A major incent ...
The development of the ‘‘new’’ wind and solar technologies is of great importance for the future contribution of RESs to energy sup ...
Although technology change (usually involving an improvement in energy efficiency) is not inherently a geographic process, it does ...
The energy that people use every day comes from many different sources. The resources are divided into two main groups: renewa ...
Renewable energy sources cannot run out and causes so little damage to the environment that its use does not need to be restric ...
In most countries, geothermal resources are classified as natural resources belonging to the government. Since the 1980s, there has been a worldwide trend to corporatize and/or privatize government commercial activities. Whereas the geothermal resources in the United States have been commercially developed by the private sector since the 1960s at The Geysers, other countries, notably The Philippines, Indonesia, and New Zealand, did not started private commercial geothermal projects until the 1980s. These private power developers are known as independent power producers (IPPs). There is a perception that the private sector is more efficient than the public sector. The efficiency arises from the increased flexibility of the private sector and its accessibility to commercial funding. (more…)
"Spain has great potential but lack geothermal legislation and investment." Besides being clean, renewable and friendly, easily man ...
The Geologists Association president advocates the use of geothermal energy by its high durability and low maintenance. Besides a r ...
Geothermal drilling technology is adapted from the oil industry. Most of the geothermal wells are drilled with a rotary-type drilli ...
The total installed geothermal power generating capacity in the world is approximately 9000 MWe from 21 countries, with the United ...
According to the German standard VDI 4640 geothermal energy is stored energy as heat beneath the Earth's solid surface, encompa ...
The energy efficiencies of various fuel production pathways from well to pump. The efficiencies shown are defined as the energy in a given fuel (available at pumps in vehicle refueling stations) divided by total energy inputs during all Well-to-Pump activities, including the energy content of the fuel. One way to interpret the Well-to-Pump efficiencies in the figure is as the difference between 100% and the energy efficiencies, which roughly represent energy losses during Well-to-Pump stages for making a given fuel available at the pump. As stated in Section 3, Well-to-Pump activities include biomass feedstock production; feedstock transportation and storage; fuel production; and fuel transportation, storage, and distribution. (more…)
The combination of well-to-pump results and the energy use and emissions associated with vehicle operation (also called the pum ...
It shows Well-to-Wheels Greenhouse Gas emissions of the 23 vehicle/fuel systems. For each system, the bottom bar represents CO2 ...
Because different studies have different system boundaries and parametric assumptions, the studies described in Section 7 resulted ...
There are different types of vehicle propulsion systems and the transportation fuels that have been studied for their potential ...
At present, in the United States and worldwide, motor vehicles are fueled almost exclusively by petroleum based gasoline (or re ...
The energy that people use every day comes from many different sources. The resources are divided into two main groups: renewable energy and nonrenewable energy. Renewable energy sources are those that can be used again and again. Renewable energy resources have unlimited supply. (more…)
In Europe, modern renewable energy sources technologies were explored thoroughly for the first time after the oil embargo/ price cr ...
During the US Presidential Election 2008 Campaign, the renewable portfolio standard was one of the main agendas for Presidentia ...
The broad range of home solar energy systems are mostly known as Photovoltaic Systems (PV) or Thin Film Solar Technology. The s ...
The hydrogen can come from various sources including fossil fuels, wind, solar, biomass, nuclear, solar thermo-chemical reactio ...
Renewable energy sources cannot run out and causes so little damage to the environment that its use does not need to be restric ...
It shows Well-to-Wheels Greenhouse Gas emissions of the 23 vehicle/fuel systems. For each system, the bottom bar represents CO2 -equivalent emissions of CO2 , CH4 , and N2O, combined with their greenhouse global warming potentials (GWPs). The top bar represents CO2 emissions only. For the two ethanol pathways (corn and cellulosic ethanol), there are some negative emissions. They represent carbon uptake during biomass growth. The carbon is eventually emitted to the air during ethanol combustion air. (more…)
The combination of well-to-pump results and the energy use and emissions associated with vehicle operation (also called the pum ...
There are different types of vehicle propulsion systems and the transportation fuels that have been studied for their potential ...
The spark-ignition and compression-ignition engine and internal combustion engines technologies that are currently employed in ...
The fuel cycle for a given transportation fuel includes the following processes: energy feedstock (or primary energy) product ...
The energy efficiencies of various fuel production pathways from well to pump. The efficiencies shown are defined as the energy ...