Heat transferHeat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes. Engineers also consider the transfer of mass of differing chemical species (mass transfer in the form of advection), either cold or hot, to achieve heat transfer.
Heat exchangerA heat exchanger is a system used to transfer heat between a source and a working fluid. Heat exchangers are used in both cooling and heating processes. The fluids may be separated by a solid wall to prevent mixing or they may be in direct contact. They are widely used in space heating, refrigeration, air conditioning, power stations, chemical plants, petrochemical plants, petroleum refineries, natural-gas processing, and sewage treatment.
Sustainable energyEnergy is sustainable if it "meets the needs of the present without compromising the ability of future generations to meet their own needs." Most definitions of sustainable energy include considerations of environmental aspects such as greenhouse gas emissions and social and economic aspects such as energy poverty. Renewable energy sources such as wind, hydroelectric power, solar, and geothermal energy are generally far more sustainable than fossil fuel sources.
Heat pipeA heat pipe is a heat-transfer device that employs phase transition to transfer heat between two solid interfaces. At the hot interface of a heat pipe, a volatile liquid in contact with a thermally conductive solid surface turns into a vapor by absorbing heat from that surface. The vapor then travels along the heat pipe to the cold interface and condenses back into a liquid, releasing the latent heat. The liquid then returns to the hot interface through capillary action, centrifugal force, or gravity and the cycle repeats.
Low-energy houseA low-energy house is characterized by an energy-efficient design and technical features which enable it to provide high living standards and comfort with low energy consumption and carbon emissions. Traditional heating and active cooling systems are absent, or their use is secondary. Low-energy buildings may be viewed as examples of sustainable architecture. Low-energy houses often have active and passive solar building design and components, which reduce the house's energy consumption and minimally impact the resident's lifestyle.
Demand responseDemand response is a change in the power consumption of an electric utility customer to better match the demand for power with the supply. Until the 21st century decrease in the cost of pumped storage and batteries electric energy could not be easily stored, so utilities have traditionally matched demand and supply by throttling the production rate of their power plants, taking generating units on or off line, or importing power from other utilities.
Synthetic fuelSynthetic fuel or synfuel is a liquid fuel, or sometimes gaseous fuel, obtained from syngas, a mixture of carbon monoxide and hydrogen, in which the syngas was derived from gasification of solid feedstocks such as coal or biomass or by reforming of natural gas. Common ways for refining synthetic fuels include the Fischer–Tropsch conversion, methanol to gasoline conversion, or direct coal liquefaction. The term 'synthetic fuel' or 'synfuel' has several different meanings and it may include different types of fuels.
Fossil fuel subsidiesFossil fuel subsidies are energy subsidies on fossil fuels. They may be tax breaks on consumption, such as a lower sales tax on natural gas for residential heating; or subsidies on production, such as tax breaks on exploration for oil. Or they may be free or cheap negative externalities; such as air pollution or climate change due to burning gasoline, diesel and jet fuel. Some fossil fuel subsidies are via electricity generation, such as subsidies for coal-fired power stations.
Phase-out of fossil fuel vehiclesVehicles that are powered by fossil fuels, such as gasoline (petrol), diesel, kerosene, and fuel oil are set to be phased out by a number of countries. It is one of the three most important parts of the general fossil fuel phase-out process, the others being the phase-out of fossil fuel power plants for electricity generation and decarbonisation of industry. Many countries and cities around the world have stated they will ban the sale of passenger vehicles (primarily cars and buses) powered by fossil fuels such as petrol, liquefied petroleum gas, and diesel at some time in the future.
Jet fuelJet fuel or aviation turbine fuel (ATF, also abbreviated avtur) is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines. It is colorless to straw-colored in appearance. The most commonly used fuels for commercial aviation are Jet A and Jet A-1, which are produced to a standardized international specification. The only other jet fuel commonly used in civilian turbine-engine powered aviation is Jet B, which is used for its enhanced cold-weather performance.
