|Heat pumps for space heating or cooling and water heating||
Heat pumps deliver heating, cooling and hot water to buildings in the domestic, public and industrial sectors and can be located anywhere in the world as they utilise the constant temperature of the earth, the air temperature or water source. Heat pumps can also be reversed and function as space coolers. Most heat pumps operate on a vapour-compression cycle and are driven by an electric motor. Some heat pumps use the absorption principle, with gas or waste heat as the driving energy. This means that heat rather than mechanical energy is supplied to drive the cycle.
|High performance building façades||
The building façade is the interface between the external and internal environments of a building. Therefore, it has a large impact on occupants’ interface with the surrounding environment; energy efficiency and the indoor environmental quality performance of a building, such as lighting and HVAC electricity loads; and peak load to maintain good lighting level and thermal comfort for the occupants.
|Highly efficient heating, ventilation and air conditioning||
Heating, ventilation and air conditioning (HVAC) systems supply fresh air and condition the indoor air temperature and humidity of a building. HVAC is reported as the key energy user (37%) in US buildings (WBCSD, 2008), accounting for 59% of the energy used in China commercial buildings in 2000 (Levine et al., 2007). Therefore, HVAC is a key component of climate change mitigation potential in the building sector.
|Household biogas digesters||
Biogas is a flammable gas produced by organic materials after it has been decomposed and fermented by anaerobic bacteria in tightly sealed environmental digesters under certain temperature, humidity, acidity and alkalinity conditions. The process in which biogas bacteria decompose organic materials to produce biogas is known as biogas fermentation. Manure-based biogas digesters refer to fermentation tanks which are used to treat animal manure including human waste via anaerobic fermentation.
|Hybrid Electric Vehicles||
One approach to lowering the CO2 emission from traffic is the hybridization of vehicles. A hybrid vehicle uses two or more distinct power sources, i.e. hybrid electric vehicles (HEVs) combine an internal combustion engine and one or more electric motors. Vehicles employed in urban areas like small passenger cars, local delivery trucks and city busses benefit from hybridization and show substantially lower CO2 emissions, ranging from 23 to 43% depending on the traffic dynamics.
Hybrid technology systems combine two or more technologies with the aim to achieve efficient systems. Possible combinations are: wind-solar photovoltaic (PV) hybrid systems, wind-diesel hybrid systems, fuel cell-gas turbine hybrid systems, wind-fuel cell hybrid systems, etc. (see the short descriptions below). Hybrid systems combine numerous electricity production and storage units to meet the energy demands of a given facility or community (Solar Energy Technologies Program, 2006).
|Hydro Dams for Large-Scale Electricity Supply||
Hydro power plants capture the energy released by water falling through a turbine and converts this into mechanical power, which drives generators to produce electricity. Today’s hydropower turbines are capable of converting more than 90% of available energy into electricity.
Hydrogen is considered an important fuel for future use in transportation, central and distributed electric power, portable power and combined heat and power for industrial development. The plethora of sources for hydrogen production, along with the variety of methods to extract it, makes hydrogen a very promising fuel. The introduction of hydrogen can be feasible in both industrialised and developing countries.