Cogeneration
Due to the high cost of early purchased power, these CHP operations continued for many years after utility electricity became available.
Steam at ordinary process heating conditions still has a considerable amount of enthalpy that could be used for power generation, so cogeneration has an opportunity cost.
In such cases, the heat from the CHP plant is also used as a primary energy source to deliver cooling by means of an absorption chiller.
This requires heavily insulated pipes, which are expensive and inefficient; whereas electricity can be transmitted along a comparatively simple wire, and over much longer distances for the same energy loss.
Thermally enhanced oil recovery (TEOR) plants often produce a substantial amount of excess electricity.
Cogeneration plants are commonly found in district heating systems of cities, central heating systems of larger buildings (e.g. hospitals, hotels, prisons) and are commonly used in the industry in thermal production processes for process water, cooling, steam production or CO2 fertilization.
The terms cogeneration and trigeneration can also be applied to the power systems simultaneously generating electricity, heat, and industrial chemicals (e.g., syngas).
Bottoming cycle plants are only used in industrial processes that require very high temperatures such as furnaces for glass and metal manufacturing, so they are less common.
Large cogeneration systems provide heating water and power for an industrial site or an entire town.
[12] Some cogeneration plants combine gas and solar photovoltaic generation to further improve technical and environmental performance.
For PEM fuel cell units, which shut down at night, this equates to an estimated lifetime of between ten and fifteen years.
One author indicated in 2008 that MicroCHP based on Stirling engines is the most cost-effective of the so-called microgeneration technologies in abating carbon emissions.
[19] A 2013 UK report from Ecuity Consulting stated that MCHP is the most cost-effective method of using gas to generate energy at the domestic level.
[24] The University of Cambridge reported a cost-effective steam engine MicroCHP prototype in 2017 which has the potential to be commercially competitive in the following decades.
This hence still emits CO2 (see reaction) but (temporarily) running on this can be a good solution until the point where the hydrogen is starting to be distributed through the (natural gas) piping system.
It combines the fuel saving technique of cogeneration meaning producing electric power and useful heat from a single source of combustion.
The increased focus on sustainability has made industrial CHP more attractive, as it substantially reduces carbon footprint compared to generating steam or burning fuel on-site and importing electric power from the grid.
Smaller industrial co-generation units have an output capacity of 5–25 MW and represent a viable off-grid option for a variety of remote applications to reduce carbon emissions.
HRSGs used in the CHP industry are distinguished from conventional steam generators by the following main features: Biomass refers to any plant or animal matter in which it is possible to be reused as a source of heat or electricity, such as sugarcane, vegetable oils, wood, organic waste and residues from the food or agricultural industries.
[39] Due to this absorption, when the sugarcane bagasse is burned in the power cogeneration, dioxins [39] and methyl chloride [40] ends up being emitted.
[45] However, for a remotely operated heat pump, losses in the electrical distribution network would need to be considered, of the order of 6%.
These plants benefit from economy of scale, but may need to transmit electricity across long distances causing transmission losses.
Typically, for a gas-fired plant the fully installed cost per kW electrical is around £400/kW (US$577), which is comparable with large central power stations.
[56] Other UK measures to encourage CHP growth are financial incentives, grant support, a greater regulatory framework, and government leadership and partnership.
It defines, through calculation of inputs and outputs, "Good Quality CHP" in terms of the achievement of primary energy savings against conventional separate generation of heat and electricity.
Compliance with Combined Heat and Power Quality Assurance is required for cogeneration installations to be eligible for government subsidies and tax incentives.
By the early 1900s, regulations emerged to promote rural electrification through the construction of centralized plants managed by regional utilities.
[citation needed] The United States Department of Energy has an aggressive goal of having CHP constitute 20% of generation capacity by 2030.
The focus of the Application Centers is to provide an outreach and technology deployment program for end users, policymakers, utilities, and industry stakeholders.
High electric rates in New England and the Middle Atlantic make these areas of the United States the most beneficial for cogeneration.
