Cogeneration is a well-known technology, often coupled with District Heating (DH) networks. In most of the applications, Combined Heat and Power (CHP) units represent a connecting technology among different energy vectors, e.g. electricity, natural gas, and thermal energy distribution networks. In the transition towards a cleaner energy system featured by a high share of non-programmable renewable energy sources, the connection and the flexibility that they can provide to the energy system may play a key role. In this regard, Thermal Energy Storage (TES) systems can increase the flexibility of the CHP units by shifting the production and the subsequent consumption of both thermal energy and electricity. To increase the energy efficiency of a real CHP unit connected to a DH network, a feasibility study related to the installation of a TES unit coupled with an Internal Combustion Engine (ICE) of 1.2 MWe/1.4 MWth in a thermal plant located in the Center of Italy, connected to a DH network, has been studied in this work. In particular, the role of the TES in extending the daily operating hours of the CHP unit, rather than traditional natural gas boilers, has been investigated. The CHP unit in this particular installation generally operates from 6:00 to 21:00 for both technical and economic reasons. In the case of an 83 m3 water-based TES, the flexibility of the CHP unit could be widened to mid-seasons and summer. Indeed, the TES would allow the CHP unit to be started up two hours in advance, leading to a gross economic income of 16,625 €/year due to the white certificate mechanism supported by the Italian legislation to promote energy efficiency measures like CHP technologies. Furthermore, additional benefits can be obtained by postponing the CHP unit shut-down by two hours, achieving an overall gross economic income of 22,625 €/year.
Thermal Energy Storage (TES) to increase the flexibility of cogeneration units in District Heating (DH) networks
Cioccolanti L.;
2021-01-01
Abstract
Cogeneration is a well-known technology, often coupled with District Heating (DH) networks. In most of the applications, Combined Heat and Power (CHP) units represent a connecting technology among different energy vectors, e.g. electricity, natural gas, and thermal energy distribution networks. In the transition towards a cleaner energy system featured by a high share of non-programmable renewable energy sources, the connection and the flexibility that they can provide to the energy system may play a key role. In this regard, Thermal Energy Storage (TES) systems can increase the flexibility of the CHP units by shifting the production and the subsequent consumption of both thermal energy and electricity. To increase the energy efficiency of a real CHP unit connected to a DH network, a feasibility study related to the installation of a TES unit coupled with an Internal Combustion Engine (ICE) of 1.2 MWe/1.4 MWth in a thermal plant located in the Center of Italy, connected to a DH network, has been studied in this work. In particular, the role of the TES in extending the daily operating hours of the CHP unit, rather than traditional natural gas boilers, has been investigated. The CHP unit in this particular installation generally operates from 6:00 to 21:00 for both technical and economic reasons. In the case of an 83 m3 water-based TES, the flexibility of the CHP unit could be widened to mid-seasons and summer. Indeed, the TES would allow the CHP unit to be started up two hours in advance, leading to a gross economic income of 16,625 €/year due to the white certificate mechanism supported by the Italian legislation to promote energy efficiency measures like CHP technologies. Furthermore, additional benefits can be obtained by postponing the CHP unit shut-down by two hours, achieving an overall gross economic income of 22,625 €/year.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
