Energy analysis and life cycle assessment of a thermal energy storage unit involving conventional or recycled storage materials and devoted to industrial waste heat valorisation

Co-optimization of a high temperature thermal storage as per its modeling accuracy

“…A first criteria can be the sum of the system primary energy costs over a fixed number of years. Those costs are equivalent to the cumulative energy demand (CED) and being calculated by the help of the tool developed by [10]. Here 𝐸 𝑑𝑒𝑠𝑖𝑔𝑛 is the CED needed for the storage construction, 𝐸 𝑜𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔 is the CED needed to operate the storage system during a year of operation, 𝐸 𝑙𝑜𝑠𝑠 is the CED of generated losses by the storage system over a year of operation, and 𝐸 𝑓 𝑢𝑒𝑙 is the CED of consumed fuel that can be substituted thanks to the storage flexibility over a year of operation.…”

“…In order to discuss the difference between the two business models in a way that is independent of the length of operation, the Energy Payback Time (EPBT) is introduced in this section, as proposed in [10]. This criteria is used to calculate the time needed to payback the initial investment (here 𝐸 𝑑𝑒𝑠𝑖𝑔𝑛 ), which allows to determine the storage capacity to install with shortest payback time as follows: (10) Here, for each design the EPBT criteria is evaluated as defined in Eq. (10).…”

“…This criteria is used to calculate the time needed to payback the initial investment (here 𝐸 𝑑𝑒𝑠𝑖𝑔𝑛 ), which allows to determine the storage capacity to install with shortest payback time as follows: (10) Here, for each design the EPBT criteria is evaluated as defined in Eq. (10). This criteria is calculated without taking into account the loss cost 𝐸 𝑙𝑜𝑠𝑠 in BM n o 1 and with loss cost in BM n o 2.…”

“…Here, a sensible thermocline high temperature thermal energy storage (HTTES), using air as HTF and rocks as HSM, will be studied [8]. This technology has proven to be cost effective and recently undergone numerous developments as shown in [9][10][11]. In a multi-energy network, the HTTES system represents an important flexibility to accommodate intermittent energy resources but also to meet uncontrolled demand.…”