Dynamic Modelling and Techno-Economic Assessment of a Compressed Heat Energy Storage System: Application in a 26-MW Wind Farm in Spain

Abstract

One of the main challenges for a further integration of renewable energy sources in the electricity grid is the development of large-scale energy storage systems to overcome their intermittency. This paper presents the concept named CHEST (Compressed Heat Energy STorage), in which the excess electricity is employed to increase the temperature of a heat source by means of a high-temperature heat pump. This heat is stored in a combination of latent and sensible heat storage systems. Later, the stored heat is used to drive an organic Rankine cycle, and hereby to produce electricity when needed. A novel application of this storage system is presented by exploring its potential integration in the Spanish technical constraints electricity market. A detailed dynamic model of the proposed CHEST system was developed and applied to a case study of a 26-MW wind power plant in Spain. Different capacities of the storage system were assessed for the case under study. The results show that roundtrip efficiencies above 90% can be achieved in all the simulated scenarios and that the CHEST system can provide from 1% to 20% of the total energy contribution of the power plant, depending on its size. The CHEST concept could be economically feasible if its capital expenditure (CAPEX) ranges between 200 and 650 k€/MW.

Selection of Heat Pump Capacity Used at Thermal Power Plants under Electricity Market Operating Conditions

“…At the same time, the thermal capacity of HPU is limited by the volume of LPH generated at the TPP. (11):…”

“…Researchers in articles look at various options of HP application in systems of district heating based on the conditions of energy markets in Denmark [7], Sweden [8], Norway [9], and China [10]. There is also significant research done on heat pump technology applications aimed at improving the sustainability of energy supply in Spain [11], China [12], Norway [9], and Germany [13].…”

Dynamic modelling of an Organic Rankine Cycle Compressed Heat Energy Storage (ORC-CHEST) system integrated with a cascaded phase change materials (PCM) based packed bed unit

“…Jockenhӧfer et al [5] carried out a technical investigation on a fully heat integrated subcritical ORC-CHEST proposing a cascaded sensible heat-PCM TES combining a pressurized water storage for the sensible part and a latent heat storage (eutectic mixture of potassium nitrate and lithium nitrate with Tmelt = 133 ºC) for the phase change zones. Aiming to develop a dynamic model of the ORC-CHEST coupled with a 26 MW wind farm located in Spain, Sánchez-Canales et al [6] carried out a techno economic analysis of the case scenario. The results showed that, with a round trip efficiency above 90 %, the ORC-CHEST is an economically viable energy storage system only when its capital cost (CAPEX) ranges between 235 and 765 k$/MWe.…”

“…R1233zd(E), R-1234ze(Z) and R-1233zd(E)/R-1233zd(E) were selected as the best working fluids for HTHP and the ORC assuming a system maximum temperature as high as 133 ºC. Trebilcock [8] presented the design and operation modes of a ORC-CHEST system based on the model developed by Sánchez-Canales et al [6]. The results confirmed the potentiality of the system achieving round trip efficiency values higher than 100 % when using waste heat/cold sources available.…”

Justification of the power of the heat pump used in the cooling system of the steam turbine condenser of the CCGT-CHP

“…Анализируются возможные варианты применения ТН в системах централизованного теплоснабжения, в условиях энергетических рынков различных стран [8][9][10][11]. Рассматриваются возможности повышения устойчивости энергоснабжения за счет применения ТН [12][13][14]. Проводится оценка перспектив использования ТН в комплексе с различными энергоустановками [15,16].…”