Innovative household systems based on solid oxide fuel cells for a northern European climate

Abstract

Energy saving is an open point in most European countries where energy policies are oriented to reduce the use of fossil fuels, greenhouses emissions and energy independence and to increase the use of renewable energies. In the last several years, new technologies have been developed, and some of them received subsidies to increase installation and reduce cost.This article presents an innovative cogeneration system based on a solid oxide fuel cell (SOFC) system and heat pump for household applications with a focus on primary energy and economic savings using electric equivalent load parameter which is a function of the electricity and heat demand of the user, and allows different operation strategies to be considered. The proposal is to maximize the efficiency of the system and to make it profitable, even though technologies with a high purchase cost are considered. Simulations of the system are performed under different strategies at a resort located in a northern European climate (Denmark) to cover electricity, space heating and domestic hot water (DHW) demands. The results of these simulations are analyzed with thermodynamic and technoeconomic benchmarks, considering different economic scenarios. The calculations show the high primary energy saving and profitability of the system.

Thermodynamic Investigation of a Shared Cogeneration System with Electrical Cars for Northern Europe Climate

“…Heat at high temperature (780 °C) produced by SOFC is recovered to feed the Stirling engine. The fuel cell model is already proposed in [25,26,29] with a nominal electric power of 10 kW which is also adapted for the simulation of the system proposed here ( Table 1). The model is slightly modified for using in different configurations in order to simulate different types of fuel in input as described in [29].…”

“…According to [25,35,36], a total energy demand of 14.85 MWh for DHW, 53.63 MWh for SH and 15.14 MWh for electricity is estimated. Figure 8 represents energy demands for each season: winter (December, January and February), spring (March, April and May), summer (June, July and August) and autumn (September, October and November).…”

“…Electric Load Following (ELF) is an operation strategy proposed in [40] and already used by the authors in previous studies [25,26]. This operation strategy considers both user electricity and heat demands together and simultaneously.…”

“…The equations proposed in [25] require the user electricity demand (EUSER), the user heat demand (HUSER), and the efficiencies of both the SOFC (ηtrans) and the GSHP (COP) as input data [eq. (1) and eq.…”

“…An experimental analysis of some kinds of modules demonstrated that the thermal and electrical efficiencies are determined by mass flow of cooling water, the inlet temperature and the solar radiation [23]. Heat pumps were also proposed to achieve high efficiency system for hot water production in [24] and cogeneration systems by integrating the heating systems were also proposed to attain better electricity and heat demands (for the user) in Northern [25] and Mediterranean [26] climates.…”