Combined Heat And Power Fuel Cell Systems Research Articles

Progress of SOFC Residential CHP System: Over 50,000 Units Market Experience of Osaka Gas

Osaka Gas began selling the second-generation residential SOFC CHP “ENE-FARM type S” in April 2016, which was developed in collaboration with Aisin Seiki, Kyocera and Noritz. In April 2018, power efficiency when the rated output can be stably is improved 53.5 % (net AC, LHV) from 52.0 % (net AC, LHV). The cumulative sales volume of Osaka Gas’s the residential fuel cell CHP system as in March 2019 was over 100,000. The cumulative number of SOFC-type was more than half. We have been trying to improve its quality and specifications, and reduce its cost. For example, we have improved the merchantability by adding a self-sustaining power generation function and using the Internet. ENE-FARM type S performed at approximately 2,000 customer homes though a power failure occurred mainly in Osaka due to Typhoon in 2018. It was an opportunity that one of the benefits in residential CHP was socially recognized.

Performance of residential fuel-cell-combined heat and power systems for various household types in Japan

A residential fuel-cell-combined heat and power (FC-CHP) system is considered a promising low-carbon technology that can reduce residential energy consumption and thus, achieve Japan's greenhouse gas (GHG) emissions reduction targets. However, to consider future directions for the systems' research and development, it is critical to understand the relationships between the performances of FC-CHP systems and residential energy demand profiles, which vary by household characteristic. This study evaluates the effects of applying city gas-fueled FC-CHP systems to Japanese households with different attributes. We compare total costs and GHG emissions for residential energy use between the FC-CHP systems and a conventional system. The economic performance results suggest that the basic PEMFC-CHP systems have an economic advantage only for four-person families with teenage children and further development efforts for low-output FC-CHP systems are required to enable various households save energy costs. The environmental evaluation results show that SOFC-CHP systems can drastically reduce GHG emissions from particularly small-sized households.

IMS Ecubes launches fuel cell CHP system

IMS Ecubes launches fuel cell CHP system

Process Intensification in Fuel Cell CHP Systems, the ReforCELL Project

This paper reports the findings of a FP7/FCH JU project (ReforCELL) that developed materials (catalysts and membranes) and an advance autothermal membrane reformer for a micro Combined Heat and Power (CHP) system of 5 kWel based on a polymer electrolyte membrane fuel cell (PEMFC). In this project, an active, stable and selective catalyst was developed for the reactions of interest and its production was scaled up to kg scale (TRL5 (TRL: Technology Readiness Level)). Simultaneously, new membranes for gas separation were developed. In particular, dense supported thin palladium-based membranes were developed for hydrogen separation from reactive mixtures. These membranes were successfully scaled up to TRL4 and used in lab-scale reactors for fluidized bed steam methane reforming (SMR) and autothermal reforming (ATR) and in a prototype reactor for ATR. Suitable sealing techniques able to integrate the different membranes in lab-scale and prototype reactors were also developed. The project also addressed the design and optimization of the subcomponents (BoP) for the integration of the membrane reformer to the fuel cell system.

Development of New Model of Fuel Cell Systems

Tokyo Gas has developed a residential fuel cell CHP system named “ENE-FARM” jointly with Panasonic, and began to sell ENE-FARM as the world’s first commercial fuel cell cogeneration system in May 2009. Following the first-generation model of ENE-FARM, the second-generation was released in 2011, and the third-generation in 2013. The cumulative sales of ENE-FARM have reached 40,000 units as of January 2015. After the third-generation, the new fourth-generation model of ENE-FARM has been launched since April 2015. This new model was developed in order to meet customer expectations such as reduced cost, integration of optional units for a power outage and greater flexibility of installation. These improvements can contribute to the customer satisfactions and the expansion of ENE-FARM spread. In this paper, specifications and main features of the new model ENE-FARM are described

Energy System and Thermoeconomic Analysis of Combined Heat and Power High Temperature Proton Exchange Membrane Fuel Cell Systems for Light Commercial Buildings

The United States Department of Energy’s Pacific Northwest National Laboratory is teaming with industry to deploy and independently monitor 5-kilowatt-electric (kWe) combined heat and power (CHP) fuel cell systems (FCSs) in light commercial buildings. Results of an independent evaluation of manufacturer-stated engineering, economic, and environmental performance of these CHP FCSs are presented here. An important contribution of this paper is the precise definition and development of these essential terms for quantifying distributed CHP generator energy use within buildings: (1) electricity and heat utilization, (2) electrical and heat recovery efficiencies, (3) in-use electrical and heat recovery efficiencies, (4) percentage usage of electricity, and (5) percent usage of recoverable heat. Key additional parameters evaluated include the average cost of the CHP FCSs per unit of power and per unit of energy, the change in greenhouse gas (GHG) and air pollution emissions with a switch from conventional power plants and furnaces to CHP FCSs, the change in GHG mitigation costs from the switch, and the change in human health costs from air pollution. CHP FCS heat utilization is expected to be under 100% at several installation sites; for six sites, during periods of minimum heating demand, the in-use CHP FCS heat recovery (HR) efficiency based on the higher heating value of natural gas is expected to be only 24.4%. From the power perspective, the average per-unit cost (PUC) of electrical power is estimated to span $15–19,000/kWe (depending on site-specific installation, fuel, and other costs), while the average PUC of electrical and HR power is $7,000–9,000/kW. Regarding energy, the average PUC of electrical energy is $0.38–$0.46/kilowatt-hour-electric, while the average PUC of electrical and HR energy is $0.18–$0.23/kWh. GHG emissions were estimated to decrease by one-third after replacing a conventional system with a CHP FCS. GHG mitigation costs were also proportional to changes in GHG emissions. Estimated human health costs from air pollution emissions decreased by a factor of 1000 with changing to CHP FCS. Reported for the first time here is the derivation of the PUCs of power and energy for a CHP device from both standard and management accounting (MA) perspectives. Results show that the average PUC of combined electrical and HR power is equal to the average PUC of electric power applying an MA approach, and also equal to the average PUC of HR power applying an MA approach. Similar relations hold for the average PUC of energy. Results presented here demonstrate the value of using the equations herein for economic analyses of CHP systems to represent the average PUC of electrical power, HR power, or both, and for energy.

Modelling of a Solid Oxide Fuel Cell CHP System Coupled with a Hot Water Storage Tank for a Single Household

In this paper a solid oxide fuel cell (SOFC) system for cogeneration of heat and power integrated with a stratified heat storage tank is studied. The use of a storage tank with thermal stratification allows one to increase the annual operating hours of CHP: heat can be produced when the request is low (for instance during the night), taking advantage of thermal stratification to increases the heat recovery performance. A model of the SOFC system is presented to estimate the energy required to meet the average electric energy demand of the residence. Two fuels are considered, namely syngas produced by gasification and natural gas. The tank model considers the temperature gradients over the tank height. The results of the numerical simulation are used to size the SOFC system and storage heat tank to provide energy for a small household using two different fuels. In particular it was shown that in the case of syngas, due to larger system heat output, a larger tank volume was required in order to accumulate unused heat over the night. The detailed description of the tank model will be useful to energy system modelers when sizing hot water tanks. Problem formulation is reported also using a Matlab script.

Viessmann installs first fuel cell CHP system in UK home, ahead of 2016 market rollout

The first mass-produced domestic fuel cell system commercially available in the UK, the Vitovalor 300-P from Viessmann, has been installed in a family home in Wolverhampton. The installation of this innovative clean energy technology will see the homeowner some £1000 (US$1540) per annum better off, and cut their carbon footprint in half.

Design and optimization of a proton exchange membrane fuel cell CHP system for residential use

This work deals with the analysis of a micro-cogeneration system for residential use based on a 1kWe proton exchange membrane (PEM) fuel cell. A detailed system analysis of the fuel cell stack operating at an average temperature of 62°C and the surrounding balance-of-plant (BoP) are taken into account. The gas processing section and the heat recovery system were also designed and optimized in term of heat recovery. Low-grade waste heat, mainly recovered from the PEM stack and the burner exhaust, has been found suitable for feeding a low-temperature thermal user such a radiant floor heating system (operating at ∼35–45°C). According to this configuration, the heat-exchanger network has been optimized following the pinch analysis methodology, and the floor heating system has been sized accordingly.The micro-cogeneration system has been modelled in term of mass and energy balances while efficiency maps were obtained for a varying fuel utilization and current density of the stack. The maximum electrical efficiency achieved is around 36% (AC, LHV), with a stack current of 30A and a Fuel Utilization (FU) of 80%. The global efficiency (that includes also heat recovery toward the thermal utility) is above 75% for same stack operating conditions.From the floor heating system sizing, the considered micro-CHP PEM system is able to supply around 22.4% of the heat demand by a 50m2 medium-low efficiency building (class E – EU classification) during the winter season. Nevertheless, taking into account a high efficiency building (class A++ – EU classification), the heat released by the PEM plant can supply the overall required thermal load without requiring an auxiliary boiler.

First fuel cell CHP system designed for residential and small-scale commercial use

Oregon-based ClearEdge Power has developed the first fuel cell energy system of its kind for residential and small-scale commercial applications. Comparable in size to a standard refrigerator and offering combined heat and power (CHP), consumers and small-to-medium businesses are able to utilize fuel cells like never before. With a significant grant from the US Department of Energy to accelerate domestic market adoption of fuel cell technology and the company's plans for additional international expansion, this technology is poised to revolutionize where and how consumers and businesses generate energy.

Optimizing the Design and Deployment of Stationary Combined Heat and Power Fuel Cell Systems for Minimum Costs and Emissions—Part I: Model Design

Stationary combined heat and power (CHP) fuel cell systems (FCSs) can provide electricity and heat for buildings and can reduce greenhouse gas (GHG) emissions significantly if they are configured with an appropriate installation and operating strategy. The maximizing emission reduction and economic saving simulator (MERESS) is an optimization tool that was developed to evaluate novel strategies for installing and operating CHP FCSs in buildings. These novel strategies include networking, load following, and the use of variable heat-to-power ratios, all of which industry typically has not implemented. A primary goal of models like MERESS is to use relatively inexpensive simulation studies to identify more financially and environmentally effective ways to design and install FCSs. Models like MERESS can incorporate the pivotal choices that FCS manufacturers, building owners, emission regulators, competing generators, and policy makers make, and empower them to evaluate the effect of their choices directly. MERESS directly evaluates trade-offs among three key goals: GHG reductions, energy cost savings for building owners, and high sales revenue for FCS manufacturers. MERESS allows one to evaluate these design trade-offs and to identify the optimal control strategies and building load curves for installation based on either (1) maximum GHG emission reductions or (2) maximum cost savings to building owners. Part I discusses the motivation and key assumptions behind MERESS model development. Part II discusses run results from MERESS for a California town and makes recommendations for further FCS installments (Colella , 2011, “Optimizing the Design and Deployment of Stationary Combined Heat and Power Fuel Cell Systems for Minimum Costs and Emissions—Part II: Model Results,” ASME J. Fuel Cell Sci. Technol., 8(2), p. 021002).

Life cycle assessment of an alkaline fuel cell CHP system

A life cycle assessment (LCA) of an alkaline fuel cell based domestic combined heat and power (CHP) system is presented. Literature on non-noble, monopolar cell design and stack construction was reviewed, and used to produce a life cycle inventory for the construction of a 1 kW stack. Inventories for the ancillary components of other commercial fuel cell products were consulted, and combined with information on the fuel processing requirements of alkaline cells to suggest a hypothetical balance of plant that would be required to produce AC electricity and domestic grade heat from natural gas and air. The emissions from manufacturing and disposing of this fuel cell CHP system were estimated to be equivalent to 510–1000 kg of CO 2 and 1.0–2.0 kg of particulate matter. As with platinum based polymer electrolyte fuel cells (PEMFC), emissions of sulphur dioxide were the most significant impact, resulting in degraded human health in the regions where catalyst metals are mined. Improving the operating lifetime and reducing catalyst loadings were identified as the most effective routes to reducing this environmental impact, as they are with other fuel cell technologies. These impacts were compared to the results of existing LCAs for other fuel cell technologies. It was found that an alkaline fuel cell stack produces less environmental impact than an equivalent solid oxide or phosphoric acid (SOFC or PAFC) stack, while no conclusive comparison with PEMFC could be made. The inclusion of energy consumption during stack manufacture and data on the more exotic material inputs were highlighted as a problem in these studies.

Solid oxide fuel cell systems for residential micro-combined heat and power in the UK: Key economic drivers

The ability of combined heat and power (CHP) to meet residential heat and power demands efficiently offers potentially significant financial and environmental advantages over centralised power generation and heat-provision through natural-gas fired boilers. A solid oxide fuel cell (SOFC) can operate at high overall efficiencies (heat and power) of 80–90%, offering an improvement over centralised generation, which is often unable to utilise waste heat. This paper applies an equivalent annual cost (EAC) minimisation model to a residential solid oxide fuel cell CHP system to determine what the driving factors are behind investment in this technology. We explore the performance of a hypothetical SOFC system—representing expectations of near to medium term technology development—under present UK market conditions. We find that households with small to average energy demands do not benefit from installation of a SOFC micro-CHP system, but larger energy demands do benefit under these conditions. However, this result is sensitive to a number of factors including stack capital cost, energy import and export prices, and plant lifetime. The results for small and average dwellings are shown to reverse under an observed change in energy import prices, an increase in electricity export price, a decrease in stack capital costs, or an improvement in stack lifetime.

Demonstration of a residential CHP system based on PEM fuel cells

Abstract Fuel cell-based CHP systems are very attractive for stationary energy generation, since they allow production of electricity and heat in a decentralised, quiet, efficient and environmentally friendly way. As a means of evaluating this new technology, Enel Produzione installed a beta-version fuel cell CHP system, supplied by H-Power, at its experimental area sited in Livorno (Italy), and submitted it to a series of tests. The system is a co-generative unit, converting natural gas into electricity and heat: the former is delivered to local loads using electric load following capability; the latter is delivered to the experimental area hydraulic refrigeration circuit. Experiments were aimed at assessing the suitability of this kind of system to supply Italian residential customers. Factors such as performances, flexibility and operational requirements were evaluated under all the possible operating conditions, both under grid connected and stand alone configurations. At the same time, a mathematical model of the FC/CHP unit was developed to allow for the prediction of system performances and operating parameters under off-design conditions. This model can be used as an effective tool to optimise system operation when a particular customer has to be supplied. Results show that the prototype behaved as expected by a first “proof of concept” system and outline improvements to be achieved in order to satisfy the energy needs of small residential applications.

Evaluation of Energy, Environmental, and Economic Characteristics of Fuel Cell Combined Heat and Power Systems for Residential Applications

Residential combined heat and power (CHP) systems using fuel cell technology can provide both electricity and heat and can substantially reduce the energy and environmental impact associated with residential applications. The energy, environmental, and economic characteristics of fuel cell CHP systems are investigated for single-family residential applications. Hourly energy use profiles for electricity and thermal energy are determined for typical residential applications. A mathematical model of a residential fuel cell based CHP system is developed. The CHP system incorporates a fuel cell system to supply electricity and thermal energy, a vapor compression heat pump to provide cooling in the summer and heating in the winter, and a thermal storage tank to help match the available thermal energy to the thermal energy needs. The performance of the system is evaluated for different climates. Results from the study include an evaluation of the major design parameters of the system, load duration curves, an evaluation of the effect of climate on energy use characteristics, an assessment of the reduction in emissions, and a comparison of the life cycle cost of the fuel cell based CHP system to the life cycle costs of conventional residential energy systems. The results suggest that the fuel cell CHP system provides substantial energy and environmental benefits but that the cost of the fuel cell sub-system must be reduced to roughly $500/kWe before the system can be economically justified.

Implications of electricity liberalization for combined heat and power (CHP) fuel cell systems (FCSs): a case study of the United Kingdom

Globally electricity markets are heading in the direction of the United Kingdom’s liberalized model, in which transactions are increasingly transparent such that prices more closely reflect their underlying costs. Increased transparency in the structure of electricity markets augurs to have both negative and positive effects for embedded generators such as combined heat and power (CHP) fuel cell systems (FCSs). Embedded generators are decentralized generators in close proximity to consumers that feed part of their electricity directly into a local low-voltage distribution network and, in some cases, part to a direct source of demand onsite. First, this article analyses the negative consequences that the UK’s liberalized model has had on current embedded generators. Second, it discusses the potential positive effects that the liberalizing trend could have on future embedded generators. Finally, based on these lessons, it draws conclusions about design strategies for CHP FCSs as future embedded generators.