Abstract: A cooling system of a fuel cell is provided with a main cooling flow passage and a bypass cooling flow passage which is arranged parallel with the main cooling flow passage and diverts the same coolant, as flow passages through which coolant flows. A radiator and a coolant circulation pump and the like are arranged in the main cooling flow passage. Coolant from the main cooling flow passage enters the bypass cooling flow passage and reaches a second heat exchanger via a case of a motor of an ACP and the like. At the second heat exchanger, heat exchange is also performed with a supply gas flow passage, after which the coolant returns to the main cooling flow passage. The manner in which the coolant is distributed can be changed depending on where the coolant is diverted from the main cooling flow passage and the arrangement of the circulation pump.

Abstract: A fuel cell system includes a fuel cell stack which includes a plurality of fuel cells contacted in series by a plurality of interconnects. The various embodiments provide systems and methods for coupling a fuel cell stack with an electric bypass module within a hot zone. The bypass module may include elements for conducting a current between interconnects in a fuel cell stack and thereby bypass a failed fuel cell that has become a resistive parasitic load.

Abstract: A hydrogen generator of the present invention includes a reformer (16) for generating a hydrogen-containing gas through a reforming reaction using a raw material; a combustor (102a) for heating the reformer (16); a combustion air supplier (117) for supplying combustion air to the combustor (102a); and an abnormality detector (110a) for detecting an abnormality; and a controller (110) configured to control the combustion air supplier (117) such that the reformer (16) is cooled with a higher rate in an abnormal shut-down process executed after the abnormality detector (110a) detects the abnormality, than in a normal shut-down process.

Abstract: This disclosure relates to module level redundancy for fuel cell systems. A monitoring component monitors a set of operational parameters for a fuel cell group. The fuel cell group includes a set of fuel cell units, each having a set of fuel cell stacks. The fuel cell stacks include a set of gas powered fuel cells that convert air and fuel into electricity using a chemical reaction. The monitoring component determines that the set of operational parameters do not satisfy a set of operational criteria, and, in response, a load balancing component adjusts the electrical output capacity of the set of fuel cell units included in the fuel cell group.

Abstract: To provide a solid oxide fuel cell device capable of smooth transition from a startup state to an electrical generating state. The present invention is a solid oxide fuel cell device (1) for generating electricity, having a fuel cell module (2); a reformer (20) for reforming fuel, heated by the combustion of remaining fuel not used in the generation of electricity; a fuel supply means (38); a water supply means (28); an electrical generation oxidant gas supply means (45); and a control means (110) for controlling the fuel supply means and water supply means at the time of startup when the solid oxide fuel cell units are raised to a temperature at which electrical generation is possible; wherein the control means controls the fuel supply means during the SR operation such that electrical generation is started after reducing the fuel supply flow rate prior to starting electrical generation.

Abstract: A fuel cell system having a hydrogen supply path for supplying a hydrogen gas to a fuel cell, an injector which is provided in the hydrogen supply path and which regulates the pressure of the gas on the upstream side of the hydrogen supply path to inject the pressure-regulated hydrogen gas to the downstream side of the hydrogen supply path, and a surge tank 81 which is provided in the hydrogen supply path on the upstream side from the injector and which suppresses the fluctuation of the pressure of the gas in the hydrogen supply path.

Abstract: A system and method for estimating an amount of carbon support loss in fuel cells of a fuel cell stack in a vehicle, for example, during vehicle off-times. The system and method include estimating an amount of time that a hydrogen concentration in the fuel cell stack is zero and calculating an amount of carbon loss based on the amount of time that the hydrogen concentration in the fuel cell stack is zero.

Abstract: A control unit operates a fuel-cell power generation apparatus efficiently according to power consumption and supplied hot-water heat consumption which are different in each home. A generated-power command-pattern creation section creates a plurality of generated-power command patterns which are obtained from a combination of a start time and a stop time of the fuel-cell power generation apparatus, based on a power-consumption prediction value. A hot-water storage-tank heat-quantity calculation section calculates a stored hot-water heat quantity for a predetermined period in a hot-water storage tank, based on a supplied hot-water heat-consumption prediction. A fuel-cell system-energy calculation section calculates fuel-cell system energy which indicates the energy of a fuel required in hot-water supply equipment and electricity required in electric equipment when the fuel-cell power generation apparatus is operated in each generated-power command pattern.

Abstract: A casing of a fuel cell system is divided into a fluid supply section, a module section, and an electrical equipment section. A detector, a fuel gas supply apparatus, an oxygen-containing gas supply apparatus, and a water supply apparatus are provided in the fluid supply section. A fuel cell module and a combustor are provided in the module section. A power converter and a control device are provided in the electrical equipment section. The module section is interposed between the fluid supply section and the electrical equipment section.

Abstract: A fuel cell system is disclosed in which the oxidative degradation of an anode of a fuel cell during an operation stop period is restrained. The fuel cell system (39) of the invention comprises a fuel cell (1) configured to generate electric power by use of hydrogen contained in a fuel gas supplied to an anode (1a) and oxygen contained in an oxidizing gas supplied to a cathode (1c); and a combustor (4) configured to combust flammable gas, and is formed such that after stopping the power generation, the flammable gas is introduced into and kept in the cathode (1c) and when discharging the flammable gas from the cathode (1c), the flammable gas is combusted by the combustor (4).

Abstract: A system for optimizing the purge cycle of a fuel cell stack responsive to the performance of the fuel cell. The system includes a controller that measures a process parameter indicative of the rate at which water is being produced in the fuel cell. If the measured value exceeds a threshold value, then the purge assembly is automatically actuated.

Abstract: A fuel cell system capable of improving the voltage controllability of a converter provided in the system is provided. A controller judges whether or not a passing power of a DC/DC converter falls within a reduced response performance area for the number of active phases as of the present moment. When the controller determines that the passing power of the DC/DC converter falls within the reduced response performance area, the controller determines the number of phases which avoids the driving within the reduced response performance area, and outputs a command for switching to the determined number of phases (phase switching command) to the DC/DC converter.

Abstract: The invention relates to a method and to a device for discharging used operating media of a fuel cell (1) in a fuel cell system (20), at least some of which are explosive, comprising a sensor unit (30) for examining the operating media discharged from an operating space (27). In order to discharge the used operating media from the fuel cell system independently of the operation of the fuel cell system and taking safety regulations into account, a mixing zone (32) is provided for mixing the operating media with a scavenging medium (28) to obtain waste air (33), wherein the operating space (27) is closed by a fan (29), and the sensor unit (30) is disposed downstream of the mixing zone (32), viewed in the flow direction of the waste air (33).

Abstract: A fuel cell system is provided which can extend the time during which a high-potential avoidance control is performed as much as possible, thereby reducing deterioration of a fuel cell. The fuel cell system includes: a fuel cell that generates electric power upon a supply of a reaction gas; a power storage device that is charged with at least a part of power generated by the fuel cell; and a controller that controls an output voltage of the fuel cell with, as an upper limit, a high-potential avoidance voltage lower than an open end voltage thereof. The controller variably sets the high-potential avoidance voltage in accordance with the amount of charge SOC of the power storage device.

Abstract: A method for determining when to inject hydrogen gas into the anode side of a fuel cell stack associated with a fuel cell vehicle when the vehicle is off. The method includes estimating the concentration of hydrogen gas in the anode side of the fuel cell stack using a gas concentration model and determining if the estimated concentration of hydrogen gas is below a first predetermined threshold. If the estimated hydrogen gas is less than the threshold, then hydrogen gas is injected into the anode side from a hydrogen source. While the hydrogen gas is being injected, the method compares the estimated concentration of the hydrogen gas in the anode side to a desired concentration, and generates an error signal there between. If the error signal is greater than a second predetermined threshold, the algorithm continues to inject the hydrogen into the anode side of the fuel cell stack.

Abstract: A system and method for determining whether valves in a fuel cell system bleed manifold unit (BMU) are blocked with ice or have otherwise failed. The system opens a first bleed valve, closes a second bleed valve and opens an exhaust valve, and then reads a pressure signal to determine whether there is flow through a flow restriction to determine whether the first bleed valve or the exhaust valve is blocked. The system then closes the exhaust valve, leaves the first bleed valve open, and again reads the pressure signal to determine the pressure drop across the flow restriction, which will indicate whether the flow restriction the pressure sensor lines are blocked. The system then closes the first bleed valve and opens the second bleed valve to determine whether the pressure signal indicates a flow through the second bleed valve.

Abstract: In certain embodiments of the present disclosure, a proton exchange membrane fuel cell is described. The fuel cell includes a twin-cell electrochemical filter. A flow of reformate H2 and pulse potential are switched between each respective filter cell such that when CO-contaminated H2 is fed to one filter cell, generally simultaneously a pulse potential is applied to the other filter cell.

Abstract: A fuel cell system includes at least one fuel cell stack designed to react reactants for current generation, a cold start detection apparatus for detecting a cold start state of a fuel cell stack and a load which may be connected to the fuel cell stack 2. A control device is designed to connect the load when the fuel cell stack 2 is in the cold start state. The supply of the reactants for the fuel cell stack is conformed to connection of the load, and the control device is designed with software and/or circuitry so as to vary the connected load in one or more step load changes in response to detection of the cold start state of the fuel cell stack.

Abstract: A fuel cell vehicle is provided. At the time of regeneration of electric power by a motor, an ECU places a DC/DC converter in a direct connection state under control, and stores electric power in a battery while decreasing oxygen concentration or hydrogen concentration by a gas supply unit to decrease electric power generated by a fuel cell.

Abstract: A fuel cell system can be initiated in shorter time while minimizing the deterioration of a fuel cell. The fuel cell system includes a fuel cell stack having a fuel electrode, an oxidizer electrode and an electrolyte membrane disposed there between, the fuel cell producing electricity by an electrochemical reaction of a fuel gas and an oxidizer gas, which are supplied to the fuel electrode and the oxidizer electrode, respectively; a fuel gas supplying device for supplying the fuel gas to the fuel cell stack; an oxidizer gas supplying device for supplying the oxidizer gas to the fuel cell stack; a current controlling device for extracting a current from the fuel cell stack; and a voltage sensor disposed in at least two of the fuel cell stacks.

Abstract: The present invention relates to a fuel cell system for vehicles and a method for controlling the same which stably maintains an output of a fuel cell by precisely estimating a recirculated hydrogen amount to a stack. A fuel cell system according to the present invention may include: a stack comprising a plurality of unit cells for generating electrical energy by electrochemical reaction of a fuel and an oxidizing agent; a blower for recirculating a gas exhausted from the stack so as to supply the gas back to the stack; an ejector for recirculating the gas exhausted from the stack, receiving hydrogen so as to mix the hydrogen to the recirculated gas, and supplying the mixture to the stack; a sensor module for detecting a driving condition of the vehicle; and a control portion for controlling operations of the blower and the ejector by using the driving condition of the vehicle and performance maps of the blower and the ejector.

Abstract: A fuel cell system may include a cathode loop having an operating pressure during fuel cell system operation. The cathode loop may include a normally open mechanical check valve disposed at a water pooling location within the loop and having a cracking pressure approximately equal to the operating pressure.

Abstract: A method of operating a fuel cell system which is controlled by an electronic device includes: transmitting a bit stream including a bit string which indicates identification information of the fuel cell system and a bit string which indicates status information of the fuel cell system to the electronic device through a serial communication line; receiving a bit stream including a bit string which indicates control information of the fuel cell system from the electronic device through the serial communication line; obtaining the control information of the fuel cell system from the received bit stream; and controlling power production of a fuel cell by controlling operations of peripheral devices of the fuel cell system based on the obtained control information of the fuel cell system.

Abstract: An arrangement is disclosed for reducing use for safety gases in a high temperature fuel cell system, each fuel cell in the fuel cell system including an anode side, a cathode side, and an electrolyte between the anode side and the cathode side. The fuel cells can be arranged in fuel cell stacks. The fuel cell system can include a fuel cell system piping for reactants, and feeding of fuel to the anode sides of the fuel cells. Electrical anode protection can be achieved by supplying a predefined voltage separately to at least two fuel cell stacks or groups of fuel cell stacks to prohibit oxidation of anodes.

Abstract: A fuel cell system mounted in a vehicle includes a fuel cell, a collision prediction device, a discharge device, and a controller. The fuel cell includes a gas channel to which a reactant gas is to be supplied to generate electricity. The collision prediction device is configured to predict probability of collision of the vehicle. The discharge device is configured to discharge the electricity from the fuel cell. The controller is configured to control the discharge device to discharge the electricity from the fuel cell in a case where the collision prediction device predicts that the probability of collision of the vehicle is higher than a predetermined probability.

Abstract: To provide a fuel cell system capable of performing a purge operation necessary for realizing a stable output and being miniaturized without using a controller or a sensor, there is provided a fuel cell system having a main power generation part and a sub-power generation part positioned on a downstream side of a fuel flow path of the main power generation part, including: a purge valve provided on a downstream side of the fuel flow path of the sub-power generation part; and an actuator for opening/closing the purge valve with an electromotive force of the sub-power generation part.

Abstract: A method for controlling cathode air flow at system start-up by controlling a stack by-pass valve. The method includes determining a concentration of hydrogen in a cathode side of the fuel cell stack. The method also includes determining a volumetric flow rate through a cathode compressor, determining a volumetric flow rate through the cathode side and determining a fraction of volumetric flow rate through the cathode side to the total flow through the compressor. The method determines a modeled hydrogen outlet concentration from the fuel cell stack based on the volumetric flow rate through the compressor, the fraction of volumetric flow rate through the compressor to the total flow through the compressor and the concentration of hydrogen in the cathode side. The method uses a desired fraction of volumetric flow rate through the cathode side and the total flow through the compressor to determine the position of the by-pass valve.

Abstract: A sulfur breakthrough monitoring assembly for use in a fuel utilization system for detecting sulfur-containing compounds in desulfurized fuel, said monitoring assembly comprising: a heater for heating desulfurized fuel to a predetermined temperature, the predetermined temperature being between 450° C. and 600° C., a sulfur breakthrough detector adapted to receive heated fuel from the heater and including at least a reforming catalyst bed for reforming the heated fuel and a plurality of temperature sensors including a first temperature sensor for sensing temperature of the heated fuel before the fuel is conveyed through the reforming catalyst bed and a second temperature sensor for sensing temperature in the reforming catalyst bed, and a controller for determining whether concentration of the sulfur-containing compounds in the fuel exceeds a first predetermined concentration based on temperature outputs from the first and second temperature sensors.

Abstract: A fuel cell system which can encase a dilution device while keeping the height of a fuel cell case as low as possible by utilizing the lower space in the case effectively. A fuel cell system comprises a fuel cell stack generating power through an electrochemical reaction between a gas supplied to the anode side and a gas supplied to a cathode side, a dilution device for diluting an anode off gas discharged from the fuel cell stack with a cathode off gas and discharging the diluted gas, and a fuel cell case for encasing the fuel cell stack and the dilution device. In this fuel cell system, a lateral opening of the fuel cell case for passing an exhaust pipe extending to the exhaust downstream of the dilution device is arranged above the lowermost portion of the inner surface of the dilution device with respect to the gravitational direction.

Abstract: Thermally primed fuel processing assemblies and hydrogen-producing fuel cell systems that include the same. The thermally primed fuel processing assemblies include at least one hydrogen-producing region housed within an internal compartment of a heated containment structure. In some embodiments, the heated containment structure is an oven. In some embodiments, the compartment also contains a purification region and/or heating assembly. In some embodiments, the containment structure is adapted to heat and maintain the internal compartment at or above a threshold temperature, which may correspond to a suitable hydrogen-producing temperature. In some embodiments, the containment structure is adapted to maintain this temperature during periods in which the fuel cell system is not producing power and/or not producing power to satisfy an applied load to the system. In some embodiments, the fuel cell system is adapted to provide backup power to a power source, which may be adapted to power the containment structure.

Abstract: The present invention provides an apparatus and methods for variably supplying power from a stand-alone fuel cell power supply system including a power conversion unit, a power switching unit and a load control unit. Preferably, a controller manages system configuration to switch the loads, the power conversion and the delivery between the two without reducing capacity by redundantly backing up each individual portion with a bank of at least two modules for each unit. Preferably, controller actuated devices are triggered automatically in response to monitors that sense performance operating parameters and detect values operating outside a threshold range.

Abstract: A fuel cell system and a method of operating the same, the fuel cell system comprising: a fuel cell including at least one unit cell; an switch having first and second ends connected to different type electrodes of the fuel cell; and a circuit unit to detect whether a load is applied to the fuel cell, to control the operation of the switch according to the detection, cycle the switch open and closed to short circuit the fuel cell, in order to prevent the fuel cell from overheating and to consume a residual fuel in the fuel cell. The fuel cell system may further include a converter, a secondary cell, a battery charger, and a switching unit between the load and the fuel cell.

Abstract: A method includes an in-stop-mode power generating process of, if an instruction to stop an operation of a fuel cell is detected, stopping supply of a fuel gas, and supplying an oxide gas to the fuel cell to generate power from an oxide-gas supply apparatus, and then stopping power generation of the fuel cell, and a gas replacing process of, after the power generation of the fuel cell is stopped, activating the gas replacement apparatus at a predetermined timing to supply a replacement gas to the anode side of the fuel cell to replace the fuel gas on the anode side with the replacement gas.

Abstract: An air and coolant control system comprising: a heat source configured to receive air, generate heat, receive coolant, conduct the received coolant to a coolant outlet, and transfer the generated heat to the received coolant, thereby removing the generated heat from the heat source as the coolant is conducted out of the heat source; an air supply source configured to supply the air to the heat source; an air supply control system configured to adjust the supply of air from the air supply source to the heat source based on a dynamic feedback temperature characteristic from the heat source; a coolant supply source configured to supply the coolant to the heat source; and a coolant control system configured to adjust the flow rate of the coolant based on an estimated feed-forward heat source characteristic and to adjust the temperature of the coolant based on the dynamic feedback temperature characteristic.

Abstract: Even if a failure occurs in a bypass valve during low-efficiency power generation, the occurrence of an excessive stoichiometry ratio in a fuel cell can be prevented. An output from a pressure sensor or a current sensor is monitored by a control device, and when a failure associated with a closed-valve malfunction of the bypass valve occurs, the degree of opening of the pressure regulating valve is increased to increase an amount of cathode-off gas exhaust, and a revolution speed of an air compressor is reduced to an amount of air discharged by the air compressor, thereby preventing an excessive stoichiometry ratio in the fuel cell.

Abstract: A fuel cell system includes a fuel cell module and a condenser apparatus. The condenser apparatus includes a first condenser using an oxygen-containing as a coolant, and a second condenser using hot water stored in a hot water tank as the coolant. Further, the fuel cell system includes a control device for controlling at least one of a flow rate of the exhaust gas supplied to the first condenser and a flow rate of the exhaust gas supplied to the second condenser based on at least any of a water level of the hot water in the hot water tank, a temperature of the hot water in the hot water tank, and a water level of the condensed water in the condenser apparatus.

Abstract: A method of operating a fuel cell system includes characterizing the fuel or fuels being provided into the fuel cell system, characterizing the oxidizing gas or gases being provided into the fuel cell system, and calculating at least one of the steam:carbon ratio, fuel utilization and oxidizing gas utilization based on the step of characterization.

Abstract: A fuel cell system for a vehicle includes a fuel cell arrangement that is coupleable to a vehicle drive as a primary load, and to a plurality of secondary loads. A control apparatus which controls the primary load and the secondary loads includes a monitoring circuit that is operable in a special operating mode of the fuel cell system, with the secondary loads being switched on and/or off as a manipulated variable in order to maintain the output voltage, as a reference variable, at a low voltage value that is formed by a cell voltage of the fuel cells of less than 0.45 V on average.

Abstract: The present invention provides a method for removing residual water in a fuel cell, which controls the humidity of purge gases to effectively remove residual water in the fuel cell and to maintain the humidity in a membrane at a constant level, thus ensuring the durability of the membrane. For this purpose, the present invention provides a method for removing residual water in a fuel cell, characterized in that the relative humidities of purge gases supplied to an anode and a cathode are controlled to selectively reduce water content in the fuel cell and water content in a membrane.

Abstract: A method of operating a capacitive deionization cell using a regeneration cycle to increase pure flow rate and efficiency of the cell.

Abstract: Provided is a solid oxide fuel cell comprising the following: a fuel gas flow path, a fuel electrode layer provided around the fuel gas flow path and containing an iron group element and a ceramic, a solid electrolyte layer provided around the fuel electrode layer, and an air electrode layer provided around the solid electrolyte layer. In a high-temperature state where the temperature of the solid oxide fuel cell, in which a fuel gas is supplied from one side of the fuel gas flow path and exhausted through an opening provided on the other side of the fuel gas flow path, is close to a power generation temperature, the solid oxide fuel cell is subjected to a process for regulating oxidation expansion rate of the fuel electrode layer, the oxidation expansion occurring when an oxidant gas flows in through the opening.

Abstract: A fuel cell system has a fuel cell generating power using a fuel gas and an oxidizing agent gas serving as materials of the system and a material supply section supplying the materials to the fuel cell. The power generated by the fuel cell is extracted to a load. A device for controlling the fuel cell system has: a material flow calculation section calculating a material flow supplied to the fuel cell so as to cause the fuel cell to generate the power of a required power generation amount; a material reduction limit detection section calculating a limit for reducing the material flow, based on a power generation state of the fuel cell; and a material flow change section controlling the material supply section so as to change the material flow calculated by the material flow calculation section to the limit calculated by the material reduction limit detection section.

Abstract: The present invention aims to provide a hydrogen generating method for generating hydrogen-containing gas little contaminated with nitrogen, CO, etc., by decomposing fuel containing an organic compound at low temperature while requiring the supply of no or little electric energy from an external source, and a hydrogen generating system based on the method. A hydrogen generating system based on the method can work under multiple conditions: (a) it works under a condition where electric energy is withdrawn from the hydrogen generating cell with the fuel electrode (12) serving as a negative electrode and the oxidizing electrode (14) as a positive electrode; and (b) it works under another condition where external electric energy is provided to the hydrogen generating cell with the fuel electrode (12) serving as cathode and the oxidizing electrode (14) as anode.

Abstract: A ventilation system for a fuel cell power module is provided. The ventilation system includes a ventilation enclosure for evacuating fluids from the fuel cell power module, the ventilation enclosure having an air inlet for providing ingress of air to the enclosure. The ventilation system further concludes a ventilation shaft in fluid communication with the ventilation enclosure and an evacuation pump arranged to exhaust fluid from the ventilation enclosure to a desired location.

Abstract: Provided are an apparatus and a method for managing a fuel cell vehicle system, and more particularly, an apparatus and a method for managing a fuel cell vehicle system capable of optimally maintaining a driving method based on environmental information and product information.

Abstract: Provided are an apparatus and a method for managing a stationary fuel cell system, and more particularly, an apparatus and a method for managing a stationary fuel cell system capable of optimally maintaining a driving method based on environmental information and product information.

Abstract: The present disclosure is directed to systems and methods for maintaining hydrogen-selective membranes during periods of inactivity. These systems and methods may include heating and maintaining at least the hydrogen-selective membrane of a hydrogen-producing fuel processing system in a thermally buffered state and/or controlling the chemical composition of the gas streams that may come into contact with the hydrogen-selective membrane. Controlling the chemical composition of the gas streams that may come into contact with the hydrogen-selective membrane may include maintaining a positive pressure of an inert, blanket, reducing, and/or non-oxidizing gas within the membrane separation assembly and/or periodically supplying a reducing gas stream to the membrane separation assembly.

Abstract: A system and method for preventing anode reactant starvation. The system includes a hydrogen source, an anode bleed valve, and a cell voltage monitor. The system also includes an anode sub-system pressure sensor and a controller configured to control the anode sub-system. The controller determines the average cell voltage and estimates the hydrogen molar fraction and/or nitrogen molar fraction in the anode sub-system. The controller also receives measurement data from the cell voltage monitor and the pressure sensor, and determines whether there is a decrease in the minimum cell voltage in response to changes in the anode pressure. If the controller detects a decrease in the minimum cell voltage in response to changes in the anode pressure, the controller corrects for the decrease by increasing anode pressure and/or by decreasing the molar fraction of nitrogen in the anode sub-system.

Abstract: A fuel cell system which prevents the deterioration of the fuel cell stack when feeding of the oxidant gas is paused under a load to perform a fuel conservation operation. Controller shuts down oxidant gas compressor and cooling water circulating pump to execute fuel conservation operation at a low fuel cell system load. The controller gives a current draw instruction to electric power controller. In the fuel conservation operation, electric power controller draws a current larger than zero from fuel cell stack, and keeps the total charge drawn per unit time constant or substantially constant.

Abstract: A method of operating a fuel cell electrochemical system includes receiving at least one of a cost of electricity and a cost of fuel and adjusting at least one of an operating efficiency and throughput of the fuel cell based on the at least one of the received cost of electricity and the received cost of fuel.