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Osaka Gas’ residential polymer electrolyte fuel cell (PEFC) cogeneration system
About the fuel cell

What is a fuel cell?

A fuel cell produces electricity by making hydrogen and oxygen react chemically..
In the following, basics of the fuel cell system are presented.

Principle of power generation based on the fuel cell

A fuel cell is based on a reverse reaction of water electrolysis. Hydrogen (*) reacts with oxygen in the air to produce water. In this process, electricity and heat are generated. It is a power generation system that does not produce greenhouse gases like CO2 in the process of power generation.

* Hydrogen is obtained by reforming city gas.

Types of fuel cells and their major applications

About the configuration of fuel cell cogeneration system and devices used in the fuel cell cogeneration system

About the component devices and functions
Fuel processing system Click here for more information
Extracts hydrogen from natural gas.
Heat exchangers
Recovers heat from the cell stack and fuel processing system to produce hot water.
Cell stack 
Click here for more information
Generates direct current electricity by using hydrogen and oxygen.
Hot recovery unit
Stores hot water and supplies it on demand for hot water and heating.
Converts direct current electricity into alternating current electricity
Backup boiler
If the amount of hot water in the storage tank is not enough, city gas is fired to heat the water.
About the cogeneration system

A gas cogeneration system is a highly-efficient distributed energy system that produces electricity when and where electricity is needed.

The 56% of primary energy in a conventional fossil-fired power station, is losing in the form of waste heat during the power generation process and about 4% in the transmission of electricity, in a result overall efficiency of the system ends up to about 40%.

On the other hand, a gas cogeneration system is an epoch-making system in which 70% to 90% of the primary energy is used effectively. Natural gas sent without losses is converted into electrical energy on the site where it will be used, and the waste heat is recovered , and utilized for hot water supply and air conditioning.

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