Optimal Scheduling of a Fuel Cell for Combined Heat and Power

There is an urgent need to reduce emissions produced from the heating sector in order to meet overall greenhouse gas (GHG) emission targets. Hydrogen offers the potential to significantly reduce GHG emissions resulting from heating if either the hydrogen is produced renewably, or when hydrogen is produced from fossil fuels, carbon capture and storage is implemented. In order to use hydrogen for heating, there is the potential to convert local gas networks from natural gas to hydrogen, such as proposed by the Leeds city gate scheme. Using hydrogen powered fuel cells for combined heat and power (CHP) means that it is possible to produce both heat and power for domestic properties. This will increase the efficiency and value of the fuel use, as well as providing an extra revenue source through electricity generation.
This work describes the development of a model and optimisation methodology to schedule a domestic fuel cell CHP device in order to maintain the internal temperature of a dwelling within defined limits whilst minimising the cost of operation of the system. A model has been developed which simulates the ability of a building to act as an energy store by including its thermal capacitance. The model uses mixed integer linear optimisation and a receding time period implementation to optimally schedule the operation of the fuel cell whilst keeping the internal temperature of the building within limits. The model accounts for factors such as fuel cell start up/shut down cost and maximum ramp rate. Environmental factors such as predicted temperature and insolation as well as building occupation and use are used as inputs to the model. The results show the proposed methodology can schedule the fuel cell such that internal building temperatures are kept within limits whilst reducing overall costs.
Keywords: hydrogen, fuel cells, combined heat and power

Acknowledgement: The scientific work was supported by FLEXIS (Flexible Integrated Energy Systems).