Session 16, Paper 4, CIBSE ASHRAE Technical Symposium, Dublin, Ireland, 3-4 April 2014
Combined heat and power (CHP) systems can increase energy efficiency, resulting in lower energy costs and reduction in greenhouse gas (GHG) emissions. Fuel cell (prime mover) based micro-CHP is an energy conversion system which receives and converts energy as supplied from hydrogen, natural gas or other hydrocarbons to both electricity and heat. Micro-CHP systems for use in commercial and residential properties are designed to supplement the current Grid supplied electricity system as well as the gas fired combi boilers by producing the heating and electrical energy demand of buildings in the UK and EU. Several micro-CHP systems are already available in the market with varying degrees of success. Fuel cells are the most efficient way to convert the hydrogen to heat and power at the point of use for decentralized stationary systems. Although the application of fuel cells to powering buildings is relatively new, due to their ability to run at low heat-to-power ratio, fuel cell based CHP systems are expected to become a more attractive alternative for the market. The heat-to-power ratio is defined as the rate of useful thermal energy production to that of electrical energy production. CHP system efficiency is determined by the system type, size, and the operating conditions of the prime mover. Here is presented an overview of current fuel cell micro-CHP systems, specifically Solid Oxide Fuel Cell (SOFC)-based micro CHP systems, and provides an overview of the advantages and challenges of SOFC systems for residential buildings.