Polygeneration systems in buildings

Abstract Whether considering a simple hearth fire in a Neolithic hut, a south-facing glazed window in a medieval European castle, or a steam-powered factory during the Industrial Revolution, fuel-based and solar-based polygeneration concepts have been used throughout history to serve the energy needs of buildings and their occupants. Modern polygeneration systems such as combined heat and power (CHP) plants, combined cooling, heating, and power (CCHP) systems, and building-integrated photovoltaic–thermal (BIPV/T) devices serve the complex energy demands of modern buildings, including heating, electricity, cooling, daylighting, and ventilation. The built environment must rapidly move toward improved energy efficiency, increased penetration of renewable energy technologies, and elimination of fossil fuel use to address the climate crisis and ensure sustainable use of global natural resources. This chapter examines polygeneration systems in buildings with a focus on emerging low-carbon approaches. The chapter begins with an overview of the types and magnitudes of energy demands typically found in buildings, together with a discussion of future energy vectors, supply–demand matching, and the growing role for energy storage. This is followed by a review of modern polygeneration approaches such as hydrogen fuel cells and multifunction solar building envelopes, which address the growing Net Zero and Positive Energy building agendas.