The benefits of 4th generation district heating in a 100% renewable energy system

Abstract

District heating is a well-established system for providing energy efficient space and domestic hot water heating in dwellings in particularly in temperate and cold climate zones. Research has shown that going from the current 3rd generation district heating (3GDH) systems towards 4th generation district heating (4GDH) systems can facilitate a better integration between energy sectors, reduce grid losses and assist the integration of renewable energy sources. This article investigates the economic and energy effects of going from 3GDH to 4GDH for the specific case of Aalborg Municipality, Denmark based on overall hourly energy systems simulations. The analyses include effects from changes in excess heat potentials, changes in grid losses, and changes in efficiencies of conversion units in the district heating. Altogether, the analyses of the Aalborg case reveal that going from 3GDH to 4GDH decreases the primary energy consumption of the entire energy system by around 4.5% and the costs of the system by 2.7%.