The status of 4th generation district heating: Research and results

Abstract

Highlights:  Provides a review of 4 th Generation District Heating (4GDH) in scientific papers  Shows how 4GDH is an important integrated part of future sustainable energy systems  Quantifies costs and benefits of 4GDH in a future sustainable energy system  Shows how benefits exceed costs by a safe margin  Shows the significant benefits of systems integration

The Role of Low Temperature Waste Heat Recovery in Achieving 2050 Goals: A Policy Positioning Paper

“…Taking the interest of low temperature district heating investments into account, it is noted that, in Denmark, the 4DH research centre was active between 2012 and 2018 with contributions from several Danish and international universities, together with many Danish district heating and companies. Researchers within this centre have written a 4GDH definition paper ( [17]) and a 4GDH status paper ( [16]). Many papers have also been published in scientific journals from the annual international 4DH conferences since 2015 ( [15]).…”

District Heating Tariffs, Economic Optimisation and Local Strategies during Radical Technological Change

“…The 4GDH concept has addressed this question [3,8]. The technical solution is to lower distribution temperatures with forward/return temperatures reduced to around 55/40 • C. Lower distribution temperatures allows access to larger amounts of waste heat from industries, increases the efficiencies of renewable heat sources, and increases the coefficient of performance (COP) of large-scale heat pumps when converting renewable-based electricity to heat [9,40,41]. The third element makes it possible for the district heating sector to balance the fluctuations from wind and solar electricity generation and provide access to large-scale heat storage units [42,43].…”

“…Facing this technological change in electricity production, district heating grids are risking being left as uncompetitive stranded assets. However, research addressing this issue has identified large potentials for district heating systems in a renewable energy system, the so-called fourth generation district heating (4GDH) system [8][9][10]. The strategic role of district heating in this vision-from which it may derive its future economic value-implies, among others, the ability to convert excess electricity from fluctuating renewables to heat at high efficiencies.…”

“…There is now a considerable knowledge base on needed technical components and building modifications necessary for 4GDH [9]. A recent publication highlighted a need for research into the field of regulatory framework for the advancement of 4GDH [23].…”

Optimal Scheduling of Combined Heat and Power Generation Units Using the Thermal Inertia of the Connected District Heating Grid as Energy Storage

“…Besides work looking into providing flexibility for renewable electricity integration within the power sector, work on a cross-sectoral integration including all sectors and/or energy carriers has been published [2]. Hence, tools and approaches integrating different energy systems are needed [3]. For providing flexibility to the power system, energy storage systems are crucial.…”