Techno-Economic Analysis of Rural 4th Generation Biomass District Heating

Abstract

Biomass heating networks provide renewable heat using low carbon energy sources. They can be powerful tools for economy decarbonization. Heating networks can increase heating efficiency in districts and small size municipalities, using more efficient thermal generation technologies, with higher efficiencies and with more efficient emissions abatement technologies. This paper analyzes the application of a biomass fourth generation district heating, 4GDH (4th Generation Biomass District Heating), in a rural municipality. The heating network is designed to supply 77 residential buildings and eight public buildings, to replace the current individual diesel boilers and electrical heating systems. The development of the new fourth district heating generation implies the challenge of combining using low or very low temperatures in the distribution network pipes and delivery temperatures in existing facilities buildings. In this work biomass district heating designs based on third and fourth generation district heating network criteria are evaluated in terms of design conditions, operating ranges, effect of variable temperature operation, energy efficiency and investment and operating costs. The Internal Rate of Return of the different options ranges from 6.55% for a design based on the third generation network to 7.46% for a design based on the fourth generation network, with a 25 years investment horizon. The results and analyses of this work show the interest and challenges for the next low temperature DH generation for the rural area under analysis.

Identification of key performance indicators and complimentary load profiles for 5th generation district energy networks

“…The majority of operational DHNs in the UK are largely 3 rd generation (3G) networks [8,9], with high supply temperatures (circa 90°C) [10], high thermal losses [11], and are difficult to manage [12,13]. It has been shown on many occasions that reducing the supply temperature and incorporating a larger share of low-grade heat into DHNs can offer improved efficiency but will still face many of the same challenges as 3G DHNs [14][15][16][17][18][19]. These problems include high thermal losses (particularly in low population density areas), few connections to the network (connection uncertainty), and difficulty in procuring usable low-temperature sources.…”