Biomass District Heating Systems Research Articles

A profitability index for rural biomass district heating systems evaluation

Biomass heating networks are an efficient and low-emission alternative for rural municipalities without natural gas supply. One of the main challenges for their implementation on a larger scale is to reduce the uncertainty in the profitability evaluation. The linear heat density is the index commonly used to evaluate the potential for heating networks investments. It provides highly accurate estimations in high-density building networks. However, it does not provide accurate enough evaluations for low-building-density networks, resulting in relevant deviations when applied to biomass district heating networks. This work proposes a new index to evaluate the profitability of biomass heating networks in rural environments based on the analysis of investment, operation, and biomass costs. It is developed based on the cost-benefit analysis of biomass heating networks. The new index has been applied to 499 rural municipalities in Spain, showing a high accuracy in estimating the profitability of investments, with R2 values between 0.8179 and 0.9442, compared to 0.2408 if linear heat density was used for the same cases. The analyses show the interest of this approach for the evaluation of biomass district heating potential in areas with dispersed populations.

Biomass district heating system in Italy: A comprehensive model-based method for the assessment of energy, economic and environmental performance

In the framework of the energy strategy toward 2050, district heating systems (DHS) offers a great flexibility in terms of heat generation technologies and renewable resources integration, resulting, in case of proper management and supply conditions, in fossil primary energy and greenhouse gases savings compared to conventional technologies. In Italy, only the 2.5% of the thermal final uses are satisfied by DHS and, although widely available over the territory, those fuelled by wooden biomass represent less than the half of the total. Many studies in this framework have highlighted the need of methods and tools for a better understanding of the operative conditions, of the potentialities and of the optimal evolution of biomass DHS. To that end, a proper simulation model has been developed and calibrated on a real case study operating in cogeneration, in an urban area of Northern Italy. After investigating the current performance of the real case, some criticalities have been described and new operating scenarios have been defined and simulated. The achieved results represent a support for the stakeholders involved in BDHS and for future energy policies, providing hints on possible challenging evolutive scenarios and on measures to enhance the energy performance and the economic appeal.

A biomass universal district heating model for sustainability evaluation for geographical areas with early experience

Biomass district heating systems are an optimal economic and environmental solution for generating and distributing thermal energy. One of the main challenges for a broader development of these systems is the complexity of its implementation in the absence of established regulations in the legal, commercial, technical, or economic fields, a situation that occurs in geographical areas with early experience. This work proposes a model for the sustainability of biomass district heating systems, including the whole value chain, taking into account the role of the stakeholders. The design of this Biomass Universal District Heating (BioUnivDH) optimises the implementation and sustainability of the district heating system in geographical areas with early experience. It is conceived to identify implementation barriers and to contribute to their elimination. The model identifies the stakeholders of the project through the analysis of their relationships, objectives, and expectations. This model allows comparison between different systems, and it improves the decision-making process with a holistic approach that identifies strategies for successful implementation and operation based on economic, environmental, and social acceptance criteria. Finally, to show the application of the BioUnivDH model, it is applied in four heating system projects based on biomass and implemented in four Spanish cities.

Analysis of the Methodology to Obtain Several Key Indicators Performance (KIP), by Energy Retrofitting of the Actual Building to the District Heating Fuelled by Biomass, Focusing on nZEB Goal: Case of Study

In order to achieve the objectives of the European 20/20/20 strategy, and to obtain a greater energy efficiency, integration of renewable energies and the reduction of carbon emissions, a District Heating (DH) system has been designed by the University of Valladolid (UVa), Spain, one of the most important DH fed by biomass fuel in Spain, supplying heating and domestic hot water (DHW) to 31 buildings in Valladolid, the majority of them, educational buildings on the University Campus. The aims of this paper were to study the change from an energy system fueled by natural gas to District Heating by biomass in a building on the campus of the University of Valladolid—the School of Engineering (EII)—studying its consumption from its connection to the District Heating system. An energy management methodology such as ISO 50001 is carried out, applied to efficiency systems in buildings, thus establishing new criteria of sustainability and economic value. In this paper, energy management will also be analyzed in accordance with the proposed tools of an Energy Management System (EMS) applied to the EII building, through the measurement of energy parameters, calculation of thermal consumption, thermal energy savings as a result of the change from system to District Heating by biomass, economic savings, reduction of environmental impact and indicators of thermal efficiency I100 and CUSUM indicator. Finally, the primary renewable and non-renewable energy efficiency indicators for the new District Heating system will be determined. The concept of the near Zero Energy Buildings is defined in the European Union (EU) in order to analyze an approach to an nZEB which results from replacing the natural gas heating system by a biomass District Heating system.

Potential of biomass district heating systems in rural areas

Biomass district heating systems are a promising way to increase thermal efficiency in rural areas. These areas have specific characteristics, such as a relative low linear heat density and proximity to biomass resources. Generally, rural areas show higher levels of energy poverty than urban areas and a higher number of partially used or unoccupied dwellings. These factors greatly affect the energy provided by a district heating system and should therefore be properly assessed when designing a sustainable facility. This manuscript develops a methodology for implementing biomass district heating facilities in rural areas, taking into account their specific characteristics. As a case study, the methodology is applied to 499 rural municipalities with a population above 1500 inhabitants in the continental region of Spain. Results show a potential for 154 biomass district heating systems with an internal rate of return above 5%, and 31 systems above 10%. On the other hand, only three district heating systems are classified as non-profitable. The massive implantation of these systems in the region under study reduce CO2 emissions from fossil fuels in 5.4 million tons per year and would imply and important impulse to local economy.

Biomass District Heating Systems Based on Agriculture Residues

This paper presents a methodology for analyzing the regional potential for developing biomass district heating systems combining forestry biomass and agriculture residues as fuel. As a case study, this methodology is applied to the continental region of Spain. With this analysis the potential for the implementation of biomass district heating systems based on the use of agriculture residues is applied to 501 rural municipalities in Spain. The renewable forestry biomass and agriculture residues resources availability is analyzed and the biomass required for heating is assessed. The results of applying the methodology show the interest of the combination of biomass sources in a relevant number of municipalities with estimated Internal Rate of Return (IRR) values above 10% and for the analyzed region an IRR mean value of 4.3%.

District heating systems based on low-carbon energy technologies in Mediterranean areas

Heating and cooling are responsible for 70% of energy consumption in European buildings, with renewables covering only 18%. To reduce emissions in the building sector, district heating based on low-carbon energy is identified as a key technology for the transition to a low-carbon economy. However, currently only 16% of thermal district networks are based on biomass, and around 3.2% on solar. This paper analyses the application of solar and biomass district heating systems in the low-to-moderate population density areas of the Mediterranean. These areas are characterised by high solar and biomass availability, and lack of space restrictions, along with particular challenges for implementation. A methodology for viability analysis and optimised integration is presented. The methodology is applied to a case study in the south of Spain. The results show that with a linear heat density greater than 1.5 MWh/m, there could be viability with internal rates of return higher than 7.4 and 9.8%, and payback period below 13 and 10 years, for solar and biomass systems respectively. The use of seasonal thermal energy storage allows the solar fraction to be increased from 55 to 75%. Sizing and design strategies for their viable implementation in Mediterranean areas are extrapolated from the analyses.

Biomass district heating methodology and pilot installations for public buildings groups

The objective of the paper is to show how locally available biomass can support a small-scale district heating system of public buildings, especially when taking into account energy audit in-situ measurements and energy efficiency improvement measures. The step-by-step methodology is presented, including the research for local biomass availability, the thermal needs study and the study for the biomass district heating system, with and without energy efficiency improvement measures.

An applied methodology for assessment of the sustainability of biomass district heating systems

In order to maximise the share of biomass in the energy supplying system, the designers should adopt the appropriate changes to the traditional systems and become more familiar with the design details of the biomass heating systems. The aim of this study is to present the development of methodology and its associated implementation in software that is useful for the design of biomass thermal conversion systems linked with district heating (DH) systems, taking into consideration the types of building structures and urban settlement layout around the plant. The methodology is based on a completely parametric logic, providing an impact assessment of variations in one or more technical and/or economic parameters and thus, facilitating a quick conclusion on the viability of this particular energy system. The essential energy parameters are presented and discussed for the design of biomass power and heat production system which are in connection with DH network, as well as for its environmental and economic evaluation (i.e. selectivity and viability of the relevant investment). Emphasis has been placed upon the technical parameters of biomass logistics, energy system's design, the economic details of the selected technology (integrated cogeneration combined cycle or direct combustion boiler), the DH network and peripheral equipment (thermal substations) and the greenhouse gas emissions. The purpose of this implementation is the assessment of the pertinent investment financial viability taking into account the available biomass feedstock, the economical and market conditions, and the capital/operating costs. As long as biomass resources (forest wood and cultivation products) are available and close to the settlement, disposal and transportation costs of biomass, remain low assuring the sustainability of such energy systems.

DISTRICT HEATING SYSTEM DESIGN FOR RURAL NOVA SCOTIAN COMMUNITIES USING BUILDING SIMULATION AND ENERGY USAGE DATABASES

There are several benefits to district heating systems. The system design requires knowledge of community peak heating load and annual heating energy requirements. For this purpose, a residential energy model was developed using several energy usage databases. Hourly, peak, and annual heating demands were estimated by simulating 15 archetype houses using an hour-by-hour building simulation program, ENERPASS. Estimated heating profiles from model houses were used to design a district heating system for a hypothetical rural community in Nova Scotia. The findings show that building simulation is a very flexible and valuable tool in identifying the required peak and hourly energy demand of a community for the design of district energy system, and biomass district heating system can reduce community greenhouse gas emissions.

Design of biomass district heating systems

Abstract The biomass exploitation takes advantage of the agricultural, forest, and manure residues and in extent, urban and industrial wastes, which under controlled burning conditions, can generate heat and electricity, with limited environmental impacts. Biomass can – significantly – contribute in the energy supplying system, if the engineers will adopt the necessary design changes to the traditional systems and become more familiar with the design details of the biomass heating systems. The aim of this paper is to present a methodology of the design of biomass district heating systems taking into consideration the optimum design of building structure and urban settlement around the plant. The essential energy parameters are presented for the size calculations of a biomass burning-district heating system, as well as for the environmental (i.e. Greenhouse Gas Emissions) and economic evaluation (i.e. selectivity and viability of the relevant investment). Emphasis has been placed upon the technical parameters of the biomass system, the economic details of the boiler, the heating distribution network, the heat exchanger and the Greenhouse Gas Emissions.

Socio-economic impacts of energy crops for heat generation in Northern Greece

Bioenergy is considered to be an attractive option mainly due to driving forces of an environmental nature (e.g. climate change and sustainability issues). This is particularly the case for energy crops, which show higher productivity per land unit than their conventional counterparts. In addition, by comparison, such crops are more homogeneous in terms of their physical and chemical characteristics than residual resources that are often described as the biomass resource of the future. However, despite the long-term research and the considerable efforts to promote them, implementation is still rather slow across Europe. In this paper, two perennial energy crops, cardoon and giant reed, are evaluated in Rodopi, northern Greece, as alternative land use, through comparative financial appraisal with the main conventional crops. Based on the output of this analysis, the breakeven for the two energy crops is defined and an economic and socio-economic evaluation of a biomass district heating system is conducted. Results prove that energy crops can be attractive alternatives if they are properly integrated into existing agricultural activities and complement the current cropping options. As such, they provide raw material for local heat applications, thus resulting in increased income for the region and an increase in the number of jobs.

Solar Assisted Small-Scale Biomass District Heating System in the Northern Part of Sweden

This article presents a case study of a projected solar assisted biomass district heating system in the north of Sweden. It is generally known that a biomass district heating system combined with solar heat brings many important benefits. The most common system solution is to install a heat store and a large solar collector field near the heating central. No plant of this type is however in operation in the northern part of Sweden. The main reason for this is that the solar irradiation at these latitudes is very low when the demand for heat is high. Solar heat could however be useful during summer in order to generate hot tap water. One problem is that the heat losses, calculated as percentage of the delivered heat, become very large during these months. This article presents the idea of allowing the connected households to generate their own hot tap water using solar collectors and heat stores installed in each house. The district heating network can therefore be closed in summer, which eliminates the heat losses outside the heating period. A case study of a projected plant has been carried out and it is shown that it is possible to reduce the heat losses by 20% compared to a conventional system. This idea also provides many other important technical and economic benefits.