District Heating Cost Optimization

Author(s):  
Aaron P. Eicoff

When buildings of various use-types are served by a district energy system, many societal benefits occur, including improved capacity utilization, reduced energy use, and more cost-effective redundancy. In addition, a central system may benefit financially from commodity leveraging, utility incentives and cogeneration. Energy conversion and transport efficiency for steam and hot water are explored and presented. System optimization curves, including generation and distribution, are presented along with long-term financial comparisons to decentralized systems.

2019 ◽  
Vol 111 ◽  
pp. 06009
Author(s):  
Tymofii Tereshchenko, ◽  
Dmytro Ivanko ◽  
Natasa Nord ◽  
Igor Sartori

Widespread introduction of low energy buildings (LEBs), passive houses, and zero emission buildings (ZEBs) are national target in Norway. In order to achieve better energy performance in these types of buildings and successfully integrate them in energy system, reliable planning and prediction techniques for heat energy use are required. However, the issue of energy planning in LEBs currently remains challenging for district heating companies. This article proposed an improved methodology for planning and analysis of domestic hot water and heating energy use in LEBs based on energy signature method. The methodology was tested on a passive school in Oslo, Norway. In order to divide energy signature curve on temperature dependent and independent parts, it was proposed to use piecewise regression. Each of these parts were analyzed separately. The problem of dealing with outliers and selection of the factors that had impact of energy was considered. For temperature dependent part, the different methods of modelling were compared by statistical criteria. The investigation showed that linear multiple regression model resulted in better accuracy in the prediction than SVM, PLS, and LASSO models. In order to explain temperature independent part of energy signature the hourly profiles of energy use were developed.


2020 ◽  
pp. 14-24
Author(s):  
Tina Lidberg ◽  
Thomas Olofsson ◽  
Louise Ödlund

Lowering temperature levels of a district heating (DH) system may offer several advantages such as reduced distribution losses, increased efficiency of flue gas condensation equipment and increased electricity generation in combined heat and power plants. In a broader perspective this can result in more efficient use of natural resources as well as reduced climate-impacting emissions. This study examines how decreased DH supply temperatures influence the power-to-heat ratio and thereby electricity production and fuel use in a combined heat and power plant. Carbon dioxide equivalent (CO2-eqv.) emissions and primary energy use were calculated with three different marginal electricity perspectives. A regional DH system situated in mid-Sweden was used as a case study and the energy system cost optimization modelling tool MODEST (Model for Optimization of Dynamic Energy Systems with Time-Dependent Components and Boundary Conditions) was used. The results show that decreasing the DH supply temperature results in increased electricity production as well as increased fuel use within the system. Further, there is a significant difference in CO2-eqv. emissions and primary energy use for the studied marginal electricity perspectives.


Author(s):  
Jaspreet S. Nijjar ◽  
Alan S. Fung ◽  
Larry Hughes ◽  
Hessam Taherian

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.


2020 ◽  
Vol 160 ◽  
pp. 01004 ◽  
Author(s):  
Stanislav Chicherin ◽  
Lyazzat Junussova ◽  
Timur Junussov

Proper adjustment of domestic hot water (DHW) load structure can balance energy demand with the supply. Inefficiency in primary energy use prompted Omsk DH company to be a strong proponent of a flow controller at each substation. Here the return temperature is fixed to the lowest possible value and the supply temperature is solved. Thirty-five design scenarios are defined for each load deviation index with equally distributed outdoor temperature ranging from +8 for the start of a heating season towards extreme load at temperature of -26°C. All the calculation results are listed. If a flow controller is installed, the customers might find it suitable to switch to this type of DHW supply. Considering an option with direct hot water extraction as usual and a flow controller installed, the result indicates that the annual heat consumption will be lower once network temperatures during the fall or spring months are higher. The heat load profiles obtained here may be used as input for a simulation of a DH substation, including a heat pump and a tank for thermal energy storage. This design approach offers a quantitative way of sizing temperature levels in each DH system according to the listed methodology and the designer's preference.


Author(s):  
Christopher D. Wright ◽  
Robert B. Stone

Techniques for residential energy usage monitoring is an emerging field that is currently drawing significant attention. This paper is a description of the current efforts to monitor and compare the performance of three solar-powered homes built at Missouri University of Science and Technology. The homes are outfitted with an array of sensors and a data logger system to measure and record electricity production, system energy use, internal home temperature and humidity, hot water production, and exterior ambient conditions the houses are experiencing. Data will be collected to measure the performance of the houses, compare to energy modeling programs, design and develop cost effective sensor systems for energy monitoring, and produce a cost effective home control system.


Author(s):  
George A. Mertz ◽  
Gregory S. Raffio ◽  
Kelly Kissock ◽  
Kevin P. Hallinan

In response to both global and local challenges, the University of Dayton is committed to building a net-zero energy student residence, called the Eco-house. A unique aspect of the Eco-house is the degree of student involvement; in accordance with UD’s mission, interdisciplinary student teams from mechanical engineering, civil engineering and the humanities are leading the design effort. This paper discusses the conceptual design of a net-zero energy use campus residence, and the analysis completed thus far. Energy use of current student houses is analyzed to provide a baseline and to identify energy saving opportunities. The use of the whole-system inside-out approach to guide the overall design is described. Using the inside-out method as a guide, the energy impacts of occupant behavior, appliances and lights, building envelope, energy distribution systems and primary energy conversion equipment are discussed. The design of solar thermal and solar photovoltaic systems to meet the hot water and electricity requirements of the house is described. Eco-house energy use is simulated and compared to the energy use of the existing houses. The analysis shows the total source energy requirements of the Eco-house could be reduced by about 340 mmBtu per year over older baseline houses, resulting in CO2 emission reductions of about 54,000 lb per year and utility cost savings of about $3,000 per year. Detailed cost analysis and cost optimization have not been performed but are critical aspects of the UD Eco-house project, which will be performed in the future.


Author(s):  
Joe Huang ◽  
Donghyun Seo ◽  
Moncef Krarti

The Changning District in Shanghai has expressed interest to becoming a green neighborhood and has asked for recommendations on how to reduce the energy usage in public buildings in their district. The objective of this short study is to identify the likely range of further reductions in the energy use and carbon emissions of new buildings through energy-efficiency improvements and the use of renewable energy, i.e., solar hot water (SHW), photovoltaics (PV), and ground-source heat pumps (GSHP), as compared to buildings that meet the current public building energy code in Shanghai. This analysis is done using DOE-2.1E computer simulations of three prototypical building models — an office, a hotel, and a mixed-use retail/office building — that have been calibrated against measured energy data from such buildings in the Changning District. After the building models have been calibrated, they are then used to establish the baseline energy use for code-compliant buildings, and to calculate the energy savings for 16 potential EEMs (Energy Efficiency Measures) that exceed the building energy code. A LCC (Life-Cycle Cost) analysis is done to compare the energy cost reductions to the capital costs for the EEMs, with the result that some EEMs are rejected as being not cost-effective over a 25 year period. The usage of the EEMs accepted as cost-effective is found to reduce the energy usage of the three building types by 30–40% in the office, 43–46% in the hotel, and 35% in the retail, depending on the assumed discount rate. If all the EEMs are considered regardless of cost, the energy savings increase to 44% in the office, 47% in the hotel, and 36% in the retail.


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