scholarly journals Integrating Mobile Thermal Energy Storage (M-TES) in the City of Surrey’s District Energy Network: A Techno-Economic Analysis

2021 ◽  
Vol 11 (3) ◽  
pp. 1279
Author(s):  
Maha Shehadeh ◽  
Emily Kwok ◽  
Jason Owen ◽  
Majid Bahrami

The City of Surrey in British Columbia, Canada has recently launched a district energy network (DEN) to supply residential and commercial buildings in the Surrey Centre area with hot water for space and domestic hot water heating. The network runs on natural gas boilers and geothermal exchange. However, the City plans to transition to low-carbon energy sources and envisions the DEN as a key development in reaching its greenhouse gas emissions (GHG) reduction targets in the building sector. Harvesting and utilizing waste heat from industrial sites using a mobile thermal energy storage (M-TES) is one of the attractive alternative energy sources that Surrey is considering. In this study, a techno-economic analysis (TEA) was conducted to determine the energy storage density (ESD) of the proposed M-TES technology, costs, and the emission reduction potential of integrating waste heat into Surrey’s DEN. Three transportation methods were considered to determine the most cost-effective and low-carbon option(s) to transfer heat from industrial waste heat locations at various distances (15 km, 30 km, 45 km) to district energy networks, including: (i) a diesel truck; (ii) a renewable natural gas-powered (RNG) truck, and (iii) an electric truck. To evaluate the effectiveness of M-TES, the cost of emission reduction ($/tCO2e avoided) is compared with business as usual (BAU), which is using a natural gas boiler only. Another comparison was made with other low carbon energy sources that the city is considering, such as RNG/biomass boiler, sewer heat recovery, electric boiler, and solar thermal. The minimum system-level ESD required to makes M-TES competitive when compared to other low carbon energy sources was 0.4 MJ/kg.

Author(s):  
Mary E. Clayton ◽  
Ashlynn S. Stillwell ◽  
Michael E. Webber

With a push toward renewable electricity generation, wind power has grown substantially in recent U.S. history and technologies continue to improve. However, the intermittency associated with wind-generated electricity without storage has limited the amounts sold on the grid. Furthermore, continental wind farms have a diurnal and seasonal variability that is mismatched with demand. To increase the broader use of wind power technologies, the development of systems that can operate intermittently during off-peak hours must be considered. Utilization of wind-generated electricity for desalination of brackish groundwater presents opportunities to increase use of a low-carbon energy source and supply alternative drinking water that is much needed in some areas. As existing water supplies dwindle and population grows, cities are looking for new water sources. Desalination of brackish groundwater provides one potential water source for inland cities. However, this process is energy-intensive, and therefore potentially incongruous with goals of reducing carbon emissions. Desalination using reverse osmosis is a high-value process that does not require continuous operation and therefore could utilize variable wind power. That is, performing desalination in an intermittent way to match wind supply can help mitigate the challenges of integrating wind into the grid while transforming a low-value product (brackish water and intermittent power) into a high-value product (treated drinking water). This option represents a potentially more economic form of mitigating wind variability than current electricity storage technologies. Also, clean energy and carbon policies under consideration by the U.S. Congress could help make this integration more economically feasible due to incentives for low-carbon energy sources. West Texas is well-suited for desalination of brackish groundwater using wind power, as both resources are abundant and co-located. Utility-scale wind resource potential is found in most of the region. Additionally, brackish groundwater is found at depths less than 150 m, making west Texas a useful geographic testbed to analyze for this work, with applicability for areas with similar climates and water supply scarcity. Implementation of a wind-powered desalination project requires both economic and geographic feasibility. Capital and operating cost data for wind turbines and desalination membranes were used to perform a thermoeconomic analysis to determine the economic feasibility. The availability of wind and brackish groundwater resources were modeled using geographic information systems tools to illustrate areas where implementation of a wind-powered desalination project is economically feasible. Areas with major populations were analyzed further in the context of existing and alternative water supplies. Utilization of wind-generated electricity for desalination presents a feasible alternative to energy storage methods. Efficiency, economics, and ease of development and operation of off-peak water treatment were compared to different energy storage technologies: pumped hydro, batteries, and compressed air energy storage. Further economics of compressed air energy storage and brackish groundwater desalination were examined with a levelized lifetime cost approach. Implementation of water desalination projects using wind-generated electricity might become essential in communities with wind and brackish groundwater resources that are facing water quality and quantity issues and as desires to implement low carbon energy sources increase. This analysis assesses the economic and geographic feasibility and tradeoffs of such projects for areas in Texas.


2021 ◽  
Vol 11 (11) ◽  
pp. 5142
Author(s):  
Javier Menéndez ◽  
Jorge Loredo

The use of fossil fuels (coal, fuel, and natural gas) to generate electricity has been reduced in the European Union during the last few years, involving a significant decrease in greenhouse gas emissions [...]


2015 ◽  
Vol 6 ◽  
pp. 1487-1497 ◽  
Author(s):  
Nicole Pfleger ◽  
Thomas Bauer ◽  
Claudia Martin ◽  
Markus Eck ◽  
Antje Wörner

Thermal energy storage (TES) is capable to reduce the demand of conventional energy sources for two reasons: First, they prevent the mismatch between the energy supply and the power demand when generating electricity from renewable energy sources. Second, utilization of waste heat in industrial processes by thermal energy storage reduces the final energy consumption. This review focuses mainly on material aspects of alkali nitrate salts. They include thermal properties, thermal decomposition processes as well as a new method to develop optimized salt systems.


2020 ◽  
Author(s):  
Aleksandr Ivakhnenko ◽  
Beibarys Bakytzhan

<p>In global socioeconomic development facing climate change challenges to minimize the output of greenhouse gas (GHG) emissions and moving to a more low-carbon economy (LCE) the major driving force for success in achieving Sustainable Development Goals (SDGs) is the cost of energy generation. One of the main factors for energy source selection in the power supply and energy type generation process is the price parameters often influenced at different degree by government policies incentives, technological and demographic challenges in different countries. We research the energy sources situation and possible development trends for developing country Kazakhstan with resource-based economy. In general, the economic aspects affect the quality and quantity of energy generated from different sources with incentives for environmental concern. Traditional energy sources in Kazakhstan, such as coal, oil and natural gas remain low-cost in production due to high reserve base, which leads to steady growth in this area. In general, the cost for generating 1 kWh of energy from the cheapest carbon source of energy sub-bituminous coal is about 0.0024 $, for natural gas 0.0057 $, conventional oil 0.0152 $ (conventional diesel is 0.0664 $) and for expensive unconventional oil 0.0361 $, whereas renewable hydrocarbons could potentially become more competitive with unconventional oil production (methanol 0.0540 $, biodiesel 0.0837 $, bioethanol 0.1933 $ for generating 1 kWh). Furthermore, we consider the main non-traditional and renewable energy sources of energy from the sun, wind, water, and biofuels, hydrogen, methane, gasoline, uranium, and others. There is a difference between the breakeven prices of conventional gas and biomethane (0.0057 $ and 0.047 - 0.15 $ respectively averaging 0.0675 $ per 1 kWh for biomethane) which is often related to the difference in their production methods. The main advantage of biomethane is environmentally friendly production. We also propose an assessment of fuel by environmental characteristics, where one of the hazardous sources Uranium is forth cheap 0.0069 $ per kWh, but the environmental damage caused by its waste is the greatest. At the same time hydropower is seven times more expensive than uranium, but it does not cause direct health damage issues, however influencing significantly ecosystem balance. Hydrogen fuel is the most expensive among others. Overall in Kazakhstan energy-producing from the sun, wind and biogas is more expensive comparing with global trends from 0.4 to 5.5 cents per 1 kWh, but remains cheaper for hydropower. In addition, based on the research findings we analyzed the potential for sustainable non-renewable and renewable energy development in the future for the case of the resource-based economy in Kazakhstan. </p>


Cryogenic Energy Storage (CES) improves power grid application with renewable intermittent power sources. In CES, off-peak excess electricity liquefies air or natural gas. Cryogenic fluid so obtained is stored in large Dewar tanks for long periods of time. Whenever electricity need is in peak, work available in cryogen is recovered by thermodynamic cycle using hot storage waste heat (HSWH) that has been generated by liquefier’s compressor. Many researchers focus on liquid air energy storage (LAES). But, natural gas (NG) is good working substance for CES liquefaction process. This paper reviews NG-CES containing high grade cold storage (HGCS). Cold stored HGCS is utilized to raise CES efficiency and hike liquefier yield. This paper models HGCS unit and compares output with experimental data. Impact of cold recycling is analyzed for liquefier yield and storage efficiency.


Author(s):  
Andrei Yu. Petrov ◽  
Abdolreza Zaltash ◽  
Edward A. Vineyard ◽  
Solomon D. Labinov ◽  
D. Tom Rizy ◽  
...  

The performance of a commercially available direct-fired desiccant dehumidification unit (DFDD) has been studied as part of a microturbine generator (MTG)-based Integrated Energy System (IES) at Oak Ridge National Laboratory (ORNL). The IES includes a second-generation air-to-water heat recovery unit (HRU) for the MTG. The focus of these tests was to study the performance of a DFDD in baseline (direct-fired with its natural gas burner) mode and to compare it with a DFDD performance in the exhaust-fired and combined modes as part of the ORNL IES, when waste heat received from the MTG was used for desiccant regeneration. The baseline tests were performed with regeneration air heated by a natural gas burner (direct-fired). The testing of the waste-heat, or exhaust-fired DFDD as part of IES involved using the exhaust gas from the HRU for regeneration air in the DFDD after hot water production in the HRU. Hot water from the HRU was used to produce chilled water in an indirect-fired (water fired) absorption chiller. The combined DFDD was the combination of natural gas burner and exhaust-fired testing. The study investigated the impact of varying the process and regeneration conditions on the latent capacity (LC) and latent coefficient of performance (LCOP) of the DFDD, as well as overall IES efficiency. The performance tests show that LC increases with increasing dew point (humidity ratio) of the process air or the increased amount of waste heat associated with increased MTG power output. In addition, baseline LC was found to be three times higher than the LC in the exhaust-fired mode of operation. LCOP in baseline operation is also almost three times higher than that obtained in the exhaust-fired mode (55.4% compared to 19%). But, at the same time, addition of the DFDD to the IES with the MTG at maximum power output increases the overall IES efficiency by 4–5%. Results of the combined tests performed at a reduced MTG power output of 15 kW (51,182 Btu/h) and their comparison with the baseline and exhaust-fired tests show that activation of the DFDD gas burner during exhaust-fired tests increases the LC over the baseline value from 91,514.9 Btu/h (25.8 kW) to 101,835.8 Btu/h (29.8 kW). The LCOP during the combined mode is less than the “baseline” LCOP, because in addition to gas input, the low-grade MTG/HRU exhaust heat input to the DFDD are also being considered. The overall IES efficiency during the combined mode is approximately 8% higher than without the DFDD integrated into the IES.


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