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HESs for Carbon-Free District Heating and Cooling
Published in Yatish T. Shah, Hybrid Energy Systems, 2021
The combination of solar heating and biomass heating is a promising strategy for smaller rural communities due to its contribution to security of supply, price stability, local economic development, local employment, etc. On the one hand, solar heating requires no fuel, and on the other hand, biomass heating can store energy and release it during winter when there is less solar heat available. Thereby, heat storage (buffer tanks for short-term storage and seasonal tanks/basins for long-term storage) needs to be integrated. The main advantages of a biomass/solar heating concept are reduced demand for biomass, reduction of heat storage capacity, and lower maintenance needs for biomass boilers. With increasing shares of fluctuating renewable electricity production (PV, wind), the power-to-heat conversion through heat pumps can furthermore help to balance the power grid. If the planning process is done in a sustainable way, small modular DH/cooling grids have the advantage that, at the beginning, only one part of the system can be realized and additional heat sources and consumers can be added later. This modularity requires good planning and appropriate dimensioning of the equipment (e.g., pipes). It reduces the initial demand for investment and can grow steadily [14,16].
Saving nature with bits and bytes?
Published in Steffen Lange, Tilman Santarius, Smart Green World?, 2020
Steffen Lange, Tilman Santarius
One aspect of our future electricity system therefore involves increasing the flexibility of demand. But, how can consumption be adjusted to the fluctuations in wind and solar power? What happens when the wind is still for so long that the temperature in the cold store rises too high? And what happens in the opposite case on particularly stormy days when the wind power remains unsold because there is simply too much electricity being generated? This is where we need electricity storage systems and methods of converting surplus power into other forms of energy such as gas and heat – known as “power-to-X”. For example, electrolysis can be used to convert electricity into gas (power-to-gas) that can then be used to generate heat or fuel gas-powered vehicles. Power-to-heat involves converting electricity into heat – this is the principle on which heat-pump boilers are based. Battery storage systems and power-to-X are both important elements of the transition to an energy system based entirely on renewables. There is currently much discussion of which of these methods of storing surplus electricity or using it elsewhere is best from an environmental point of view.46
Modular Systems for Energy Usage in District Heating
Published in Yatish T. Shah, Modular Systems for Energy Usage Management, 2020
Especially the combination of solar heating and biomass heating is a promising strategy for smaller rural communities due to its contribution to security of supply, price stability, local economic development, local employment, etc. On the one hand, solar heating requires no fuel, and on the other hand, biomass heating can store energy and release it during winter when there is less solar heat available. Thereby, heat storage (buffer tanks for short-term storage and seasonal tanks/basins for long-term storage) needs to be integrated. The main advantages of a biomass/solar heating concept are reduced demand for biomass, reduction of heat storage capacity, and lower maintenance needs for biomass boilers. With increasing shares of fluctuating renewable electricity production (photovoltaic, wind), the Power-to-Heat conversion through heat pumps can furthermore help to balance the power grid. If the planning process is done in a sustainable way, small modular DH/cooling grids have the advantage that, at the beginning, only one part of the system can be realized and additional heat sources and consumers can be added later. This modularity requires good planning and appropriate dimensioning of the equipment (e.g., pipes). It reduces the initial demand for investment and can grow steadily [3, 5].
Numerical investigation on the thermal response of an unsteady magnetohydrodynamics straight porous fin
Published in International Journal of Ambient Energy, 2023
The study of heat transfer is a topic of major contemporary interest both in engineering and science. Thermal insulation engineering, solar engineering, heat storage beds, electronic cooling, geothermal power generation, heat exchangers, fiber coating, etc., are the few noteworthy applications of the heat transfer effect (Cengel and Ghajar 2015). One of the tools which help to achieve heat transfer efficiency is the usage of fins. Fins are the extended surfaces of the devices which aid to enhance heat transfer rate and they play a significant role in heat exchanging devices like heat exchangers in power plants, car radiators, etc. For instance, the regulations of heat inside the combustion chamber of automobile engines are a more critical factor without fins. It plays a major role to upgrade the heat transfer rate and therefore, excellent performance, safety, and fuel consumption of a vehicle are achieved. The convective removal of heat from a surface can be substantially improved by installing an extension on that surface. Those extensions are designed in a variety of shapes and materials on the basis of desired industrial requirements (Dwivedi and Mohan 2014 and Natrayan, Selvaraj, Alagirisamy, and Santhosh 2016). The intention of fin installation on the heat-transferring surface is not only to enhance but also to reduce the heat transfer rate depending on the demands. In several electronic and thermoelectric devices, rejecting waste heat in an economical and trouble-free way is essential.
Comparison of flexibility options to improve the value of variable power generation
Published in International Journal of Sustainable Energy, 2018
Juha Kiviluoma, Erkka Rinne, Niina Helistö
Flexibility from DH systems was considered with several scenarios depicting different potential technologies in the DH systems. Heat pumps and electric boilers can convert power to heat for DH systems. At the same time, heat storage tanks can be used as a buffer to better match with DH loads. Heat storages had an investment cost based on storage size (€/kWh) instead of discharging capacity, since the storage capacity is the driving factor in their investments. These insulated large heat storages are assumed to have a 0.03% self-discharge in each hour. The electrical energy consumed by the heat pumps or the heat used for the loading of thermal storages is subtracted from generation in electrical energy or heat energy balance equations, respectively.
Impacts of thermal energy storage on the management of variable demand and production in electricity and district heating systems: a Swedish case study
Published in International Journal of Sustainable Energy, 2020
Petra Holmér, Jonathan Ullmark, Lisa Göransson, Viktor Walter, Filip Johnsson
The impacts of different types of thermal energy storage (TES) on the electricity and district heating (DH) systems are examined using a Greenfield investment model, with the focus on the integration of variable renewable energy. The impact of TES is investigated for a region that corresponds to southern Sweden, with large seasonal variations in demand for heat and electricity, well-established DH in both large and small towns, and good wind resources. Through its ability to disconnect heat generation from the load, TES is found to: Allow CHP and power-to-heat technologies to generate heat in a more opportunistic fashion, as dictated by the net demand of the electricity system. This results in an increase in wind investments when there is low flexibility and poor access to low-cost energy in the system; otherwise, there is a shift from off-shore to on-shore wind power. While this shift does not significantly affect the system cost, it indicates an increased capability to make use of more-intermittent energy production;Add additional value to a flexible system that comprises DSM and hydrogen storage;Enable lower levels of investment and more even production in the DH sector, which to a large extent displaces the peak HOBs;Promote investments in solar heating when interactions between the electricity and DH systems are disincentivised by, for example, an electricity tax.