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Modular Systems for Energy Conservation and Efficiency
Published in Yatish T. Shah, Modular Systems for Energy Usage Management, 2020
ZEBs harvest available energy to meet their electricity and heating or cooling needs. By far the most common way to harvest energy is to use roof-mounted modular solar photovoltaic panels that turn the sun’s light into electricity. Energy can also be harvested with modular solar thermal collectors (which use the sun’s heat to heat water for the building). Modular heat pumps either ground source (otherwise known as geothermal) or air-source can also harvest heat and cool from the air or ground near the building. Technically, heat pumps move heat rather than harvest it but the overall effect in terms of reduced energy use and reduced carbon footprint is similar. In the case of individual houses, various microgeneration technologies may be used to provide heat and electricity to the building, using solar cells or wind turbines for electricity, and biofuels or solar thermal collectors linked to a modular seasonal thermal energy storage (STES) for space heating. An STES can also be used for summer cooling by storing the cold of winter underground. To cope with fluctuations in demand, ZEBs are frequently connected to the electricity grid, export electricity to the grid when there is a surplus, and drawing electricity when not enough electricity is being produced [7]. Other buildings may be fully autonomous.
Thermal Energy Storage
Published in Sotirios Karellas, Tryfon C. Roumpedakis, Nikolaos Tzouganatos, Konstantinos Braimakis, Solar Cooling Technologies, 2018
Sotirios Karellas, Tryfon C. Roumpedakis, Nikolaos Tzouganatos, Konstantinos Braimakis
Finally, hot water storage using aquifer thermal energy storage (ATES) systems has attracted considerable attention because it represents a cost-effective solution for seasonal thermal energy storage. It relies on storage of groundwater in an aquifer, such as an underground layer of water-bearing permeable rocks or unconsolidated materials. At least two thermal wells—holes drilled into the ground to penetrate an aquifer—are used in ATES systems to extract or inject groundwater from or into the ground via pumping. With this arrangement and during the summer months, excess thermal energy is pumped into the injection well. During the winter, warm groundwater stored in the aquifer can be pumped from the extraction well through a heat exchanger to satisfy the heating load of a building directly or to provide low quality energy to a heat pump. Combined ATES-heat pump systems have been shown to improve the coefficient of performance (COP) conventional heat pumps operated with ambient air by 65%. Storage temperatures in ATES systems vary typically in the range of 10–40°C, but successful operation has been demonstrated at temperatures up to 90°C (Ghaebi, Bahadori, and Saidi 2014).
Measuring stiffness of soils in situ
Published in Fusao Oka, Akira Murakami, Ryosuke Uzuoka, Sayuri Kimoto, Computer Methods and Recent Advances in Geomechanics, 2014
Fusao Oka, Akira Murakami, Ryosuke Uzuoka, Sayuri Kimoto
Estimation of ground temperature profiles is of particular relevance for a number of applications that utilise the ground as a reservoir or source of thermal energy. Typical examples include passive heating and cooling of buildings, ground source heating and inter seasonal thermal energy storage. In particular inter-seasonal heat storage systems include activities that demand an annual cyclical thermal energy supply like heating for buildings and winter thermal maintenance of highways or aircraft stands. These systems can be enhanced if the surface of the pavement is also used as collector during the summer months. Several studies related with the practical uses of inter-seasonal heat storage in soils have been carried out in the past and there are also private industries employing this technology (Bobes-Jesus, et al., 2013; Morita & Tago, 2000).
The sizing of energy storages or how valuable is the last step?
Published in Advances in Building Energy Research, 2020
Alexander G. Floss, Michael Schaub
For the second series of simulations, a heat pump (10 kW heating capacity) is added to the system (6 kW PV-system, the fixed battery capacity of 10 kWh) and the size of the thermal water storage is increased in steps from 300 to 50,000 litres. The results are summarized in Table 3. By adding the heat pump to the system, the TOEC grows by 20% to 3700 kWh, using only a small thermal storage tank of 300 litres. Also, the gas consumption decreases by almost 50% from 4122 to 2123 kWh a year. Expanding the storage tank size increases the TOEC. With a 50,000-litre storage, a TOECS of 83% is reached which means that most of the PV electricity yield (PVEY) can be used on-site. But what looks great at first glance does not always provide advantages. The real purpose is not to achieve particular key indicator values, but to reduce the gas and electricity needed from the supply networks. While the electricity required from the grid is constant in case of an ideal operating control system, the consumption of the gas boiler is minimal at a storage size of 2000 litres. The energy input to the storage tank rises with increasing storage size. But due to higher losses of larger tanks, the energy output of the storage tank is maximum at 2000 litres. Looking at the storage efficiency, which is defined as the thermal energy output divided by the thermal energy input, a decrease from 87% to 31% can be noticed with an increase in size. So, storage sizes larger than 2000 litres do not act as storage, but as an additional consumer. For seasonal thermal energy storage other technologies than sensitive (water) storages should be utilized.
A numerical and experimental study of hydronic heating for road deicing and its energy flexibility
Published in Science and Technology for the Built Environment, 2022
Ali Saberi Derakhtenjani, Andreas Athienitis
Geothermal energy can be a good alternative heat source for such a hydronic heating system. In the 1990s, several pilot plants for geothermal heat pump systems were realized in Japan and central Switzerland (Eugster 2007). A vertical single U-shaped borehole geothermal system was investigated by Balbay and Esen who showed that a bridge slab can be deiced effectively (Balbay and Esen 2010). Also, as demonstrated by (Mirzanamadi et al. 2018), solar energy can be collected during the summer and stored in seasonal thermal energy storage and then the stored heat is released for deicing during cold periods (Chen et al. 2011).