Can thermal storage assist with the electrification of heat through peak shaving?

The majority of heat in the UK comes from the combustion of natural gas, and heat is responsible for 37% of the nation’s carbon emissions. Thus the decarbonisation of heat is a major challenge. Electrification is one possible approach to decarbonisation; however, huge increases in the electrical grid’s generation and transmission capacity would be needed to meet the peaks in space heat demand during cold winter weather. Thermal energy storage (TES) may have a role to play in alleviating this problem, by shifting heat demand by hours or longer periods, enabling peaks to be shaved.This work considers the utility of two varieties of thermal energy storage for this application. Adsorption thermal storage (ATS) is a technology offering long term storage at a high energy density, but is a costly and relatively immature option. By contrast, storage of sensible heat in hot water tanks is already widespread, although it has relatively short storage duration and lower density.Here, we simulate the deployment of these technologies in a small residential neighbourhood, in tandem with demand-side management (DSM), to attempt the reduction of peaks in demand. With no storage or DSM, electrification causes peaks to increase by a factor of 2.36. Results so far suggest that both TES technologies have potential to reduce peaks, with a 14% decrease achievable by either 5 m3 of hot water storage, or 0.25 m^3 of ATS, in each dwelling. However, it is thought unlikely that adsorption storage is attractive for a purely peak shaving application, given its cost and complexity

Characterising the discharge cycle of CaCl 2 and LiNO 3 hydrated salts within a vermiculite composite scaffold for thermochemical storage

Transpired solar collectors (TSC) are an efficient means of building heating but due to the demand/use mismatch their capabilities are maximised when paired with a suitable storage technology. The Hydration and/dehydration of inorganic salts provides an appropriate energy storage medium which is compatible with the air temperature provided by a conventional TSC (<70 °C). The study reports on technical appraisal of materials which are compatible with building scale energy storage installations. Two salts (CaCl2, and LiNO3) were impregnated into porous vermiculite to form a salt in matrix (SIM). Their performance during the discharge portion of the cycle at high packing density was examined using a laboratory scale reactor. Reactor and exit temperature increases were considerably lower than those predicted from first principles. Peak reactor temperature rises of only 14 °C were observed with a reduction in temperature output from this initial peak over 60 hours. Poor salt utilization resulting from deliquescence near the reactor inlet was identified as being the source of the reduced performance. Changes in reactor size, orientation and cycling between input periods of moist and dry air did not improve reactor performance. The investigation has identified that moist air transit through the packed SIM reactor column is limited to approximately 100 mm from the air inlet. This has implications for reactor design and the operation of any practical building scale installation. Predictions of building scale energy storage capabilities based on simple scaling of laboratory test considerably under estimate the volume and complexity of equipment required

Development of improved nickel catalysts for sorption enhanced CO2 methanation

Sorption enhanced CO2 methanation is a complex process in which the key challenge lies in the combined optimization of the catalyst activity and water adsorption properties of the zeolite support. In the present work, improved nickel-based catalysts with an enhanced water uptake capacity were designed and catalytically investigated. Two different zeolite frameworks were considered as supports for nanostructured Ni, and studied with defined operation parameters. 5Ni/13X shows significantly increased, nearly three-fold higher, operation time in the sorption enhanced CO2 methanation mode compared to the reference 5Ni/5A, likely due to its higher water sorption capacity. Both catalysts yield comparable CO2 conversion in conventional CO2 methanation (without water uptake). Regeneration of the catalysts performance is possible via a drying step between methanation cycles under both reducing and oxidizing atmospheres; however, operation time of 5Ni/13X increases further after drying under air

Numerical and experimental study of a solar assisted zeolite heat storage system for low-energy buildings

Les systèmes de stockage de chaleur par sorption (SSCS) ouvrent de nouvelles perspectives dans l'exploitation de l'énergie solaire pour le chauffage des bâtiments résidentiels. En effet, ces systèmes sont très prometteurs dans la mesure où ils permettent un stockage de chaleur sur de longues périodes (le stockage est réalisé sous forme de potentiel chimique) et offrent des densités énergétiques importantes (jusqu'à 230 kWh/m3 de matériau en moyenne) en comparaison aux systèmes classiques comme le stockage par chaleur sensible (qui, pour le cas de l'eau, dispose d'une densité énergétique moyenne d'environ 81 kWh/m3 de matériau pour une variation de 70°C) et le stockage par chaleur latente (qui atteint des densités énergétiques de 90 kWh/m3 de matériau).La présente thèse vise à étudier les performances d'un système de stockage de chaleur par sorption à base de zéolithe 13X intégré à un bâtiment type basse consommation. Des modèles mathématiques de transferts couplés de masse et de chaleur des différents composants du système sont développés et validés par le biais de l'expérimentation. La simulation numérique dynamique, comme outil de dimensionnement, permet, à partir des résultats d'analyses de sensibilité paramétrique sur les différents composants du système, l'étude de son fonctionnement et les critères de sa faisabilité.Sorption heat storage systems (SHSS) open new perspectives for solar heating of residential buildings. These systems allow long term heat storage (storage is done in the form of chemical potential) and offer high energy densities (up to 230 kWh/m3 of material on average) compared to conventional heat storage systems such as sensible heat storage (which, for the case of water, has an average energy density of approximately 81 kWh/m3 of material for a temperature change of 70 °C) and latent heat storage (nearly reaching energy densities of 90 kWh/m3 of material on average).This thesis aims to study the performance of a sorption solar heat storage system on zeolite 13X, integrated to low-energy building. Mathematical models of coupled heat and mass transfer of various components of the system are developed and validated through experimentation. Numerical dynamic simulations allow to study the functioning of the SHSS in specific conditions, and its design with the results from the parametric sensitivity analysis on its components

Procédé de stockage d'énergie solaire thermique par adsorption pour le chauffage des bâtiments : modélisation et simulation numérique

Sorption heat storage systems (SHSS) open new perspectives for solar heating of residential buildings. These systems allow long term heat storage (storage is done in the form of chemical potential) and offer high energy densities (up to 230 kWh/m3 of material on average) compared to conventional heat storage systems such as sensible heat storage (which, for the case of water, has an average energy density of approximately 81 kWh/m3 of material for a temperature change of 70 °C) and latent heat storage (nearly reaching energy densities of 90 kWh/m3 of material on average).This thesis aims to study the performance of a sorption solar heat storage system on zeolite 13X, integrated to low-energy building. Mathematical models of coupled heat and mass transfer of various components of the system are developed and validated through experimentation. Numerical dynamic simulations allow to study the functioning of the SHSS in specific conditions, and its design with the results from the parametric sensitivity analysis on its components.Les systèmes de stockage de chaleur par sorption (SSCS) ouvrent de nouvelles perspectives dans l'exploitation de l'énergie solaire pour le chauffage des bâtiments résidentiels. En effet, ces systèmes sont très prometteurs dans la mesure où ils permettent un stockage de chaleur sur de longues périodes (le stockage est réalisé sous forme de potentiel chimique) et offrent des densités énergétiques importantes (jusqu'à 230 kWh/m3 de matériau en moyenne) en comparaison aux systèmes classiques comme le stockage par chaleur sensible (qui, pour le cas de l'eau, dispose d'une densité énergétique moyenne d'environ 81 kWh/m3 de matériau pour une variation de 70°C) et le stockage par chaleur latente (qui atteint des densités énergétiques de 90 kWh/m3 de matériau).La présente thèse vise à étudier les performances d'un système de stockage de chaleur par sorption à base de zéolithe 13X intégré à un bâtiment type basse consommation. Des modèles mathématiques de transferts couplés de masse et de chaleur des différents composants du système sont développés et validés par le biais de l'expérimentation. La simulation numérique dynamique, comme outil de dimensionnement, permet, à partir des résultats d'analyses de sensibilité paramétrique sur les différents composants du système, l'étude de son fonctionnement et les critères de sa faisabilité

A review of potential materials for thermal energy storage in building applications

International audienc

Insights into biofuel development in Burkina Faso: Potential and strategies for sustainable energy policies

International audienceIn many African countries, the upswing in oil prices is one factor that favours the adoption and implementation of a national biofuel policy. This trend has a major impact on state budgets and domestic trade balances, while also limiting the access of rural inhabitants to modern energy services. Contribution of biofuels in stabilizing the energy sector, influences ongoing negotiations on the global dynamics of climate change, the reduction in greenhouse gas (GHG) emissions and sustainable development. The question of biofuels as an alternative energy thus depends on international, national and local considerations. Biofuels represent opportunities, e.g., energy independence and security, new national income and employment sources, as well as potential food security problems. African policy makers therefore need to make the right choices to guide the development of biofuel production and use. This article aims to support the development of a biofuel policy by reviewing the latest technical, economic, environmental and social knowledge so as to be able to evaluate the potential and limits of biofuels in Burkina Faso