Isothermal Deep Ocean Compressed Air Energy Storage: An Affordable Solution for Seasonal Energy Storage

There is a significant energy transition in progress globally. This is mainly driven by the insertion of variable sources of energy, such as wind and solar power. To guarantee that the supply of energy meets its demand, energy storage technologies will play an important role in integrating these intermittent energy sources. Daily energy storage can be provided by batteries. However, there is still no technology that can provide weekly, monthly and seasonal energy storage services where pumped hydro storage is not a viable solution. Herein, we introduce an innovative energy storage proposal based on isothermal air compression/decompression and storage of the compressed air in the deep sea. Isothermal deep ocean compressed air energy storage (IDO-CAES) is estimated to cost from 1500 to 3000 USD/kW for installed capacity and 1 to 10 USD/kWh for energy storage. IDO-CAES should complement batteries, providing weekly, monthly and seasonal energy storage cycles in future sustainable energy grids, particularly in coastal areas, islands and offshore and floating wind power plants, as well as deep-sea mining activities

Application of rescaled adjusted partial sums (RAPS) method in hydrology-an overview

To describe the behaviour of watercourses, numerous parameters should be considered, such as water flow, depth/water level, velocity, and the amount of deposit in a waterbed. In addition, many other parameters should be analysed to understand the mechanism of specific watercourses. The most typical parameters are those associated with water quality, such as water temperature, and pH value, and temperature, as well as various climate parameters, such as precipitation, evaporation, and insolation, which are visualised in the form of a time series. The measurement frequency can differ for each parameter. Depending on the number of available measurements, hourly, daily, monthly, and yearly data can be obtained, which can then be used to form a time series. Many well-established and applicable procedures and models for time-series analyses exist, including the rescaled adjusted partial sums method (RAPS). This method is devised to detect possible irregularities and/or fluctuations within the original time series, which cannot be achieved using typical time[1]series analysis methods. This paper presents a comprehensive review of the application of the RAPS method in hydrology, where the advantages and disadvantages of the method are discussed

Sedimentary Basin Water and Energy Storage: A Low Environmental Impact Option for the Bananal Basin

Groundwater storage is an important water management solution that is overlooked by several countries worldwide. This paper evaluates the potential for storing water in the Bananal sedimentary basin and proposes the construction of canals to reduce sediment obstructions in the river flow and harmful flood events. This would allow for better control of the water level. The water stored in the sedimentary basin can be used as a climate change adaptation measure to ensure that the level of the flood plain is maintained high during a drought or low during an intense flood event. Additionally, the flood plain will function as a water reservoir, regulate the river flow downstream from the flood plain, and enhance hydropower generation. A significantly smaller reservoir area is expected to store water, as the water will be stored as groundwater in the sedimentary basin. Results show that the Bananal basin has the potential to store up to 49 km3 of water, which can add up to 11.7 TWh of energy storage to the Brazilian energy matrix for a CAPEX energy storage cost of 0.095 USD/kWh. This is an interesting solution for the Araguaia basin and several other basins worldwide

Sedimentary Basin Water and Energy Storage: A Low Environmental Impact Option for the Bananal Basin

Groundwater storage is an important water management solution that is overlooked by several countries worldwide. This paper evaluates the potential for storing water in the Bananal sedimentary basin and proposes the construction of canals to reduce sediment obstructions in the river flow and harmful flood events. This would allow for better control of the water level. The water stored in the sedimentary basin can be used as a climate change adaptation measure to ensure that the level of the flood plain is maintained high during a drought or low during an intense flood event. Additionally, the flood plain will function as a water reservoir, regulate the river flow downstream from the flood plain, and enhance hydropower generation. A significantly smaller reservoir area is expected to store water, as the water will be stored as groundwater in the sedimentary basin. Results show that the Bananal basin has the potential to store up to 49 km3 of water, which can add up to 11.7 TWh of energy storage to the Brazilian energy matrix for a CAPEX energy storage cost of 0.095 USD/kWh. This is an interesting solution for the Araguaia basin and several other basins worldwide

Electric truck gravity energy storage: An alternative to seasonal energy storage

The global shift toward a sustainable and eco-friendly energy landscape necessitates the adoption of long-term, high-capacity energy storage solutions. This research introduces an inventive energy storage concept involving the movement of granular materials from a lower elevation to a higher point within natural terrains such as mountains or excavated mining sites. Electrical energy is employed to charge electric batteries that elevate the granular material, thereby storing potential energy. Subsequently, this material is transported down during the electricity generation phase, and the regenerative braking mechanism converts the gravitational energy to replenish the vehicle's battery. The stored energy within these vehicles is then dispatched during peak demand periods or utilized by the vehicles for other freight transportation purposes. Our findings demonstrate a power cost of 1200 USD/kW, an energy storage expense spanning from 1 to 10 USD/kWh, a levelized cost of storage ranging from 35 to 200 USD/MWh, and a global annual potential of approximately 5.4 PWh. Electric vehicle gravity energy storage showcases its capability to bolster sustainable development by offering seasonal and multi-year energy storage services

Underground Gravity Energy Storage: A Solution for Long-Term Energy Storage

Low-carbon energy transitions taking place worldwide are primarily driven by the integration of renewable energy sources such as wind and solar power. These variable renewable energy (VRE) sources require energy storage options to match energy demand reliably at different time scales. This article suggests using a gravitational-based energy storage method by making use of decommissioned underground mines as storage reservoirs, using a vertical shaft and electric motor/generators for lifting and dumping large volumes of sand. The proposed technology, called Underground Gravity Energy Storage (UGES), can discharge electricity by lowering large volumes of sand into an underground mine through the mine shaft. When there is excess electrical energy in the grid, UGES can store electricity by elevating sand from the mine and depositing it in upper storage sites on top of the mine. Unlike battery energy storage, the energy storage medium of UGES is sand, which means the self-discharge rate of the system is zero, enabling ultra-long energy storage times. Furthermore, the use of sand as storage media alleviates any risk for contaminating underground water resources as opposed to an underground pumped hydro storage alternative. UGES offers weekly to pluriannual energy storage cycles with energy storage investment costs of about 1 to 10 USD/kWh. The technology is estimated to have a global energy storage potential of 7 to 70 TWh and can support sustainable development, mainly by providing seasonal energy storage services