According to a 1.6GWh energy storage deployment agreement signed between Energy Vault and DG Fuels, the energy storage system developed by Energy Vault will be used for the production of synthetic sustainable aviation fuel by DG Fuels. DG Fuels has developed a fuel production process based on carbon conversion and hydrogen electrolysis, which is said to achieve a carbon conversion efficiency of 93%. The company said that this process can reduce the amount of traditional jet fuel used.

Energy Vault has developed a long-term energy storage technology that lifts, lowers and swings heavy objects from a crane mounted on a tower to achieve energy storage. The company claims that this energy storage technology is scalable, and the continuous discharge time can reach 2 to 12 hours. Although the company has not yet delivered any energy storage systems to customers, the company's goal is to publicly list its shares through a merger with Special Purpose Acquisition Corporation (SPAC) Novus Capital Corporation II.

The energy storage developer has not yet completed or deployed the energy storage system it seeks to create, but in the regulatory documents submitted before the planned merger of the SPAC revealed that DG Fuels hopes to deploy the energy storage technology in its multiple production facilities. The first is a 500MWh energy storage project deployed in Louisiana, USA. Energy Vault stated that the project is expected to begin construction in mid-2022. Followed by similar projects deployed in British Columbia and Ohio in Canada, Energy Vault said that the investment in this transaction will reach 520 million U.S. dollars. The long-term energy storage system developed by Energy Vault will be combined with solar power generation facilities to consolidate and shape the power output of renewable energy to meet the demand for green hydrogen production by DG Fuel, and provide power for electrolyzed water to produce hydrogen and oxygen. DG Fuel claims that its production process has zero carbon emissions.

Molten salt, antifreeze and engine for long-term energy storage and heating

At the same time, Malta is a long-term energy storage developer headquartered in Massachusetts. The company has developed a grid-scale thermal energy storage technology and is discussing the deployment of a 1GWh energy storage system in Maritimes, Canada.

The company said it is negotiating with the local utility company NB Power and plans to deploy an energy storage system in New Brunswick, Canada. The energy storage system may be put into use in 2024. Malta’s thermal energy storage technology can provide up to 200 hours of continuous discharge time, although the company has previously stated that it is developing an energy storage system for energy storage application scenarios that require 10 to 12 hours. The system can convert electricity into heat, and then store the heat in molten salt. At the same time, the generated cold energy is stored in a large storage tank containing a special coolant, which is somewhat similar to antifreeze.

Then, a turbine driven by the temperature difference is used to convert the cold and heat energy back to electrical energy as needed. The company claims that its energy storage system can be constructed using abundant materials, combining different processes from mature technologies and industries. Malta and Siemens Energy signed an agreement in July 2021 to jointly develop turbines for their energy storage systems. In March 2021, the company completed a $50 million financing. Its investors include the co-founders of Facebook. Dustin Moskowitz and Bill Gates’ Breakthrough Energy investment company. Keywords: new energy, international engineering news

NB Power will use this technology to store electricity when it is needed, enabling local communities to diversify their resource mix, and provide clean energy for the electrification of homes and businesses and electric vehicles. Malta stated that the heat used as a byproduct of the operation of the energy storage system can also be used for heating in districts and industrial and commercial sectors.Editor/Baohongying