ACR Journal

April 2022 | May 2022 NEWS 08 Volume 8 No.3 BITZER powers new EnergiVault A new energy storage technology is using BITZER open-drive screw compressors to generate high e ciency cooling as an alternative, low-carbon power source. The patented EnergiVault, being developed by O-Hx, is designed to support decarbonisation of industrial processes, and commercial and residential buildings using stored 'coolth' as a source of energy. EnergiVault was recently awarded government funding in the form of a Business Accelerator grant to commercialise the technology. Cooling energy generated by the BITZER-powered refrigeration system is stored in a thermal battery containing a reservoir of phase-change material (PCM). The battery is 'charged' by the refrigeration system using o -peak electricity, and then drawn-down during high-tari periods, significantly cutting end users' power bills. Waste heat generated by the refrigeration system is captured by EnergiVault’s heat recovery system, and can be used for space heating or hot water for domestic use or industrial processes. "Unlike lithium batteries, which can discharge only around 70% of their power, all the energy stored in an EnergiVault can be used without harming the device or its future storage capacity," says Bob Long, the inventor of EnergiVault. "The charging process using ammonia refrigeration, for example, is highly e cient, due to the inherent e ciency of the refrigerant and BITZER screw compressors. Any conversion losses are comfortably exceeded by the savings achieved through using o -peak electricity." EnergiVault’s refrigeration charging system is rated at 40-60kW. With a storage battery containing around 10 tonnes of PCM, a 1MW thermal store can be charged over 16 hours and discharged at a cooling rate of 1MW in an hour, or 500kW for two hours. EnergiVault can be used standalone or multiplexed to generate whatever power is required for an application. One of the keys to the system is a custom-designed algorithm that manages how the unit is charged, maintained and drawn-down to maximise energy savings. It ensures that the lowest-cost power source is used at all times, while maintaining maximum battery power back-up. Through a combination of demand shifting, heat recovery, reduction in part-load chiller cycling, and overall e ciency optimisation, EnergiVault is claimed to reduce energy costs by up to 62%, depending on the application. Long added: "The only potential mechanical risk factor in the process is the battery charger – the refrigeration system. We chose BITZER compressors as they are supremely e cient and reliable. After four decades' experience with them in the industry, I am totally confident in the technology. "BITZER UK has been very supportive of EnergiVault's development, and we are looking to use further BITZER components – line accessories, oil coolers, oil reservoirs – in the design." Kevin Glass, managing director of BITZER UK, said: "EnergiVault is an exciting development and demonstrates the potential of refrigeration-based power storage systems as transformational solutions. The push for net-zero carbon will require a complete rethinking of our energy infrastructure. With its thermodynamic and e ciency advantages, refrigeration o ers the exciting prospect that our industry could be in the vanguard." O-Hx was established in 2016 to develop and commercialise EnergiVault across the world. Partnering with environmental incubator 350 PPM, O-Hx is now launching a series of funding rounds to achieve substantial growth in the cooling energy storage hybrid sector. EnergiVault uses high efficiency BITZER open-drive ammonia compressors in the battery charger refrigeration system. It can also use other low-GWP refrigerants to suit the application SMI LANDS NEW CO-OP CONTRACT Thermal insulation specialist Seymour Manufacturing International (SMI) has gained a major contract with the Co-op which will see products supplied to more than a dozen of its UK distribution centres. The Telford-based company has worked with the Co-op for more than 35 years and this latest deal includes the supply of over 1,000 UK-manufactured Tempro thermal roll cage liners which will be used to keep fresh bananas in the best possible condition for customers, and to reduce food waste. This is a new design with improved thermal properties, compared with previous roll cage liners sold in the past. The first phase of deliveries was completed prior to Christmas, with the entire order scheduled for completion by the end of September this year. SMI director Jill Seymour said: “Our Tempro thermal roll cage covers and liners o er enormous savings and benefits when transporting frozen, chilled or ambient products. “Products such as the Co-op liners are tailor-made to specific customer requirements, and we have been working hard on refining our designs and trial tests for this project over many months. “We are delighted to be working with the Co-op organisation on this exciting project, which we are sure will make life considerably easier for their delivery teams and provide outstanding thermal protection.”