A 650kWh commercial demonstration unit with cloud dashboard and integration to a building management system was installed at the Alnwick facility of drug development and manufacturing accelerator Quotient Sciences, with benefits to date including:
- Economic savings from charging with cheaper overnight electricity and from efficient trickle charge of the battery to replace inefficient chiller cycling.
- Continuity of operations under high temperatures / humidity, when previously cooling demand could not be supported by existing systems.
- Resilience from always having cold energy stored on site, in case of core system failure or shutdown.
The patented system consists of a charger which creates a unique ice slurry to be held as the phase change material in the thermal store, or battery, offering a huge increase in the surface area over which thermal transfer takes place. EnergiVault can be used alongside an existing chilled water system, on its own, or in place of an additional chiller.
As with a chiller added to meet increased peak cooling loads, it can reduce the risk of production or building shutdowns, while additional features such as time of use (ToU) shifting, chiller optimisation, heat recovery and energy monitoring can be applied across a site’s entire cooling plant. Using artificial-led intelligence, it is able to access the electricity supply at low tariffs and periods of low carbon intensity. In addition, thermal energy batteries do not reduce in capacity over time and therefore avoid the resulting loss in energy capacity experienced by lithium-ion storage.
Stuart Munro, head of facilities at the Alnwick site, said EnergiVault had supported the business in numerous ways; replacing a broken compressor at the height of summer until a replacement arrived, taking on small loads during the day rather than firing up the larger existing chillers, and taking advantage of of-peak tariffs to charge the thermal store.
He added: “I was fairly nervous at first because this site is my responsibility and if we messed up the cooling it could bring down the business. But actually, the communication has been great and there’s been zero negative impact to us. It’s been a really good journey and there’s more to come.’’
O-Hx director David Grundy said: “It is quite remarkable what we have achieved. At the start of 2022 we had a small proof-of-concept machine and a lot of desktop analysis. In the 18 months or so since then we have raised £1m in investment and used that to develop a full-scale commercial demonstration unit which is working beyond our expectations. We have also completed our design-for-manufacture and developed a new storage tank that can hold more energy and discharge more quickly. We are now ready to sell and install EnergiVault for commercial customers.”
Summary of results
Quotient Sciences required EnergiVault to support its systems in three of the four standard operating modes:
- Chiller optimisation – discharging to avoid inefficient chiller cycling.
- Peak demand support – discharging when existing systems are unable to cope with cooling demand, or to replace existing chillers (eg for regular maintenance), with a range of instantaneous load support.
- Uninterruptible cooling – retaining a proportion of available stored energy at all times, to cover any unforeseen chiller outages.
The fourth mode – load-shifting – has been tested via full charge-discharge routines but not directly tested on an operational basis due to Quotient’s operating requirements and tariff structures.
Full data from the ongoing trial and more information on EnergiVault is available in a new white paper highlighting the growing global need for energy storage. It is free to download from the O-Hx website:
https://bit.ly/O-HX_heating_demand_low_carbon_solutions_whitepaper