The role of storage in making the energy transition happen
Dutch company iwell has installed a large battery system in Utrecht Lage Weide, at the Eneco power company site. “Our battery solution enables Eneco to use stored power to balance incoming and outgoing energy on the grid,” says Kolijn Venema, Technical Project Manager, iwell. “The plant can now cope with peaks in demand by initially using sustainably generated energy and scaling up the plant’s production capacity step by step. This reduces gas consumption. For this, we used a 14000 kWh ‘MegaCube’.”
Challenge
“iwell also uses Tesla BESS systems – and Tesla requires Arc Flash calculations to be carried out before any (maintenance) work may be performed,” says Christan van Dorst, Manager Technical Engineering, HyTEPS. “One of iwell’s partners recommended HyTEPS, who conducted an Arc Flash Compliance study for us. This type of study looks at safety and compliance with standards related to arc flash in electrical systems, as well as determining appropriate PPE. The study includes comprehensive assessment of a facility and its electrical systems to identify and mitigate potential arc flash hazards.”
Goal
- Conduct arc flash surveys, including labels and PPE guidelines
- Provide reports as a basis for management meetings
- Recommend, implement, and test solutions
Solution
Kolijn: “There are six huge containers with battery systems on site, including three transformers that transform low-voltage into medium voltage. These transformers are connected directly to medium voltage. This introduces questions about safety. The battery system at Lage Weide features a total of 9 circuit breakers (one per battery container and one per transformer). This is intended to protect the equipment, but above all ensure that no personal injury occurs should anything go wrong. HyTEPS was tasked with calculating exactly how much energy could be released if a short circuit were to occur somewhere. We shared technical documentation so that they would have a clear picture of the installation and how it is constructed. HyTEPS built a model and simulated the behavior of security systems in our installation. It turned out that we had to adjust some circuit breaker settings and the protection policy so that in the event of a short circuit, an excessive amount of electrical energy cannot be transferred to a person.”
Christan: “We calculated the arc flash energy – which turned out to be too high – and then developed a proposal to reduce it. Selectivity, often used to locate fault currents in electrical installations and prevent unnecessary downtime, can affect the selectivity configuration of protective devices. In the event of an arc flash, longer delay associated with the short circuit shutdown time can result in dangerous levels of arc flash energy being released from a distribution box. In this case, too, we had to deal with suboptimal settings. The new ‘trip’ time of the breakers is now 012 s and 0.08 s – previously it was 0.48 s and 0.27 s.”
Results
The proposals were implemented, and the installation is now running on the basis of these configurations. The new protective device settings reduce the energy level released during an arc flash and at the same time ensure coordination between all protective devices in the short-circuit and instantaneous range. In the event of an arc flash, the appropriate device will always be switched off in the right way. By making changes to the installation, cabinets have become safer. The required Personal Protective Equipment (PPE) can also be defined per cabinet along with arc flash labels with relevant information for the employee to be able to work safely.
“HyTEPS has certainly helped us to improve the installation security concept,” Kolijn concludes. “It was surprising in a way, because we had assumed that existing security settings would ensure good safety for everyone. But according to the arc flash study, they turned out not to be insufficient. We had to fine-tune them. As far as I know, Arc Flash Compliance studies are not required in the Netherlands, but mandatory in the USA, for example. Personally, I feel companies have a kind of moral obligation to carry out such studies, for the personal safety of people working around and on the installations.”
“Working with Christan and the engineers from HyTEPS was very enjoyable. They ask smart questions in order to completely understand our needs and requirements. Personally, I also liked the fact that HyTEPS employs people from all over the world, partly from an ideological background.”