Extremely accurate manufacturing is key to the KINEXT's efficiency

THU 17 AUG 17

As the production of KINEXT units gathers pace, we take a closer look at the required manufacturing expertise. Eelco Osse, CEO of our manufacturing partner Boessenkool, describes what it takes to ensure a consistently reliable product.

The KINEXT storage units are produced in Almelo, the Netherlands by S4 Manufacturing, a joint venture between S4 Energy Nederland and machine manufacturer Boessenkool (part of the Osse Equipment Manufacturing Group). A 5.5 metre vertical lathe was acquired specifically for the production of KINEXT units. It is the largest of its kind in the Netherlands. Combined with Boessenkool's expertise, our facility has all the requirements to deal with the extremely small tolerances involved in serial production of the KINEXT.

Extreme accuracy
The accuracy of the KINEXT production process is measured in 1/100s or even 1/1000s of millimetres. "Such accuracy is essential to produce a working product at all", says Eelco Osse, "but also to guarantee the high efficiency which is one of the key USPs of the KINEXT unit. If we were to exceed the small tolerances, the rotor would be imbalanced. Which would also make the manufacturing process much more time-consuming and costly, and would lead to a much higher risk of failing parts."

The final challenge, moreover, is to ensure consistent accuracy throughout serial production. Osse: "One of the steps we've taken is to design a magnetic positioning device to speed up the manufacturing process of the rotor. This device enables the operator to position the rotor plates according the exact specifications of the KINEXT design. Quite a challenge, but it means we can consistently deliver a product within the specified tolerances as well as control the cost of manufacturing."

Boessenkool is a Dutch, family-owned machine manufacturing firm with a 110-year old history and a strong international portfolio. "We specialise in high-quality, certified welding work and complete machining of large products which require extreme accuracy", says Osse. "For example, we have been producing turbine casings for over 40 years, presently as a preferred supplier for GE. We also work for research institutes such as CERN in Geneva, developing one-off, high-end equipment."

With state-of-the-art equipment, proprietary measuring methodologies and decades' worth of craftsmanship, Boessenkool has built a reputation for quality that transcends the Netherlands. 60% of its orders are placed by international clients in industries such as offshore, aviation, agriculture and healthcare.

The KINEXT potential
S4 Energy selected Boessenkool as a manufacturing partner on the strength of its innovative attitude and track record. These proved invaluable in upscaling the principle of kinetic storage to the unprecedented size of the KINEXT units. After a functional prototype had been produced and exhaustively tested, the cooperation was extended to form a joint venture with S4 Energy Nederland for the commercial production of KINEXT systems.

"We believe in the KINEXT concept", says Osse. "The energy transition is well underway and is a growth market for us. For example, we produce parts for manufacturers of wind turbines. But we're also aware of the resulting challenges for grid management. The KINEXT is an intelligent, well-engineered concept. It's a smart solution for a rapidly growing, crucial challenge in energy management, and we're convinced of its market potential."

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