Converting residual gas into electricity 10 April 2019

With a groundbreaking Stirling engine from the Swedish environmental technology company Ripasso Energy, the largest ‘waste-to-energy’ project of its kind ever implemented in Africa may be realised – with the help of Lesjöfors.

Ripasso Energy is a Swedish clean tech company founded in 2008 with a mission to further refine the incomparable ability of Stirling technology to convert thermal energy to electricity. Ripasso Energy’s Stirling engine can handle a wide range of fuels. The company’s latest product, the PWR BLOK 400-F, converts industrial residual and flare gases into electrical energy at a high rate of efficiency.

High volume production of bent pressings
A few years ago, Ripasso Energy started a project with Lesjöfors AB, in Värnamo, Sweden, when the Stirling engine needed further development and prototypes for new surface enlargement components. The surface enlarger makes the heat absorption in the engine more effective while lowering the exhaust temperature. In each Stirling engine, a large number of surface enlargers, which have a critical function, are used. Ripasso required the components in a heat resistant material that can withstand extreme temperatures and a cost-effective production method. After a number of months of intensive work and testing of several prototypes, the winning solution was a pressing in an optimal material for the task, which could be manufactured in a multislide machine at the Lesjöfors factory.

“Our cooperation with Lesjöfors is characterised by a great response to our needs. The company is highly skilled for a high‑quality, cost-effective product development. With great knowledge and a great teamwork, Lesjöfors has been an important partner for us,” commented Christian Jensen, design engineer at Ripasso Energy.

Large environmental benefits in South Africa
Ripasso Energy has signed a letter of intent with Glencore operations where a large number of PWR BLOK are planned to be installed in the company’s facilities in South Africa. Ripasso Energy will use the energy from the plant’s gases and generate electricity that Glencore commits to buy. Carbon dioxide emissions are estimated after installation to decrease by up to 476,000 tonnes per year. The project is the largest of its kind in Africa and an opportunity to show that the technology works on a large-scale.

“The declaration of intent with Glencore is a great success for Ripasso. It confirms that the PWR BLOK is an optimal solution to make the most of the energy in gases, both from a cost and environmental perspective. Close collaboration with our subcontractors is crucial to delivering innovative solutions and products of the highest quality. Lesjöfors is one of our most important suppliers who, with great dedication and expertise, has contributed to improving our product. We look forward to a long and close partnership,” says Gunnar Larsson, CEO of Ripasso Energy.

Broad knowledge and long experience
Lesjöfors is at the absolute forefront of pressings and stampings technology. With a wide range of technologies, the optimal production method can be used, whether it is a few components or extreme volumes of millions of items. The competence covers the whole chain, from design to development and production.

“We are happy to be involved in such an exciting development project that can add so much positive value for the environment. Thanks to our extensive experience of complicated geometries, efficient manufacturing methods and material knowledge, we have been able to contribute to the power generating system of the future,” says Lesjöfors.


Will Lowry Editor t: +44 (0) 1727 814 509


Will joined Fastener + Fixing Magazine in 2007 and over the last 12 years has experienced every facet of the fastener sector - interviewing key figures within the industry and visiting leading companies and exhibitions around the globe.

Will manages the content strategy across all platforms and is the guardian for the high editorial standards that the Magazine is renowned.