Margien trained as a Chemist at Utrecht University, and graduated in heterogeneous catalysis. She worked at DSM as a Researcher, Product manager and Purchasing manager, among others. Margien then joined NedStack, the Dutch company making PEM Fuel Cells and systems, as Sales Manager. She sold the world's first 1MW PEM powerplant here Margien then started at Bredenoord, a family-owned company that makes, sells, rents and services gensets worldwide. Being in the Management Team she was responsible for the departments New Business & Innovation, Marketing & Communications. Here, she developed and intruduced many new sustainable products to the markets; such as fuel cell generators, various battery products and containers and worked with many alternative fuels such as H2, Methanol, HVO. The products were mainly used in temporary power installations and microgrids for various market segments.

She then worked as Director at the CleanTech Region Foundation to make the region more sustainable. This foundation was the economic Board based on the collaboration of government, education and entrepreneurs. Currently, she is Chief Commercial Officer QuinteQ. This Dutch startup develops and builds the compact, mobile and most advanced flywheel systems from 100 kW to 60 MW based on Boeing technology. She is actively looking for parties interested in using this kinetic battery in larger European projects involving hybrid energy storage technology. The QuinteQ flywheel can handle endless charge cycles for especially short term storage, is circular, and can also be deployed in temporarily situations and be combined with other (more longterm) storage systems. She is currently working on demonstration projects around peakshaving and energy regeneration at military microgrids, subways, trams, trains, tower cranes, cranes at ports, lifts at mining and power quality and peakshaving at microgrids combined with long-term energy storage.