She developed the prototype for a machine that turns discarded plastic into paving stones.
Ms Matee produces the plastic pavers under her company Gjenge Makers.
Ms Matee, who majored in material science and worked as an engineer in Kenya’s oil industry, was inspired to launch her business after routinely coming across plastic bags strewn along Nairobi’s streets.
“Plastic is a material that is misused and misunderstood. The potential is enormous, but its after life can be disastrous,” she says.
The Young Champions of the Earth prize is awarded every year to seven entrepreneurs under the age of 30 with bold ideas for sustainable environmental change.
The seven winners, hailing from different regions around the world, receive seed funding, mentoring and communications support to amplify their efforts.