In Zimbabwe, a major road upgrade project will use off grid tollbooths to recoup a portion of the project’s costs. Made possible by the combined use of energy efficient design, solar power, and diesel generators, these tollbooths are believed to be the first ever to supply 100% of their power without an electric grid.
The road runs from Botswana to Mozambique and will include a total of eight tollbooths. According to the project’s senior electrical engineer and electrical design manager Paul Trewartha , this project works because of the significant efficiency measures included in the final design. Efficient lighting and a load management system dropped demand from an estimated 30 kW per booth to just 17kW.
For the balance, these tollbooths will have enough solar capacity to supply an estimated 80% of power needs. The remainder will be supplied using diesel generators.
- June 2013 edition of Engineering and Technology (E&T) magazine.