The company listed on the Australian Securities Exchange in May last year with 88 megawatts under BOO contracts.
By August 2018 that had grown to 189MW.
Significant contracts secured during the past 12 months include the Tanami gold mine for Newmont Mining Corporation, the Dalgaranga project for Gascoyne Resources and the Mt Morgans gold project for Dacian Gold.
The company has 12 contracts in place representing 420MW of generation capacity under control.
Zenith managing director Hamish Moffatt said the results were testament to the company's delivery of innovative, reliable and cost-effective power generation solutions.
"Looking ahead we've set ourselves a goal of converting a significant portion of our current 380MW pipeline to contracted capacity as well as explore early opportunities in renewable power, smart-grid and storage," he said.