Under terms of the PPA, EDF Energy will buy power as well as renewable certificates from the device for the first year of the project at a pre-agreed price.
Developed by tidal stream technology company Tidal Energy, DeltaStream is a grid-connected demonstration device capable of generating sustainable tidal power.
Scheduled to be deployed in Ramsey Sound, Pembrokeshire, the device will start producing power electricity for Welsh households soon.
TEL managing director Martin Murphy said: "DeltaStream is not just about proving a new, innovative technology – it is about proving that tidal power can make a real and lasting contribution towards the UK’s renewable energy targets and energy security.
"Taking the first steps to commercialisation, by securing a buyer for the electricity generated, is essential to that."
EDF Energy Export Sales and Procurement Manager Dan Brimelow said: "Technologies like tidal power help improve the diversity of electricity supplies and reduce our reliance on imported energy which is good for the country’s future energy security.
"By taking the time to understand Tidal Energy’s plans, we structured a PPA that gives them the income certainty they need to satisfy investors, and also manages the risks around forecasting how much power they would produce."
