Saudi Electricity Company (SEC) has extended the submission date for bids for the contract to build the 550MW Duba 1 integrated solar combined-cycle (ISCC) plant.

Prequalified contractors now have until 16 November to submit bids for the engineering, procurement and construction (EPC) contract. The original submission date was 15 October.

The Duba 1 ISCC is planned to run on a mix of natural gas and solar energy, and will have a total development cost of $600m. The Duba plant will have a guaranteed total output of 485-550MW, which will include 40MW to 50MW output from the solar system. The planned commissioning date of the plant is 2017.

MEED reported in April that SEC had dropped plans to develop the Duba 1 scheme as an independent power project(IPP) and was instead preparing to tender the plant as a standard EPC deal. SEC has split the project into two contracts: the EPC contract and an original equipment manufacturer (OEM) contract, which will involve supplying and operating and maintaining equipment for the power facility.

SEC issued tender documents to companies for the OEM contract in April.

SEC is also planning to develop a second phase of the Duba scheme, Duba 2, which was also proposed as an IPP. It is currently unclear whether the second phase will remain an IPP, or will also be switched to an EPC deal. The proposed Duba 2 IPP will have a larger capacity of 1,800MW and an estimated budget of $2.7bn. The planned commissioning date for the Duba 2 IPP is 2018.

SEC is also developing an ISCC project at the Saudi Arabian Mining Company’s (Maaden’s) Waad al-Shamal industrial development in the north of the kingdom. The plant is scheduled to have a 1,000MW combined-cycle gas turbine component and a 50MW 50MW solar component.