The bid deadline for Qatar’s independent water and power project (IWPP), known as Facility D, has been extended again.

Qatar’s General Electricity & Water Corporation (Kahramaa) has given bidders until 29 May to submit their documents, extending the earlier deadline of 4 April.

Potential contractors were prequalified towards the end of last year and the list is dominated by Japanese firms such as Sumitomo and Mitsui. Consortiums have been formed and have the provisional backing of commercial banks in place, including several Japanese financial institutions.

The IWPP is estimated to require $3bn-worth of investment, with a large proportion of this to be project financed by banks. It is thought that government-backed export credit agencies (ECAs) such as Japan Bank for International Cooperation (JBIC) will have to play a role to raise the necessary financing.

The proposed plant will have a power generation capacity of 2,400MW and a desalination capacity of 130 million imperial gallons a day (MIGD).

The extension to the bid deadline is likely to delay Qatar’s planned reverse-osmosis (RO) independent water project (IWP) at Ras Laffan, which is only expected to be tendered once there has been further progress on Facility D.

Kahramaa’s last major desalination project was the $500m Ras Abu Fontas A2 plant, which reached financial close in early December 2013.

A conventional $180m debt financing was provided by the local QNB Group, while a $270m Islamic loan facility was provided by the local Barwa Bank, Masraf al-Rayan and Qatar Islamic Bank.