High Performance Tubing Helps Solar Plant Generate Energy In The Dark

Gemasolar Power PlantThe multi award winning plant which generates electrical power for over 27,500 homes per year has been operational since October 2011 and in its first year has broken all expectations.

Gemasolar is a first-of-its-kind, utilising brand new technology which enables it to produce electricity for 15 hours without the sun. This means that for the first time, solar energy has become manageable and capable of responding to large scale commercial demand.

The plant works through a combination of elements: heliostats, a central receiver tower and a molten salt storage system. 2,650 heliostats aim solar radiation at the tower’s receiver system, the radiation heats molten salts that circulate inside the tower to temperatures over 500 °C. These salts are then pumped from the molten salt tank to the receiver at the top of the tower where they are heated to extreme temperatures after which they descend to the hot molten salt tank or directly to the heat exchanger where they generate steam. When more energy is produced than the turbine needs the level in the hot tank increases, enabling the power plant to generate electricity for up to 15 hours without any incoming solar radiation.

The majority of the tubing provided by Fine Tubes was 25mm OD seamless tubing which is housed inside the tower and is used to contain the 565°C nitric salt. Made from the corrosion-resistant nickel-chromium alloy 625, the tubing can withstand high temperatures and extreme service conditions. Fine Tubes also supplied over 300m of 19mm OD heat exchanger tubes made from the same nickel-chromium alloy 625, but with a thicker wall to resist the high pressures within the steam generators.

The Gemasolar plant has won the CSP Today USA ‘Thermosolar Innovation 2011’ prize, while Torresol Energy (a joint venture between SENER and Masdar, the Abu Dhabi Future Energy Company) has won three of the European CSP Today prizes, for ‘Commercialized Technology Innovation 2011’ and ‘Most Effective Project Development 2011’ and in 2012 in the ‘CSP Dispatchability Solution’ category.　

Several potential new plants are being planned and as each plant is estimated to use around 50km of tubing, Fine Tubes is already working with Sener on further collaborations.