(pictures of the visit available at http://ypenergy.org/dubai-abu-dhabi/?p=229)
Visiting Shams 1
YPE Dubai & Abu Dhabi chapter organized a site visit to Shams 1 on Saturday December 15th
, 2012. The visit was a unique opportunityto observe the final stages of constructing MENA’s first and one of the world’s largest Concentrated Solar Power (CSP) plant. Shams 1, the region’s first utility scale solar power plant, is developed by a special vehicle company called Shams Power Company, 60% of which is owned by MASDAR, with the remaining share split between France’s TOTAL and Spain’s solar-giant ABENGOA.
Having the chance to visit Shams 1 was truly an exciting opportunity to the 10 YPE members who were selected. The plant is located 6 km from Madinat Zayed, itself 120 km away from Abu Dhabi city. Members were coming from different parts of the country to attend this site visit and car sharing was organized to accomodate everyone. After a 3.5-hour drive the YPE visitors arrived at Shams 1 at around 2:30 PM.
The visitors were warmly welcomed by Shams Power Company representatives and were guided to the meeting room, where Engineer AbdulazizAl Obaidi, Senior Process Engineer at Shams 1, was scheduled to give the visitors a technical presentation about the plant.
Shams Presentation and Technical Aspects
Engineer Abulaziz confirmed that the construction of Shams 1 is complete and the plant is currently undergoing the final stages of commissioning. The plant is expected to transmit its first kWh to the main grid before the end of this year, with an official opening ceremony in the 1st quarter of 2013.
Technically, the plant utilizes Concentrated Solar Power (CSP)technology, as opposed to more traditional photovoltaic cells. CSP uses mirrors to concentrate the sun’s solar radiation on a central tube where a special Heat Transfer fluid (often oil) is heated. A heat exchanger is then used to transfer the heat to water to produce steam, which is then used to drive a turbine and generate electricity.
Some of the unique features of the Shams 1 include its use of a gas-powered booster-heater to increase the temperature of steam to 540 ̊ C to improve the turbine’s efficiency (figure 2). As a result, 82% of the heat content in the steam is from solar and 18% is from gas. Solar by itself would generate up to 60 MW only.
Moreover, the plant has a gas-fired Heat Transfer Fluid boiler that allows the plant to generate electricity even when there is no solar radiation. Engineer Abulaziz insisted this will be occasionally used, however it is available in case ADWEA (Abu Dhabi Water and Electricty Authority) requested a specific electrical output while there is insufficient solar radiation to generate the required electricity.
All generated power will be transmitted to the main grid & procured by ADWEA. A Green Power Payment agreement is in place to pay Shams 1 a special tariff for generated electricity. ADWEA will shoulder a small share of the agreed tariff while the Abu Dhabi department of finance will cover the rest.
(in pictures: Figure 2: Explaining the working mechanism of the plant)
Shams 1 is expected to generate power for 1800 hours/year (yielding a capacity factor of 20%). The plant is expected to produce 180 GWh of electricity annually, enough to power 20,000 homes. That will reduce carbondioxide emissions by 170,000 tons annually, the equivalent of taking 150,000 cars of the roads every year. Shams 1 is a registered Clean Development Mechanism (CDM) project under the UN carbon trading system. The project will generate 170,000 carbon credits annually.
The mirrors in Shams 1 will be cleaned twice a week. Engineer Abulaziz explained that the norm is once a week, but the cleaning frequency has been increased to prevent loss of efficiency from the excessive dust in the region. Cleaning will be done using special vehicles designed for this purpose.
(in pictures: Figure 3: Vehicles cleaning mirrors in Shams 1
Shams Site Tour
Upon the completion of the very interesting presentation followed by an interactive Q&A session; the ten YPE enthusiasts were given an exclusive site tour to the Shams 1 project. The tour was guided by Engineer Abdulaziz and the visitors were given the chance to closely observe the rows of parabolic shaped mirrors that were sorted in “Loops” running in parallel into two different sections giving the arrangement its H-Shape.
The visitors were educated about the mechanical support system of the parabolic mirrors and were introduced to the procedure of single-axis tracking of the sun that ensures maximum utilization of sunligh.
(in pictures: Figure 4: Parabolic mirror and the central tube carrying the HeatTransfer Fluid)
The tour continued through the plant that has a total operation area of 2.5 Km², where the next stop was the Power Block. The visitors were able to track the process of converting solar radiation into heat starting from the modular distributed system and reaching the dual-fuel fired heater that is used to provide the required level of thermal energy. The tour continued to the stage where the booster heater came into use, the booster heater’s main function is to enhance the efficiency of the steam turbine by supplying further heating to the steam. The visitors could now visually witness the link between the booster heater and the steam turbine that drives the generator and connects to a nearby transformer that eventually ties in with the grid system.
The tour was completed with the assembly of the YPE visitors to take a group photo and share thoughts and ideas about the intriguing Shams 1 Project.