Home Articles PS20 Solar Plant, Spain – Harnessing the sun for sustainable energy

PS20 Solar Plant, Spain – Harnessing the sun for sustainable energy

PS20 solar plant has helped Spain meet its renewable energy target

A20-megawatt power plant near Seville, Spain, set the record for the largest commercial solar power tower in the world when it was inaugurated by the King and Queen of Spain in September 2009. Owned by Abengoa Solar, a leader in solar technology, the PS20 concentrating solar power (CSP) plant is twice the size of its predecessor (PS10) and is just one of the four solar plants operating on the Solucar Platform in Sanlucar la Mayor, Seville.

Three more solar plants are under construction. The Solucar Platform will eventually generate 300 megawatts from four types of solar energy technologies including tower, trough, photovoltaic and dish. Upon completion in 2013, the 1.2 billion euro platform will produce enough energy for 153,000 households and prevent the emission of 185,000 tonnes of carbon dioxide per year, according to Abengoa Solar.

The four operating plants are already delivering power to the grid under the existing feed-tariff system, helping to meet Spain’s renewable energy plan target. With the commissioning of each new plant, Abengoa Solar improves the technology and reduces generating costs, making CSP a more than ever attractive alternative energy source. Abengoa’s commercial test of CSP technology began with the 11-megawatt PS10 plant, which was commissioned in 2007.

The 80 million euro PS20 plant demonstrated that the technology could be ramped up to to double the generating capacity. The 531-foot tall PS20 tower captures sunlight reflected from 1,255 mirrored heliostats lined up like soldiers on a 235-acre solar field. Each heliostat has a 1,291-square foot surface area to track the sun and reflect solar radiation onto a receiver placed on top of the tower. The concentrated rays from the solar field produce steam, which is further converted into electricity by a turbine.

The CSP technology was designed by Abengoa Solar, one of the five Abengoa business units that apply innovative solutions for sustainable development in the infrastructure, environment and energy sectors. PS20 improved upon the technology with a more efficient receiver in the tower as well as improved operational controls and better thermal energy storage. The plant was built by Abener-Abengoa’s engineering, procurement and construction business unit with front-end engineering design by Energoprojekt Gliwice (EPG).

EPG’s scope of work for PS20 included technical specifications for basic engineering equipment; detailed engineering for piping, civil, structural, mechanical, electrical and instrumentation; and engineering supervision together with Abener and Abengoa.

Engineering a power tower of this magnitude required many modifications to the PS10 design. EPG brought a fresh perspective, as PS20 was its first solar tower. “We had to improve many aspects of PS10, based on lessons learned by Abener. We had much longer steam accumulators, bigger pipe and equipment sizes as well as bigger displacements, relative to the thermal expansion,” said Andrzej Kuropka, EPG CAD specialist.

EPG’s designers also had to take into account that the displacement cycle occurs twice a day with the plant’s periodic operating schedule controlled by the sun’s daynight cycle. Such atypical equipment requirements caused frequent design modifications. Using 3D design tools and a multidiscipline workspace called ENERGO, EPG was able to deliver high-quality documentation based on an up-to-date 3D model, despite the number of changes.

EPG used PlantSpace P&ID, PlantSpace Piping and PlantSpace Equipment to perform basic and detail design in a multidiscipline 3D modelling environment. Because the PS10 plant had been designed in a 2D environment, EPG had to create 3D models from scratch using piping specifications and data sheets from the PS10 equipment and instrumentation.

The models were used by all design disciplines. Drawings or models delivered by subcontractors and vendors were implemented in the 3D environment to check for and eliminate collisions, verify maintenance access and analyse construction processes. The interoperability of Bentley’s software also allowed EPG to import data in different formats. For example, structural and civil designs developed on the AutoCAD platform were easily integrated into the 3D model for clash detection and layout drawing generation.

The ENERGO workspace enabled designers to work in parallel with access to up-to-date files and the latest versions of models stored on the network server. MicroStation VBA macros were developed for model maintenance functions such as attaching reference files according to the ENERGY workspace rules, updating the last version of a file on the server, controlling user rights for file updating, locking files to prevent further updates and creating an audit trail for each file. Macros were also used to automate the sizing of dimensions and annotations in accordance with drawing scale; and interpret dimensions and annotations in accordance with rules contained in codes and standards.

The application of this multidiscipline workspace to the 3D design environment improved the engineering design process.

EPG has applied the experience gained on the PS20 solar power tower to next generation solar energy projects. “The experience was used for developing and building the first high-temperature power tower, Eureka,” Kuropka said. Joining PS10 and PS20 on the Solucar Platform, this experimental tower takes Spain-and the world-another step closer to the widespread use of sustainable energy from sunlight.