The following excerpt is from an article posted in CSP Today by Heba Hashem and Sam Phipps on 18th April, 2014.
An innovative 50 MW CSP plant that is due to be built in Cyprus with EU support could pave the way for its graphite based storage system elsewhere in the world, engineers say.
The EOS project, which will be sited at Alasa, in the Limassol district of the Mediterranean island, was proposed by the Cypriot government under the EU NER300 scheme and was approved in late March this year.
Utilising Australian company Solastor’s Concentrated Solar Thermal (CST) storage system, EOS will feature three-metre high tanks atop relatively low (20 metre) towers that stand at the centre of a bank of heliostats.
The steel tanks contain high purity graphite blocks, with water pumped through embedded coils of stainless steel pipes. Heat exchangers create super heated “dry” steam, which is discharged to a turbine to produce electricity for the power grid.
The steam is converted back to water, pumped into a holding tank and then back into the tower tank in a sealed system. “Solastor and the engineering contractor have a memorandum of understanding and we are just waiting for the finalising of the EU grant,” said a source close to the project. “We expect it to be between €47m and €60m, and the total cost of the plant will be about €175m.”
Project features
The EOS 50 MW CSP project will supply about 5 per cent of Cyprus’s electricity generation, with power on demand, even after sunset.
Each heliostat will be approximately 10 sq metres, with 100 to 120 reflectors per tower. This modular design is well suited to the uneven terrain of Cyprus, enabling modules to be positioned at various levels, on separate terraces, rather than on one vast expanse of flat land.
The plant will comprise up to 600 modules, a power station with two steam turbine generators, a switch sub-station to transmit energy to the national grid, and a series of steam condensers.
The heliostats will be toroidal and made of metal, covered with a form of silver foil, rather than the more usual glass. The super-heated steam generated by the array can either produce electricity via the steam turbine – for the national grid or to power specific installations – or it can provide “thermal input”: the industrial steam for processing, heating/cooling and waste combustion such as incineration of biomass or household waste.
Much of the equipment and infrastructure for EOS will be built in Cyprus, providing local construction and engineering jobs.
Alfa Mediterranean Enterprises Ltd is developing the project on a total area of some 1.8 million sq metres.
Another application of Solastor’s CST technology is a 3 MW facility at Lake Cargellico, also in New South Wales.
Located on the outer limits of the main power grid, the town was susceptible to blackouts and power instability before the solar thermal plant, which consists of eight modules and a steam turbine, started producing electricity in May 2011.
Lloyd Energy Systems won a grant from the Australian government to support construction of the facility but sold its interests in Lake Cargellico in 2011.
The EOS 50 MW CSP project will supply about 5 per cent of Cyprus’s electricity generation, with power on demand, even after sunset.