The Spain-based engineering and technology group Sener says that it is expecting to achieve “significant” reductions in the investment required for concentrated solar power (CSP) schemes through research and development of thermal storage systems.
Th company is developing two new types of thermal storage system that can be applied to CSP plants to increase their flexibility and economic competitiveness.
Reducing the costs and improving the performance of such systems will have a major impact on overall plant costs and therefore on the development of the CSP generation market, says the firm.
Sener is currently developing a single-tank thermal storage system as well as a graphite thermal storage system. It is planning to test the former as a reduced-scale prototype in the Valle 2 CSP plant that is currently under construction in Cádiz, Spain.
The single tank storage system would incorporate an insulation barrier to separate the hot and cold salts. In this system, the insulation barrier would move up and down according to the quantity of salts in each state.
The single tank has a capacity similar to that of the dual-system tanks used in many of Sener’s current CSP plants, and it is permanently full. In this system, all of the pumps have short shafts, which are more common in the marketplace and, therefore, less expensive.
Sener is also participating in the Helsolar project, the objective of which is to develop and validate a graphite thermal storage system suitable for average-high temperatures (650°C) and high thermal differences (~400°C). The project is being led by Sener and includes partners GrafTech International and the University of California in Berkeley.
Most of Sener’s CSP plants are currently equipped with molten salt storage systems that allow energy from the sun to be stored before being used to generate electricity. These storage systems consist of two tanks – one to store hot salts and the other cold salts.
Sener has provided solar technology to a total of 19 solar plants, including Gemasolar, which is the first commercial CSP plant in the world to be equipped with central tower molten salt receiver technology.