Multi Tower Systems and Simulation Tools

As the worldwide power demand increases, many countries seek to reduce their environmental footprint by supplementing the conventional power supply with renewable energies. While the share of volatile power producers such as PV and wind increase on the power market, dispatchable renewable energies become more important to ensure grid stability. Solar power towers with molten salt storage has the potential to contribute in this role. Technical innovations are required to reduce costs and/or increase efficiency to achieve lower levelized cost of electricity. Since the heliostat field is a major cost component of a solar tower power plant, it is subject to many research projects (1-5). The GRIDSOL project (6) presents a novel concept to develop multi-tower heliostat fields as part of a Smart Renewable Hub (SRH). This paper focusses on improving heliostat field efficiency by introducing a second tower into the heliostat field and allowing the heliostats to change receivers during operation. The main goal of the project was to find the most cost effective multi tower configuration, including heliostat field size and position of the towers, as well as an optimized heliostat field. Drawbacks such as an increased technical complexity, component utilization factors and additional costs for a second tower and additional piping are discussed.