Blueprint for Molten Salt CSP Power Plant Final report of the project “CSP-Reference Power Plant” No. 0324253

Kurzfassung

This report shows the results of the German national research project “CSP-Reference Power Plant”. The major goal of the project consortium from German industry supplemented by DLR is the development and optimization a solar tower plant with 2-tank molten salt thermal storage and the publication of a blueprint. This report and blueprint shall be used as starting point for future Concentrating Solar Power (CSP) power plants and can help to save costs and time for future plants. Solar photovoltaic power plants may deliver cheap electricity during daylight hours. Therefore, a complementary renewable electricity production is needed to increase the overall renewable power generation and satisfy the demand. Here CSP may step in by harvesting the solar energy during daylight hours, storing heat in cost effective thermal storage units and providing electricity on demand after sunset and during the whole night if required. To suit these requirements in the best way, the consortium develops the reference CSP plant with one common approach but considers two typical operation strategies: 1. The power block starts around sunset and operates at full load until sunrise of the next day, if the storage content is sufficient (called Night-time Operation). 2. The power block starts around sunset and operates at full load until midnight, or until the storage is empty (called Peaker Operation). These two scenarios are indicative for more specific ones which may be tailored for a certain site. The overall design idea is that the most economic plant consists of the most economic subsystems considering their integration and the load demand. The solar or heliostat field is one of the essential subsystems and accounts for about 20 % of the overall costs. sbp sonne gmbh finds that a solar field of about 1.5 km² leads to the lowest specific costs. At sites suitable for solar tower systems, this field size is sufficient to provide heat for a 700 MWth solar receiver and the matching storage capacity is in the range of 5 to 7 GWhth if the solar field shall be able to fill it during good days. Similarly, a power block of 200 MWe shows the lowest specific costs among MANs turbine portfolio capable for daily start-up and shutdown. This conceptual overall design serves as starting configuration to further detail and optimize the subsystems. An annual performance simulation is done to find the storage capacity leading to the lowest LCOE and to calculate the possible LCOE of the optimized plant under different financing conditions. The plants optimized for the two different operating scenarios are using identical subsystems. The only difference between them is that the peaker plant has two 200 MW power blocks instead of one. Calculated LCOE are between 0.089 and 0.124 €/kWh for the night-time operation plant andbetween 0.130 and 0.182 €/kWh for the peaker plant, depending on financing conditions and life time assumptions. Higher LCOE for the peaker plant are caused by the fact that investment and O&M costs are increased since this plant needs 2 power blocks with reduced operating hours compared to the plant designed for night-time operation.