The 150MW Ourazazate Noor III CSP Tower in Morocco has exceeded performance targets on output and storage integration in its first few months of operation. Xavier Lara, Senior Consultant at CSP engineering group Empresarios Agrupados (EA), said that financing costs for tower storage projects should fall in line with parabolic trough rates going forward.
The Noor plant is showing the best performance ever seen for CSP tower with storage since December. In the same month, Assembled Chemical Weapons Assessment ACWA power brought online its 150MW Noor III central tower plant with 7.5 hours of storage capacity in Morocco. Noor III is the world’s largest operational tower plant and only the second to combine molten salt storage technology.
Lara says that data from the first few months of operation shows Noor III is surpassing performance targets on total output, ramping rates, as well as the integration of the thermal energy storage and steam generation systems. Lara also notes another key area which will be closely monitored will be the ability of the stream turbine to withstand thermal stresses associated with the temperature gradients during frequent ramp-ups and cooling.
Germany’s Siemen’s is to supply four stream turbine generators and auxiliary equipment for the parabolic trough and tower plants.
Financing cost
High capital expenditure (capex) cost of CSP plants and limited installed capacity means financing costs remain much higher than for PV and wind plants. Lower installed capacity and high-profile performance issues on early projects are causing financing costs for CSP plants to remain at a premium level.
Developers leverage the greater storage efficiency of tower designs hence demand for tower capacity is on the rise. Data from the New Energy Update CSP Global Tracker shows that currently around 610MW of CSP tower capacity is under construction in Chile, China, and UAE.
CSP performance
New projects in China will provide further insights on the performance of CSP tower with storage plants. CSP projects could also help share industry learnings and reduce risk profiles. Last October, U.S.A’s National Renewable Energy Laboratory (NREL) launched a 12-month study of CSP project costs. They are focusing on performance issues and unexpected costs.