Analysis of an integrated CSP-PV hybrid power plant

Abstract

In the past, CSP and PV have been seen as competing technologies. Despite massive reductions in the electricity generation costs of CSP plants, PV power generation is -at least during sunshine hours -significantly cheaper. If electricity is required not only during the daytime, but around the clock, CSP with its inherent thermal energy storage gets an advantage in terms of LEC. There are a few examples of projects in which CSP plants and PV plants have been co-located, meaning that they feed into the same grid connection point and ideally optimize their operation strategy to yield an overall benefit. In the past eight years, TSK Flagsol has developed a plant concept, which merges both solar technologies into one highly Integrated CSP-PV-Hybrid (ICPH) power plant. Here, unlike in simply co-located concepts, as analyzed e.g. in [1] -[4], excess PV power that would have to be dumped is used in electric molten salt heaters to increase the storage temperature, improving storage and conversion efficiency. The authors demonstrate the electricity cost sensitivity to subsystem sizing for various market scenarios, and compare the resulting optimized ICPH plants with co-located hybrid plants. Independent of the three feed-in tariffs that have been assumed, the ICPH plant shows an electricity cost advantage of almost 20% while maintaining a high degree of flexibility in power dispatch as it is characteristic for CSP power plants. As all components of such an innovative concept are well proven, the system is ready for commercial market implementation. A first project is already contracted and in early engineering execution.

Techno-Economic Evaluation of CSP–PV Hybrid Plants with Heat Pump in a Temperature Booster Configuration

“…Numerous studies have analyzed hybrid plants [1][2][3][4][5][6][7][8][9][10] and some plants have already been constructed [11][12][13]. Different levels of hybridization are possible [1].…”

“…Physical proximity and integration reduce grid load and enable coordinated operation and production planning for subsequent days. Some studies [1,3,4] have investigated this integration using an electric resistance heater (ERH). Heat pumps (HP) represent another promising technology for the coupling due to their higher efficiency, but their investment costs are also higher.…”

“…The study showed that CSP-PV hybrid plants are an economically interesting option, enabling the adjustment of feedin according to demand. Gedle et al [3] developed a systematic optimization methodology for an integrated hybrid CSP-PV plant, which included electric heaters to utilize part of the electricity from the PV plant to heat a fluid that was then thermally stored. This energy was later converted back into electricity.…”