Techno-Economic Optimization of a Hybrid PV-CSP Plant With Molten Salt Thermal Energy Storage and Supercritical CO2 Brayton Power Cycle

• High-efficient supercritical CO2 (sCO2) power blocks and the hybridization with solar photovoltaic (PV) plants have been identified as two viable solutions to enhance the economic competitiveness of Concentrating Solar Power (CSP) plants. This work introduces an innovative hybrid PV-CSP system layout with molten salt thermal energy storage and a sCO2 power block. An active hybridization has been proposed employing a molten salt electric heater that allows storing the excess PV production as thermal energy. The scalability of the plant has been investigated using size-dependent cost functions and introducing a novel methodology for scaling the sCO2 turbomachinery efficiencies. The conducted techno-economic optimizations show that the proposed hybrid PV-CSP plants can be cost-competitive. For a European solar resource location - 1900 kWh/(m2yr) - Levelized Cost of Electricity (LCOE) values lower than 66 EUR/MWh and capacity factors higher than 70 % can be achieved at 100 MWe. For a high-irradiance location - 3400 kWh/(m2yr) - a capacity factor of 85 % and a LCOE of 46 EUR/MWh have been found for the same scale. The selection of the sCO2 power cycle has a marginal impact on these results so that a simple recuperated cycle can yield similar LCOEs as the recompressed, reheated, and intercooled layouts. For smaller scales, systems with large gaps between the PV and CSP capacities are preferred, laying the optimal conditions for the electric heater integration with utilization factors up to 21 %. 

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Energiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Energy Engineering (hsv//eng)

Nyckelord

CSP

Electric heater

Hybridization

PV

sCO2

Carbon dioxide

Cost functions

Electric energy storage

Fused salts

Heat storage

Solar heating

Solar power generation

Solar thermal energy

Thermal energy

Concentrating solar power plant

Economic optimization

Hybrid photovoltaics

Hybridisation

Molten salt

Photovoltaics

Supercritical CO2

Techno-economics

Concentrated solar power

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