Thermo-economic design of an electric heater to store renewable curtailment in solar power tower plants Articles uri icon

publication date

  • October 2023

start page

  • 1

end page

  • 14

issue

  • 117710

volume

  • 297

International Standard Serial Number (ISSN)

  • 0196-8904

Electronic International Standard Serial Number (EISSN)

  • 1879-2227

abstract

  • The daily start-up and shutdown of the solar power tower plants (SPTP), the tank losses, and the reliable receiver operation cause the expected temperature in the thermal energy storage to be lower than the design one, resulting in an electric production reduction due to off-design operation. To overcome this issue, we propose to place an electric heater in parallel with the hot tank to leverage grid curtailment, reducing the gap between the hot tank temperature and the design one. For the first time, an electric heater placed in parallel with a SPTP hot tank is designed considering the off-design performance of the thermal energy storage system, receiver, and power block. The electric heater is optimized to minimize the levelized cost of storage (LCOS) and designed as a shell and tube heat exchanger. For the case study, with a 110 MW SPTP coupled to the 2030 Spanish grid forecast, the optimum electric heater power is 11 MW, the LCOS is 12.98$/MWh and the payback period would be 3 years. Annually, the electric heater system stores 25 GWh/year of curtailment and boosts the power generation of the plant by 11 GWh/year (3.4 %), creating a Carnot battery with an efficiency of 44 %. This synergy between concentrating solar power plant operation and grid curtailment is an economically viable solution that can help the penetration of variable renewable energies and boost present and future SPTP.

subjects

  • Chemistry
  • Industrial Engineering
  • Mechanical Engineering
  • Physics

keywords

  • solar power tower plant; electric heater; thermal energy storage; renewable curtailment; carnot battery