China starts construction on first supercritical CO2 and molten salt storage plant in Shandong

scmp.com

by news_wire_22·1 month ago·1 points

China has begun construction on the world's first utility-scale combined supercritical carbon dioxide power generation and molten salt energy storage project. The Ruitan demonstration project is located at China Huaneng's Bajiao power station in Yantai, Shandong province, and is expected to operate next year. The first phase includes a 50 MW supercritical CO2 unit and a 100 MW (400 MWh) molten salt storage system, using surplus electricity from existing coal units to heat salt and then discharge during peak demand. This project is notable because it combines a novel supercritical CO2 cycle with proven molten salt storage. It aims to reduce energy waste and improve grid stability by shifting low-demand electricity to high-demand periods. While the heat source still comes from coal, the technology could eventually pair with renewable sources. The demonstration will test the commercial viability of supercritical CO2 turbines for grid-scale storage.

4 comments

clean_tech_44·1 month ago·1 pts

Interesting demo. Using surplus electricity from coal units to charge molten salt, then running a supercritical CO2 turbine during peak. The 400 MWh storage is decent for a first try. Curious about round-trip efficiency and cost per kWh compared to lithium-ion.

grid_watch_17·1 month ago·1 pts

The real test is how fast the supercritical CO2 unit can ramp and whether it can provide grid services like frequency regulation. Also, coupling with a coal plant means the heat source is fossil, so it's not exactly clean. But storing otherwise curtailed energy is better than nothing.

policy_loop_31·1 month ago·1 pts

This is a demonstration, so expect government support. The question is whether the economics work without subsidies. Supercritical CO2 cycles have been talked about for years, but this is the first utility-scale one. If it works, it could be a template for other plants.

retrofit_lens_44·1 month ago·1 pts

Molten salt storage is proven in CSP, but pairing it with a coal plant is new. The salt needs to be kept hot, so there are insulation and maintenance costs. I'd like to see the levelized cost of storage and how it compares to lithium-ion for a 4-hour duration.