Optimizing Capacity Charges with Energy Storage
Project Overview
To offset rising capacity payments and improve energy efficiency, Ruentex Materials Co., Ltd, a leading cement manufacturer in Taiwan, deployed a 3.06 MWh battery energy storage system (BESS) at its Dongshan plant. The system was installed to manage peak demand, reduce contracted load, and optimize time-of-use (TOU) consumption while supporting the company’s long-term sustainability strategy.
By charging during off-peak hours and discharging during high-rate periods, the plant is expected to save an estimated NT$15.5 million (~USD $484,000) annually in electricity and capacity costs. With a projected three-year payback period and immersion-cooled safety design, this project demonstrates a replicable model for industrial facilities seeking to reduce costs, ensure reliability, and advance decarbonization goals.
Location
Dongshan, YiLan County, Taiwan
Application
Peak Shaving, Time-of-Use (TOU) Optimization, Capacity Charge Reduction
Objective
Reduce annual capacity payments, lower peak demand charges, optimize time-of-use energy consumption, and support long-term sustainability goals.
Battery Capacity
3.06 MWh
Product
Etica Legion C20
Challenge
Ruentex Materials, with electricity consumption exceeding 5,000 kW annually, was facing steep costs under Taiwan’s Large Electricity User Agreement. While the company had already adopted solar power, it was not enough to meet mandated requirements, leaving significant capacity payments in place. To remain competitive, the facility needed a solution to offset these charges, manage peak demand, and better align energy use with time-of-use pricing. As with other large industrial users, safety and fire prevention were also key concerns when evaluating energy storage options.
Key challenges included:
High capacity payments and demand charges under the Large Electricity User Agreement
Solar generation alone insufficient to meet compliance requirements
Exposure to TOU pricing differentials without flexibility to shift production loads
Need for an expandable solution to support future multi-container deployments
Safety concerns around fire risk and long-term system reliability
Solution
Etica deployed a 3.06 MWh, 20-foot battery energy storage enclosure paired with a 1.5 MW Delta PCS to reduce capacity payments and optimize time-of-use energy consumption. Etica managed full integration, including civil, electrical, and mechanical engineering, site preparation, fire protection, and SAT testing, ensuring a turnkey deployment. The system was programmed to:
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Charge during off-peak hours when electricity rates were lower
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Discharge during high-rate periods to reduce contracted load and avoid peak charges
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Offset annual capacity payments under Taiwan’s Large Electricity User Agreement
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Enable scalability for future expansion to six additional containers (18 MWh total planned)
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Enhance safety and reliability with immersion cooling technology and comprehensive system integration
This solution provided Ruentex with a reliable, expandable platform to control energy costs, improve sustainability, and prepare for larger-scale energy storage deployment.
Results
The BESS system delivered measurable cost savings and operational benefits:
NT$3.3 million/year (~USD $103,000) saved through time-of-use (TOU) optimization by shifting charging and discharging
NT$12.16 million/year (~USD $381,000) saved in reduced capacity payments under the Large Electricity User Agreement
Total annual savings: ~NT$15.5 million (~USD $484,000)
Payback period: ~3 years
Safety: System designed with immersion cooling to mitigate fire risk; safety inspection scheduled for September 2025
These savings are expected without disrupting cement production, demonstrating the effectiveness of automated peak shaving, capacity charge reduction, and scalable energy storage for large industrial facilities.
Products
Fire Safe Energy Storage Solutions
Legion C20
Power Cabinet
Guardian Outdoor
SMART. RELIABLE. SCALABLE.
Unlock Savings with Energy Storage
Reduce peak demand charges, optimize time-of-use pricing, and future-proof your facility with safe, immersion-cooled battery storage built for industrial performance.
