Flexible Proposals for Energy Storage Solution

Self-Build IRR Simulation

Background: A factory with an average demand of 500 kWh, operating 24 hours a day, uses Taipower’s high-voltage three-tier tariff. The goal is to reduce actual electricity costs through peak shaving and valley filling with behind-the-meter storage, and evaluate the return on investment.
The storage system uses a 1.6MW / 3.08MWh liquid-cooled 20-ft container. Programmatic operation excludes electricity market outsourcing fees.
- Summer: one charge/discharge cycle per day
- Non-summer: two charge/discharge cycles per day
Participates in Taipower’s reliable bidding demand response program, based on 2025 working days (max 36 hours/month, 2 hours/day, 18 days/month). Discharge occurs only upon notification
Participation capacity decreases annually due to battery degradation, calculated at 90% of the year’s maximum discharge capacity. Demand response revenue is not included
Charging is billed at off-peak rates; discharging is calculated using summer peak and non-summer mid-peak price differences. Annual electricity price increases are not factored in.
With 30% equity and a 3% annual interest rate, the IRR is approximately 7.64%. Payback period: 10 years, Estimated savings over 15 years: NT$43 million

Background：A factory operates on a two-shift schedule, producing related products. Main loads come from ten XXX units, with cooling provided by XXX kW chillers and compressed air by XXX kW air compressors—both equipped with variable-frequency drives to reduce power demand.
- Storage System Specs: 1.6MW / 3.08MWh liquid-cooled 20-ft container, Programmatic operation; excludes electricity market outsourcing fees, Summer: one charge/discharge cycle per day, Non-summer: two charge/discharge cycles per day.
- Demand Response Participation:Participates in Taipower’s reliable bidding model (2025 working days), Max 36 hours/month, 2 hours/day, 18 days/month, Discharge only upon notification.
Leasing Plan:
- No upfront costs for equipment, maintenance, or insurance Factory only provides a suitable installation site and pays for electricity used by the system
- Pricing is based on annual usable battery capacity, Starting rate: NT$1,200/kWh per month, Rates decrease annually with battery capacity, After 10 years, ownership of the storage system transfers to the factory
- Estimated Benefits under this operating model, the factory can save approx. NT$1.74 million over 15 years (around 4.73%),In addition, the system provides backup capacity and power quality services—without any extra fees

Background: A factory operates on a three-shift schedule with an average demand of 500 kW and a contracted capacity of 600 kW. Occasional over-contract usage occurs during the day, while nighttime consumption is slightly below average.
- Storage System Specs: 1.6MW / 3.08MWh liquid-cooled 20-ft container, Programmatic operation; excludes electricity market outsourcing fees, Summer: one charge/discharge cycle per day, Non-summer: two charge/discharge cycles per day.
- Demand Response Participation: Participates in Taipower’s reliable bidding model, (2025 working days)Max 36 hours per month, 2 hours per day, 18 days/month, Discharge only upon notification.
Profit-Sharing Mechanism
- No upfront costs for equipment, maintenance, or insurance Factory only provides a suitable installation site and pays for electricity used by the system
- Monthly electricity cost savings are calculated based on the previous year’s actual bills (including basic charges, variable charges, and over-contract penalties; excluding power factor adjustments), 70% of the monthly savings is shared with the service provider
- If monthly usage drops below 80% of the same month in the previous year, savings are calculated using the previous year’s usage, with 70% shared
- Estimated Benefits: Under this operating model,the factory can save approx. NT$1.78 million over 15 years (around 3.97%)，In addition, the system provides backup capacity and power quality services—without any extra fees

Background:A factory faces RE100 and net-zero requirements, and must gradually increase its green power usage.
- Plans to sign a CPPA with Daypower Energy for over 100 million kWh annually, with a transfer period of more than 10 years.
- After deducting daytime base demand, sufficient contracted capacity remains to store transferred green power in the energy storage system.
- Evening peak usage is high, and the factory aims to increase nighttime green power consumption.
Bundled Green Power Transfer Plan
- Daypower Energy provides a 1.6MW / 3MWh water-cooled storage container connected to the internal grid.The factory does not pay for equipment setup, maintenance, or insurance—only provides a suitable site and covers electricity used by the system.
- Daypower Energy supplies green power during the day. The storage system stores excess green power and acts as part of the internal grid load, increasing total green power usage.
- The factory pays Daypower Energy NT$0.03–0.10 per kWh of transferred green power as compensation for system setup and maintenance. After 10 years of leasing, ownership of the storage system transfers to the factory.
- Benefits from peak/off-peak price differences, backup power during outages, and improved power quality belong entirely to the factory.。

Background:A factory plans to install a rooftop solar power plant to reduce electricity costs through self-generation.
- The rooftop can support over 1MWp, but the factory’s regular demand is lower than peak solar output.No feeder line is available for selling excess power or transferring it, leading to high curtailment and reduced investment returns.
- The plan is to store excess solar power and sell renewable certificates, while also managing peak/off-peak tariffs to maximize savings
Co-Construction plan
- Integrates solar plant construction with energy storage, offering a single bundled price for complete energy services.
- Customized to match the factory’s usage profile, maximizing self-consumption and coordinating certificate sales to designated buyers.
- Can be paired with other power services and business models to create the most effective partnership based on factory needs.