The primary profit model for industrial and commercial energy storage is "peak-valley arbitrage." This involves charging the storage system during off-peak hours when electricity prices are low, and discharging it during peak hours to supply power to industrial and commercial users. As different provinces have varying peak-valley electricity price differentials for industrial/commercial use, the economic benefits of energy storage systems also differ significantly across regions.

Taking a large metal processing enterprise in Hunan Province as an example:
- The facility operates under a two-part tariff system for large industrial electricity consumption
- Plans to install a 250kW/1500kWh energy storage project on-site
- The storage system will connect to the factory"s 10kV grid through parallel connection via 10kV high-voltage switchgear busbars
- The factory"s daytime load can fully absorb the energy discharged by the storage system
- The transformer capacity meets the charging requirements of the energy storage system

Current Hunan Province"s proxy electricity purchase prices are as follows:

The peak - valley electricity price difference is 0.786 yuan / kWh. In the months of 1, 7, 8, 9, and 12, the peak - valley price difference is 1.005 yuan / kWh, presenting significant peak - valley arbitrage opportunities. The time - of - use electricity prices are shown in the figure below.

Based on the electricity - consumption analysis, the peak period lasts for 8 hours, split into two intervals: 3 hours in the morning and 5 hours in the afternoon. There are 4 - hour flat - rate periods before each peak period, and an 8 - hour valley period in the early morning.

The project adopts a "charge - once - and - discharge - once" strategy: charging for 8.5 hours and discharging for 6 hours each day, making up 1.0 charge - discharge cycle daily. It charges fully during the valley period (23:00 - 07:30), discharges for 2 hours during the peak period (10:00 - 12:00), and discharges for 4 hours during the high - peak period (18:00 - 22:00).

The project is financed with 20% from the owner and 80% through loans. Loans are repaid with equal principal and interest, at an annual interest rate of 4.0% over 20 years. Equipment and civil construction costs are depreciated linearly over 20 years. The equipment VAT rate is 13%, the civil construction VAT rate is 9%, and the income tax rate is 25%. Annual operation and maintenance costs are 1% of equipment costs, and the annual system shutdown rate for maintenance is 7%. The project doesn't include the owner's profit - sharing ratio and civil construction costs but considers the revenue from recycling 70% of the electrolyte after the all - vanadium flow battery system's 20 - year life. According to the operating analysis, the economic data of the project is obtained through the NeLCOS® energy - storage calculator: the total investment is about 3.8325 million yuan, with a 250kW - power and 1500kWh - capacity all - vanadium flow battery energy - storage system, a 20 - year design life, and an annual discharge of 509,000 kWh. The system can achieve an internal rate of return (IRR) of 7.96% over its life - cycle, with a capital investment payback period of 9.27 years, proving the technical feasibility and economic return potential of the scheme in the peak - valley arbitrage scenario.

For investors and users, professional and precise energy storage economic calculation is not only the cornerstone of profit guarantee, but also the "digital moat" to avoid policy and market risks. Zhonghe Energy independently developed and operated NeLCOS® energy storage calculator can calculate the input - output ratio of energy storage systems for customers and investors from the levelized cost of electricity over the full life cycle, annual return on investment, and energy storage configuration plan. Click the link below to easily obtain data for decision - making reference.（https://nelcos.z-henergy.com/）

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