With the rapid development of China's chemical industry and the increasing emphasis on energy management, energy storage technology has become an important means for chemical enterprises to optimize energy efficiency and reduce costs. As a high - safety - level place, the chemical industry involves complex and dangerous production processes with high temperature, high pressure, strong corrosiveness, and flammability and explosiveness, which puts strict requirements on the safety and reliability of energy storage systems.
In this context, the owner of a large chlor - alkali chemical plant in Jiangsu Province, considering both safety and economy, plans to install a 70MW/448MWh all - vanadium flow battery energy storage system. To ease the initial investment pressure, it innovatively adopts a vanadium electrolyte leasing model, turning the electrolyte from fixed - asset investment into operating lease cost. For precise planning, the project uses the NeLCOS® energy storage calculator from ZH Energy to analyze the project's technical suitability and economic return path from the full - life - cycle levelized cost of storage (LCOS) and internal rate of return (IRR).
Based on the current agency electricity purchase price in Jiangsu Province, the peak - valley electricity price difference is 0.781 yuan per kWh, and the peak - valley electricity price difference in July, August, December, and January is 0.988 yuan per kWh, indicating a huge peak - valley arbitrage space.
According to the electricity consumption analysis, there are two peak periods each day, totaling 8 hours. The first peak period lasts for 3 hours in the morning and the second lasts for 5 hours in the afternoon. Between the two peak periods, there are 8 hours of flat - rate periods, and 8 hours of valley periods in the early morning. The project adopts a "one - charge - one - discharge" mode: the energy storage system is charged for 8 hours and discharged for 6.4 hours each day, totaling 1.0 charge - discharge cycle per day.
However, the main transformer capacity of the chemical plant is 150,000 kVA, with an average monthly maximum power load of 120,000 kW, accounting for 80% of the transformer's rated capacity and approaching full - load operation. According to the owner - provided annual load data, the daily load curve shows high consistency.
Under the traditional peak - shaving and valley - filling mode, energy storage needs to be charged during the valley and flat periods. However, the valley - period load of this enterprise is already relatively high. Directly installing an energy storage system would increase the enterprise's basic electricity fee, specifically the maximum demand fee. According to the owner's feedback, by optimizing the production sequence, a 70MW charging capacity can be reserved for the energy storage system during the evening valley and daytime flat periods, avoiding additional demand fee pressure.
The investment structure is 20% self - funded by the owner and 80% financed through loans. The loan is repaid in equal principal and interest installments over 20 years with an annual interest rate of 3.5%. In terms of revenue distribution, the owner receives 18% of the energy storage's total income (before deducting electrolyte lease, operation and maintenance, and financial costs), amounting to 20 million yuan annually. In cost accounting, design and construction costs are not included. The value - added tax rate is 13% for equipment and 9% for construction. The corporate income tax rate is 25%. Operation and maintenance costs are accrued at 0.3% of the equipment cost, with 5% of the year reserved for shutdown maintenance. The electrolyte lease fee is calculated at 8% of the total price based on a purchase price of 20,000 yuan per cubic meter, totaling 37.9259 million yuan per year.
According to the above operational analysis, using the NeLCOS® energy storage calculator from ZH Energy, the project's economic data is as follows: total investment is about 385 million yuan, energy storage equipment unit price is 0.86 yuan per MWh. Configuring a 70MW/448MWh all - vanadium flow battery energy storage system, with an annual discharge of 155.344 million kWh and a designed service life of 20 years. Through the deep adaptation of the vanadium electrolyte leasing model, the internal rate of return (IRR) is 15.63%, and the capital investment is expected to be recovered in 4.46 years. The NeLCOS® energy storage calculator independently developed by ZH Energy can calculate the input - output ratio of energy storage systems for customers and investors from the aspects of full - life - cycle levelized cost of electricity, annual return on investment, and energy storage configuration scheme, providing decision - making reference data.
Click to get the full - life - cycle levelized cost of electricity calculator for free: NeLCOS®
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