How to Assess a BESS Project Financial Model in China: the Revenue Lines the Rules Allow (Energy Arbitrage Under Spot or Agency Prices, Ancillary Services, the 2026 Grid-Side Independent Storage Capacity Price Scaled by Peaking Capability, Provincial Discharge Compensation), the Cost Lines (Charging Treated as a User, Grid-Loss and System-Operation Charges, 10-Year Minimum Tax Depreciation and the ≤5 Million Yuan Expensing Rule), and the Utilisation Evidence (611 → 911 → 1,195 Equivalent Hours, 2023–2025)

Short answer. A storage model is only as good as the rule behind each line. On the revenue side the Chinese texts now allow four: (1) energy arbitrage — in areas where the spot market runs continuously, charging and discharging prices follow market rules or real-time spot prices; elsewhere charging is priced at the grid's agency purchase price for industrial and commercial users and the discharge price formation is set by the provincial price authority taking account of charge/discharge losses; (2) ancillary services, where independent storage shares or bears costs by its on-grid or off-grid energy in each settlement period, must bid if it already receives capacity payments, and is treated as a generator when discharging and a user when charging; (3) a capacity price that each province may grant (各地可给予) to listed grid-side independent storage that serves the safe operation of the power system and is not co-located (配储) storage, introduced at national level in January 2026 (whether and at what level it applies depends on the province's implementing document and project list) and set from the local coal-power capacity price scaled by peaking capability — full-power continuous discharge hours divided by the year's longest net-load peak duration, capped at 1 — and withdrawn once a reliable-capacity compensation mechanism exists; and (4) provincial compensation such as Inner Mongolia's 0.35 yuan/kWh of discharge for independent stations commissioned in or before 2025. On the cost side the same texts make charging a user transaction paying grid-loss and system-operation charges under a single-part transmission tariff, refunded for discharged energy, while the 2022 notice exempts charging energy corresponding to grid discharge from transmission tariffs and government funds; tax depreciation of machinery and production equipment runs at least 10 years, and only assets that qualify — products updated quickly because of technological progress, or year-round strong vibration or high corrosion — may shorten that to no less than 60% or use accelerated methods, with one-off expensing for items of 5 million yuan or less bought through 2027. The utilisation that drives arbitrage revenue is published: 611, 911 and 1,195 equivalent hours nationally in 2023, 2024 and 2025, and 573 and 626 hours in the two grid areas in the first half of 2026. This guide reads the rules and the regulator's numbers; it quotes no project's revenue, tariff spread, capex or IRR.

1. Revenue lines and the text behind each

CNWattHub reading: the capacity-price arithmetic is a duration test. The notice scales the coal benchmark by full-power discharge hours over the longest net-load peak — a 2-hour station in a province whose peak lasts 4 hours cannot score more than half, and the cap of 1 means a long-duration station gains nothing above parity. The model should show the ratio, not a flat yuan/kW figure copied from coal. The Q&A's 165 yuan/kW·year (at least 50% of coal fixed cost) is a floor for coal, not a storage number, and a province that has not adopted the storage capacity price gives the line no basis at all.

2. Cost lines the rules impose

• Charging as a user. Under the 2026 notice, pumped storage and grid-side independent storage are treated as users when charging, pay grid-loss and system-operation charges, provisionally under a single-part transmission tariff, and are refunded transmission charges for the energy they discharge.
• The 2022 exemption. An independent station's charging energy corresponding to discharge to the grid does not bear transmission-distribution tariffs or government funds and surcharges.
• Ancillary cost sharing. Independent storage shares or bears ancillary-service costs by energy in each settlement period.
• Tax depreciation. Minimum 10 years for machinery and production equipment (20 for buildings, 3 for electronic equipment); shortened life no less than 60% of the minimum, or double-declining-balance or sum-of-years methods, but only for fixed assets that qualify under Art. 98 — those whose products are updated quickly because of technological progress, or that operate year-round under strong vibration or high corrosion. The regulation does not say which class a battery system falls in or that it qualifies; the model should state the class it uses and the basis for any accelerated method. Equipment and instruments with a unit value of 5 million yuan or less bought between 1 January 2024 and 31 December 2027 may be expensed in full in the year of purchase; higher-value items follow the regulation and the 2014/2015 accelerated-depreciation notices.

CNWattHub reading: a model that charges at the agency price but books discharge at spot in a province without continuous spot is mixing regimes; a model that applies the 2022 exemption and also pays full transmission charges on charging double-counts the cost; and a tax line that depreciates a battery over 10 years while the technical model augments at year 7 should say which governs the cash flow.

3. Utilisation: the regulator's numbers

CNWattHub reading: 1,195 equivalent hours in 2025 is a national average across all stations and all duties; a model's cycle count should be compared with the grid area's figure and with what the province's dispatch regime allows — the 2025–2027 action plan has non-spot areas add storage dispatch by merit order and spot areas dispatch by market results.

4. The policy direction

The 2025–2027 action plan targets more than 180 GW of new-type storage by 2027 with about 250 billion yuan of direct project investment, pushes storage into energy and ancillary markets (regulation, reserve, exploratory ramping and inertia products), and calls for improved capacity-price mechanisms, an orderly reliable-capacity compensation mechanism and market-formed charge/discharge prices. The 2022 notice sets the conditions under which a project registers as independent storage (independent metering and control, dispatch access, legal personality). The 2021 time-of-use notice sets the retail spread that behind-the-meter models rely on — peak-valley ratios in principle of at least 4:1 where the system peak-valley difference exceeds 40% and 3:1 elsewhere, with encouragement for industrial and commercial users to configure storage and dynamic adjustment of time bands with reference to spot signals.

CNWattHub reading: the direction of travel is from administered lines (capacity price, provincial compensation) to market lines (spot, ancillary, reliable-capacity compensation); the 2026 notice already writes the hand-over clause. A model whose value sits mostly in administered lines beyond the dates those texts name is carrying policy risk it should label.

5. The cost benchmark

Lazard's June 2025 LCOS v10.0 gives unsubsidised levelised cost of storage of $129–277/MWh for a 100 MW/2-hour and $115–254/MWh for a 100 MW/4-hour utility-scale standalone system and $319–506/MWh for a 1 MW/2-hour C&I system, and attributes the year's notable declines to cell oversupply and to higher cell capacity and energy density. CNWattHub reading: these are US-assumption ranges, useful for the shape of the cost stack and the direction of change, not for a Chinese project's capex; a Chinese model should carry its own quoted EPC price and cite it.

6. An assessment sequence built from the sources

CNWattHub's reading of the sources as a checklist:

1. Regime. Continuous spot or not; charging price rule and discharge price rule accordingly.
2. Registration. Independent storage conditions met; co-located storage not treated as mandated revenue.
3. Capacity price. The province's implementing document actually grants it (the notice says provinces may); serves system security and not co-located storage; on that province's project list; duration ratio shown; end date when reliable-capacity compensation starts.
4. Ancillary. Products available; bidding duty if capacity-paid; cost sharing by energy; itemised bill.
5. Provincial compensation. Eligibility window and successor-rate assumption.
6. Grid charges. User treatment when charging; refund on discharge; the 2022 exemption.
7. Utilisation. Cycles versus 1,195 h national and the grid-area figures; dispatch regime.
8. Tax. Asset class under Art. 60 (10-year minimum for production equipment); accelerated or shortened only if the asset qualifies under Art. 98 (fast technological renewal, or strong vibration/high corrosion), with the basis stated; ≤5 million yuan expensing through 2027.
9. Retail spread (behind the meter). TOU ratios and dynamic adjustment.
10. Cost sanity. Lazard's ranges for shape, own quotes for level.

Scope limits

This guide reads the 2025 pricing reform, the 2022 and 2026 NDRC/NEA notices and the 2026 Q&A, the 2025 ancillary-service rules and 2024 price notice, the 2021 time-of-use notice, the 2025–2027 action plan, NEA's January and July 2026 press conferences, Inner Mongolia's compensation report, the tax regulation and announcement, and Lazard's LCOS. It quotes no project revenue, spread, capex, IRR, provincial list, provincial capacity-price level or lease rate, and no text issued after July 2026.