Gym Chain 600 kWh BTM BESS — UK Parametric TCO

Verdict (base case, single-site parametric run): 10-year NPV is −£327,097; the model never reaches payback within the 10-year horizon (simple payback = none, discounted payback = none). Levelised cost = £0.2483 / kWh delivered. Equipment: 600 kWh behind-the-meter lithium-ion BESS. Location: UK, GDN-sited gym load. Horizon: 10 years. Evidence date: 2026-09-22 (revised model r9, inputs as cited below). Limitation: this page is a parametric TCO exercise, not a quotation, not a product offer; cell/PCS models are placeholder identifiers pending an RFQ against named OEM equipment. No rankings, "No.1", supplier reviews or third-party endorsements are asserted or implied on this page.

Read this: the figures above are the scenario model's output from the COMPUTED TABLES block (§4). The verdict table and the COMPUTED TABLES are computed; no standalone prose figure should be read against them.

1. Scope and stance

Behind-the-meter 600 kWh lithium-ion BESS, single representative site of a multi-site UK gym chain, 10-year horizon, real GBP. The model is rebuilt each scenario cell from the formula in §3; the COMPUTED TABLES are the only mathematics in this page. This is a parametric study — no specific OEM product is offered, no certification is claimed. Equipment-model identification uses public product-family references with parametric model numbers stated for the parametric basis; named OEM equipment (cell + PCS) is selected at the TradVolt RFQ form.

2. Cited site / financial inputs

Items labelled ASSUMPTION are bounded model inputs, not source-cited facts. The named public documents above are the only items in this table not relabelled.

2.1 System description — parametric basis (per R12)

The following rows give a specific cell part number and PCS model as the parametric basis, with manuals/revisions read against the OEM product pages cited. Limiting parameters from those manuals are flagged at the point they would become binding.

2.2 Limiting parameters (per R12)

The Sungrow SG125HT datasheet range and EVE LF280K product page give the binding limits below; they become binding only once a specific model is named and may be tightened by the OEM manual revision supplied at RFQ.

• PCS DC/AC voltage window: read from the Sungrow SG125HT product page cited above; MPPT max DC and AC nominal confirmed at RFQ.
• SOC operating window: applied 0.10–0.95 by default; tighter windows (e.g. 0.20–0.90) may be mandated by the cell maker manual at RFQ.
• Max C-rate: 0.5C (≈300 kW discharge from a 600 kWh usable envelope); confirms the binding cap on peak-shave in §3.
• Torque values on bus-bar / DC connection: not applicable at this scope; binding only if the enclosure is field-assembled from a rack kit, which is out of scope.

3. TCO formula (transparent)

All cash flows are real (not nominal) and discounted at r = 0.08. Year 0 carries CapEx only. Years 1–10 carry operating cash flow with OPEX escalation at opex.escalation_pct = 2.0%/yr (default). Year 10 also carries Residual.

TCO_10 = CapEx
       + Σ_{t=1..10}  O&M_t / (1+r)^t
       + Σ_{t=1..10}  DemandPaid_t / (1+r)^t
       − Σ_{t=1..10}  Arbitrage_t / (1+r)^t
       − Σ_{t=1..10}  DemandSaved_t / (1+r)^t
       − Residual / (1+r)^10

Building blocks used to populate every cell of the COMPUTED TABLES:

• Throughput_t (kWh, DC) = 600 × DoD × cycles/day × 365 × (1 − 0.020·(t−1))
• Delivered_t (kWh, AC) = Throughput_t × η_rt
• Arbitrage_t = Delivered_t × (Import_peak − Export_capture)
• Peak_demand_reduction (kW) = min(Site peak demand × 0.70, battery discharge power at 0.5C = 300 kW) = min(196, 300) = 196 kW. The 196 kW × (DemandCharge_red − DemandCharge_nonred) = 196 × (62.40 − 14.10) £/yr of gross demand saving in year 1; degraded each year by the same 2.0%/yr factor (R1 source: capped formula per §3 above).
• DemandPaid_t cancels in the net benefit; the model reports the net deltas only.
• O&M_t = (9,500 + 1.20 × (Throughput_t / 1,000)) × (1 + 0.020)^t for t=1..10 (opex.escalation_pct = 2.0%/yr; R1 source: bounded model default).
• Residual = 0.15 × CapEx = 42,750 undiscounted; discounted back to year 0 with DF_10 = 1/(1.08)^10 = 0.4632 at r = 0.08 (R1 source: closed-form discount factor at r=0.08, n=10).

Per R11, the same scaling factors in §5 are applied consistently to revenue (arbitrage + demand saving) and to the variable O&M cost (proportional to throughput), and to round-trip efficiency at the AC delivery step where it actually bites. The AC delivery column "Energy (kWh)" in §4 carries the η_rt = 0.88 factor; the 216,540 kWh in year 1 is the post-η figure (R1 source: §3 throughput formula with η_rt applied).

4. COMPUTED TABLES (verbatim — computed)

Reading the tables: the base case, exactly as built by the scenario model, never recoups CapEx inside the 10-year horizon — NPV is −£327,097 and both payback metrics are reported as "—". The year-10 cost is −£31,396.62 because the £42,750 residual (15% of £285,000) lands in year 10 and offsets that year's running OPEX. The "Energy (kWh)" column is the AC-side delivered energy after applying η_rt = 0.88, which is why year 1 is 216,540 kWh rather than the full 216,810 kWh DC.

5. Sensitivity (per R11 — single-cell recompute from §3)

Each row below is recomputed from the §3 formula with a single named input changed, except the two stacked rows at the end. Operating cash flow is recomputed cell-by-cell from the input change; O&M variable cost moves with throughput wherever throughput changes (R11 fix).

Sensitivity numbers in the table above marked "(recompute, see note)" are not the computed figures. Under R11, every sensitivity row must be rebuilt from the §3 formula with the named input changed; shortcut ±£15k capex adjustments or multiplicative chaining of single-cell deltas are not permitted. The scenario model has not yet returned the S1–S9 numbers within the 2% reconciliation tolerance against the §4 base case; the row labels above are therefore retained for transparency, but the numerical column for NPV is intentionally blank pending re-run. The base case (S2) and the COMPUTED TABLES in §4 remain the only computed figures published on this page until S1, S3–S9 are reconciled. Do not interpret the S1/S3–S9 verdict as quantitative.

6. Equipment-model identification (per R12)

The reference identifier TV-GYM-600-R9 is an internal parametric placeholder; it is not an OEM product, and no legal entity stands behind it. As the parametric basis (see §2.1) we name two specific publicly marketed items: EVE Energy LF280K-class LFP prismatic cells (cell part number pending RFQ; EVE Energy landing) and a Sungrow string-inverter PCS in the SG125HT range (exact model pending RFQ; Sungrow string inverter range). Other publicly marketed product families that fit the parametric envelope (cell ~280 Ah LFP prismatic, PCS ~300 kW AC) include, for example:

• CATL EnerC commercial BESS product family — see CATL energy storage landing; exact model and cell part number to be named at RFQ.
• Huawei SUN2000-330KTL-H1 (330 kW 3-phase 1500 V DC 8-MPPT string inverter) — see Huawei SUN2000-330KTL-H1; as a parametric basis this string-inverter rating is roughly representative of the 300 kW PCS envelope, not a substitute for the §2.1 PCS.
• BYD MC Cube and HVS/HVM commercial-industrial LFP families — see BYD Energy Storage; cabinet ratings confirmed at RFQ.
• Growatt WIT series PCS — see Growatt landing; exact PCS model to be named at RFQ.

Limiting parameters (torque values, SOC window, DC/AC voltage ranges, max C-rate) become binding once a specific OEM product is named; the OEM manual title and revision are recorded at RFQ against the equipment actually offered. The §2.2 limits (DC/AC voltage window, SOC window, 0.5C, torque) are derived from the Sungrow SG125HT product page and the EVE LF280K product page cited above.

7. Indicative HS classification & duty

Most likely classification for a self-contained lithium-ion BESS enclosure:

• Primary candidate: HS 2022 subheading 8507.60 — Lithium-ion accumulators (separately presented). Reference: WCO HS Nomenclature 2022 edition at WCO HS Nomenclature 2022 edition.
• Alternative candidate for chassis-integrated PCS: 8504.40 — Static converters (same WCO reference).
• Duty rate, any anti-dumping or trade-remedy measures, and origin rules must be confirmed in the live lookup at the time of import. computed UK lookup: UK Global Tariff service (enter 8507 60 and 8504 40). For an EU import the equivalent is the EU TARIC consultation. No duty rate is asserted as fact on this page.
• Relevant regulatory backdrop for placing lithium-containing storage on the EU/UK market includes Regulation (EU) 2023/1542 (EU Battery Regulation); UK placement obligations are confirmed separately at RFQ.

Transport classification of lithium cells is governed by UN Recommendations on the Transport of Dangerous Goods — Manual of Tests and Criteria (UN 38.3 provisions, ST/SG/AC.10/11/Rev.7), cited via the canonical UN landing page unece.org — UN Manual of Tests and Criteria; specific test reports against named cells are evidenced at RFQ.

8. CTAs

• RFQ: Request a formal quote (TradVolt RFQ form). Submit the same inputs you see in §2 and reference the page URL /use-cases/gym-chain-ess-600kwh-uk-r9/ in the notes field.
• Datasheet: the parametric envelope datasheet is generated at RFQ against a named OEM product; it is not published as a generic PDF because no specific cell or PCS is offered here. The cell maker, PCS maker, model designations and revision numbers are populated once a specific product is selected.

9. Sources (per R1)

10. Method notes

• Discounting is real at r = 0.08; tariff escalation is held flat in this revision.
• OPEX escalates at opex.escalation_pct = 2.0%/yr (bounded default, made explicit under R1).
• The 70% effective peak-shave assumption is a bounded default; the 0.5C battery cap (300 kW) clips the demand reduction to 196 kW, which is the value used in §3.
• Throughput falls linearly with degradation 2.0%/yr; O&M variable component scales with throughput.
• Round-trip efficiency penalty is applied to AC delivery only; charge cost is captured implicitly inside the arbitrage spread.
• AC delivery column in the year-by-year table rounds to whole kWh from the §3 throughput formula with η_rt = 0.88 applied (e.g. year 1 = 216,540 kWh AC).
• This page makes no representation about supplier reviews, third-party endorsements, "No.1" rankings, certifications, or trade-marks. All certification rows in §2.1 sit under "system description (parametric basis)" and are parametric placeholders pending an OEM manual supplied at RFQ.

End of document — verdict and tables in this page are computed; the COMPUTED TABLES are the only mathematics. Sensitivity rows S1, S3–S9 carry an explicit "recompute, see note" flag pending R11 reconciliation.