Behind-the-meter battery storage for commercial-tariff properties. Cut 30–45% of peak electricity costs through off-peak-to-peak arbitrage on Vietnam's 22 kV business tariff — one of the widest retail spreads in Asia.
On 22 April 2026, MOIT restructured Vietnam's time-of-use windows. The evening peak now runs as a single continuous block from 17:30 to 22:30, Monday to Saturday — five hours, 66% wider than the old 17:00–20:00 window. The morning peak (09:30–11:30) was abolished. Tariff levels are unchanged: peak still VND 5,025/kWh, off-peak still VND 1,609/kWh on 22 kV business. The 3.1× spread is intact — the window over which it earns has expanded.
For commercial buildings, the new peak window aligns directly with the hours your sites burn most electricity: offices closing down, retail and F&B in their prime trading slot, showrooms in evening-traffic hours, mixed-use evening occupancy. The hours that just got more expensive for you are the hours your BESS now runs the building from stored energy. Capacity charged at off-peak (00:00–06:00) and discharged across the new 5h evening peak — an arbitrage opportunity that got bigger overnight, on regulation that is in force now.
Scope: this page covers retail, F&B, offices, showrooms, gyms, cinemas, and mixed-use buildings on Vietnam's commercial tariff (kinh doanh). If you're running a hotel, see /solutions/hotels. Manufacturing-tariff sites (factories, production facilities) follow a different logic — see /solutions/factories. Third-party data centres are now classified commercial too but get their own page under /solutions/data-centres.
Vietnam's commercial tariff at 22 kV (Decision 1279/QĐ-BCT) sets peak electricity at VND 5,025/kWh and off-peak at VND 1,609/kWh. Commercial customers pay roughly 58% more per peak kWh than manufacturers on the same voltage — but the BESS that arbitrages the spread costs the same. Same capex, wider margin, better IRR.
Retail, F&B, showrooms and entertainment venues concentrate load in the 17:00–22:30 window — lining up almost perfectly with Vietnam's peak tariff window under Decision 963/QĐ-BCT (effective 22 April 2026): 17:30–22:30 Mon–Sat, 5 hours continuous. The window is 66% wider than the pre-963 17:00–20:00 peak. These are exactly the hours BESS discharges, and exactly the hours commercial buildings burn most electricity.
A retail chain or dealership group with 10+ sites gets one audit, one rollout schedule, one M&V contract, and one capex curve. Single-project EPC contractors can't do this efficiently. Pure financiers won't originate and execute. We do both.
For retail chains, F&B groups, auto dealership networks, and multi-location commercial operators, BESS isn't a per-site capex decision — it's a group-level treasury question. Every site has a different tariff voltage, a different load profile, and different retrofit constraints. What you need is a partner who can rank your portfolio by payback, deploy in phases, and deliver one consolidated M&V report to your CFO.
That's what we do. We audit the portfolio, prioritise by monthly bill size and tariff voltage, and roll out the first four sites within nine months. The rest follow on a predictable schedule. Your group finance team sees one set of IRRs, one capex line-item, and one O&M contract — not twelve procurement exercises running in parallel.
A concrete working example: a 40-site dealership showroom programme across Vietnam. The brief was uniform hardware, uniform contract structure, phased capital deployment, and TOU-arbitrage plus workshop-UPS value stacking. One audit, one specification, one rollout.
Arcus Energy sits between project developers and pure financiers. We originate projects, arrange finance (Zero Capex via third-party investors; Self-Invest via VietinBank, BIDV, Vietcombank and others), and deliver the assets. That combination is what makes a 40-site rollout work on one timetable.
The minimum viable single commercial site for BESS economics is roughly a monthly EVN bill above $1,500, load that actually runs during the 17:30–22:30 Mon–Sat peak window (Decision 963/QĐ-BCT), and a 22 kV business tariff connection. Retail chains, restaurants, office buildings, gyms, cinemas, and flagship showrooms typically qualify. Warehouses and back-office-only sites usually don't — their peak-hour load is too low to justify the capex.
Above $2,500/month the economics become genuinely strong. Above $5,000/month BESS is often a clear yes before a site survey even begins. Our full BESS calculator lets you enter your own bill and load profile and get a specific payback in 30 seconds — it's tuned for exactly this commercial-tariff use case, and pulls through to the same Excel model we run for full-site engineering reviews.
We don't push one over the other. The right answer depends on whether your group has capital to deploy, or wants this solved without touching its balance sheet.
For owners who want the electricity bill solved, not a new asset class to manage.
For groups with cash on balance sheet looking for infrastructure yield — not a discount.
Not sure which fits? Our team will model both against your portfolio and show you the numbers side by side.
For a commercial site on 22 kV business tariff, the BESS is sized to shave the peak tariff window — roughly 5 hours per day, Monday through Saturday. We size the battery power to 80% of the average load during peak hours in the site's lowest-consumption month. Sizing to the lowest month guarantees the battery is fully utilised every month — no oversized capacity sitting idle in low season.
Energy capacity is typically two hours of discharge. For a 300 kW peak load retail flagship or mid-size office, that means roughly 240 kW / 480 kWh — one outdoor liquid-cooled container, connected at low voltage behind the main switchboard.
Our standard supply is CFGE containerised liquid-cooled LFP at 92% depth-of-discharge and 90% round-trip efficiency. Cycle life is 8,000 cycles to 80% SOH — 25+ years of useful life on the cells alone at one cycle/day across the new 5h evening peak (Decision 963/QĐ-BCT, 17:30–22:30 Mon–Sat). The container footprint is roughly one 20-foot shipping container, outdoor-rated, and slots behind the main switchboard with a single connection point.
Multi-site portfolios use identical hardware across every site — which is what makes group-level M&V and warranty tracking work.
Three specific forces are tightening the economics of BESS in Vietnam this year. All three work against the operator who waits.
Battery-grade lithium carbonate nearly doubled between December 2025 and January 2026 — roughly +95% in two months, per Fastmarkets. S&P Global's 2026 outlook forecasts the global lithium surplus narrowing into a deficit, driven by grid-scale storage demand. Cell and system prices have followed upstream costs higher. The "prices fall every year" assumption that held through 2023–24 has reversed. Capex locked in today is cheaper than capex locked in next quarter.
On 22 April 2026, MOIT issued Decision 963/QĐ-BCT and restructured Vietnam's time-of-use windows. The evening peak now runs 17:30–22:30 Mon–Sat — five continuous hours, 66% wider than the old 17:00–20:00 window. Tariff levels are unchanged; the 3.1× peak-to-off-peak spread on 22 kV business tariff is intact. The earning window over which a BESS arbitrages that spread has expanded overnight, and the hours that just got more expensive for commercial buildings (offices closing, retail/F&B prime trading, showrooms, mixed-use evening occupancy) are exactly the hours a BESS now runs the building from stored energy. The arbitrage opportunity got bigger, on regulation that is in force now.
A retail flagship or mid-size commercial site on 22 kV business tariff typically pays $1,500–$3,000 per month more than it has to, every month a BESS isn't installed. Twelve months of delay on a 10-site portfolio is $180,000–$360,000 of recoverable margin permanently given to EVN. Rising capex on the install side, an evening peak window that just got 66% wider on the operating side — every month of delay is a month of the new wider arbitrage window paid to EVN at full rate. The economics tighten in two directions simultaneously. Nothing about waiting makes the numbers better.
An active multi-site BESS programme across 40 showroom sites in a single phased rollout. The value case stacks two revenue streams: (i) peak/off-peak arbitrage on commercial tariff — VND 5,025/kWh peak, VND 1,609/kWh off-peak, 22 kV — and (ii) workshop UPS reliability during EVN outages, where each minute of workshop downtime has measurable service-revenue cost.
BESS sizing is uniform across sites: CFGE containerised liquid-cooled LFP at 250 kWh per site. Rollout is phased across regional clusters with one consolidated M&V methodology and one capex curve feeding group-level treasury reporting.
Specific IRR and payback figures are portfolio-confidential. Request a portfolio audit for indicative numbers tuned to your own site mix.
BESS is sized to 80% of the average load during peak tariff hours in the site's lowest-consumption month, with a 2-hour discharge duration. Rule of thumb: approximately 0.15 MWh of BESS capacity per $500 of monthly EVN bill at 22 kV commercial tariff.
A 10-minute load review with our team gives the exact number for your site. Run the full BESS calculator for a 30-second indicative answer.
Monthly EVN bill above $1,500 on 22 kV business tariff, with actual load running during the 17:30–22:30 Mon–Sat peak window (Decision 963/QĐ-BCT, effective 22 April 2026). Below that threshold, the capex doesn't earn its keep.
Above $2,500/month the economics become genuinely strong. Above $5,000/month BESS is often a clear yes before a site survey even begins. Retail, F&B, offices, gyms, cinemas and flagship showrooms typically qualify; warehouses and back-office-only sites usually don't.
Partly. Hotels are also on commercial tariff with the same 3.1× spread, but the hotel page has a mini-calculator tuned to hotel load profiles and hotel-market-specific content (portfolio rollout across resort regions, Pacifico engagement, HorecFex).
If you're a hotel operator, start at /solutions/hotels.
Commercial tariff (kinh doanh), 22 kV, under EVN Decision 1279/QĐ-BCT (effective 10 May 2025): peak VND 5,025/kWh, standard VND 2,887/kWh, off-peak VND 1,609/kWh. Time-of-use windows under Decision 963/QĐ-BCT (effective 22 April 2026): peak 17:30–22:30 Mon–Sat (5 hours continuous, no peak Sunday); off-peak 00:00–06:00 daily; standard the remainder. The 3.1× peak-to-off-peak spread is one of the most favourable retail tariff spreads in Asia.
BESS charges at the off-peak rate and discharges at the peak rate. The arbitrage margin is the revenue.
The two-part tariff — separating a capacity charge (VND/kW/month) from an energy charge (VND/kWh) — rolls out to manufacturing pilot customers from July 2026 at ≥200,000 kWh/month, ≥22 kV.
Commercial tariff customers (retail, F&B, offices, hotels, showrooms) are not in the pilot. Broader rollout is 2028–2030.
When it does reach commercial customers, BESS becomes more valuable, not less — because shaving peak kW directly cuts the capacity charge, on top of the arbitrage revenue already modelled.
Sometimes. Most urban retail, office, and showroom properties have limited roof area, multi-tenant complications, or the roof is used for HVAC plant, signage, or advertising. Where roof area is available and single-tenant, rooftop solar is additive — it recovers the daytime standard-rate window and, if paired with BESS, can store solar generation for discharge into the 17:30–22:30 Mon–Sat peak (Decision 963/QĐ-BCT). After Decision 963, solar-plus-BESS is the only path to monetise solar generation against peak tariff — which strengthens the hybrid case where roof access permits.
Factories are where the solar-plus-BESS hybrid case is canonical; commercial sites are BESS-led with solar as an optional overlay.
For a single site: 4–6 months from contract signature to commissioning. Grid connection approvals are the long pole, not civil works.
For a 10-site portfolio: first four sites commission in 8–9 months, the rest follow on a predictable schedule. A 40-site rollout typically completes within 24–30 months across regional clusters.
Ten-minute conversation. We'll tell you which of your sites fit, what a phased rollout looks like, and what capex lands at today's supplier pricing — not next quarter's.