# Grid-Tied Peak-Shaving Customization grid-tied microgrid engineering targeting demand charges and time-of-use tariffs for factories, industrial parks and retail complexes with high demand charges. **Fig. 1｜**How the money is made: charge in the valley and shoulder periods, discharge during peak windows, and flatten monthly maximum demand — optimizing energy charges, demand charges and time-of-use spread together. Grid-tied peak shaving customization · restructuring a two-part electricity bill Peak shaving customization: one battery, three lines of value Commercial electricity bills normally combine an **energy charge with a demand (capacity) charge**, then add critical-peak uplifts. Storage earns its keep three ways: shaving the monthly peak demand, moving energy from expensive to cheap hours, and **holding up critical load in milliseconds** when the utility dips. Our job is to size power and capacity against your real load shape and local tariff, then write those rules into the EMS as an executable schedule. **20%–40%**Typical reduction in billed maximum demand **4–6 years**Static payback where tariffs cooperate **1–2 cycles/day**Common cycling strategy **below 20 ms**Support during a supply disturbance 1. Where the return comes from Looking only at the peak/valley spread understates the project; demand control alone misses arbitrage. The three orientations below are rarely equal. Arbitrage only Buy low, sell high in your own bill. Fit: wide peak/valley spread, load well aligned with tariff windows Risk: depends on policy, consumes the most battery cycles Demand control only Push down the highest 15-minute average. Fit: short sharp peaks (injection moulding, stamping, compressors) Risk: high power, short duration, so capacity utilization stays low Combined The optimum for most sites. Same asset shaves demand and discharges in peak hours EMS selects the day's strategy from a load forecast Adds ride-through, avoiding short-interruption losses 2. Six capabilities that decide payback 01 Forecast and track the 15-minute window Estimate running demand in real time and pre-discharge ahead of a known inrush, rather than reacting after the peak has already been recorded. 02 SOC schedules and reserve floors Generate separate SOC curves by season and day type and reserve headroom for backup, letting energy arbitrage yield to protection when needed. 03 Anti-backflow and reactive support Enable anti-backflow where export is contractually forbidden, and provide kVAr to keep the power-factor penalty off your bill. 04 Millisecond transfer: storage as an online UPS Sensitive lines suffer more from short dips than from long outages. Internal transfer performs below 10 ms, external STS below 20 ms — enough for the vast majority of industrial loads. 05 Coordination with transformer and genset When the transformer cannot cover a short peak, storage or the genset supplies the difference; where chargers are the cause, storage provides dynamic capacity and defers reinforcement. 06 Data closure Daily charge/discharge records are kept in billing units so theoretical and actual savings can be reconciled every month and the strategy refined. 3. Keeping the three accounts separate Demand saving = Δ demand kW × demand charge × 12 months _Δ demand = peak 15-minute average before − target value after_ Arbitrage = Σ(peak energy × peak price) − Σ(valley energy × valley price) ÷ system efficiency Static payback ≈ investment ÷ (annual demand saving + annual arbitrage − annual O&M and losses) **Practical rule** — size power (kW) from the peak you intend to remove, size capacity (kWh) from how long you need to sustain it. Most commercial projects land on two to four hours of discharge. 4. Typical configurations Starting points by transformer size and load character CustomerTransformerPCS powerStorageMain strategy Small machining / plastics630–1250 kVA250–500 kW500 kWh–1 MWhDemand control first Medium factory1.6–2.5 MVA500 kW–1 MW1–2 MWhDemand plus arbitrage Campus / multi-building4–10 MVA1–3 MW2–6 MWhMulti-transformer coordination Site with chargingAs metered peak500 kW–2 MW1–4 MWhDynamic capacity plus managed charging 5. Recommended platforms [SP125HCPS Microgrid storage converter Rated power 125 kVA Transfer below 10 ms (STS option) Coupling DC or AC Peak efficiency 98.5% View details →](/en/product/sp125hcps) [SP625HCG2 Integrated hybrid cabinet Integration PCS + MPPT + EMS + distribution Interfaces Grid / genset / PV / battery Paralleling Multiple units supported Use case Factory shaving and backup View details →](/en/product/sp625hcg2) [STS200 / 400 / 600 Static transfer switch Rated power 200 / 400 / 600 kW Transfer time below 20 ms Grid tolerance 400 V/230 V, −20% to +15% Purpose Uninterrupted supply to sensitive feeders View details →](/en/product/sts200-400-600) [SP125HSPS Liquid-cooled storage converter Rated power 125 kVA DC side 680–950 V Cooling Liquid, suits hot or sealed rooms Use case Peak shaving, PV-plus-storage View details →](/en/product/sp125hsps) 6. How we run the project Tariff analysis Collect twelve months of bills and split energy, demand, power-factor and time-of-use components. Load analytics Read the 15-minute curve, identify what creates peaks and when. Strategy and sizing Choose the strategy mix, then compare two or three power/capacity options with payback. Integration design Connection point, cable routes, cabinet placement, fire provisions. Install and commission Full FAT, grid-synchronisation tests and protection settings review. Operation tuning Calibrate against the first real bill, then review quarterly. 7. Sites in service 1.5 MW plastics plant: demand shaving plus line continuity Factory sites: compact integrated cabinet footprint Campus: rooftop PV and storage working together Self-consumption: raising the share you use yourself 8. Frequently asked Our bills are unreadable — where do we start? Send twelve months of PDF bills. We separate demand, energy, power-factor and time-of-use components, then show exactly how much is addressable. How do we avoid buying capacity we never use? Power follows the surge you need to remove, capacity follows how long you need to sustain the discharge. Two to four hours covers most commercial cases; extreme short spikes justify high power with small capacity. Will it interfere with production? The system parallels the bus, so only a short planned shutdown is needed to connect. In operation the EMS runs automatically and a bypass is available at any time. Can it double as backup power? Yes. We reserve emergency SOC for critical loads and pair it with an STS or internal transfer, giving short-interruption continuity proportional to the reserved energy. Send twelve months of bills and load data We will break down your tariff and return viable power/capacity options with a static payback calculation. [Request a peak shaving proposal](/en/contact)