BESS for Metalworking & CNC Shop in Dnipro: Pre-Design Survey Checklist

Why Metalworking Shops in Dnipro Need This Survey

Dnipro's industrial profile—metallurgy, pipe rolling, aerospace—means the local grid is built for heavy loads but still suffers from voltage sags and frequency dips. For a CNC shop pulling 150–800 kW, the sharp peaks from welding and induction furnaces cause nuisance trips and inconsistent machining quality. You cannot fix that with a UPS alone.

The grid operator, DTEK Dnipro Electric Grids, enforces specific connection rules. Without a load profile and a clear understanding of your existing connection contract, any BESS sizing is guesswork.

Step 1: Measure Your Load Profile

Before anything, install a power quality analyzer at the main LV switchboard for at least two weeks. Capture current, voltage, power factor, and harmonics at 1-second intervals. This will show the amplitude and duration of peaks from welding and furnace starts.

• Identify peak demand in kW and its frequency (daily, per shift).
• Record voltage sags (RMS dips below 90% of nominal) – these are your main quality issue.
• Measure reactive power and harmonics (THD) – induction furnaces often inject 5th and 7th harmonics.

Without this data, the BESS size is a rough estimate. For example, a 150 kW peak lasting 2 minutes might need only 5 kWh, but if it recurs every 20 minutes, you need a battery that can cycle frequently.

Step 2: Pull Connection Documents and Verify Grid Constraints

Contact DTEK Dnipro Electric Grids and request your connection agreement, technical conditions, and any recent grid impact studies. Check your contracted capacity (in kVA) and whether you are on a tariff that penalizes peak demand.

Verify the voltage class: most shops are connected at 0.4 kV, but some larger ones have 10 kV transformers. At 0.4 kV, BESS integration is straightforward, but if you have a 10 kV connection, you may need a medium-voltage transformer for the BESS.

Also, ask about grid impedance at your point of common coupling – this affects how much voltage sag you experience. DTEK can provide short-circuit power at your node; typical values in Dnipro for industrial zones are 50–200 MVA.

Step 3: Define the BESS Function (Peak Shaving, Power Quality, or Both)

Two main use cases: peak shaving (reduce demand charges by flattening peaks) and power quality (mitigate sags and flicker). Both are relevant, but they lead to different battery sizes.

For peak shaving, you need enough kWh to cover the peak duration. For power quality, you need fast response (milliseconds) and high C-rate (e.g., 2C or more) but less energy. A hybrid approach is common: a lithium battery (LiFePO4) with an EMS that handles both.

In Dnipro, where grid stability is already stressed by heavy industry, voltage sags may be frequent – a BESS with fast response can bridge them until the grid recovers.

Step 4: Sizing and Implementation Notes for Dnipro Conditions

Based on typical data from similar shops, a 150 kW load with a 300 kW peak for 5 minutes would need about 25 kWh of usable energy. But because Dnipro's grid has frequent sags, you might size for 1C to 2C discharge rate to ensure quick response.

Consider the ambient temperature: Dnipro has cold winters and hot summers, so outdoor cabinets must be rated for -25 to +45°C. Our IP55/C4 cabinets meet that.

Installation at 0.4 kV is straightforward, but if you need to integrate with existing switchgear, plan for a dedicated breaker and current transformers. The EMS/SCADA can communicate via Modbus TCP to your PLC.

Payback: with Dnipro's commercial electricity rates (about 4.5 UAH/kWh and demand charges around 300 UAH/kW per month), peak shaving can reduce total bill by 8–12% – payback in 4–6 years, depending on battery cycling.