Industrial Battery Energy Storage for Kremenchuk: Engineering, Sizing, and Grid Connection

Input Data: What We Need from Your Site in Kremenchuk

Before any number is calculated, we need your load profile. Not the average, not the peak — a 15-minute interval record for at least one year, preferably from your commercial metering. For a 215,000-population city with this industrial mix, the grid is not weak, but it is not infinitely stiff either.

We also need your current contract with Poltavaoblenergo: the permitted capacity, the voltage level (6/10/35 kV or 0.4 kV), and the tariff class. If you are on the hourly billing for the day-ahead market, the business case is entirely different from a flat tariff.

Power and Capacity Sizing: From kW to MWh

For oil refining, a 1 MW / 2 MWh system can shave the morning peak that coincides with the wider city load. For railcar production, where welding lines create 0.5-second spikes, a 2 MW / 1 MWh battery with high C-rate (1C or 2C) is more appropriate. The ratio is not random: it is derived from your load duration curve.

We size for an economic optimum, not for maximum coverage. Typically, we target 20-30% of your peak demand, with a duration of 1 to 4 hours. The payback in Poltava Oblast, given current industrial tariffs (around 6-8 UAH/kWh) and the frequency of grid instability, is 4 to 6 years for a 1 MW system. Without your load profile, that figure is rough.

One hard limit: at 0.4 kV, a battery above 500 kW is impractical. The cable cross-sections and switchgear become oversized, and Poltavaoblenergo will likely require a dedicated transformer. So for large industrial plants, we connect at 10 kV or 35 kV.

Connection Topology: How We Tie into Your Grid

The standard topology is a transformer-less inverter block connected to the MV bus via a dedicated transformer. For example, a 5 MW battery on the 10 kV side uses a 6.3/10 kV step-up transformer and a feeder circuit breaker. This is the cleanest approach for medium voltage.

If you have a 0.4 kV LV bus and the battery is under 500 kW, we connect directly behind the main LV breaker. That is the simplest, but it means the battery cannot export to the grid — it only offsets your own consumption. That is fine for most industrial users.

For a plant with multiple workshops, a common coupling at the main substation is better. We then coordinate the battery with your existing capacitor banks and transformer tap changers via an EMS. The EMS/SCADA we supply can also react to a signal from Poltavaoblenergo, if they ask for reactive power support — but that is a separate agreement.

We have seen cases where a poorly designed connection, e.g., a battery on the same transformer as a large motor, causes voltage flicker. That is why we always run a harmonic study and a transient stability analysis before finalizing the single-line diagram.

What Goes Wrong If You Size It Badly

Undersizing: you install 500 kW but your peak is 2 MW. The battery saturates, you still pay the demand charge, and the payback stretches to 8 years. Worse, the battery cycles daily to its full depth, and after 3 years you are replacing cells. We have seen that in the field.

Oversizing: a 5 MW battery on a site with a 1 MW average load. It charges for 5 hours and idles for 19. The capacity is never used, the inverter operates at 20% efficiency, and the capital cost is 3 times what is needed. In Kremenchuk, where a 5 MW system costs around 2-3 million USD, that mistake is painful.

The connection is a common failure point. If you submit an application to Poltavaoblenergo without a proper feasibility study, they may reject it or impose technical conditions (TU) that require expensive upgrades on your side. We handle that process: we design to the TU, and we know what Poltavaoblenergo expects because we work with them on multiple projects.

Why BESS Ukraine Engineering Group for Your Kremenchuk Project

We are a full-cycle EPC contractor: audit, design, supply, installation, commissioning, and service. We have delivered systems from 50 kW to 5 MW across Ukraine, and we know the local grid code in Poltava Oblast. We use LiFePO4 cells from CATL and other Tier-1 manufacturers, with liquid cooling and BMS that gives you cell-level monitoring.

Our outdoor cabinets are IP55/C4, built for the humid continental climate here — the Dnipro river proximity means corrosion is a real issue. We also offer 20/40 ft container solutions for larger capacities. We do not do residential systems — that goes to our partner SolarProm.com.ua.

Call us at +380 44 339-50-20 or email engineering@bess.com.ua. We will start with a site audit and a load profile analysis, and give you a concrete proposal with numbers.