Wagon Slovakia Košice wanted to produce its own electricity, keep it on site and stop paying peak prices for the rest. We built a 71.4 kWp photovoltaic system with a 100 kW / 229 kWh VisionBattery storage system that also runs price arbitrage: it charges when electricity is cheap and discharges when it is expensive.
Client story · Photovoltaics and battery storage
Battery storage and photovoltaics for Wagon Slovakia Košice
Solar on the roof and a 229 kWh battery that buys electricity when it is cheap and uses it when it is expensive.
71.4 kWp
Photovoltaics from 168 panels
229 kWh
Battery storage, 100 kW of power
80 MWh
Solar electricity a year
About the client
WAGON SLOVAKIA KOŠICE, a.s. was founded in 1995. It runs restaurant cars and mobile bars, provides accommodation in sleeper and couchette cars and offers other on-board services. Its team of more than 250 people looks after passengers every day on trains in Slovakia, the Czech Republic and Austria.
A company that size uses electricity every day at its base in Košice. The aim was simple: make a large part of it on site, store what is not used straight away, and cut what has to be bought from the grid.
One system, three jobs
Produce. 168 panels of 425 W make up a 71.4 kWp photovoltaic system. Fronius Eco inverters turn their output into electricity the site can use.
Store. A 100 kW / 229 kWh VisionBattery system, battery and power conversion system (PCS) in one enclosure, keeps the surplus for the hours when the panels produce little or nothing.
Buy low, use high. The battery runs price arbitrage. When the electricity price is low, it charges from the grid; when the price is high, it discharges and covers the site’s consumption. The difference between the two prices is a saving on every cycle, even on days with little sun.
What we installed
- 168 photovoltaic panels, 425 W each
- 71.4 kWp total output
- Fronius Eco inverters
- VisionBattery storage and PCS
- Battery storage: 100 kW / 229 kWh
- Price arbitrage: charge cheap, discharge expensive
- Built in 6 months
The figures
80 MWh
Expected solar production a year
40 %
Expected annual saving on energy costs
4 years
Expected payback
Expected values from the project calculation. Actual results depend on the consumption profile and on how far apart low and high electricity prices are.
Photo from the project
The VisionBattery storage enclosure at Wagon Slovakia Košice.
What it means for your site
Photovoltaics alone lowers the bill during the day. Adding storage moves that energy into the evening and the night, and with price arbitrage the battery keeps saving money even when the sun does not shine: it fills up when electricity is cheap and supplies the site when it is expensive.
Planning the panels and the battery as one project costs less than adding storage later, because the inverters, the grid connection and the permits are sized for both from the start.
Questions owners ask us
Electricity prices change during the day. With price arbitrage the battery charges in the cheapest hours and discharges in the most expensive ones, so the site buys less energy at high prices. It works best with a dynamic or spot-based tariff. Part of the capacity can stay reserved for your own solar surplus.
If you are planning both, yes. One project means one design, one grid connection request and inverters sized for the full system. Storage can also be added to an existing installation later.
This one took six months from start to commissioning. You have a sizing proposal within a week of sending us your consumption data. The rest depends on permits and the grid connection.
Free sizing proposal
See what solar and storage would do for your site
Send us your annual consumption and tell us about your roof. We come back with a configuration and a price.
✓ We reply the next working day
✓ Sizing proposal within a week
✓ No obligation, no sales pressure
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