500kWh Battery Storage Project in Bulgaria

A solar and battery storage project near Veliko Tarnovo, Bulgaria is now in operation, combining approximately 200kW of solar PV with a 500kWh battery energy storage system.

The installation uses 333 Bluesun 600W solar panels, giving the PV array a total capacity of about 199.8kW. Two 100kW Bluesun inverters manage the power conversion, while the 500kWh battery stores solar energy for later use.

This is a practical commercial solar-plus-storage project: generate power during the day, store part of it when needed, and use the battery to make the site’s energy supply more flexible.

Watch the Bulgaria Project Video

The video gives a closer look at the installed battery system and solar project, together with feedback from the site.

Why Pair 200kW of Solar with 500kWh of Battery Storage?

Solar panels and batteries do different jobs.

The roughly 200kW PV system determines how much solar power can be generated at a given time, while the 500kWh battery determines how much energy can be stored for later use.

During sunny hours, solar power can supply the site’s electrical loads directly. When generation is higher than immediate demand, available energy can be stored in the battery instead of being used only at the moment it is produced.

The stored energy can then be used later in the day when solar production drops or when the site needs additional power.

This makes the solar installation more useful across a wider part of the day rather than limiting its value to daylight hours.

A Longer Storage Duration for Commercial Use

The project combines 200kW of inverter power with 500kWh of battery capacity.

That does not mean the battery will always discharge at the full 200kW. Actual battery output changes with the site load and the selected operating strategy.

For example, if the battery were supplying an average load of 100kW, 500kWh of nominal storage would represent several hours of operation before allowing for usable depth of discharge and system losses.

If the load is lower, the operating time becomes longer. If the load is higher, the battery discharges faster.

This is why commercial battery systems should be sized around the actual load profile rather than battery capacity alone.

Solar Generation and Storage Working Together

The project uses 333 high-power 600W solar modules, providing approximately 199.8kW of installed PV capacity.

Two 100kW inverters handle the solar power conversion and help match the system to the commercial site’s power requirements.

Adding the 500kWh battery gives the owner more control over that solar energy. Depending on the operating settings, stored energy can be used for:

• Increasing on-site use of solar power
• Supplying loads after solar production falls
• Reducing dependence on grid electricity during selected periods
• Smoothing short-term changes in site demand
• Providing additional energy flexibility for daily operation

Rather than treating the PV system and battery as two separate pieces of equipment, the project uses them as one energy system.

Why the Actual Load Matters

A 500kWh battery is not automatically the right size for every 200kW solar project.

One factory may use most of its solar power during working hours and need only limited storage. Another site may have significant evening demand and benefit from a larger battery.

Before selecting the battery capacity, it is useful to look at:

• Daytime and evening electricity consumption
• Maximum site load
• Solar generation during different seasons
• How much solar energy is normally unused or exported
• The desired battery operating time
• Local electricity prices

These numbers provide a much better starting point than simply choosing a battery according to the solar system size.

From Solar Power to Better Energy Management

What makes this Bulgaria project interesting is not one individual component. It is the way the equipment works together.

The solar array produces the energy, the two 100kW inverters manage power conversion, and the 500kWh battery gives the site the ability to store part of that energy instead of using it immediately.

For commercial users, this flexibility can be just as important as adding more solar panels. The goal is not only to generate renewable electricity, but also to make better use of it throughout the day.

For more battery configurations for residential, commercial and industrial projects, explore Bluesun’s lithium solar battery solutions.