Frequently asked questions


What does a PV plant consist of?

The main components of a PV system are:

  • PV modules that convert solar energy into electrical energy;
  • mounting structure for installing the modules;
  • inverters that convert the DC voltage from the modules into AC;
  • cables. connectors;
  • distribution and combiner boxes;
  • earthing and lighting protection systems.
Is my roof suitable for installation of PV modules?

The photovoltaic plant can be installed on all types of roofs – sloping, flat, even round, regardless of the roofing (tiles, bitumen, LT sheet metal, etc.).

How big should the rooftop be in order to put PV modules on it?

1 photovoltaic panel has an area of 2.60 sq.m. There is a difference, however, whether the roof is pitched, flat and with what exposure it is.
We give you an example of the area required for the following systems:
For a 5kW system (about 9 panels – 550 W):

  • pitched roof – according to the specifics of the pitch, the size may vary, you need about 40 sq.m. rectangular area
  • flat roof (when installing the panels at a 20° slope) – 60 sq.m

For a 30kW system (54 panels):

  • pitched roof – 165 sq.m
  • flat roof (when installing the panels at a 20° slope) – 220 sq.m
Can I sell the electricity?

You can build a PV plant and either sell all the energy produced or priority consume the produced energy and only sell the excess to the grid company.
Building such plants is accompanied by coordination procedures and documents by the EDC and the municipality. More about the procedures can be found here here.

Can I heat water with PV modules?
Solarity BG has develop a PV system boiler in which you can use solar modules to heat water.
More information can be found here.
What kind of documents are needed for selling the electricity?
The first step in the procedure for building a power plant for the sale of energy is to obtain an opinion on the conditions and manner of connection from the relevant for your region electricity distribution company. For this purpose, it is necessary to attach an up-to-date sketch and a document of ownership of the property.
Applications can be found here:
Application for research – Електроразпределение Юг ЕАД
Application for research – Електроразпределителни мрежи Запад АД
Application for research – Електроразпределение Север АД

In order to build an FPP entirely for the sale of energy at a preferential price, you must meet the following conditions:
FEC to be installed up to 30kWp installed power and to be installed on the roof;
The property should be in an urbanized area;
The property should have a legal building, which should be connected and have an open account to the energy distribution company.

You can find more about the whole administrative procedure here.

How long is the warranty of the PV modules?

Most PV modules have a 10-year full warranty and 10 years warranty on 90% performance and 20 year warranty on 80% performance.

Are the PV modules hail resistant?

Yes. The PV modules are made with special tempered glass which is hail resistant. They should meet certain international standards, namely IEC-61215 for polycrystalline and monocrystalline panels and IEC-61646 for thin-film panels. Upon certification the PV modules undergo a hail impact test where they are pelted with 25 mm (7.53g) hailstones at a speed of 23 m/s.

What is the purchase price for the electricity from a PV plant?

The current preferential prices for the purchase of energy from FTPP, effective from 01.07.2022, are:
For FTPP up to 5kW, installed on roofs and facades – BGN 201.35/MWh, with a net specific production of 1,380 kWh/kWp.;
For FTPP from 5kW to 30kW, installed on roofs and facades – BGN 168.24/MWh, with a net specific production of 1,380 kWh/kWp.

Frequently asked questions


What maintenance does a PV plant need?

Information I need after I have a system.

How much electricity will the PV plant produce for 1 year?

The annual performance of a photovoltaic plant depends on the equipment installed and the overall project implementation.
For comparison:

  • 5kW PV plant will produce for 1 year around 7MWh.
  • 15kW PV plant will produce for 1 year around 21MWh.
  • 30kW PV plant will produce for 1 year around 42MWh.
Should I insure the PV plant?

Yes. Insurance of the plant is crucial to protect your investment. The insurance must cover both natural disasters (floods, fires, earthquakes, lightning strikes), as well as theft, intentionally caused damage to equipment or plant and etc.

How much are the operational costs?

Information I need after I have a system.

Can I monitor the performance of the PV plant remotely?

Yes, with the help of APC – an energy monitoring and management system. You can see more details here.

Can I store the energy?

Information I need after I have a system.


Flexible solutions for roof photovoltaic installation


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