Do I need to insure my solar PV system??

The insurance of solar PV systems is an individual decision. If you have taken out a loan for the system, you will probably need to insure it. In general, you need to decide what the risks are and whether this will give you more peace of mind. For example, we rarely insure our systems.

As far as we know, currently only Unica insures solar PV systems and power plants.

Under the insurance “All risks of solar PV and thermal solar power plants” all types of solar PV and thermal solar power plants can be insured, owned by legal entities and individuals.

The object of the insurance are operational technical facilities for electricity generation, thermal installations for water heating and other additional devices.

The coverage is based on all risks. Any unforeseen or sudden loss, damage or damage to the objects or parts of them for any reason is subject to compensation, except for the risks excluded in the general conditions of the insurance.

Can I install a solar PV system myself?

The ready-made configurations of solar PV systems that we offer include connection diagrams that make their installation easy to perform by the customer. Off-grid systems, depending on their size, require basic knowledge of electrical engineering and their self-assembly is completely acceptable. It is important to follow the attached diagrams and instructions for installation and use of the separate components.

In on-grid systems, the requirements for compliance with security conditions are slightly different. Relevant protocols and declarations of conformity by technical persons must be submitted for connection to the network.

What is the technical warranty of the solar PV modules ?

The technical warranty of the solar PV modules, which we integrate into our solar PV systems is guaranteed by Munich Reinsurance Company:

Гаранционен период на панелите
A chart of the length of the warranty period of the CSUN solar PV modules

The modules come with a 12-year technical warranty. Additionaly, there is a 12 year guarantee for maintaining 90% of the power capacity of the modules and a 20 year guarantee for 83% of their power capacity.

The solar PV modules, which we integrate into our ready-made solar PV systems and the off-grid systems which we design come with a 10 year tehnical warranty and 25 years for maintaining 80% of their power capacity.

Detailed information about the technical characteristics of the solar PV panels which we offer, can be found in our online store at

If the location does NOT have access to an energy source other than a solar PV system, can I use energy appliances with a power capacity larger than that of the system ?

Not possible, unfortunately. It is for this reason that when calculating the power of an off-grid system, all electrical appliances, including their nominal power capacity and hours of usage, are taken into account. If you turn on a device that consumes more than the maximum power of the inverter, it will simply report an error and stop. If the overload is very high, there is a risk for the inverter fuse and even the inverter itself burning out.

I have a house and I would like to power it with solar energy entirely. How many solar PV modules do I need?

With off-grid solar PV systems households rely entirely on the electricity they produce. These systems are most often used when there is no access to the grid or it is very expensive to connect to it. Or you aim to avoid the lengthy procedure that comes with getting connected to the grid. This type of solar PV system can have all kinds of power capacity. An off-grid system can power from a simple lamp to an entire production base.

The sizing of off-grid systems is a complex process and depends on many factors. It depends on whether the system will be used all year round or seasonally. It depends on the power of the appliances, how many hours a day they will be used, the location of the system and many more.

In order to calculate exactly what kind of off-grid system you need, you must first gather information about the appliances you will use and their unit capacities. Estimate how many hours a day they will work and then send us an inquiry so that we can offer you the best solution.

Contact us for a free consultation.

I have my eye on a plot of land with a dilapidated house/ without a roof, with several dilapidated walls. If I manage to restore it with a few beams and a tin roof, and I find the lot number for electricity consumption, will it be legally eligible for solar PV system construction?

For the construction of a solar PV power plant on a dilapidated house, you will most likely receive a grid connection refusal. Although it appears on the municipal plans, you need to bear in mind that a person from EVN does a site inspection and takes pictures of the property and buildings. That is, if the house is visibly dillapidated, it will not be recognized as a building. If you restore it so that it is intact, in our opinion, you will not have any problems.

If I sign a PPA, the contract will be valid for 15 years, but feed in tariffs will be changed annually or will the tariff which was set at the time of contract signing be valid for the duration of the contract?

The feed-in tariffs for solar PV energy are determined annually by a decision of the Energy and Water Regulatory Commission (EWRC) on July 1. The new tariff applies to all new investments in solar PV systems which are connected to the grid after this date. Its value is fixed for the term of the Power Purchase Agreement (until 2035). That is, at whatever price you sign a contract, it will remain the same until the end of 2035.

Is it possible for feed-in tariffs to be cancelled for solar PV systems up to 30kWp?

The feed-in tariffs for the purchase of energy from solar PV systems are determined with a decision of the Energy and Water Regulatory Commission (EWRC) every year on July 1 and they are fixed for the term of the Power Purchase Agreement, but not longer than 31.12.2035. After this date, all solar PV plants start selling the electricity produced on the electricity market, as all power plants over 30kWp trade the produced energy at the moment.

There are constant rumors about what will happen to preferential prices. Our advice is not to believe everything you hear, because the people who really know what will happen are very few and work in EWRC and do not have the habit of exporting such information.

Can I use a three-phase inverter with a single-phase grid?

No, unfortunately, it is not possible to connect a three-phase inverter to a single-phase network. Only the opposite scenario is possible – connecting a single-phase inverter to a three-phase network. The three-phase inverter will not start without seeing three phases and a “zero”.

You could contact us for a free consultation.

What is the total value of the investment in a 30kW solar PV system and what are the associated monthly costs and revenues from the system?

The value of the investment in a 30kW grid-connected solar PV power plant depends on a number of factors. It depends on the type of equipment, the location of the property, as well as the type of structure on which the panels will be mounted. Equipment costs also often change depending on supply and demand at a given time. At the moment we offer design, delivery of the equipment, construction and commissioning of 30kWp at a value between 40,000 and 45,000 BGN incl. VAT.

The revenue from the investment depends mainly on the feed-in tartiff at which the respective Power Purchase Agreement has been signed. The tariff is determined with a decision of the EWRC every year on July 1. It is fixed for the term of the Purchase Agreement, but not longer than 31.12.2035. After this date, all solar PV plants start selling the produced electricity on the electricity market.

As of 1-07-2021, the tariff for feeding energy from a power plant with a capacity of 5 to 30 kilowatts is BGN 160,11 per MWh (excl. VAT). By law, EDCs are required to purchase the entire amount of energy produced by these power plants until reaching 1 380 hours of annual system operation time. A 30kW system in Bulgaria produces between 35 and 40MWh per year, which is within the allowable production for purchase at a feed-in tariff.

0.03 x 1 380 = 41.40 mWh

This production generates between BGN 6,000 and 6,500 per year for the investor. The revenue varies on a monthly basis, depending on the season and the intensity of sunshine in a given month.

The only costs are fees and taxes on these revenues. The system does not require any technical support. It needs regular cleaning of the solar panels to ensure maximum efficiency in their operation.