Everything you need to know about solar plants

The price of a solar plant depends on several key factors:

• the type and capacity of the existing electricity connection
• the type and area of the roof or other mounting surface
• current and planned future electricity consumption

We approach every client - household or business - individually. After a site visit and consultation with our advisors, we prepare a concrete quote tailored to your needs and budget. Contact us for a free calculation.

The payback period depends on several factors:

• Total electricity consumption - higher consumption justifies a more powerful plant and a faster payback
• Geographic location - in Dalmatia solar irradiation is more than 20% higher than in continental Croatia
• Panel orientation and tilt - the difference between north and south exposure is up to 30%; the optimal tilt is around 30°
• Equipment quality - systems with power optimisers (SolarEdge) or micro-inverters (Enphase) achieve up to 15% higher efficiency than conventional string inverters

A plant with an average capacity of 6.5 kWp has a payback period of 6 to 8 years, with a panel lifespan exceeding 25 years.

The Environmental Protection and Energy Efficiency Fund (EPEEF) regularly publishes tenders and public calls for financial support for switching to renewable energy sources.

Energycom provides expert assistance and advisory services for EPEEF applications - from preparing documentation to monitoring tenders. Our experienced staff will guide you through the entire process and maximise your chances of obtaining grants.

We use only equipment from proven manufacturers, which means we pass on to the customer the manufacturer's warranty on panels and inverters of up to 25 years.

In accordance with the Construction Act, our workmanship warranty lasts 2 years. As a special benefit, we gift all households a one-year insurance policy covering natural disasters such as hail, lightning and fire.

All solar systems we install have real-time monitoring via a mobile or web application. Wherever you are, you can always see how much your plant is producing and manage its operation.

As an additional option we also offer a total consumption meter, which gives you an overview of the production-to-consumption ratio and the ability to optimise plant operation for maximum savings.

After connecting a solar plant, electricity billing changes to the net metering model. It is important to distinguish between two models:

• Household model - a more favourable billing arrangement provided that the household takes more electricity from the grid annually than it feeds into it
• Business model - applies if the household feeds more energy into the grid than it consumes, or for all business entities

Detailed information about the new billing process is available on the HEP website, and our advisors will be happy to explain all the details tailored to your situation.

We offer installation on almost all types of surfaces:

• Pitched and flat roofs - covered with tiles, sheet metal or other roofing material
• Car parks and canopies - ideal for commercial buildings and large areas
• Ground surfaces - solar farms and larger installations

For each type of surface we have developed appropriate substructures that ensure safe and long-lasting installation without damaging the load-bearing surface.

All solar systems convert sunlight into direct current (DC) via the photovoltaic effect. An inverter converts this into alternating current (AC) for use in the home. There are three main system types:

• On-Grid (grid-tied) system - connected to the public grid; surplus energy is fed into the grid and any shortfall is drawn from it. The most popular and cost-effective type for most households. Cannot operate during a power outage.
• Off-Grid (island) system - completely independent of the public grid; requires a larger battery system to store energy for 2 or more days. Ideal for remote areas without a grid connection.
• Hybrid system - combines the advantages of both; connected to the grid but also has battery storage. Can operate during a power outage and stores or feeds surplus energy into the grid.

Solar panel efficiency indicates what percentage of the solar irradiation falling on the panel is converted into electricity. Thanks to advances in technology, the average efficiency of modern panels has risen from the former 15% to more than 22% today.

Efficiency is affected by:

• Cell type - N-type cells (TOPCon, HJT, IBC) offer higher efficiency and less degradation than conventional P-type cells
• Temperature - panels are more efficient at lower temperatures; high summer temperatures slightly reduce output
• Shading and orientation - partial shading can significantly reduce the output of conventional string systems, while systems with optimisers minimise this

The panels we install - Trina Vertex S+ N-type - achieve an efficiency of 22.5% with a 30-year linear degradation warranty and retained capacity of at least 89.4% at the end of the warranty period.

A photovoltaic module consists of the following key components:

• Solar cells - the heart of the panel; made of semiconductor material (usually silicon) that generates electric current when exposed to sunlight. The modern standard is monocrystalline half-cut N-type cells with an efficiency of 21-22%.
• Front protective glass - 3.2 mm tempered glass protecting the cells from mechanical damage and weather while maintaining high transparency
• Back sheet - a plastic or glass layer providing electrical insulation and moisture protection
• Aluminium frame - provides mechanical rigidity and enables simple installation on the substructure
• Junction box - contains protective diodes and connection cables; ensures safe and reliable panel interconnection