Selection by parameters

Solar Panels for Roof

Solar panels on the roof: how many you need and which model to install

A rooftop PV system in Ukraine in 2026 is not about the "green tariff" (frozen since 2022, with Net Metering under discussion) but first and foremost about autonomy. A typical customer this year: a one- or two-story house of 100-200 m² in Kyiv, Lviv, Dnipro or Odesa region. Available roof area: 30-60 m². Our warehouse stocks mono PERC+ panels Veichi series VCS-108H (400 W), VCS-144H (500-555 W) and VCS-156H (585-600 W) at 20-22.5% efficiency (per the manufacturer datasheet).

The roof-capacity rule of thumb we use in-house. Pitched metal tile: one 555 W panel occupies ~2.6 m² of footprint with mounts and ventilation gaps. So 30 m² fits 11 panels (6.1 kW), 50 m² fits 18 panels (10 kW). This is the baseline for a south-facing pitch at 30-35°. East or west pitch cuts generation by 15-20%; north pitch we do not install at all.

First question we ask: 400, 500 or 600 W

Two factors: roof area and rafter load capacity. 400 W goes on small roofs (15-25 m²), old roofing with a 22-25 kg/m² limit, or balcony PV. 500-555 W is the baseline for a normal private roof of 30-50 m² (the most ordered class in our shop). 600 W is taken when the customer wants fewer joints or maximum watts per square meter, but the rafter capacity and the panel access route (1.13 × 2.47 m fits poorly through narrow stairs) must be verified.

What we always verify before ordering. First: roof orientation and pitch (south at 30-35° is the sweet spot, east-west loses 15-20%). Second: shading from chimney, trees, neighboring building between 09:00 and 16:00 – even one shaded panel in a string without optimizers can drag the branch down 30-50%. Third: roofing type (metal tile, standing seam, profiled sheet – no issue; natural tile or soft roofing needs special sealed mounts). Fourth: is a battery in the plan – without one the PV system runs only when the grid is up. Veichi warranty: 12 years on materials, 25 years linear performance (84.8% of nameplate after 25 years). We ship from Kyiv in 1-3 days.

How much energy a rooftop PV system generates in Ukraine

Baseline: 1 kW of installed capacity in Ukraine yields 1000-1200 kWh/year (south averages 1200, north 1000). Month by month: summer (June-August) 150-180 kWh per 1 kW; spring/autumn 80-120 kWh per 1 kW; winter (December-January) 30-50 kWh per 1 kW. Winter generation drops 4-5x due to short days and low sun angle. Plan around this rather than the annual average.

What you need besides panels for a rooftop system

  • Hybrid inverter: the heart of the system, converts DC to 220/380 V and manages the battery. We ship Veichi SISV or Deye SUN-K depending on the task.
  • LiFePO4 battery: storage for night consumption and blackout reserve. Pylon US3000C, Deye SE-G5.1 Pro, Volts.
  • Mounting system: aluminum profiles and clamps for your roofing. We pick this together with the panels.
  • Cables and protection: MC4 connectors, DC breakers, DC isolator. The small parts without which the system does not start.

Frequently Asked Questions

How many solar panels fit on a roof?

Work from the slope area: a 430 W module occupies about 2 m² (1722×1134 or 1762×1134 mm), a 620 W module about 2.70 m² (2382×1134 mm). Divide the usable slope area by that figure, then subtract edge setbacks and clearance around chimneys and dormer windows. A 40 m² slope realistically takes around 15–16 small or 11–12 large modules once setbacks are counted — the exact number comes from a layout on the actual roof, not from dividing areas.

How many panels are needed for 5 kW, and what will they produce?

Twelve 430 W modules give 5.16 kW; eight 620 W modules give 4.96 kW. In Ukraine each installed kilowatt yields roughly 1,000–1,100 kWh per year, so a 5 kW array produces about 5–5.5 MWh. The real figure depends on slope orientation and tilt: a south-facing slope performs noticeably better than east or west, and shading on even one panel drags down the whole string.

How much do roof solar panels cost?

Cost is set by the number of modules, not by roof area, so compare in currency per watt. Per watt, 400 W and 600 W modules sit in much the same corridor — brand, cell technology and efficiency (roughly 20–24% across the catalogue) affect price more than format does. Beyond the panels themselves the budget covers mounting hardware matched to the roof type, cabling, DC protection and the inverter; each model carries its current price on its product card.

Will the roof carry the weight of the panels?

A single module weighs 20 to 34 kg depending on format: 1722×1134 mm units are around 21 kg, 2278×1134 and 2382×1134 mm units 27.2–33.5 kg, and the largest 710 W modules 38 kg. An array of 12 panels comes to roughly 250–400 kg including rails and clamps, spread across the rafters rather than loaded at points. Snow and wind loading is a separate calculation: a panel acts as a sail, and the quality of the fixing into the battens matters more than the module weight itself.

What roof coverings can panels be mounted on?

The panel is the same in every case — only the mounting differs. Metal tile and profiled sheet take brackets that penetrate the covering with a sealed pass-through, standing-seam roofs take clamps with no drilling, and flat roofs take tilted frames set to a chosen angle. Bifacial modules mounted flush on a pitched roof add almost nothing: their advantage appears on a flat light-coloured roof or a ground mount.