How the solar plant data are computed

Yield and tilt

PVGIS 5.3 (PVcalc, SARAH3 database) of the European Commission’s Joint Research Centre: 1 kW peak of crystalline panels on a free-standing frame, 14% system losses. PVGIS itself finds the tilt and azimuth with the highest yearly yield. The request is for the place’s coordinates rounded to 0.01° (≈ 1 km), so neighbouring places may share values. A 5, 10 or 15 kW plant’s yield is the yield of 1 kWp times its power.

Comparisons and ranks

The median is the middle value among the oblast’s (or rayon’s) places that have PVGIS data; the same month by month. The rank is the position by yearly yield among those places (equal values share a rank). «The nearest bigger centre» is the nearest rayon or oblast centre with a larger population in GeoNames. Distances are straight-line.

Row spacing

A table of two panels in portrait (the most common class of the catalogue’s checked panels), tilted at the PVGIS optimum. The row pitch is the shortest distance from one row’s front edge to the next one’s at which the rows do not shade each other from 10:00 to 14:00 solar time on 21 December (the lowest sun of the year). GCR is the share of the ground under panels: the table’s length along the slope over the pitch. The free «Tilt angle and row spacing» calculator and the designer compute it the same way.

Snow and wind

Characteristic S₀ and W₀ under DBN V.1.2-2:2006 with amendments No. 1 and No. 2 — for the regional centres of the Solispec engine’s table. For a place we take the nearest regional centre the way the designer does, and give the distance to it; where the place lies outside the outline the designer uses to match a site to a centre, the centre is the nearest by distance. Above 500 m a.s.l. the values grow — the calculators account for the site’s altitude.

Climatic region and T_min

The region and the absolute minimum air temperature follow DSTU-N B V.1.1-27:2010, table 1 and figure 1 (for regions I and II the colder end of the range). At the lowest temperature the panels’ open-circuit voltage is highest — it decides how many panels one string can take (DSTU HD 60364-7-712).

The 10 kW frame example

The ground frame the Solispec engine designs for the loads of the nearest regional centre: panels of the catalogue’s most common class, two-row tables, bored piles. The steel mass, the number of piles and the approximate cost of materials come from the same calculation as in the designer; prices as of the date in the calculation.

Data and licences

Places, coordinates, elevation and administrative divisions — GeoNames (CC BY 4.0); we filtered the places, chose the Ukrainian names and corrected the rayon names. Yields — PVGIS © European Union, 2001–2026. Norms — DBN V.1.2-2:2006, DSTU-N B V.1.1-27:2010.

Poland, Germany, Spain

For the main cities of Poland, Germany and Spain (GeoNames: every one with at least 50,000 people and every capital of a voivodeship, Land, autonomous community or province) the yield, tilt and azimuth come from the same PVGIS 5.3 with the same parameters, and the row pitch from the same table geometry. They are compared with the median of the country’s main cities and with Kyiv; the rank is by yearly yield among the country’s cities. The pages are in the country’s language, Ukrainian and English.

Snow, wind and the climatic region are not shown for these cities: the Solispec engine computes loads by the Ukrainian DBN V.1.2-2 only, and abroad they follow the national annex to the Eurocode — in Poland PN-EN 1991-1-3 and PN-EN 1991-1-4 with the NA, in Germany DIN EN 1991-1-3/NA and DIN EN 1991-1-4/NA (Schneelastzone, Windzone), in Spain CTE DB SE-AE and UNE-EN 1991. For such a site the characteristic S₀ and W₀ are entered in the designer by hand, and an engineer checks the calculation.

Preliminary calculation: a design needs an engineer’s check.