Bart Szablowski

Gross or net: why two shop prices are not comparable Which solar panel shops print prices with VAT and which without, market by market, and how to turn any shop price into a figure you can compare. How big are modern solar panels Length, width, weight, watts per square metre and per kilogram for every module in our catalogue, and what the common formats mean for roofs and lifting. How many solar panels does a household need Yearly kWh, your site's yield in kWh/kWp and one module's power give the module count. Worked for Warsaw, Munich and Seville, with the catalogue spread. How to read a solar panel datasheet A field by field guide to the solar module datasheet, with typical values from our catalogue and three arithmetic checks that catch a figure that is wrong. Is a bifacial solar panel worth it? When the back of a bifacial module pays off, ground mount or roof, how bifaciality factors are spread in our catalogue and what bifacial modules cost per watt. Pallet or single module: which is cheaper per watt? How much cheaper per watt is a pallet or multipack of solar panels than a single module? Live shop offers, same shop and same module, with counts. How to choose panels for a hot climate For a hot climate, compare the temperature coefficient before NOCT. A worked example, catalogue spreads and what a better coefficient costs in shops. How to choose panels for a small roof or a balcony On a small roof or balcony, module size sets how many whole modules fit. A worked example with catalogue formats, efficiency bands and Polish shop prices. Product warranty versus performance warranty The product warranty covers defects, the performance warranty a power schedule. How long each runs in our catalogue, by cell technology and maker. The same module, different shop: how much prices differ How far apart shop prices sit for the exact same solar module, measured on live offers before VAT, and what stock status and shop habits add to the gap. Solar panel price per watt by market What a rooftop solar module costs per watt before tax in each market, from live shop offers, with the spread inside each country and what it means for a buyer. STC power versus what you actually get Why a solar panel rarely delivers its rated power, and how much heat, weaker light and power tolerance take away, from catalogue figures and PVGIS. TOPCon or PERC when buying today? TOPCon or PERC? Efficiency, heat losses, warranted ageing and price per watt compared across our module catalogue and live Polish shop offers. Voc, Isc and your inverter: reading voltage and current Where Voc and Isc sit on a datasheet, how far cold raises the voltage and heat the current, and which inverter limits they are checked against. Warranty terms across manufacturers Which manufacturers state the longest product and performance warranties in our catalogue, counted per company with a minimum number of datasheets each. Which power class is cheapest per watt Does a watt cost less on a bigger solar module? Live shop offers split into five power classes, in Poland and across markets, with spreads and shop counts. Cell technology and the temperature coefficient Datasheet temperature coefficients grouped by cell technology across our catalogue, with medians, spreads and what the gap is worth on a hot roof.