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PV module price index: New dimensions, new problems

Over the past 12 months, PV panels have become larger and heavier thanks to larger wafer dimensions. In my view, there is one main reason driving this: to make production more efficient, and thus less expensive. Especially in times of scarce resources and high raw material prices, this seems the only way for manufacturers to make a profit without their cell and module prices rising excessively. But for planners, installers, and dealers, this creates new, sometimes intractable challenges.

A larger cell area also invariably entails a higher output amperage. Although cells are first cut in half or even smaller, operating currents of 12, 13 or even 18 amps are no longer a rarity. This poses a challenge in finding a way to connect strings that are compatible with the intended inverter. Often, new modules have such a high max current that two parallel strings can no longer be connected to a single input, which makes efficient utilization of the inverter difficult.

Neither their size nor weight of modules larger than 2m² allows single-person handling adhering to occupational health and safety measures. Products for ground mount applications, which recently have reached power ratings north of 550 W, leave mechanical handling as the only option. These products can only be safely installed with a suction lifter and robotic arm – provided there is no strong wind.

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Packing density and pallet weight is another topic that has received far too little attention. Increasing the glass area invariably increases the unit weight, especially in the case of glass-glass modules. At the same time, however, the frames are thinner – in the worst case, at the expense of stability. A pallet containing 31 modules at 32 kg weighs in at more than 1,000 kg. Freight forwarders like to apply surcharges to such loads, which makes transport even more expensive. Usually module crates are stacked two high in the truck or container, and then have to be unloaded and moved to a temporary storage facility – or worse, to a construction site. This is no longer possible with a pallet truck, hydraulic lift or other light equipment; heavy equipment must be available.

For rooftop modules, further optimization is needed to ensure trouble-free installation, ideally by a single person. A module area of 2m² should be the upper limit in any case, which is true with the current cell efficiencies for module types up to 400 W. If we move from the flat roof to the pitched roof segment, especially for small systems, aspects such as aesthetics and service life come into play. Black framed, or even glass-glass modules are a good choice. Since an individual weight of 25 kg should not be exceeded, the modules should have an output of up to 350 W. For smaller roofs on detached or terraced housing, panels in the classic 48- or 54-cell format – for example, measuring 1.5 x 1 meters at 300 W – are an option. This is because, as modules get larger, limited clamping area makes it increasingly difficult to design a sound substructure.

The ideal ground-mount module may be somewhat larger. For ease of processing, however, 2.5 m² and 30 kg should be the upper limit – a format of 2.3 x 1.1 meters and 550 W, for instance – at least for a mostly manual installation. On the shipping side, packing densities of 24 to 26 modules per pallet have a long and proven track record. Modules can also be transported upright – on a euro pallet or an industrial pallet, for instance. This enables efficient loading, but the individual weight should be kept below 900 kg. An option to remove individual modules without the package collapsing rounds off my wish list.

I reach these recommendations on the basis of the above mentioned criteria, all of which seem important to me. In the hopes of stimulating a long overdue discussion on these issues, I welcome other opinions.

Overview of the price points broken down by technology in June 2020,
including changes over the previous month (as of March 15, 2021):
Module class €/Wp Trend
Feb. 2021
Jan. 2021
Crystalline modules
Bifacial 0.33 -2.9% -2.9% Modules with bifacial cells, transparent backsheets, or glass-glass, framed and unframed
High efficiency 0.32 -3.0% 0.0% Crystalline panels at 330 Wp and above, with PERC, HJT, n-type, or back-contact cells, or combinations thereof
All black 0.33 0.0% 0.0% Module types with black backsheets, black frames, and rated power between 290 Wp and 390 Wp
Mainstream 0.23 -4.2% 0.0% Modules typically featuring 60 cells, standard aluminum frames, white backsheets, and 275 Wp to 325 Wp.
Low cost 0.18 +5.9% +12.5% Factory seconds, insolvency goods, used or low-output modules, and products with limited or no warranty
Notes: Only tax-free prices for PV modules are shown, with stated prices reflecting average prices on the European spot market (customs cleared)

By Martin Schachinger,

Source: pv magazine