Analysis: The power-game between the large solar panels

Thanks to innovations, the nominal power of solar panels has steadily increased over time. Customers of panel manufacturers expect improved module capacities every year. But the development has its limits and they now seem to have been reached. But the manufacturers are not easy to catch. The result: the development of 'Incredibly Large Panels'. But is the market ready for that?

It used to be clear: all panels were fairly the same size and the panel power was a good measure of how far cell technology had come. Everything was standardised and the economies of scale for the entire industry kept costs down. This also allowed other manufacturers in the PV chain to standardise their products. For example, the optimiser and (micro)inverter manufacturers were able to deal with a small range of products for the entire market, and the same was true for the manufacturers of mounting material.

Two camps That time seems behind us. In the struggle to find new ways to develop ever more powerful modules at lower system costs per watt peak, the answer came from China: We make the cells and the panels bigger. There will be modules of more than 400 watt peak. After the initial excitement, the realisation also descended that the panels are not getting better: they are only getting bigger!

Two camps have now emerged. The 182 millimetre camp is led by LONGI Solar, JA Solar, Tongwei and Jinko Solar, while the 210 millimetre camp is led by Trina Solar and Risen Energy. Power ratings range from 320 watt peak to 800 watt peak, but power density only varies from 193 to 212 watt peak per square meter. This has to do with the fact that the 'dead areas', such as edges and spacing between cells, make up a relatively smaller part of the module.

Jumbo Blue is the elephant among the panels JA Solar is now leading the way with the Jumbo Blue: with a size of 220 millimetre’s by 180 millimetre’s and a power of 800 watts peak, this panel can indeed be called the elephant among the panels. But how practical are these panels really?

It seems that the module manufacturers have decided that the cost and convenience benefits of standardisation of formats may disappear. Instead, they follow a product strategy to scale up panel sizes to increase power.

Placement in sea containers fully thought out China seems to be focusing on utility-scale systems, and don't blame them, because that is the largest market worldwide. Only one thing matters in this market: the lowest possible costs and the highest possible yield. Normally, the product range from China is quite uniform, but in this area there is clear competition between the two formats.

LONGI Solar is campaigning hard to let it be known that their system leads to lower balance of system costs. These are all the other costs that come with installing PV, such as labour, assembly and construction. The expansion in China is mainly done in new factories where everything has been adapted to the new formats.

With the current scarcity of sea containers, the placement of the modules in these containers has also been fully thought out. For example, 'Camp 182' stacks their modules upright on the long side so that two pallets can be stacked on top of each other. At 'Camp 210' the modules are on their short side and the pallets cannot be stacked. Both camps claim to have the lowest transport costs. A very important factor, given the very high costs for container transport today.

Immense consequences for the entire PV chain Unfortunately, the module manufacturers in China do not fully understand the consequences for the PV chain as for suppliers of inverters, optimisers and especially mounting material, for which these decisions have immense consequences. But it also has an impact on glass, junction boxes and cabling. Modules used to give 9 amperes and now it can go up to no less than 18 amperes, then it is good to realise that you are dealing with greater cable losses: they do not scale linearly, but square with the current.

And then we haven't even talked about the installer himself. Then there is the weight of 23 kilos, which often has to be lifted by two people. For these modules you usually have to be two. That is why in my opinion it will never be possible to make them popular for roofs, this will be a system for the ground.

Effect of the wind load In the future, will the industry move away from the format war and settle for a few standardised formats for different applications? It's hard to predict what's going to happen, but I'm sure some people, who make mounting hardware for these modules, for example, are hoping for that.

Also, the last word has not yet been spoken about the effect of the wind load on large panels. The '182 millimetre camp' has all kinds of wind load tests performed in which their panels come out better than the 210 millimetre panels. They do not name these panels as such, but subtly describe them as oversized. When I see these wind load comparison experiments, I wonder why we don't see the difference between 182 millimetre modules and the current 166 millimetre or 158.75 millimetre based modules. Wouldn't the current modules be more favourable?