Chinese PV maker JinkoSolar has delivered its answer to the problem of rooftop solar shading with the Australian launch of its JinkoMX module series, which use “DC optimiser” technology from US company Maxim Integrated Products.
The panels, launched in Australia last week, incorporate a chip from Maxim that allows them to generate more electricity than standard modules under “non-ideal” conditions, such as when nearby buildings or trees cast a shadow over part of a rooftop solar system.
Each module has three maximum power point tracker (MPPT) channels, so that if any single cell develops a problem then only one-third of the panel is affected, not the entire panel. Conventional solar panels, meanwhile, operate at the power level of the weakest cell.
“Maximum point power tracking (MPPT) is performed at the cell string level. By replacing each diode with an MPPT tracking device, the on-off response to performance mismatch is eliminated,” the company says.
“Each cell string contributes maximum power without interfering with the power production capability of the others. This enhanced degree of flexibility leads to increased energy production, eliminating performance loss due to module mismatch, degradation, soiling, localized shading, and row shading loss mechanisms.”
The technology rivals that of micro-inverters, which are likewise used to improve the yield of a rooftop solar system in shaded conditions and/or situations where one or several panels are producing less power than others.
Like microinverters, power optimisers promise overall higher energy yields than string inverters, as well as module-level performance monitoring and superior performance where shading is an issue, as Solar Choice points out in this useful explainer.
Also like micro-inverters, the JinkoSolar MX module offers installers more flexibility on how panels are arranged on a rooftop, allowing for multiple orientations, module power ratings, and unequal string lengths in parallel, without losing energy.
Unlike microinverters, power optimiser systems still use a central string inverter, which means that they still have a potential single point of failure.
“On a micro-inverter system, if one microinverter (or panel) fails, the rest of the system will continue generating electricity as per usual. By contrast, if a conventional string inverter goes down, it takes the whole system with it – producing no electricity at all,” says Solar Choice.
According to JinkoSolar, however, its maximiser panels can achieve a yield of up to 10 per cent higher than microinverter panels and up to 30 per cent more than conventional modules in rooftop applications.
“The JinkoMX module is the next generation of optimisation,” said JinkoSolar’s Australian business development manager Daniel Kogoy, in a statement.
“By replacing the bypass diodes with cell string optimisers we see optimisation that is 3 x more granular than first generation optimisers and micro inverters.
“Hot spots, a cause of long term panel degradation, are completely eliminated,” he said.
Kogoy says the JinkoMX module is as easy to install as a conventional solar module and is inverter agnostic.