Updates to this story
Global shipments of Photovoltaic (PV) Module Level Power Management (MLPM) system are set to explode over the next few years due their capability to apply Moore’s Law to the solar market.
It is forecast that that global MLPM installations are forecast to reach 7.8 Gigawatts (GW) by 2014, representing a Compound Annual Growth Rate of a massive 204.3 percent, rising from just 30 megawatts in 2009, according to iSuppli figures.
It had already been expected that the PV market would continue to gather pace at a fast rate, but the capacity for MPLM to apply Moore’s Law of exponential improvement means that this is only set to continue
“The Silicon Valley mantra of smaller, faster, cheaper hasn’t really applied to the Photovoltaic market—until recently, that is, when MLPM systems started being employed in solar installations,” said Greg Sheppard, chief research officer at iSuppli.
“Rather than reducing costs the way microchips do—by becoming smaller and faster—PV systems historically have achieved the ‘cheaper’ part of the equation by delivering on the three efficiencies of solar technology: efficient energy conversion, efficient manufacturing methods and efficient use of materials. However, the PV market is beginning to take a page from Moore’s Law with the arrival of MLPM systems.”
MPLM systems are becoming more favourable to manufacturers as they provide increased energy harvest at an individual module level rather than at a total module string level as is the norm.
This can mean that MPLM systems can harvest three percent to 20 percent more kilowatt hours of PV electricity during the course of a year, dependent on the location of installation and ‘shadowing conditions’.
It is noted that while MPLM systems cost significantly more per watt than standard inverters the gap in price is shrinking fast.
The main difference between micro-inverters and traditional inverters is that they function on a per-module basis rather than for a string of modules. Optimisers perform the Maximum Power Point Tracking (MPPT) algorithm and are used in conjunction with a string inverter that has removed the MPPT function to reduce costs.
It is also noted that MLPM systems are more chip intensive than that of regular inverters leading to a higher Bill of Materials. However such reliance on chis can actually help MLPM systems as they allow the driving out of costs, benefiting from functional integration and the lower power-draw due to the constantly evolving nature of chip-process technologies.
A further benefit of the MLPM system is that it offers greatly extended lifetime warranties over traditional inverters, lasting 15 years or more which is more linked to the payback lifetime of PV installations.
The US residential installation market has already begun picking up micro-inverters as they have proved to be easier to work with in terms of design a PV system for a specific size such as a roof.
It is thought that traditional string and central inverters will continue to be chosen over MLPM in many regions and applications such as utility-scale projects, but MLPM systems are expected to flourish elsewhere in the installation market.
Optimisers have apparently also found an interim market where MLPM systems are being used to boost the harvest of already installed module that have dropped below installation warranty levels.