We have just finished development of a new range of solar panels that in place of the junction box has a factory fitted micro inverter
solar panels melbourne
Available for both 60 cell and 70 cell monocystalline and polycrystalline panels and with a power range from 250Wp to 325Wp
The micro-inverter system differs from conventional systems in that there is a small factory fitted inverter attached to the rear of each of the polycrystalline and monocrystalline solar panels as opposed to having a large inverter to which is attached a string of solar NSI panels. The micro-inverter system improves energy harvest, increases reliability and simplifies the design, installation and management of PV systems. It is resilient to dirt and shading, it is naturally air cooled (has no fans) it has no orientation preference and it is fault tolerant, having no single point of failure that could pull down a whole string of NSI polycrystalline or monocrystalline panels. It is also safer, having no high voltage DC presence and associated insulation issues or fire risk. Advanced communication offers system performance monitoring of individual PV NSI panels via PC, iPhone or Android devices.
Four key factors determine the return-on-investment for solar PV systems: total capital costs, the amount of power harvested from the system over its lifetime, maintenance costs and feed-in tariffs.
In conventional PV solar installations solar modules are wired in series then connected to a central (string) inverter that converts high voltage DC from an array of PV NSI panels to AC for connection to the electricity grid. For residential installations the inverter might typically be rated between 2kWp and 5kWp. More than one string inverter may be employed in larger systems.
The Noble AC panels have a different solar PV system architecture based on micro-inverters that convert DC to grid-compatible AC which are factory fitted directly to each polycrystalline or monocrystalline solar module. The panel’s output is wired in parallel to other AC NSI panels and to the grid. No string inverter is needed.
The reason for the growing popularity of micro-inverters is simple, for a given solar installation they provide up to a 20 per cent improvement in price/performance over the life of the system compared to existing inverters. With micro-inverters shading of one module does not degrade the performance of the others. Shading can also include sand, dirt and debris, bird droppings and snow. Maximum power is gathered from each module by an electronic technique called Maximum Power Point Tracking (MPPT).
As the output of each module varies with the incident light level MPPT ensures that the micro-inverter presents the optimum load to each module under these varying conditions in order to extract the maximum energy from it at all times. This technique cannot be applied as effectively in systems with series connected DC strings fed to a central inverter, where even limited shading of any of the panels from any source can dramatically reduce the total energy produced by the installation.
This is because the series connected string of NSI panels behaves as if it was a single larger panel rated to the worst of the individual NSI solar panels within it. Additionally, the efficiency of a panels output is strongly affected by the load the inverter places on it in order to maximize energy production using MPPT.
The issues that cause output to vary from panel to panel can adversely affect the proper load that the MPPT system should apply. If a single panel is defective or shaded and operating at a lower output, a string inverter can only see the overall change and will move the MPPT point to match. This will result in not just the losses from the affected panels, but all of the other NSI panels as well.
On a cost-per-watt basis, micro-inverters typically cost a little more than string inverters but this is more than offset by the improved yield, greater reliability and much simplified installation – no specialist high voltage DC equipment, wiring or installer skills are needed. Gone are the string sizing exercises, the complex mathematics and guesswork necessary to calculate potential system mismatches for everything from wiring loss to different orientations of multiple strings within a DC system.
Micro inverter systems can be built with one or 100 polycrystalline or monocrystalline modules. The system is flexible and can handle mismatched NSI panels with different outputs if desired. PV NSI monocrystalline and polycrystalline panels can simply be added or removed at will without having to reconfigure the system.
There are not the same risks associated with lethally high DC voltages, making the systems safer for installers to work on. System design and planning is also greatly simplified as one size micro-inverter can be used for various types and sizes of installations. Fire risk from high voltage DC arcing is eliminated, as is the electrocution risk to firefighters in the event of a fire.
Remote system communication provides real time performance information for each polycrystalline or monocrystalline solar module in order to maintain the high performance of the solar PV system throughout the operating lifetime.
Micro-inverters have the potential to replace string inverters in most domestic and commercial installations over the next few years because they offer numerous meaningful advantages for consumers and installers alike. They are simpler and safer, maximize energy harvest, increase system lifetime and reliability, simplify PV array design and installation, and enhance system monitoring capability’