How does a GenU solar energy system work?

Photovoltaic (PV) solar power generation works by harvesting the energy of the sun. Our PV panels convert the sun's energy into direct current (DC) electricity. Your home runs on alternating current (AC). To match the electric system in your home, a DC to AC inverter is required. GenU solar energy solutions combine panels and inverters engineered to optimise this process.

Solar PV Panels

Special materials such as silicon (known as semiconductors) exhibit a range of unique electrical properties. One of these properties allows electromagnetic radiation from the sun to excite free electrons within the material, resulting in a flow of electric current. In order to make use of this source of power, the silicon is arranged in flat array called a solar PV panels. The two most common methods of manufacturing solar panels are monocrystalline and polycrystalline. Monocrystalline panels use a grid of individual cells with a dark black appearance, while polycrystalline panels have a continuous silicone coating of a mottled dark blue colour. Monocrystalline was once considered superior, however with advances in technology both types now offer similar efficiencies relative to cost and panel size.

DC to AC Inverters

In New Zealand, electricity is supplied to consumers in the form of 240V 50Hz AC. Solar panels produce DC which is not compatibile with this system. In order to make use of solar electric power, it must be converted to AC by a device called an inverter. PV solar panels, have an optimal operating state for given environmental conditions (temperature, light intensity, shading, etc). Modern inverters maintain this state through a process known as Maximum Power Point Tracking (MPPT). Two inverter topologies are available, central (string) inverters and more recently micro-inverters.

Central inverters have been the most common inverter type in NZ since the introduction of PV solar panels to the market. The system works by joining multiple PV panels in the system to a relatively large central inverter for conversion to AC.

Micro-Inverter systems are a more recent development where each individual PV panel is matched to it's own micro-inverter. Multiple micro-inverters independantly deliver AC power.

Micro vs Central Inverters

Micro-inverters apply MPPT to each panel within an array independantly, reducing the impact of any variation in performance between panels. This also means panels within an array subject to different shading conditions (such as that caused by changing cloud cover) do not degrade the overall output to the extent of a central inverter based system. Because micro-inverters and PV panels are matched on a one to one basis, all components are sized correctly even if system expansion becomes desireable in the future. In certain situations (where all factors are carefully considered) central inverters can be a lower cost solution.