When installing a solar PV system for a building, as part of the full design, an inverter is needed. An inverter converts the variable direct current (DC) output which is produced from a solar system into alternating current (AC) so it can be used within the property. When designing a PV array you have a few options depending on where you would like the energy to be directed, be in the home, out to the grid or stored in batteries.
STRING INVERTERS GRID-TIED & STAND ALONE
Part of the overall PV system design is to select a suitable inverter. Once you have confirmed the solar PV kWp size you are installing, you then have the option to either string together modules or tiles in series or in parallel. Most PV systems in the UK chose to daisy chain the strings in series connecting a full array into one circuit. As this would require one or more inverters generally installed inside the building, the main benefit to this design is lower costs for both initial installation future maintenance in the event of failure.
Most inverters are grid-tied; this means that if the solar array is generating energy and it is not being used on site, the electricity produced is fed back into the local national electrical grid network (DNO) For safety, in the event of any technical fault on the utility grid, these inverters are designed to quickly disconnect as to avoid sending electricity whilst the fault is being fixed.
Standalone inverters are used in an isolated system where the inverter draws its DC energy from batteries which have been charged by photovoltaic arrays.
As we are independent of any manufacturer of inverter we will select the right one which optimizes the AC electrical generation of your system.
Solar micro-inverters are designed to operate with a single PV module. Each microinverter is installed at the panel, converting from DC to AC at roof level. Designing in this way allows parallel connection of multiple, independent panels. Choosing micro inverters means that you can optimize the generation of the panel. This is best suited where a small array is being installed, or if sections of solar array are subjected to shade as to ensure that the overall performance of the array is unaffected.
A power optimizer is a DC/DC converter which is connected to each solar panel or embedding by some module manufacturers. This replaces the standard junction box. This increases the energy output from a PV array by constantly tracking the maximum power point of each individual module. Choosing to install an optimized system manufactured by SolarEdge, when connected, each individual optimizer has been designed to communicate with a monitoring portal. This means that you can monitor the performance of each and every panel.
Using optimizers on each module allows for a more flexible design. Best if space is a premium and you need to configure the panels in multiple orientations.
SolarEdge power optimizers automatically maintain a fixed string voltage, allowing installers even greater flexibility with longer strings and strings of different lengths in order to design optimal PV systems.