ON-Grid Solar Systems
Schematically, the operation of such a system is shown in the figure below. In fact, the inverter is connected to the consumer’s network in parallel and feeds the connected equipment of the subscriber, and transfers the surplus to the grid. In the evening, energy can be returned to the consumer from the grid as needed. Such a system is the simplest by the way of connection and installation, but it requires a special legislation and the presence of a bi-directional meter.
The network, thus, serves as a “virtual” energy store. To date, these systems are the most popular in the world and no require maintenance. An obvious advantage of such systems is their efficiency (inverters have a conversion factor of up to 95%) and cheapness in case of using a string- or central inverter. I would like to especially note the On-Grid systems with so-called micro invertors, i.e. with the inverters connected directly to each panel.
Such systems have an even greater efficiency in converting the direct current of solar panels to alternating current (98%), and in addition, the micro inverters exclude the effect of shadowing of the panels on the operation of the entire system, and considerably simplify installation, although at present the solar stations at the micro inverters are much more expensive then the systems with a central or string-inverter.
The main and perhaps the only disadvantage of On-Grid systems is the fact that these systems can not serve as a backup source of energy in the case when grid is down.
The main components of On-Grid stations are:
- Solar panels
- ON–Grid inverter
- Bi-directional counter
Turnkey solutions for On-Grid PV power plants