On-Grid

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Showing all 3 results

Favorable on-grid solar systems of solarweasel.com – with the On Grid solar plant or also net-coupled Photovoltaikanlage, widespread in Germany, a direct connection is manufactured to the öffenltiche current net. Thus the plant operator has the advantage that this can fall back at any time to the supply of the public net. In addition, with an on-grid system, the electricity is generated decentrally, i.e. directly at the consumer, which means that high transport losses can be avoided, which in turn has a positive effect on the energy transition.

There are several ways to deal with the electricity generated by the solar system. The most common method in Germany and most industrialized countries is to use the generated electricity in one’s own household and to feed the surplus electricity into the public grid. For this surplus, the consumer receives compensation according to the Renewable Energy Sources Act (EEG) and can significantly reduce his own electricity costs, depending on his own needs. As a rule, an On Grid system pays for itself after only a few years and it is possible to save over ten thousand euros within twenty years. Often this is a great incentive to decide on the purchase of a new photovoltaic system.  But also the use of an energy storage is a variant, which one finds primarily in areas with unstable power supply. Here, the surplus solar power is not only fed into the public grid, but also into an energy storage system in order to have a certain backup available in case of a power failure. Some on grid systems run on the principle of zero feed, where no power is fed into the grid.

The difference between a PWM and an MPPT charge controller: first, we should clarify the function of a charge controller. In stand-alone solar systems, very expensive power storage devices (accumulators) are often installed to temporarily store the excess power generated so that it can be retrieved in the event of a power outage or at night. However, such power storage is highly susceptible to deep discharge or overcharge and could suffer significant damage as a result. Automated charge controllers are installed so that consumers do not have to monitor the battery charge themselves. These therefore regulate the incoming current in order to protect the power storage units. Each solar system supplies a certain voltage depending on the strength of the solar radiation. In the case of strong solar radiation, this can be 18 V. However, an installed battery requires a voltage of 12 V to charge it. The PWM charge controller now breaks down the voltage generated by the modules to the required 12 V, whereby high losses occur, since at 18 V significantly more power (watts) can be supplied. The maximum power is thus severely limited. As soon as the battery is charged, the PWM controller interrupts the power supply several times per minute to avoid overcharging the battery. An MPPT (Multi Power Point Tracking) charge controller, which is much more expensive to purchase, monitors the output of the solar panels and instead of simply breaking down the voltage, it converts it to the required battery voltage. This form of charge controller is much more effective than a PWM charge controller, but due to the high purchase costs, an MPPT charge controller is usually only worthwhile from a certain size of solar system.

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