Solar PV inverter - MPPT charge controller

Solar PV inverter - MPPT charge controller. Thifferent types of PV inverters makes it hard to choose. The best photovoltaic converter is always the one that is fitting your energy project. How to select photovoltaic charge controller for your purpose is not easy. There are many types on the market. I'll try to make it more easy for by explaning my experiance with the advantages of mppt DC converters for different prices and costs.

Solar PV inverter - MPPT charge controller

Everyone knows that solar powered systems need PV inverter to transform the DC power from the panels to an AC powered system for making a connection to the electrical energy network. There are many brands on the market from high-quality European quality up to an excellent working Chinese quality for a lower price. Often German products are working with higher efficiency and therefore a lower cost price in terms of years to use the equipment.

What is the function of a charge controller?

It is an indispensable link in photovoltaic installations, cabling and the meter cupboard. It is a device that converts the direct input voltage of the PV array into an alternating high voltage of 230 volts and 50 Hz. As soon as the boards catch sunlight and there is enough startup voltage to the inverter, it will start operating. The function that the mppt charge controller performs is converting direct current to alternating current.

It is essential that the inverter takes into account various things such as keeping the alternating current in sync with the power of the grid. It is also important that it regulates that solar cells operate on the most efficient voltage. Its also called Maximal Power Point Tracking (MPPT).

What is Maximum Power Point Tracking (MPPT).

MPPT is a mechanism ensures that the maximum photovoltaic wattage is received from the solar panel under all circumstances. The inverter does this by not maximally but maximally charging the PV panel. The power that it can supply changes continuously due to the evolution of radiation (light intensity), possible partial shade, for example moving branches of trees, but also the temperature of the cell.

A Maximum Power Point Tracker (mppt controllers) is a mechanism that searches the PV array for the point of maximum delivery and gets the most out of the PV modules in all situations.

What is the function of a PV inverter?

The ultimate goal is to generate as much energy from the modules as possible and to convert them into alternating current for the electricity network. In other words, the purpose is to achieve maximum efficiency. It also has a safety function. The inverter keeps a constant eye on the grid. The DC to AC converter is switched off immediately if the network is outside the tolerances regarding voltage or frequency.

Solar charge controllers and Inverters for Off-grid PV Systems.

The PV panels on your roof will generate electrical energy during the sun hours. The electricity is supplied to the connected equipment by the combined charge controller and inverter. When your PV array is making more electricity that is currently in need, the charger will store this energy in the additional batteries.

When your equipment requires more energy than is presently offered by the sun, the battery bank will step in and release the stored energy.

On the days that you do not use all the electra in the accommodation, the surplus fully charge the batteries.

Solar PV inverter - MPPT charge controller

Lets have a look at the brands on the market.

String inverters and grid tie inverters :

Some solid brands come from Europe. Well-known brands for different types are:

Power optimisers /power optimization and microinverters:

Some well-known brands optimisers and micro-inverters are:

  • Solar Edge
  •   Enphase
  •   APS

A power optimiser ensures that each panel is individually controlled. In the case of a microinverter, an device for each module instead of an device for the entire installation.

Very suitable for roofs with a slight shadow drop
Well applicable to multiple roof surfaces
Often long warranty conditions


More electronics, which is more likely to drop out
More expensive in purchase

When to apply:

Power optimisers and microinverters are a suitable solution if you have some shadow on your roof. They ensure that if the shadow falls on one or a few panels, the rest of the installation will continue to function. If a shadow falls on one or more photovoltaic panels with a string inverter, the entire plant will operate worse.

However, the installation is more vulnerable due to the use of optimisers and microinverters. Every time one is broken you have to replace it, while with a string inverter you only have to replace one device. The application of solar optimisers and microinverters is also more expensive than that of string converters.

Solar PV inverter - MPPT charge controller

Now you have the necessary knowledge to choose. But there are more aspects than only the technical details. For small PV systems, the choice can be quite simple. A good supplier in the neighbourhood, and is reliable. Everything neatly installed for you, and this has been doing for years. Soon have you as a customer.

But for more significant PV systems, at a later time, storing the additional energy in batteries. You have to think it over for which brand you are going to choose.

With batteries, you can achieve a greater degree of self-sufficiency. If you are not home during the day, but in the evening after sunset, you can ensure that the energy generated during the day is stored in batteries, to be available again in the evening for your appliances.

Battery inverter charger:

A battery charger converts direct current from the battery voltages (DC) into alternating current (AC). This is necessary for the protection and use of the battery for energy storage at home. The Battery Inverter is a smaller box than the storage module itself. So saving the solar system energy is usually necessary with this intermediate step. There are all in one solution for new solar panel installations.

The Tesla battery does need him for example. In the operation of the PV module battery, you can see what the order of energy from the sun comes from the socket.

What is required for solar energy storage?

First of all, you need batteries (batteries) of course. The more cells you have, the more energy you can store. The energy stored in the batteries has to be made available again when you want it. It requires a battery converter, which inverts the direct current of the batteries (DC) into the alternating current on the network (AC).

The storage of batteries for a home can take place in several ways. But how does such a battery work exactly?

The battery with energy cells in small batteries that are together in an array, connected and managed by a computer control system.

With the solar power panels, we can, at any rate, become independent of the prices on the items that you can not influence the electricity part of our energy needs. And since we do not directly consume most of the generated electricity ourselves and therefore have to return to the grid, unfortunately.

As you know, batteries are precious, and their lifespan is pretty much dependent on how they are charged and discharged. The more 'cycles' (number of times that they are charged and discharged) they undergo, the faster they lose capacity.

That is why it is important to use the batteries smartly. Only start charging when that is useful. A lot of sun in the coming time and little consumption in the short term. And then return to the grid afterwards at the best moments.

This requires a system with smart control, which, for example, takes into account the weather forecast and the current state. As I will explain to you in another article, SMA is a star in this technology with the Sunny Home Manager.