Solar Inverter | SMA best solar inverters

Solar inverter | SMA best solar inverter. There are different types of PV inverters. Off-grid and grid tie or a hybrid solar inverter. Most of them are string inverters and need multiple panels, serial connected.

The task is to transform the direct current from the photovoltaic system into a sinusoidal alternating current. The supplied ac output is synchronised with the mains sine wave single phase frequency (50 Hz).It is all necessary to put the power generation provided by the PV panels on the grid connection so that it can be used up. In the absence of a grid frequency, in case of failure or if a fuse blows in the meter box, the DC converter will switch itself off.

Solar Inverter | SMA best solar inverters

In a small inverter, there is a plug that goes into the wall socket. A larger one is connected to the mains on an operating switch. To ensure a stable and reliable connection for years of proper power distribution.

Photovoltaic panels require special DC converter because a panel gives its maximum power at a specific voltage. This is called MPP tracking. To extract as much electrical energy as possible from a photovoltaic panel, the inverter constantly searches for the point where the photovoltaic power energy of the panel is maximal.

That is called the 'Maximum Power Point' (MPP). The MPP shifts as soon as the irradiation or the temperature of the panel changes. It is therefore always provided with one or more MPP trackers. Losses in an inverter are caused by the conversion of direct current into alternating current.

The MPP tracker is always 'searching' to get the maximum power is not always taken from the PV panels. All these electronic actions result in losses. These losses now only amount to a few percents. The losses are also not always the same but depend on the power supplied by the inverter. The maximum efficiency of modern central DC Converters is between 96% and 99%.

In our opinion and experience, SMA produces the best solar inverters

Items: 12 of 2, per page

Solar Inverter | SMA best solar inverters

The maximum number of photovoltaic panels that can be handled depends on the maximum input power (DC) of the inverter. And of course the peak power per panel. Moreover, the used PV modules must have the same electrical characteristics as soon as they are connected in series (string concept).

Nowadays, more and more use of micro inverters and optimisers is made. Each panel is thus given its inverter with its MPP tracker.

Why a system with optimisers?
By giving each panel its MPP tracker, panels can be connected in different angles or roof surfaces installed in one system.

An inverter is an indispensable link in the PV systems of solar panels, cabling and the meter cupboard. As soon as the panels catch sunlight and there is enough startup voltage to the inverter, it will come into operation. The function that the inverter performs is converting direct current to alternating current. 

It is essential that the solar 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 controls photovoltaic panels to operate on the most efficient voltage. This is also called Maximal Power Point Tracking (MPPT).

Solar Inverter | The best PV inverter?

The ultimate goal is to generate as much energy from the PV panels as possible. Convert the DC power into alternating current for the electricity network. In other words, the purpose of the solar inverter is to achieve maximum efficiency.

It has also has a safety function. The photovoltaic inverter keeps a constant eye on the network. If the grid is outside the tolerances concerning voltage or frequency, it is switched off immediately.

The different types for private use differ mainly regarding capacity. For many it is interesting the possibility of live monitoring via the smartphone, tablet or PC. In this way, more information can be gathered about, for example, the efficiency of the solar cells and the generated energy.

Step 1: To monitor the performance of your solar panels online.
Some inverters have an Ethernet connection (IP connection) which you can connect directly to the Internet which has a link to the portal site of the manufacturer. There you can monitor your system. 

Some inverters do not have this ethernet connection, and you should optionally purchase a Bluetooth connector that you connect via a Bluetooth connection to your PC or tablet. It usually saves extra costs if the inverter has the connection available as standard.

Step 2: Power inverter
The power of an inverter must be tuned to the total capacity of the PV modules. The capacity of solar panels is indicated by the unit WP. This means that a certain power is delivered under ideal circumstances (25 ° Celsius). However, we never achieve these ideal conditions in portugal.

The power of the solar inverter may therefore be lower than the capacity in WP of your solar panels. Example: On an installation with 2200 WP, a 2000 Watt inverter can be used. If the photovoltaic panels are not ideally oriented to the south, sometimes a smaller inverter can still be purchased.

As a rule, an inverter is chosen that is 20% smaller and at the most 10% larger than the capacity of the number of WPs of the solar panels. But let your installer make a calculation based on the practical situation. The gradient, location in Portugal and orientation towards the south determine which inverter you need.

Do not just look at the type number of the solar inverter. Example: The SMA 3000TLhas a maximum power of 3200 W. Here you can easily connect an installation of 3300 WP.

Step 3:Well or no transformer in an inverter.
Inverters are offered both with transformer and without a transformer. The transformerless inverters generally have higher efficiency or less loss. They are often referred to as TL type, Transformerless. Some panels may only be connected to an inverter with a transformer. Otherwise, accelerated degeneration occurs. Today, most solar inverter are transformerless.

Solar Inverter | The best PV inverter?

Point 3:Do you or do not suffer from shadow
If you do not suffer from the shadow, you can skip this point. Do you suffer from shadow then this point is very relevant? The power of the solar panels is determined by the weakest link in a series or the solar panel with shadow.

This can be accommodated in 2 ways:

  1. By making a separate loop (string)of solar panels that at the same time come to lie in the shade. For that, you have to choose an PV converter with multiple trackers. A tracker optimises the power of a loop. With the characteristics of inverters, it is always indicated how many trackers the inverter has. Please note: you need to connect at least five photovoltaic panels per loop. Otherwise, the inverter will get too little power to do its job at all.
  2. Power Optimizer for more yield.
    By choosing power optimisers or microinverters. These are control units placed behind each solar panel, and each solar panel optimises individually. The power optimizers are connected to a first inverter. Power optimizers are now offered bySMA groupSolar Edge, Fronius and Postal Riko.

Step 4:Monitoring

The monitoring of your photovoltaic panels always takes place via the inverter. The inverter must, therefore, be read out. Not all inverters offer standard solutions for this. Here is an overview of possibilities:

Via Bluetooth. You can then read your inverter with a program on a PC or tablet. This form is not ideal. The connection is often not powerful enough so that you usually have faults. Moreover, you can not read the inverter from the internet.

  1. Via Ethernet.
    Your inverter is then connected via a network cable to your router. Then a connection is made with the servers of the manufacturer. Via an App or website, you can then view the performance of your solar panels from anywhere. This type of connection is efficient and stable. However, not all manufacturers offer ethernet, and sometimes an optional module has to be purchased.
  2. Via Wifi.
    This is the same principle as via ethernet. Only no network cable needs to be pulled between the inverter and router. This is an advantage over a cable connection via Ethernet, but this connection is of course slightly less stable.

Solar Inverter | SMA best solar inverter

Step 5:Warranty for inverters
SMA provide a 5-year warranty. Usually, you can buy a warranty for up to 10 years. This can be seen as an insurance policy. Manufacturers then expect very naturally: what are the costs for giving an extra guarantee and what additional revenue is in return. You can be sure that this is positive for manufacturers. In other words: the chance that the solar inverter will fail between 5 and ten years is relatively small. Is it worth you to pay extra for this?

Step 6: Inverter brand
Do I choose a European or American inverter, or am I going for a cheap Chinese brand?

If you want to go for security, you choose a German inverter such as SMA. This is a brand that have been on the market for decades and have good European help desks.

Step 7:Battery storage
With a grid tie solar inverter its very easy to store the electric energy into a battery. The other extreme is an off-grid solar system. The photovoltaic power systems that most responds to the romantic image of autonomous energy supply. 

Disconnect that cable in the ground. We take it all from our own roof and use the battery to smooth out the folds between use and production. In case there is no power supply, this is even the only solution. But there are also considerable disadvantages. If your battery is empty, you no longer have any escape possibilities. On the other hand, if your battery is full, the precious power that you still generate will be lost.

The hybrid solar system combines the benefits of both. A solar power battery storage system to store the surplus electricity  for later use. But also access to the grid for times when consumption is higher than what the battery can provide. Or for times when the photovoltaic panels still supply power while the home battery is full. In that case, abundant KWh's can be delivered to the grid. In combination with energy management software, owners of batteries can further benefit from peak and off-peak tariffs, such as purchasing and storage of grid power during off-peak hours.