The storage of solar energy in panels is very similar to traditional agriculture. In both cases, we can observe a peculiar harvest. The only difference is that the solar panel accumulates photons and converts it into an electric charge. Naturally, over time, all components degrade. And the amount of yield decreases. Let’s look at all the parameters of solar panels and consider what changes are needed in projects as the depreciation of solar equipment.

The Harvesting Process: How it works?

The solar panels need MPPT to store solar energy maximally efficiently. The power of receiving photons of light and the conversion of all this into electricity depends on this. It is worth noting that MPPT is a special algorithm for the inverter that allows you to quickly and efficiently extract energy for sending to the network. MPPT is involved in the redistribution of power between central inverters and enables the collection of energy from all battery chains.

off-grid inverter system

It is a single array that efficiently integrates all solar panels for energy storage. To the growth of technological innovations and the progress of the solar industry, modern installations are increasing in productivity. Current voltages are much higher than a decade ago. As various technologies develop, so does the photovoltaic cell chain. It also affects the overall cost and availability of the product on the market.

How does an inverter and MPPT of a PV system Work? - Sustainable Energy - TU Delft

What happens to plants with centralized MPPT functions over time?

At the moment, there is no clear understanding of what is better:

This article will only consider the principle of operation of the inverter and its effect on the structure of solar panels in general. It is worth noting that most modern American solar farms are created using central inverters. To understand how the system as a whole work Let’s draw an analogy with harvesting. For example, you decided to become a farmer and prepared a plot for planting corn. You have a field and a unique collection system that brings you a uniform crop every day.

The process is carried out evenly, and each chain of corn enters your barn to maximize the reward. Let’s check how the MPPT system works in a central inverter. For the first time of the year, you get a uniform crop without restrictions or specific problems. Unfortunately, over time, several natural factors affect the yield of corn. For example, you survived a season, a drought season, or a tropical cyclone. As a result, all your crops ripen unevenly.

It affects the harvest and changes the general approach to the use of the entire garden. Thus, there is about the same principle in solar installations. This change in yield is a mismatch. The worse it is, the less electricity you get from your solar panel. In the figure below are all the curves that show my energy generation over time and show the point of maximum power.

An example of divergent IV curves in a PV array

An example of divergent IV curves in a PV array.

At the very beginning of the solar installation, all the curves are the same. But over time, it changes. Uneven panel degradation, pollution, and other physical factors can affect the efficiency of the solar panel as a whole and the amount of energy generated. Because of this, the MPPT efficiency is reduced, and you get less power.

String-level optimizers to the rescue

Thanks to the string-level DC-DC optimizers, you can balance the productivity of solar panels and stabilize the production of solar energy with unstable congestion of solar panels. The chart below shows how to understand the return on investment and the profitability of installing optimizers to get higher yields in the future.

how the energy yield of MPPT applied to individual PV strings can exceed the energy produced

The chart above shows how the energy yield of MPPT applied to individual PV strings can exceed the energy produced by a single MPPT for an entire PV array when the IV curves of the individual strings are different.

 

This simulation of results clearly shows the difference between systems without optimizers and with those. It is worth noting that with solar developers it is necessary to increase MPP in future investments to increase overall profit. In general, Solar Optimizers is an important aspect that is necessary to regulate the production of solar energy and increase revenue in the foreseeable future.