Inverters and Power Optimizers

How do you convert the direct current (DC) produced by solar panels to the alternating current (AC) used by your home? Since the expansion of the solar industry, you get to choose! There are three configurations of inverters that can be used in your solar system today; string or centralized inverters, micro-inverters, and power optimizers.

The different types of power management. (Found on LetsGoSolar.com)

​String inverters have been the most commonly used since solar systems first gained traction. Strings are combinations of solar panels that are connected to the inverter. Strings are very susceptible to shading since the string can only operate at the capacity of the lowest panel. The plus side to the string inverter is the overall cost of the system. For this reason they are the go-to design for the large scale solar farms. They are also great for ideal situations where shading is not an issue and the panels are facing the same direction.

Micro-inverters and power optimizers are part of a group of Module Level Power Electronics or MLPE’s that provide power control right off the solar panel (module). These MLPE’s offer online monitoring of each specific panel but end up boosting the price point for each system. They also benefit the installer by reducing the design time and increasing installation safety. Installing solar panels require working on a high voltage system but the MLPE’s can lower the risk during maintenance and installation.

The biggest downside to micro-inverters are the cost, however they have many benefits! Micro-inverters convert the electricity at the source which standardizes the rest of the circuit to AC. These systems are less susceptible to failure because the control is decentralized. They do have a lower efficiency and rely heavily on internet connection. With the internet connection you are able to see the real-time production for each panel.

Power optimizers are an MLPE that combines a lot of the benefits of a micro-inverter with the lower cost of a central or string inverter. Power optimizers do not convert DC to AC they simply condition the DC electricity before it passes through an inverter.  The individual optimizer installations with the inverter installation increase the overall installing time however. This strategy still comes in below the micro-inverter price point.

The next step for many solar manufacturers are “smart modules.” These panels sample the current coming from the panel to maximize the power. Smart modules combine the functions of MLPE’s and traditional panels to create a single unit for both.  This will eventually decrease the cost of incorporating power maximizing MLPE’s and make the installations much safer.

If there is anything about solar power that you want to know about, please let us know in the comments, and we will incorporate it in a future blog post. Thank you for reading and until next time!