Developers of solar microgrids and other distributed energy systems (DES) have various solar options for microgrids available to them, ranging from the types of solar panels used, how they are mounted and what other components are deployed in support. All these considerations have various efficiency and cost impacts.
Types Of Solar PV And Their Various Applications
There are three main types of solar PV panel available to microgrid owners and developers, specifically monocrystalline, polycrystalline and thin film. Monocrystalline and polycrystalline panels consist of either 60 or 72 solar cells and are mounted, while thin film PV is usually applied to surfaces. The main differences between monocrystalline and polycrystalline panels are that monocrystalline panels are more efficient – being in the range of 17 to 22 percent – and therefore more expensive, while polycrystalline panels are less efficient – ranging from 15-17 percent – and are therefore cheaper.
The reason why polycrystalline panels are less efficient is because the solar cells they use are not made from a single silicon crystal in the way that monocrystalline solar cells are. Polycrystalline solar cells are made from silicon fragments that are melted together. This means that they have less room for the electrons to move around, adversely impacting efficiency.
Monocrystalline solar panels, as well as being more efficient, are more aesthetically pleasing. They usually have a black colour, which means they are less noticeable when mounted on dark roofs, whereas polycrystalline solar panels are usually deep blue. This is usually more important in residential settings but may apply in other situations also.
Thin film solar PV is the least efficient of the three, having an efficiency level of around 10-13 percent. For this reason, they are usually only suitable for use in large applications, often by utilities or large commercial organisations. However, the lower efficiency level also makes them the cheapest of the three. Given that they are more suitable for larger applications, thin-film would not normally be of interest to smaller microgrid projects, such as community microgrids or smaller organisations and institutions, unless, that is, the entity developing the microgrid placed high emphasis on cost reduction.
Other Components Of Solar Microgrids
Solar PV panels in a microgrid will often be accompanied by some very important supportive components, specifically a solar charge controller, an inverter and battery energy storage. The solar charge controller is a voltage regulator that prevents damage to the solar panels and batteries due to overcharging. It also helps to prolong the life of the batteries. An AC/DC inverter converts outgoing power into the form of power required by end users. Finally, energy storage batteries store excess power that is not required immediately, thereby helping to mitigate the effects of intermittency, providing power when power from the solar panels is not available.
Solar panels can be mounted on a pole (pole mounting), on a ground frame or on a rooftop. Ground frames are usually the most favoured method if there is plenty of space available. The most expensive method of the three is roof mounting, which is usually employed in residential situations due to lack of space.
To learn more about solar options for microgrids, contact our VECKTA experts today!