The many different types of mounts for solar arrays, be it fixed-, single-, or dual-axis trackers, can lead to considerable confusion when trying to decide how to mount your solar panels. However, there are several advantages and disadvantages to each type of mounting system depending on a variety of variables including climate, latitude, landscape, budget, and size of the solar array that you are hoping to build.
Fixed-axis systems are the most mechanically simple, and least expensive mounts for solar panels. They can be used on the roof or on the ground, and because of their mechanical simplicity, tend to have a longer lifespan than trackers. These mounts are also beneficial in less sunny climates, where extra expense of a solar tracker may not be worth the small increase in electrical output.
If you decide that you want a solar tracker, there are many options that you can choose from. Firstly, there are thermal (passive) and electrical (active) trackers. Thermal trackers use the heat from the sun, which heats a liquid inside of the solar panel, to rotate. These are beneficial because they have fewer mechanical parts, and are therefore less prone to failure. They are also less expensive. However they can be slow to react to solar motion. In addition, they can be imprecise in the winter because they rely on heat to rotate. Finally, there are electrical trackers, which are the most popular. They are very precise even in the winter, and can increase electrical output from 20-40% from fixed-axis mounts. However, they require a fair amount of maintenance and are more expensive than fixed-mount and thermal trackers.