What impacts the efficiency of a solar panel

One of the main things you will be looking at when considering whether to install a solar panel and which one, is energy efficiency. Solar is expensive enough as it is, and you want to save money wherever you can and make your investment a worthwhile one. Even after you have replaced your old appliances with the latest, most efficient models, you still have to consider the factors affecting the efficiency of the PV system itself – here defined as how much of the solar energy gathered by the system is converted into useable electricity. If you end up with a solar system that is only half as efficient as its competitors, then you will need to purchase twice as many solar panels to get the same light output! That is why efficiency is so important. Here are some of the factors that can make or break your solar system.

Solar panel type

The average commercial solar panel has a conversion efficiency of 11-15%. Monocrystalline solar panels are built from the highest-purity silicon and are thus the most efficient type of solar panel available. However, they are more expensive than polycrystalline and other solar panel types.



For optimum efficiency, your solar panels should be positioned so as to maximize sun exposure. In the northern hemisphere, they should be facing in a southward direction. To increase the amount of time they spend in the sun, you can alter the pitch of your house roof using racks, OR you can install solar trackers so your solar panels automatically change their orientation and ‘follow’ the sun across the sky throughout the day.


Even minor shading can have a dramatic effect on the output of your solar system. The cells in a solar panel are usually all wired up in series, and so if even one cell is affected by shade the current flowing through the whole panel is affected. Where shading of some area of the cell can’t be avoided, then you may need to avoid wiring your cells up in series. Micro-inverters offer another potential solution to this issue.


Solar panels tend to perform better in cooler temperatures, install your panels in such a way that they receive plenty of natural airflow, which has a cooling effect on warm summer days.


Solar panels do degrade over time, make sure you get a model with a warranty guaranteeing that the power output will remain strong over the long haul.

solar panel maintenance

Regular maintenance

Clean your solar panels regularly, as a build up of debris and dust WILL affect the efficiency of your system.

Cable length and thickness

A longer, thinner cable gives more opportunity for power lost as friction via resistance, so make sure you carefully the type of cable, and the voltages, used in your solar system.

Battery efficiency

The more efficient the battery you use, the greater the amount of power that goes into it is able to be utilized as light, and the less energy is lost to heat. Choose a battery with quality design and construction, and keep the charge and discharge rates of the battery low to minimize heat loss and battery damage and deterioration.

As we have seen, maximizing the efficiency of your solar system is an entire task in itself, with a whole range of factors to be considered. Make sure you look at the situation from all angles when setting up your solar panels, it may make the difference between a winning and losing investment.


Blogger, editor, developer who loves green living. Interested in photovoltaics and solar lighting. Reviewing solar products since 2013.

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