Solar panel efficiency is trending at the moment and it’s often in the news. In fact, it has become a priority for governments as well as for entrepreneurs and private homeowners, who seek to implement strategies to optimise their energy consumption by renewing their air conditioning systems, buying A-labelled appliances, improving the insulation of their homes/businesses, or installing photovoltaic panels to ease the transition to a cleaner and more sustainable energy model.
How can we measure solar panel efficiency?
One of the great attractions of photovoltaic installations – in businesses and SMEs as well as in private homes – is their efficiency.
But what do we know about solar panel efficiency?
In principle, explaining the efficiency of solar panels is a simple matter. If a solar panel has an efficiency level of 20%, it means that it can convert 20% of the solar radiation it receives into electricity.
The average efficiency of solar panels is between 17% and 19%, although some can even reach 23%.
According to this percentage, we can distinguish between:
- Panels with low-medium efficiency (16-17%).
- Panels with medium-high efficiency (18-19%).
- Panels with high efficiency (above 20%).
The efficiency of photovoltaic solar panels is directly related to their performance. And this is where the big question comes in: how many watts does a solar panel generate?
The efficiency of solar panels is determined by aspects such as the material they are made of, the temperature and daily hours of sunlight, the orientation and inclination of the solar panels, and the shade that falls on them.
Aside from that, solar panels lose efficiency over the years and, as a result, they produce less electricity despite receiving the same amount of light. One of the causes of this deterioration is that the materials wear out due to meteorological factors (rain, ice, sun, etc.).
According to some reports, the capacity of a solar panel to produce electricity deteriorates at an average rate of 0.5% per year. This means that a 20-year-old panel produces approximately 90% of the electricity it would have produced in its first year of life.
Furthermore, we must not forget that self-consumption photovoltaic installations function at lower efficiency levels in winter when compared to the summer.
In these cases, the best option is to store the surplus energy generated by the solar panels at their highest production peaks, in order to have electricity at night or on rainy or overcast days.
What is Tier 1 and what does it have to do with solar panel efficiency?
The Tier 1 ranking system is compiled by Bloomberg New Energy Finance Corporation (BNEF) and updated every four months, which is when they assess solar panel manufacturers.
For Bloomberg, Tier 1 solar panel manufacturers are companies that have provided products for five different non-funded projects and have been financed by five different banks in the last two years. In other words, this ranking is based on their creditworthiness and/or financial stability.
Of course, a manufacturer’s financial stability does not necessarily imply that it produces high-quality panels. However, banks will not finance PV installations that do not meet minimum quality and durability standards.
Likewise, only manufacturers with their own facilities can be included in this list. In other words, the list does not include those who subcontract their suppliers. In this way, the Tier 1 classification only includes manufacturers who, in principle, have better quality control and who can invest more in R&D to improve their products.
In this regard, and even though the Tier 1 classification is, perhaps, not a direct indicator of quality, it does allow us to gauge the product’s guarantee and performance, which, in the long run, is closely related to the solar panel efficiency.
Are you looking for efficient solar panels?
Here at MyGreenHouse, we work with Tier 1 manufacturers. We also guarantee the highest efficiency of your photovoltaic installation by choosing the best elements for your photovoltaic project (inverters, solar batteries, structures, solar regulators, etc.). Give us a call and we’ll give you all the information you need.