There is no one standard criteria to evaluate the efficiency of solar panels. Of course, the most commonly prevailing criteria is to review the rating and feedback of the panels for their efficiency, and longevity as against the assurance offered by the manufacturer.
In this blog, we will undergo a few steps that need to be considered when determining the efficiency of solar panels for any residential or commercial facility.
The first step towards the evaluation of the efficiency of solar panels for any facility comprised of determining the structural and mechanical integrity of the building; including the strength, condition, and age of the roof. The step should also include shading analysis to determine any obstructions to the solar radiation falling to the array of panels. Furthermore, the estimation of the solar array size requirement for the building, structural issues, height considerations, and other issues should also be evaluated at this stage.
By performing the solar screening, you don’t just get to determine the structural and mechanical integrity of the building for solar panels, but also get an idea of the economic consideration required to meet the energy needs of the building. The shading analysis included in the screening also gives a fair idea of any obstruction to the efficiency of the solar array, while also enabling you to design the best installation design.
Solar Feasibility Evaluation:
The solar feasibility evaluation is the next step that tends to determine the total energy capacity of the system, as well as, the maintenance of the array. The solar feasibility evaluation also reinforces the economic considerations of the solar panels including the energy demand of the building, estimation of total energy generation by the installed solar array capacity, as well as, the monthly and annual maintenance cost of the system.
Determining the Efficiency of Solar Panels:
Out of the various definition and criteria that are adapted to evaluate the efficiency of solar panels, the most authentic measure to calculate the efficiency is to determine the effectiveness of the solar arrays installed to convert solar radiation into electricity. In simple words, the greater the effectiveness of solar panels to convert radiations into electricity the more power you are able to generate from smaller arrays. This mainly comes handy for residential buildings which often face space limitations to install large arrays. Obviously, solar panels with higher efficiency come at premium prices and are mostly marketed for the residential market. The general mathematic formula used to calculate the efficiency of solar panels is:
Efficiency = power out / power in = module power / (width x length x 1000W/m2)
Factors influencing the efficiency of the solar panels
Various factors influence the efficiency of solar panels including;
The greater the solar radiations fall on the solar panels, the more energy production you can achieve. In this regard, the solar screening step that involves shading analysis gives a fair idea about any obstructions that stop solar radiation from falling onto the panels.
– Roof Pitch:
Another important factor that influences the efficiency of solar panels is the angle of the roof, which impacts the number of hours solar radiation may fall on the panels per day. Again, the solar screening and feasibility tests at earlier stages may reveal the best angle for the installation of the array to maximize efficiency.
As a general criterion, the orientation of the solar panels should be south facing to maximize the panels’ exposure to solar radiation and boost efficiency.
While the average lifespan of solar panels may vary between 20 to 25 years, the panels lose their efficiency as much as 0.5% per year. This means that the overall efficiency of the grid will lower over the years.