The ‘app’titude of some is remarkable. With smart phones more common than a Ranga’ in the family (Ron Weasley’s family included) and multitudinous apps that vie for everyone’s attention. It is disheartening to see the transmigration into the work field and the temptation by some shady individuals to accidentally mislead the customer on the thermal imaging of their solar panels. Going on the app store, you can see apps that show thermal images but are not genuine thermal imaging just photo manipulation and camera trickery.
Why to use thermal imaging?
The reason for thermal imaging you may ask is to see what the eye cannot and demonstrate the heat signature of an object. When correctly employed with bona fide equipment you have a reliable quantitative measurement to demonstrate loss of efficiency and therefore need for a clean.
We have seen this alternative shady’ approach on the commercial side but we recently have unsubstantiated accounts of it occurring in the residential markets as well. Yes you can pay for a helicopter to fly over and do a thermal image report for your solar panel/s but the gold standard is hands on at the panels themselves.
Can we do it?
At leaf it 2 us we again take this the next step evolutionary wise with a hands-off approach. Scanning your panels up close we avoid issues the helicopter pilots have to apply and lower considerably the Measurement of Uncertainty (MU) that the airborne approach has and save you $100’s in the process too. By being hands off we avoid any warranty voiding of your systems from placing metal probes on your panels.
Before and after photos are great but before and after thermal imaging after cleaning with liquids that by their very nature will cool and change the thermal image is not sensible. There are the percentages of transmission, which is the numerical number you can look for to show degree of change to your solar panels thereby showing you the efficiency. Again, assuming the user hasn’t popped out a sun reflector disc and augmented the shot. People searching for quality over quantity, yet in measurement terms and defensibility qualitative over quantitative reverse what you really want; cold hard numbers rather than visual acuity which is subjective and often from a distance so far less accurate or reliable. Quantitative changes that are measured gives you more facts and the before and after photos whilst eye opening are more quantitative as they provide subjective variation in the efficiency drop off of any panel or cell and are less important too.
What is the electricity conversion for your solar panels?
We mentioned in previous blogs about effective drop offs for solar panels. Not mentioning the warranty dropping off here by unprofessional cleaning. Like a painter’s palate there are often more than one factor affecting your solar panels masterpiece of electricity conversion;
a). 5% vegetation obscurement (rising in summer months with more growth).
b). 5% white dialectic material (bird deposits).
c). 5% watermark stains and lime build up.
d). 5% smoke and debris for burn offs and barbecues.
e). 7% dust and air borne particulates.
In reality these combinations are rarely found in isolation. So pick 3 or 4 and see how palatable those figures are to digest on your energy efficiency topic for your solar panels. Remember these are losses to your electrical generation.These losses are based on a regularly cleaned solar panel and degradation over several months’ exposure to the elements and environment. So, when you regularly clean your solar panels your energy production and cost savings are much clearer too.
At leaf it 2 us we apply our commercial depth and strength into the residential system for your peace of mind. Having real actual thermal cameras you can see the real thermal signature of your solar panels and the real need or otherwise to attend to them.
What are infrared rays ?
In convention, the infrared ray is defined by having the wavelength in the fixed interval 0.7 – 300 micrometers.
Are thermal and infrared radiation the same thing?
Yes, if the sources of the radiation have temperatures comparable to room temperature. Thermal temperature depends on its absolute temperature. At zero degrees, an object will emit at all wavelengths;
1). the roof top being 5 – 10 degrees hotter than at ground level. Solar Panels are positioned to not be protected from the sun’s rays. The temperature of solar panels is therefore often significantly higher than that of your car windscreen.
2). as hotter objects thermal radiation may be masked by visible light or ultraviolet light.
3). the measurement is given in Kelvin which is degrees Fahrenheit not centigrade which is 0 – 100 scale in degrees centigrade. A Kelvin is equivalent to one degrees Celsius.
4). zero degrees Kelvin is -273 degrees Celsius.
5). one millikelvin is equivalent to 1/1000th of a Kelvin or 1/1000th of a Celsius.
6). changes in Kelvin are inversely proportional to the maximized emission.
What is field of view?
Field of View this is the area measured through the lens. This is what the image that is observed on the screen as a whole;
Field of view is normally expressed in angle 25° x 19° so in this case. Horizontal view is 25 degrees versus 19 degrees of vertical view. Imaging the lens taking the image being the top of a square pyramid. (I ‘sphink’ you can imagine that!)
Now take the lens concept up a notch say in to a helicopter and see a massive pyramid in theory the pixel resolution required to match that of 1 metre from the solar panels has to be humongous. This will affect the spatial resolution.
Spatial resolution is where the number of pixels remain the same more image but less ability to measure smaller areas of temperature difference. Thinking spatial resolution think how far away from the TV you sit before the image is distorted or optimal.
What MU means for you?
Every factor that is added together limiting the accuracy of the result. Expressed as a percentage. So for an understanding a temperature on a thermometer reading depends on case, position fluid inside and accuracy of scale in this example 15 degrees Celsius with a MU of ± 3 would mean the temperature could actually be 12 – 18 degrees.
The above is to heat up (pun intended) discussion on thermal images and whether this measurement has a place in the assessment of solar panels to decide if they require cleaning. As for the fake thermal imaging Apps, maybe best to keep them just for laughs around the barbie or for photos of the barbie itself.