Economics of Cleaning the Solar Panels
Allowing the dust to accumulate on solar panels without adequate cleaning leads to huge monetary losses. Proper judgment of when to call for washing of solar panels is a compromise between gross costs of cleaning the panels and how much reduction in efficiency of solar panels can be tolerated. From economic perspective, solar panels should be regularly cleaned to improve the efficiency and maximize gain. Economics is an important factor behind any financing. Similar in case of Solar Panel Cleaning economics is also important issues. It is seen that on an average 7% annual loss on average sized system doesn’t justify the effort of cleaning. But the result is not found when the annual loss is greater than 7% on average. Important factor behind the degradation of actual Solar Generation Output is :
- Soiling Loss.
- Potential Induced Degradation.
- Isolation/Insulation Resistance.
- Loose Connections of wires/cables.
Soiling issues is important factor behind the less amount of generation of Solar Power than expected. This Panel soiling can come from :
- Atmospheric dust
- Bird Droppings
- Ash from wildfires.
- Pollen from adjacent trees
- & Other factors.
Potential Induced Degradation is a type of degradation that can build up in solar panels (and therefore arrays) over time. When the surface of the panel is dirty, it allows for interaction between these internal and external fields of the system. This interaction is the breeding ground for PID. Apart from these there is a brief summary of table which shows some generation along with increase of Cleaning cycles of Solar Panels, which is shown below:
| Parameters | Twice weekly Cleaning |
Once weekly Cleaning |
Once biweekly Cleaning |
No Cleaning |
| Energy loss (%) | 1.5 | 3 | 7 | 25 |
| Power generation output(kWh/yr) | 1600000 | 1500000 | 1400000 | 1200000 |
| Tariff (Rs. /kWh) | 5 | 5 | 5 | 5 |
| Total annual loss in energy (Rs./yr) | 120000 | 225000 | 490000 | 1500000 |
| Cleaning Cost per cycle | 5000 | 5000 | 5000 | 5000 |
| Total no. of cleaning cycles | 8 | 4 | 2 | 1 |
| Total Cleaning Cost (annually) | 480000.00 | 240000 | 120000 | 60000 |
Comparative analysis of Profits for increasing Cycle frequency
In above where in case of “No cleaning” condition the Cleaning cost is approx. rs. 60,000 where the total annual loss is approx. 15 lakhs rs. That shows the Loss in terms of Owner, but if cleaning cycle goes to 8, then Cleaning cost is approx. 4.80 Lakh rs. & total loss is approx. 1.20 lakh rs. So there is savings of rs. (4.8-1.20)=3.60 lakh rs. from owner. If we compare the 8 Cleaning cycles with no cleaning cases, then we can visualize that in case of “No Cleaning” where annual generation is 12 lakh units , same will be 16 lakh units in case of 8 cleaning cycles. So if we go for 8 cycles then (16-12)=4 lakh units will more be generated & considering tariff rs. 5 approx. profit goes to =(4*5)=20 lakhs rs. Also in terms of cleaning cost , if we go for 8 cycles, the cost approx. 4.20 lakh rs. are to be added (from table). So investing 4.20 lakh rs. the profitable amount rs.20 lakh approx. This is most profitable from owner’s side. This is a real example of economics of Solar Panel Cleaning in terms of financing. This shows the pathway for Robotic advanced module cleaning methodology in upcoming days & we believe that it has huge potential to penetrate in this market.
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