Why do we need to clean solar panels?
The answer is well known but the cost is often kept a secret from some investors. Solar panels get dirty just like the window on our house; they need cleaned regularly.
There are several options to clean solar panels, these are:
- Cleaning by hand
- Crawler based cleaner
- Manual robots
- Autonomous smart robots
Cleaning by Hand
We can clean the panels with cheap labour and brushes.
The cost is low but the team on a 5MW farm will never finish the job. It’s like painting the Golden Gate Bridge it is never finished!
It’s known that 20 men can clean 4000 m2 per week at a cost ranging $2,000 to $10,000 USD per day.
Crawler based cleaning system
Crawlers can be set up with brushes from 2 to 6 metres in width. You can clean with one pass at a speed of 2 km [1.2 miles per hour]. The cost of this option is 0.06 cents per metre or [ 3 feet].
The capital cost is high therefore you would need 1000 km of panels to clean per annum.
This option is cheap with simple robots selling for around USD 2,000. How they work:
You need staff at a cost of between 400 to 800 per day to place the Robots on the panels. If you are cleaning with water you will need to demineralized as using bore or tank water may stain the glass and leave dirty stain marks on the glass. These marks may cause a hot spot and in turn damage the panel or reduce the output.
The clean speed tis 15 to 20 metres [49 to 65 feet per hour] per hour.
The labour and running cost of the manual robot is approx. 0.06 cents USD
Capital cost is lower, cleaning speed is lower at 700 to 900 metres [2296 to 2952 ft] per hour.
Smart Autonomous Robots
In January there will be a smart autonomous solution for solar farm owners. How it works:
Each Robot has a sensor on top and alongside the recharge solar panel. It measures the local weather; like wind and rain plus the level of dust, pollen and other materials.
The robots are smart and once the panel reaches the pre-set level of dirtiness, the robots start automatically. All the robots are parked at the end of each row in a parking bay just waiting for the sensors on top of the Robot to signal to the
software to start the cleaning cycle. The cycle starts once the sun goes down and the Array is in sleep mode.
The robots work on a rail system as these units are autonomous [unmanned].
The system is fast, works without guesswork; removing the risk of over-cleaning and unnecessary cost and can be managed by the cloud base software.
Capital cost is little higher than the manual robots, but has the lowest possible cleaning cost of $3.69 USD per metre per year metre or [ 3 ft]. These calculation are based on an autonomous clean each week. If you manage a clean each week the power output and revenue remain unchanged.
As you see each option has the same cleaning costs. However, it doesn’t take into account the time it takes to clean and the loss of power output between cleans.
Long term planning & investment should consider maximizing the return for investors. Cleaning the panels should be done as required or at less weekly. To do this the only model is the Smart Autonomous Robots.
It’s time to reduce costs and use technology to increase the balance sheet.