Waterless Solar Panel Cleaning: A Complete Guide for India

Waterless (or “dry”) solar panel cleaning removes dust from modules with brushes instead of water, detergents or pressure washers. In a country where most solar capacity sits in water-stressed regions, it has gone from a niche idea to the default choice for many plant owners. This guide explains what waterless cleaning is, why it matters in India, how it works, and how to choose the right waterless method for your installation.

Why cleaning matters at all

Dust and grime on module glass block sunlight. Research by consultancy Bridge to India, reported by pv magazine India, found soiling can cut plant performance by 3–6%, and that around two cleaning cycles a month are needed to keep losses near 1%. Uncleaned panels in dusty seasons can lose far more. Cleaning is therefore one of the most valuable routine jobs on any solar plant, large or small.

The problem with cleaning using water

• Scarcity. The same research found that about 94% of India’s installed solar capacity sits in areas of medium-to-high water risk, and a large share of the water used comes from borewells.
• Volume. O&M contractors reported using roughly 1–4 litres of water per module per cleaning cycle. On a large plant cleaned twice a month, that is millions of litres a year.
• Rising cost. Water prices in Rajasthan roughly doubled in three to four years, and cleaning already accounts for 26–35% of O&M costs.
• Quality issues. Hard water leaves mineral spots, detergents can leave residue, and wet dust can turn into mud streaks if cleaning is rushed.
• Policy direction. In 2019 the Ministry of New and Renewable Energy asked states and the solar industry to preferably use robotic and other waterless cleaning to save water.

How waterless cleaning works

Most Indian soiling is dry, loose dust. A soft brush sweeping across the glass lifts and pushes it off the module edge, with no need to dissolve anything. The key is doing it often, before dew and drizzle bond the dust to the surface. There are three main ways to do it:

1. Hand-operated dry cleaners

A brush head on a long telescopic pole, pushed along the panels by one person standing on the roof or ground. Ideal for homes, small rooftops and sites with short or broken rows. The Aqualess Cleaner from MROBOTICS is an example, with a dual-bristle brush head (soft and firm fibres) and Residential and Industrial models.

2. Semi-automatic and manually operated robots

A robot that cleans a row on its own, but is started or moved between rows by an operator. A good step up for small and medium plants. The Solar Glide LTE is designed for this, with simple controls and a swappable battery.

3. Fully autonomous robots

Robots that clean every row on a schedule, charge themselves from a built-in solar panel, and report status to an app or cloud dashboard. Best for commercial, industrial and utility-scale plants. The Solar Glide BASIC, PRO and PRO MAX cover this range.

Benefits of going waterless

• Zero water bills and no tankers. No borewell drawdown, storage tanks or transport.
• Cleaner more often. Because a cycle costs little, you can clean weekly or even daily, which keeps generation consistently high.
• Lower running cost. Less labour, no water purchase.
• Safer. No wet, slippery rooftops, and with robots, nobody needs to walk the panels.
• Better for the community and environment. Water stays available for people and agriculture.

Is dry cleaning effective?

For the everyday dust that causes most soiling loss, frequent dry brushing is highly effective. Occasional stubborn deposits, such as dried bird droppings, can be spot-cleaned with a damp cloth. The real enemy is infrequent cleaning: dust left for weeks is harder to remove by any method.

Is dry cleaning safe for panels?

Yes, when it is done correctly with soft, purpose-made brushes and light pressure. Research shows that abrasion depends on both the cleaning equipment and the module’s anti-reflective coating, which is why brush quality matters. We cover the evidence in detail in our article on whether dry cleaning scratches solar panels.

Which waterless method suits you?

Installation	Recommended approach
Home rooftop (a few kW)	Aqualess Residential hand cleaner
Factory or commercial rooftop with short rows	Aqualess Industrial or Solar Glide LTE
Commercial or industrial plant with continuous rows	Solar Glide BASIC or PRO
Utility-scale solar farm	Solar Glide PRO or PRO MAX

For a deeper look at robot options, read our guide to choosing a solar panel cleaning robot.

Available across India

MROBOTICS is based in Vadodara, Gujarat, and supplies waterless solar panel cleaning solutions to cities and remote sites across India. If you are searching for solar panel cleaning near you, get in touch and we will recommend the right setup for your site.

Frequently asked questions

What is the difference between dry cleaning and waterless cleaning?

They mean the same thing: cleaning solar panels with brushes and no water or chemicals.

How often should I clean with a waterless system?

Weekly to fortnightly for manual dry cleaning in dusty months; robots are usually set to clean daily or every few days.

Can waterless cleaning remove bird droppings?

Fresh droppings often brush off; dried ones may need a light wipe with a damp cloth.

Sources: pv magazine India / Bridge to India (2018); IamRenew (2019).