How Do You Calculate the Real Loss from Dirty Solar Panels?

You bought a solar system to save on your electricity bill — but do you know how much you actually save compared to what you should be saving? If the panels aren’t cleaned regularly, the gap between the two figures may surprise you.

Calculating the Loss: A Practical Example

Let’s assume a 5-kilowatt system in Amman, producing on average 25 kWh per day in summer. If panel efficiency has dropped 20% due to dirt:

• Actual output: 25 × 80% = 20 kWh per day
• Daily loss: 5 kWh
• Monthly loss: 150 kWh
• At 0.09 dinar/kWh: 13.5 dinars a month lost in electricity
• Over 4 summer months: 54 dinars evaporated because of dust

Comparing with the Cost of Cleaning

A 5-kilowatt system usually consists of 12-15 panels. The cost to clean it with Crystaleh: 12-15 dinars. This means one cleaning a month at 15 dinars saves you 13.5 dinars a month in electricity — and the return accumulates over time with the cumulative deterioration of dirt.

Every dinar you spend cleaning solar panels comes back as a dinar on your electricity bill — which means cleaning barely costs you anything in the long run.

The Effect of Dirt on Panel Lifespan

The damage doesn’t stop at efficiency. The buildup of dirt and the humidity beneath it accelerates frame corrosion and weakens the integrity of the electrical connections. Panels that are cleaned regularly retain their efficiency longer and need less maintenance over their 25-30 year lifespan.

How Do You Know if Your Panels Are Suffering from Dirt?

• Compare today’s output with the output of the same day last month (check the inverter app)
• Inspect the panels visually in the early morning before the sun’s heat
• Look for brown or yellow discoloration on the edges of the panels
• Watch for circular white spots — a sign of evaporated rain spots