Persistent rain pushes Nigerian solar users back to generators

Every rainy season, Chuka Matthew begins rationing electricity in his Lagos home, not because his solar panels have failed, but because the sun has.

The civil servant invested over N8 million in rooftop solar to escape Nigeria’s unreliable grid, but weeks of cloudy weather mean his batteries no longer last through the night.

His experience reflects thousands of Nigerians who turned to solar power to escape the country’s unreliable electricity grid; however, the arrival of the rainy season has brought an unexpected challenge: finding enough sunlight to keep the lights on.

“My solar panel is not functioning at optimal levels right now because of limited sunlight,” Matthew said in an interview with BusinessDay. “Even after charging it with electricity, it is not able to power gadgets in the house for a long period of time. It needs sunlight.”

Matthew is one of thousands of Nigerians who are in hunt for sunlight as weeks of persistent clouds and frequent rainfall across much of the country have reduced the amount of solar energy reaching photovoltaic panels, leaving homes and businesses with undercharged batteries, shorter power supply hours and, in many cases, a reluctant return to petrol generators.

Under sunlight, his solar panel is able to charge to full capacity and can efficiently power his big freezer. But for over four days, Lagos has experienced heavy rainfall that has flooded homes, cars, and even shut down some businesses, forcing the sun to retreat as gloomy clouds take over.

Solar panels do not stop producing electricity when it rains. The problem is that thick cloud cover reduces the amount of solar radiation reaching photovoltaic cells, meaning batteries take longer to recharge and often fail to reach full capacity after several consecutive cloudy days.

The challenge comes as the country witnesses rapid growth in off-grid solar adoption. Rising electricity bills for unmetered consumers, poor grid reliability and falling prices of solar equipment have encouraged households and businesses to invest in rooftop systems, both in urban and rural centres, like Ikom – a community seated deep inside Cross River State.

Millions of small businesses now depend almost entirely on solar energy to reduce operating costs associated with petrol and diesel generators.

Hybrid systems, which combine solar, battery storage and either the national grid or backup generators, are increasingly becoming the preferred option among commercial users seeking uninterrupted electricity throughout the year.

But while solar remains one of the country’s most abundant renewable resources, seasonal weather patterns mean that standalone systems require adequate storage capacity and realistic expectations about performance throughout the year.

The Nigerian Meteorological Agency forecast at the beginning of the year indicates a longer-than-normal rainy season for Lagos, delayed cessation, and average rainfall volumes up to 1,965mm. The forecast adds severe mid-season breaks in August and persistent risk of flash flooding in coastal and low-lying areas

For businesses already battling high operating costs, the timing could be worse, particularly as heavy rainfall and flooding have a reputation for damaging electricity infrastructure, reducing transmission reliability and slowing maintenance work, added to an already ‘lost’ sunlight.

Only recently, the Transmission Company of Nigeria declared a forced majeure on two strategic substations in Lagos after floods crippled a critical electricity transmission facility, cutting several communities from power.

“The Transmission Company of Nigeria hereby declares force majeure on Oworonshoki 132/33kV and Lekki 330/132kV Transmission Substations as a result of flooding caused by continuous rainfall in Lagos,” TCN said.

Owing to the unreliability of the grid, many are finding themselves returning to petrol generators after months of reduced fuel consumption, eroding some of the financial savings that initially justified investing in solar.

Nigeria’s situation might mirror that of India, where researchers are trying to understand the science of absorbing sunlight to be able to convert it into energy for their sunlight-starved solar panels.

As dark clouds continue to blanket much of the country, many Nigerians who invested in solar to leave generators behind are now looking for ways to store up sunlight and turning once again to the familiar hum of backup engines as they wait for the sun to return.