Bangladesh Built the World's Largest Off-Grid Solar Programme

Bangladesh's IDCOL programme installed over 4 million solar home systems, bringing electricity to about 20 million people — the largest off-grid solar rollout in the world.

A rooftop solar panel in Khulna District — one of more than four million systems installed under the IDCOL programme. Photo: Helena Wright, via Wikimedia Commons (CC BY 2.0)

By the UISC BD Editorial Desk · United Information Service Center · Published 9 September 2026 · 6-minute read

In 2003, a government-owned Bangladeshi financial institution called IDCOL began a pilot to put solar panels on the roofs of 50,000 rural households that the national grid had not reached and, realistically, would not reach for years.

The pilot did not stay small. By 2018, IDCOL and 56 partner organisations had installed 4.1 million solar home systems across remote Bangladesh, delivering electricity to roughly 20 million people — about 14 percent of the national population — in fifteen years. At its peak the programme was installing more than 80,000 systems in a single month. It is the largest off-grid solar programme in the world.

The Financing Was the Innovation

Solar panels were not new in 2003. What Bangladesh built was a way to pay for them that worked for households with no savings and no credit history.

IDCOL functioned as a wholesale financier rather than an installer. It provided partner microfinance organisations with refinancing and grants; those partners sold systems to households on instalment plans, handled installation, and provided after-sales servicing. A family paid a modest down payment and then monthly instalments — frequently less than what they had previously spent on kerosene.

The economics were unusually disciplined for a development programme. Analysis cited by the ICED Facility puts the cost to government at around US$700 million for over four million households — roughly US$170 per system. Electricity access for twenty million people at that unit cost is a figure most national electrification efforts cannot approach.

What Changes in a House That Gets Power

The World Bank, which supported the programme, documented the effects. They are consistent and unglamorous: children study after dark; households stop buying kerosene and stop breathing its fumes; mobile phones charge at home instead of at a paid charging shop; small businesses stay open into the evening.

Around 200,000 rural businesses and community facilities were connected alongside households — shops, clinics and religious buildings whose operating hours had until then been set by sunset.

The Programme's Own Success Ended It

Here is the part that is often reported as failure and is better understood as completion. Solar home system sales slowed sharply in the second half of the 2010s — because the national grid finally arrived. Bangladesh's grid electrification expanded rapidly, and a household connected to the grid does not need a standalone solar system.

Academic work published in Climate Policy examined this wind-down under the title "Setting the sun on off-grid solar?", drawing out the policy lesson: off-grid solar is best understood as a bridge technology. Its purpose is to deliver electricity during the years before the grid arrives — not to substitute for it permanently. Bangladesh's programme served exactly that function, at scale, for a decade and a half, and then handed over.

Why It Still Matters

Several hundred million people worldwide still live without electricity, most of them in places where grid extension will take years. Bangladesh's programme remains the largest working demonstration that the gap can be bridged — with a financing structure rather than a subsidy, delivered through existing microfinance networks, at a unit cost low enough to be replicable.

It also sits alongside the country's grid-scale ambitions covered elsewhere on this site: the push toward 10,000 MW of renewable capacity is the next chapter of the same story, at a different scale.

Sources

"Bangladesh Solar Home Systems Provide Clean Energy for 20 Million People," World Bank — worldbank.org
"How Bangladesh rolled out the world's largest off-grid solar programme," The Progress Playbook — theprogressplaybook.com
"Case Summary: Bangladesh's IDCOL Solar Programme," ICED Facility — medium.com/iced-facility
"Setting the sun on off-grid solar?: policy lessons from the Bangladesh solar home systems (SHS) programme," Climate Policy — tandfonline.com

solar microfinance (1)