The Coal Plot That Changed Sides: Rampal’s 442 MW Solar Plant Gets an Eight-Hour Battery

Dhaka — The land beside the Rampal coal plant was supposed to grow more coal. On Wednesday it was reassigned. ECNEC, chaired by Prime Minister Tarique Rahman, approved a 442 MWp grid solar project on Block-B of the Rampal complex in Bagerhat, and ordered that the plant carry eight hours of battery storage rather than the four hours officials had been preparing on the side.

If it is built as described, it will be the country's largest solar station, sitting next to the 1.32 GW Bangladesh-India Friendship coal plant and using land that had been held for a second fossil unit. State Minister for Planning Zonayed Abdur Rahim Saki said the switch was deliberate: Block-B will not host another fossil plant. Environmental clearance for the solar project is still moving through the system.

The approval is not the same thing as a finished design. Saki told reporters after the meeting that the Prime Minister had directed battery storage into new renewable projects, so the development project proposal will be revised. The solar plant had originally been drawn to feed the grid directly, with storage handled as a separate scheme. That separation is now gone. Storage sits inside this project, and the duration has been doubled.

What was approved, and what the price tag does not yet say

The paper ECNEC cleared is titled "Construction of 442 MWp (DC) Solar Photovoltaic Grid-Connected Power Plant at Block-B, Rampal." The Planning Commission put the cost at Tk 2,502.39 crore. Of that, Tk 375.35 crore is to come from the Bangladesh Power Development Board's own funds and Tk 2,127.03 crore from the Power Sector Development Fund. Some reports rounded the package to about Tk 2,500 crore, or roughly $200 million. pv magazine described BPDB as investing about BDT 25 billion.

Those figures are the pre-revision numbers. Saki said the cost must be recalculated because storage is going from four hours to eight. The proposal had estimated generation at about Tk 6 a unit with no battery, and about Tk 9 a unit with four-hour storage. A Business Standard account of the same meeting cited a proposed tariff of Tk 6.18 a unit on the version it had seen. Saki said the final Rampal tariff will be known only after the eight-hour estimate is done. For scale, he noted that recently approved private solar projects have come in between Tk 8 and Tk 12 a unit.

BPDB will build it on 685 acres of usable land in Block-B. Other descriptions put the plot previously reserved for the second coal unit at about 371.7 hectares, which is in the same range. The hardware list is conventional utility solar: panels, inverter stations, a pooling substation, evacuation works and civil construction. Power will be stepped up to 230 kV and sent about three kilometres on a 230 kV double-circuit line into the adjacent BIFPCL 400/230 kV substation, so the coal plant's grid connection becomes the solar plant's exit as well.

Timelines in the public record do not quite match. The Asian Age, citing the proposal, says BPDB will implement the project from July 2026 to December 2029. pv magazine reported an implementation window from September 2026 to March 2029. A Business Standard account said completion was targeted for December 2030. The safe reading is that construction is meant to start in the current fiscal cycle and finish around the end of the decade, not that a single date has been locked.

Why the battery is the real decision

A solar plant without storage produces when the sun is up and disappears at dusk, which is often when Bangladesh's demand is still high. Four hours of storage covers the early evening. Eight hours, if it is actually installed at that duration and at a meaningful power rating, can carry a larger share of the plant's daytime output into the night. Saki's line after the meeting was blunt: the Prime Minister had said storage capacity must be included, so the proposal would be rewritten.

That rewrite is also where the project can slip. Batteries are the expensive, imported and thermally sensitive part of a solar-plus-storage plant in a delta climate. Doubling the hours does not automatically double the benefit if the battery's megawatt rating is small relative to the 442 MWp of panels, or if the extra cost pushes the tariff past what BPDB can defend against private solar already priced at Tk 8 to Tk 12. The government has not yet published the revised megawatt-hour figure. Until it does, "eight hours" is a duration, not a measure of how much of Rampal's output will be available after dark.

A small addition to a large target

The project paper puts national generation capacity at 32,332 MW, with renewables at 1,216 MW, or 3.76 percent. pv magazine, using a different installed-renewables count, put the current renewable fleet at 1,871 MW, of which 1,492 MW is solar. Either way, the renewable share is far from the 20 percent of the electricity mix the government wants by 2030 under the Renewable Energy Development Policy 2026–2030.

Rampal at 442 MWp would be the largest single solar plant in the country, and it would matter locally because it replaces a coal expansion rather than merely adding a green project somewhere else. It would not, by itself, close the gap to 20 percent. Rooftop solar is still expected to do much of that work. In September the government opened a $123 million fund for rooftop and other renewable projects, cut the tax burden on solar equipment imports from 17 percent to 1 percent for 180 days, and set a Tk 10.50 a unit tariff for surplus power from eligible net-metered rooftops. Payment guarantees for renewable projects were reinstated earlier in the year.

Saki said the aim was to build the Rampal plant as soon as possible to help meet demand. The proposal's own case is diversification: less reliance on gas, oil and coal, and a cut in emissions, on a site that has been politically defined by coal since the friendship plant was conceived. The feasibility trail is long. BPDB did an in-house study in March 2022. Infrastructure Investment Facilitation Company completed a detailed study in May 2025. pv magazine reported the 442 MW plan in April this year. Wednesday's ECNEC decision is the first time that plan has a political owner and a storage instruction.

The unresolved items are the ones that decide whether this is a power plant or a press release. The revised cost, the battery's megawatt-hour size, the tariff after that revision, environmental clearance, and which completion year survives the rewrite. The land decision is the part that is already real: a block kept for a second coal unit is now the site of a solar station, and the government has said the batteries have to be in the project, not in a sequel.