The measure passed in a 98-1 vote with one abstention in the upper house of parliament on Thursday, Poland’s PAP news agency reported.
The legislation, which was earlier backed by the lower chamber of Poland's bicameral parliament, now reverts to the lower house for a final vote after the Senate made a number of modifications to the proposal.
The legislation is then expected to go to President Andrzej Duda for signing into law.
Poland's conservative government last month proposed a one-off allowance to help households buy coal for home heating amid soaring energy prices.
Under the bill, all families that use coal for home heating would be eligible for a one-off PLN 3,000 (EUR 630, USD 640) allowance to cover part of the cost.
Climate and Environment Minister Anna Moskwa has told reporters the new allowance will replace an earlier measure that set a guaranteed price of PLN 996.60 (EUR 210, USD 213) per tonne of coal purchased by households.
The government has earmarked some PLN 11.5 billion (EUR 2.4 billion, USD 2.46 billion) for the initiative, according to officials.
Source: IAR, PAP