Aigner blocked the new financing proposal put together by Environment Minister Peter Altmaier and Economy Minister Philipp Rösler, which suggested compensation costs for delays in putting Germany's off-shore wind parks on the grid should also be carried by consumers.
The move has sent fresh ructions through the government coalition, which comprises the Christian Democratic Union (Altmaier's party), the Free Democratic Party (led by Rösler), and the Christian Social Union - Bavarian sister to the CDU - which Aigner belongs to.
Lower Saxony's FDP Environment Minister Stefan Birkner was livid, saying that Aigner had had "a blackout." "The CSU is torpedoing the energy transition," he told the Hamburger Abendblatt, referring to the government's long-term project of switching Germany from nuclear to renewable energy.
"Mrs. Aigner's position is irresponsible, she is endangering investments and jobs in northern Germany," he said.
But Aigner does not look like budging - a ministry statement said the proposals were a burden on the energy consumer. "They are not controllable and cannot be squared with market-based principles," the statement said.
The plan proposed by Altmaier and Rösler promises the energy companies who own offshore wind parks financial compensation if their parks are cut off from the grid for any length of time.
Aigner's reservations means that the cabinet cannot agree the proposal on August 29 as planned.