State-run PGE said that when taking the decision it took into account its near 4 billion zlotys ($958 million) net loss for 2019, the weak performance of its shares and the negative impact of the coronavirus on the economy and on power consumption.
"The management decision is related to ... the ongoing changes in the economic, social and energy business environments," it said in a statement.
The company did not say which projects it plans to scrap and was not immediately available to comment.
It said it would continue to invest in wind farms and solar energy. It also plans to complete the construction of 1.4 GW steam and gas unit at the Dolna Odra power plant.
By 2030 PGE plans to have 2.5 gigawatts (GW) installed capacity in offshore wind and 2.5 GW in solar energy.
It was not clear whether the company will continue a planned investment in a new open-pit lignite mine in Zloczew, a costly project designed to extend the life of its power plant in Belchatow, one of Europe's biggest polluters.
PGE also did not say whether it will still be involved in the construction of Poland's first nuclear power plant.
By Agnieszka Barteczko