A final statement after the meeting did not even mention coal, a major contributor to global warming.
The dirty fuel is also a key energy source for many developing economies such as India -- the world's most-populous country -- and China, the world's second-largest economy.
Campaigners were dismayed by the failure to reach agreement in Goa on COP goals including tripling the world's renewable capacity and doubling energy efficiency by 2030.
It came despite G7 leaders agreeing in Hiroshima in May to "accelerate the phase-out of unabated fossil fuels".
Global temperatures are hitting record highs, triggering floods, storms and heatwaves.
Explaining the stalemate, G20 president India said that some members had emphasised the importance of seeking a "phase down of unabated fossil fuels, in line with different national circumstances".
But "others had different views on the matter that abatement and removal technologies will address such concerns," it added.