BRUSSELS, Nov 30 (Reuters) - The European Commission unveiled a reform of Europe's power grid after 2020 on Wednesday, proposing to cut energy waste, better integrate renewables and phase out subsidies for coal-fired electricity generation.

The draft law, which still needs to be approved by member states and the European Parliament, sets a binding target to cut energy use by 30 percent by 2030 and for renewable energy to make up at least 27 percent of the bloc's power mix by 2030.

The EU executive's proposal limits wind and solar energy producers' right to be the first to sell their electricity into the grid for new projects in nations where renewables already account for a large share. But it will maintain the provisions for existing and small-scale installations.

It also caps the share of crop-based, or first generation, biofuels used in transport at 3.8 percent by 2030, seeking instead to phase in advanced biofuels and electrification to reach 6.8 percent by 2030.

Aiming to remove barriers to cross-border power flows, the Commission proposal sets up regional centres to improve cooperation among grid operators and hands more power to the EU's energy regulatory agency ACER.

It sets stricter rules on schemes to support stand-by power as insurance against blackouts, including a CO2 limit of 550 grams of CO2 per kilowatt hour for power plants.

(Reporting by Alissa de Carbonnel; Editing by Robert-Jan Bartunek) ((; +32 2 287 68 34; Reuters Messaging: Twitter: @AdeCar))