The energy transition is the change to a low-carbon, environmentally rational, reliable and economically affordable model of energy supply. It is a medium to long term transition that requires the active and sustained involvement and engagement of all political, economic and social stakeholders.

The European Union has set a series of targets for 2030 (with intermediary milestones for 2020), in line with its "European Energy Union" strategy:

• 40% cuts in greenhouse gas emissions (from 1990 levels).
• 32% share of renewables in final energy consumption.
• 32.5% improvement in energy efficiency.
• 15% electricity interconnection between Member States.

Within this strategy, it identified 5 main challenges:

• Decarbonisation (a carbon neutral economy by 2050).
• Energy efficiency.
• Energy security.
• Internal energy and research market.
• Innovation and competitiveness.

Each Member State must in turn design and implement its own Energy and Climate Plan with which to meet the Union's 10-year targets (2021-30). These plans had to be approved by the end of 2019. In the case of Spain, with a view to transitioning to an emission-neutral model by 2050 the (draft) Plan establishes the following targets:

• 21% cut in greenhouse gas emissions (from 1990 levels).
• 42% share of renewables in final energy consumption.
• 74% share of renewables in electricity generation.
• 39.6% improvement in energy efficiency.
• 15% electricity interconnection with Member States.

Image: coal-burning power station, an example of the existing energy system, now under transition.