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When people think about replacing fossil fuels, the solution seems simple: build more solar panels and wind turbines. But solar and wind output changes with the weather and time of day, while electricity supply must continuously match demand. Otherwise, clean electricity may be wasted during surplus periods, or shortages and outages may occur when generation falls.

**Clean flexibility** refers to solutions that keep a renewable-powered grid balanced and reduce dependence on fossil fuels. Ember groups these solutions into four memorable categories: Store, Shift, Share and Supply. You can read Ember’s overview here: [https://ember-energy.org/focus-areas/clean-flexibility/](https://ember-energy.org/focus-areas/clean-flexibility/).

**Store:** Save excess renewable electricity for minutes, hours or even days, so it can be used when there is less sunlight or wind. Batteries can save excess solar and wind power and release it later, such as during the evening when demand is high.

**Shift:** Encourage consumers to move electricity use to sunny or windy hours, helping lower bills and keep the grid stable. Dynamic tariffs can encourage households to charge electric vehicles or run appliances when renewable electricity is abundant.

**Share:** Use power cables to send surplus wind and solar electricity to places where it is needed, balancing supply and demand across regions. Power cables move electricity between regions. Europe’s interconnected grid links 39 countries, allowing surplus clean power in one country to support another and reducing price volatility.

**Supply:** Make existing power plants more flexible so they can reduce generation when renewable electricity is abundant. For example, India is upgrading thermal plants so they can operate safely at 55% of capacity instead of 70%, allowing more wind and solar power onto the grid while reducing system costs.

Ember groups clean-flexibility solutions into four categories: Store, Shift, Share and Supply.