Energy transition to a renewable energy system will not be easy and will require the deployment of sustainable electricity generation, such as wind and solar power, on a massive scale. Electrification, combined with the rethinking of how and especially when we use energy, is required to reduce carbon dioxide emissions to the atmosphere. Already wind and solar power are becoming the cheapest sources of electricity in many parts of the world, but their share cannot be increased beyond certain limits without destabilizing the electricity grids.