Future energy system costs will be determined by a combination of technologies that produce, store and distribute energy. Their costs and deployment will change with time due to innovation, economic competition, public policy, concerns about climate change and other factors. Figure 1 provides an historical perspective for how the energy landscape has evolved over the last 140 years. Panel shows the historical costs of the principal energy technologies and panel gives their deployment, both on a logarithmic scale. As we approach the present in panel, the diagram becomes more congested, making it clear that we are in a period of unprecedented energy diversity, with many technologies with global average costs
around $100/MWh competing for dominance.