The effort to mitigate the worst effects of climate change requires a radical shift in how we develop and use energy. That means research into new sources of energy, more cost-effective ways to apply solar and wind power, converting waste into energy, and making the systems we have more efficient. How can we best convert sunlight into energy? What are ways we can store energy from the sun and wind for later use? What are the best ways to capture and store CO2? How can we help bring power to remote villagers living far off the grid?