Join the fight for a renewable world with this indispensable introduction. Solar energy is one of the most essential tools in the fight to create a sustainable future. A wholly renewable and cost-effective energy source capable of providing domestic, business, and industrial energy, solar energy is expected to become a $223 billion a year industry by 2026. The future of global energy production demands researchers and engineers who understand the physics of harnessing, storing, and distributing solar energy.