An enormous flow of useful energy, thousands of times the current usage of humans, reaches the Earth's surface in the form of solar radiation. While a portion of this flow is used to power most processes in the natural world, a substantial amount could be collected for human utilization. Because conversion of solar energy does not directly involve exchanging matter with the environment, it is possible to use large amounts of solar energy without emitting greenhouse gases.
Though its potential is large, solar radiation has a relatively low energy density and is intermittent. The low energy density requires solar energy to be harvested over large areas, affecting the size and material intensity of collection systems. Modern solar energy collection devices are inefficient and expensive compared to other energy conversion technologies. These drawbacks cause direct solar energy to continue to be a minor component of the global energy system.
Research enabling higher efficiency and the use of cheaper materials could allow the solar energy resource to contribute significantly to a lower greenhouse gas emissions energy system. Advances in molecular-scale material engineering and direct biological conversion of solar energy to energy carriers may aid pursuit of this goal.
Investigators in Solar
