Wind power is indirect solar energy.
Thermal energy from the sun is the backbone of all energy systems on the planet. Even fossil fuels such as natural gas and petroleum can be traced back to the thermal energy consumed by plants and animals millions of years ago. Solar energy can also be found in less-obvious forms. Harnessing this power can even be as simple as opening a window in your home.
Passive Solar Energy
Passive solar design is an indirect way to utilize solar energy, based on the fundamental laws of heat transfer. Through conduction, molecules transfer heat by vibrating vigorously. Through convection, that warm air then moves from hot zones to cooler zones until there is a complete balance of thermal energy. Also, thermal energy can be collected and redirected with the proper applications of absorbent surfaces. Passive solar design makes use of all these principles by constructing buildings and homes with built-in heat movement and storage units. In fact, the simplest form of passive solar involves the construction of south-facing windows that allow radiant energy to spill in and directly warm the interior surfaces. Everything from the windows to the walls and floors of a building can be optimized for passive solar energy.
Wind Energy
Wind power is actually a form of solar energy created by the uneven heating of the Earth's surface. Through convection, warm air moves to occupy cooler areas. This equalization of thermal pressure is actually what occurs when a breeze sweeps across an open expanse. Utilizing other forms of solar power such as photovoltaics often hinge on adequate sunlight. Yet even in the presence of clouds and stormy conditions, wind turbines can harness the sun's indirect energy. This is one of the reasons that wind energy is one of the fastest-growing alternative energy sources in the world. Wind Solar Energy, an online alternative energy resource, reports that the largest wind farm in North America, the Stateline Project in Washington and Oregon, is planning to build 279 more wind turbines, which will make it the largest in the world.
Biomass
Biomass is both a renewable and indirect form of solar energy. It is essentially the organic materials of trees and plants, which store energy like biological batteries. Plants absorb solar energy through the process of photosynthesis, turning carbon dioxide into carbohydrates. When the plant dies, the carbon dioxide is released back into the atmosphere. Burning firewood for thermal heat is one of the earliest examples of how humans were able to utilize biomass as an indirect form of solar energy. Today, biomass remains the backbone of the alternative energy market. According to the Oregon Department of Energy, biomass provided more energy to the United States in 2002 than any other renewable energy source. A more modern example of biomass is ethanol, a gasoline derivative made from corn or palm-seed oil. In fact, most gas stations in the United States now offer fuels that include ethanol.
