Radiant heat and natural light are all products produced by the sun. This energy can be harnessed for multiple uses that appear to be limited to the human imagination and ingenuity.Solar energy is perhaps the most wholesome, and most readily available, renewable energy source available, and there is available technology to harness this energy, there are still significant challenges to more widespread use and adoption.Perhaps the biggest challenge to that energy industry is to develop and introduce mass production and distribution systems that will eventually result in lower unit costs that may be comparable to those of other fossil fuels sources.There are four main ways in which solar energy can be harnessed. Perhaps the most advanced is the photovoltaic process or the physical process of converting light to electricity. First observed in 1890, the photoelectric effect became the subject of considerable scientific research and in fact the most noted physicist of the last century, Albert Einstein was awarded the Nobel Prize for his work on photo electricity. Today, due to continuing technological advances Photovoltaic has become cost-effective and is being used extensively but not exclusively in a rapidly expanding fashion. The sun’s energy can also be used to produce both heating and cooling systems in both residential and commercial environments. This energy can also, obviously be used for lighting.Concentrating solar power (CSP) plants generate electricity by using mirrors or lenses to efficiently concentrate the sun’s energy. CSP employs technologies that concentrate the sun’s thermal energy to drive a conventional steam turbine. CSP also include a parabolic dish to increase the energy concentration in producing increased amounts of electricity.There are different ways in which solar energy is employed. Active solar energy systems use tools and instruments that convert the sun’s heat or light to other forms of energy. Passive solar refers to designing or building materials that take advantage of the sun’s position and availability such as solar panels.As a result of the increased awareness about the reliability and efficacy of solar technology, along with concerns about rising costs of energy derived from fossil fuels, uses of solar energy has exploded since 2005. The U.S. solar energy market has grown more than 100 percent in 2010, making it the fastest growing energy sector. This has been largely due to installations of policies at both the state and federal levels, along with incentives such as tax breaks offered to businesses, that were combined with innovative business models that are driving the cost of solar down at an accelerated pace.Solar electric capacity has more than doubled over the last year to reach 956 Megawatts in 2010. This trend is not expected to slow soon, with solar Photovoltaics installations projected to double again in 2011, and the sun may indeed be shining for solar energy.