Solar power and other renewable energy technologies are achieving grid parity here in the United States and in other countries as well. What this means is that technology is improving to the point that the price per kilowatt hour has dropped to the same levels as coal- and gas-fired electricity generation. This is due to the essential difference between burning extractable resources and the development of methods to extract free energy from the environment. Coal, oil, and natural gas are not energy sources but fuel used to create energy through mechanical work.
Solar power changes this equation to a net positive. The sun provides energy directly. The only challenge is to effectively harvest that power for electricity production and that is ultimately an engineering challenge to be solved. Existing systems such as photovoltaic cells that convert lightwaves into electricity or concentrated solar power mirror arrays using focused radiation to superheat a working fluid for turbine generation have shown both experimental and practical rewards.
The spread of rooftop PV panels on the commercial market have provided immediate benefits for both residential and commercial customers. Office buildings, large retail stores, technology centers and university buildings have adapted rooftop solar systems to reduce their own electricity costs by substantial margins. Residential customers are even experiencing the benefits of metering with the local utility companies, receiving paybacks for producing their own power.
Certain technological limitations have bedeviled scientists and engineers attempting to solve the ongoing problem of increasing energy efficiency in the technology. This entails not only the prevention of significant losses through inversion (changing current from DC to AC and back again) but also to squeeze out as many watts as possible for usable power. Another limitation long plaguing solar systems is that of the type of solar radiation that can be usefully harvested. PV cells at present can only utilize orange/yellow visible light for electricity production. However, a new concept being pursued by researchers involves only a slight modification in the design of solar panels that will make it possible to up-convert low-frequency infrared light into higher-frequency visible light. This vastly improves efficiency and makes useful electrical production possible even on cloudy days. Follow the link to look this up and learn the details of this innovation.