The costs of producing solar energy on a large scale are currently too high to make it a viable alternative power source. Existing solar power plants are heavily subsided by the government (and by consumers) in the hope of spurring innovation and to appease the public appetite for clean energy.
The technology is yet to become competitive in terms of cost. The solar panel firm, SunEdison, filed for bankruptcy protection in 2016. And yet consumers are becoming increasingly interested in adopting the benefits of solar power.
The main reasons why it's currently not realistic for communities to rely on solar power include:
Future engineering solutions may help solar power to become more viable on a large scale (i.e. better manufacturing techniques). But future discoveries in semiconductor materials are needed to make solar cells more efficient. Efficiency certainly is improving, though; solar sunflowers have a stunning efficiency of around 80%!
Still, the fundamental problems are that solar (and wind) power require expensive equipment and lots of land but does not produce constant power. This leads to idle equipment, lower power reliability and therefore, higher production costs.
Alternatively, agricultural land can be used to grow corn and sugar-cane which can be converted into a burnable fuel (i.e. ethanol) to create steam to turn a turbine. However, the costs associated with harvesting and fuel conversion are also exorbitant.
However, using land to grow fuel instead of food has a moral cost since crops would be diverted to create fuel instead of going to feed hungry people.
For some smaller applications, solar energy can be used to reduce home heating and electrical bills. People can take advantage of the sunlight to warm their home and help offset their primary heating source. (See: How does solar heating work?)
Installing solar panels to create electricity is also a viable solution for homeowners but the payback period is typically years long (5 - 20 years depending on the power requirements, location & climate). The approximate costs of producing solar energy on a small scale are as follows:
The costs of producing solar energy have come down dramatically over the years, but for many - if not most - homeowners, the cost of 'going solar' is still too prohibitive. Further technological advances are still needed to make solar power more efficient, more affordable, and widely available before it can gain better traction.