Solar energy has been growing exponentially since 1992. And in 2015, it has been able to compete with other conventional sources of energy since grid parity(the situation where an alternative energy source has become as cheap or even cheaper than the power bought from the grid) has already been reached in around 30 countries. Solar energy is now the fastest-growing renewable energy source. Now, in terms of capacity, solar energy has been at par with nuclear energy globally. In 2015, it has reached a global installed capacity of 350GW, while nuclear energy is at 391GW on the same year. In addition, with the current rate that solar energy is growing, it has been predicted that it will overtake the use of fossil fuels by 2050, with most of the globe running on energy produced by the sun.
So, without a doubt, solar energy is the energy of the future. But how was it able to achieve this unprecedented growth? It can be attributed to some characteristics of solar energy that gives it an advantage over all other forms of energy sources. These are: 1.) being a readily-available fuel source, 2.) modularity, 3.) continuous drop in cost and 4.) improvements in solar PV technology.
READILY AVAILABLE FUEL SOURCE
Every energy source that is not renewable(fossil fuels and nuclear) all rely on some sort of a limited fuel source. Also, these fuel sources are not readily available anywhere in the world. This is very different with solar energy, where its fuel source, the sun, shines literally everywhere on Earth. This means that everyone in the world, can utilize solar energy as an energy source as long as there is available land or roof area and provided that these areas are not shaded by obstructions. Even wind energy, another renewable energy source, does not have this advantage because wind turbines have requirements in terms of geographical location (in reference to wind currents) and how higher it should be than nearby obstructions.
Of all other energy sources including wind energy, solar is the only one that can be scaled down from utility scale to commercial, residential and even for the use of single appliances or devices like streetlights, calculators, etc. All other energy source can only be produced in large centralized power plants. Unlike solar energy, you can't use coal, nuclear energy or any other source to power your home..
CONTINUOUS DROP IN COST
The cost of other energy sources is driven primarily by the cost of its fuel source. For solar energy, however, since the fuel is free, the cost is primarily driven by the costs of solar panels. When solar cells were first invented, their usage was limited to powering space crafts and satellites due to the very high costs. Since then, however, the cost of solar panels has steadily dropped. This is because solar cells are primarily made up of silicon, which is one of the most abundant elements on Earth. This makes the costs of solar panels mostly dependent on the manufacturing techniques and processes used, which improves over time. The design of solar cells itself also improves over time, becoming more efficient and uses fewer materials, which would drive the costs further down.
IMPROVEMENTS IN SOLAR PV TECHNOLOGY
Over the last ten years, solar panels have seen many improvements in their design and implementation to reduce costs and improve the installation process. Modern panels and rack materials require minimal rewiring or hardware to install and are lighter and easier to manage than the heavy arrays of decades past. With these improvements, most solar panel installations can be done in a single day.
The other components in a solar installation have also seen swift development. Microinverters are a new alternative to the traditional inverter. Traditionally, a PV array is only as efficient as the least-efficient panel in the rack, since the inverter converts the current of all panels at once. New microinverters convert the electricity supplied by each panel individually, improving the efficiency of the system considerably.
Battery system development slowed after grid connections were standardized, but the technology has seen a new influx of recent interest. Most notable is Tesla’s Powerwall system, which brings home battery systems firmly into the mainstream.
Overall, the biggest development in residential solar is the reduced cost. Solar panel manufacturing dropped dramatically in price with the development of LCD TVs—both technologies utilize huge sheets of glass. This development, coupled with China’s rapid expansion in raw material harvesting and manufacturing, has dropped the price low enough to allow almost all homeowners to consider a solar power investment on their roof.