The energy that reaches Earth from the sun in an hour is enough to satisfy the electrical needs of the entire population for one year. Until recently, however, there hasn’t been any effective way to harness that energy. Technological advances have given us the ability to collect it, convert it into electricity, and even store it for later. According to the BBC, in 2019, installed solar power worldwide amounted to 600 gigawatts, a significant increase from 20 gigawatts of installed solar capacity 10 years earlier. By the end of 2020, that capacity will probably increase by 105 gigawatts. For perspective, a single large power station can put out approximately one gigawatt of electricity.
With such significant growth in the solar power industry, it makes sense to have at least a general understanding of how it all works. Here is an overview of some of the technology behind solar energy.
The major disadvantage of solar energy is that it is not available at a consistent level at all times. Depending on the season, time of day, and weather conditions, the amount of sunlight at a particular location can vary. For example, solar power for your home may be less reliable after sunset.
Fortunately, thanks to the solar power battery, there is a way to store the excess power generated and use it when the supply of energy runs low, such as at night or during a power outage. The battery kicks in when the energy supply available is not enough to meet the demand. It provides a constant and reliable supply of energy.
While it is possible to use solar power to turn traditional turbines to generate electricity, it is more common, and much more efficient, to convert solar energy directly to electricity using photovoltaic devices. Photovoltaic devices are coated with a semiconductor material, usually silicon. When exposed to sunlight, the material absorbs most of the energy. This causes electrons in the atoms of the material to dislodge and travel in one direction toward the front of the device. Just as the positive and negative terminals of a battery create a voltage potential, so does the imbalanced charge on a photovoltaic device create the same potential. However, before the energy can be discharged, it is absorbed by electrical conductors and delivered in a circuit.
The efficiency of a photovoltaic device is not 100%. Some energy converts into heat rather than electricity, some is reflected back, and some is simply unusable.
The most basic unit of a photovoltaic device is a solar cell. A single solar cell is not enough to collect enough energy to power a home by itself because it is typically very small. Individual cells are therefore frequently installed together in larger groups called panels or modules. When all the cells are hooked up together in a module, it boosts the power output of each individual cell.
A single solar panel made up of multiple cells may be enough to power a small building. However, the effect can be compounded by installing multiple solar panels on one building to form an array. If there are multiple arrays installed together and hooked up to the electrical grid, it forms an entire photovoltaic system. A large photovoltaic system of this nature can cover hundreds of acres.
Other Types of Solar Technology
While photovoltaic power is the most common type of solar technology, it is by no means the only one. Apart from concentrating solar power alluded to earlier and used to drive traditional engines or turbines, there are also solar heating and cooling technologies. As of now, these technologies are somewhat limited, but the goal is to be able to harness the power of the sun to heat and cool buildings instead of having to use fossil fuels such as natural gas. Similar technologies are being developed for solar water heating.
The negative impact of solar power on the environment is minimal, especially when compared to burning fossil fuels. The technology is becoming more affordable all the time, meaning that growth in the solar power industry is likely to continue, creating more jobs, more opportunities, and more revenue.