Today efficient provision of energy is crucial, and since non-renewable sources of energy will eventually be depleted, we must transition to other, renewable sources. The four main sources of non-renewable energy today are oil, natural gas, coal and nuclear energy – some of which also have a substantial negative impact on the environment. However, there are cleaner options – renewable energy, that naturally will not run out or be depleted. The main sources today are wind energy, hydropower, biomass, geothermal energy, and of course, solar energy.

But how efficient is solar energy actually? A study conducted by New Jersey Institute of Technology in 2017, has ranked solar energy efficiency in the top five among the renewable energy sources, a study that however consider nuclear energy to be a renewable energy source. The measure used by the institute to calculate current levels of efficiency takes the total cost of maintenance, possible fuel cost, the initial production costs and the costs of damage to the environment into consideration.

How Efficient Is Solar Energy?

Despite solar technologies already being extensively used around the globe, more research is continuously being conducted on a large scale which will further increase the efficiency of solar energy, potentially lowering the initial costs of producing solar panels massively (Kabir et al. 2018). A study by the International Energy Agency predicts that solar energy could have overtaken both the other renewable sources of energy as well as the fossil fuels by 2050 – this prediction is based on how much the cost of producing solar panels has decreased in recent years. These two studies suggest the possibility of a high increase in efficiency for solar energy.

Kabir et al. also conclude that solar energy has the highest potential to provide energy globally. A huge advantage compared to other types of renewable energy is that sunlight is available everywhere on earth, despite differences in amount.

Comparing fossil fuels to solar energy in terms of efficiency is not too easy, because of the many dimensions and factors to take into consideration. An article of EnergySage suggests that (cost-wise) solar energy, despite often being subsidised by governments, seems to be cheaper per kilowatt on average in the world – and that is even without taking all the other, environmental benefits into consideration. A paper by Kåberger also suggests this; looking at all the different types of renewable energy Kåberger says that purely economically, coal is still cheaper when it comes to producing energy per kilowatt, but states that there are many other factors, like environmental costs,  that cannot be overlooked when choosing what type of energy to use in the future.

Factors Affecting Solar Energy

The efficiency of solar energy can be generally divided into two categories; the amount of sunlight that reaches the earth and could potentially be converted into energy, as well as the technology that is used to harvest the energy from the sun. Kabir et al.’s study provides an overview of the factors that affect solar energy efficiency generally. A critical factor when it comes to how efficient solar energy is, is the amount of sunlight that reaches the earth. About 30% of the sunlight is being reflected or scattered by the earth’s atmosphere – the rest of the light will reach the surface of the earth unequally distributed but potentially useful for energy production. The amount of sunlight, which directly translates into different levels of solar energy efficiency, varies according to the time of the day, the climate in the area and the latitude. The annual average shows that equatorial Africa receives the most sunlight, but also areas like Australia, South America, the Middle East, southern parts of Asia and the south-west of the US receive quite high yearly rates of sunlight.

There are also other conditions related to efficiency in this area; a high altitude, low amount of dust particles in the air as well as a low humidity in the air all contributes to the solar energy efficiency. Ideal conditions for these factors are for instance found in Morocco in North Africa and on the Tibetan plateau in China.

Kabir et al. classify the technologies used to harvest solar energy into two categories; passive and active solar technologies. The passive technologies do not use any mechanical parts in order to transform the energy; an example is keeping your house warm through construction techniques that trap the heat from the sun inside of the building. The active solar technologies convert the sunlight into electric energy (photovoltaic technology) or harvest the heat (solar thermal technology), either to use directly for heating e.g. water, or to convert the heat further into electricity. Today, the photovoltaic technologies are the most used form to capture solar energy.

The Advantages of Solar Energy

The most central benefit that first comes to mind when talking about solar energy is the characteristic of it being non-depletable, as opposed of course to the fossil fuels. Despite differences in the amount of sunlight depending on time of the day or location on the earth, there is an abundance of sunlight – which gives it an advantaged also over a number of renewable energy sources, like geothermal energy which can only be harvested on very specific locations on earth.

The environmental impact of solar energy production is also minimal – which makes it a potential substitute for e.g. oil, which highly impact the climate negatively through high emissions of CO₂ or even renewables like biofuel associated with certain harmful emissions.

Another benefit of solar energy is the cost; despite solar cells being high in cost to produce and install, the maintenance and upkeeping costs are low, or almost non-existent – unlike the constantly high wind turbine maintenance. Another cost-advantage is that the energy production process itself doesn’t require any energy. From a long-run perspective, solar energy therefore is an economically viable solution.  Related to cost is the price stability of solar panels; they won’t fluctuate in price in the same way as e.g. oil generally does. Compared to the non-renewable energy production and its high capital intensity, transitioning to solar energy could create more jobs, as the solar energy production is comparatively more labour intensive.

Solar energy relies on solar panels that work individually, which means that even in case one panel is damaged or fails, the rest of the panels continue to supply the users with energy. The characteristic of flexibility also contributes to the solar energy efficiency; the panels can be installed close to where the energy will be used, such as the roof of the consumers house. This feature could solve energy supply problems in remote areas where installing traditional electricity lines is close to impossible, or in areas that lack the possibility to utilize other, more location-dependent renewable energy. Another factor that makes this possible is that the solar panels are completely silent and do not contribute to any noise pollution – a well-known problem in the production of wind energy.

There exists, as with everything, certain disadvantages as well, such as high initial costs that need a larger capital input, as well as some pollution during the production process of the solar panels, but as seen in this section, the advantage of solar energy are extensive. To summarize; solar energy production is based on a renewable source of energy, doesn’t have any significant negative impact on the environment and climate, is very cost efficient in the long run and could create a lot of jobs connected to the instalment of solar panels. Solar energy as the main form of energy production could potentially lead to a healthier population and contribute to a more reliable and more wide-spread supply of energy.

Benefits Of Solar Energy And The Solar Energy Efficiency

Solar energy efficiency depends on the amount of sunlight and the technologies used to utilise this energy. Compared to other renewable energies, it ranks highly and has the potential to become the most efficient one. The benefits of solar energy are varied:

• Low long-run costs
• Low environmental impact
• Flexibility

Compared to fossil fuel, solar energy is already competitive when it comes to price, and has a significantly lower environmental impact. Are you considering investing in a solar farm for yourself or for your business? You might be interested in a free photovoltaic marketplace where small and large systems are traded, whether you are looking for project rights or systems in operation, rooftop or ground-mounted, new or old photovoltaic systems. You simply need to register – which is also free!