Can one solar panel power the world?
From the destruction of the forests to build our homes and clearing for agriculture, and out of the use of fossil fuels to power our lives has come climate change. One of the most impactful ways we contribute to the rising temperature of the planet is through burning fossil fuels.
For around 200 years humans have been exploiting energy-dense fossil fuels as the main driver for economic growth. Currently, around 80% of the world’s total energy consumption is derived from fossil fuels, and a poor 12.5% from renewable resources. In addition to the pollution, environmental and health damage, fossil fuels cause, scientists estimate that their reserves will last another 70 years at the rate they are currently being consumed. We need another fuel solution.
Source: flickr, Jay Peck. Fossil-fueled power plant Neurath, Germany
The solution is solar energy, sustainable and totally inexhaustible.
Sunlight hitting the earth provides 7000 times more energy than we use globally at present. Wouldn’t it seem a waste not to maximise use of this powerful, sustainable source? Solar power is generated when energy from the sun, radiated as light and heat, is converted into electricity. It is the best source of renewable energy as sunlight has by far the highest theoretical potential, making it the most energy efficient and cost-effective renewable energy source.
The maximum conversion efficiency for sunlight into useable electricity is 93%. The current most common solar cells are made out of silicon because of the combination of their high efficiency, low cost, and long lifetime in comparison with other solar cell materials. Although they are highly efficient in regards to different solar cell materials their maximum efficiency is still quite low at 32%. This is mainly due to its ability to use 50% of the sun’s spectrum and its limited band gap (1.1 eV), a higher band gap (of 1.3 eV) would have a higher efficiency according to Shockley-Queisser limit. Solar cells contain materials with semiconducting properties in which their electrons become excited and ‘turn’ into an electrical current when they absorb sunlight (photons). Enhancing the efficiency of photovoltaic devices is currently a huge area of research, and increasingly important in fighting climate change by reducing global use of fossil fuels.
Source: wikicommon. Shockley-Queisser limit curve
So, coming back to our original question. Can one solar panel power the world?
Scientists have suggested that a 500 km by 500 km squared solar panel, most likely located in central Australia (for space and sunlight exposure), can supply the whole world’s energy needs. This single solar panel providing a whopping 16 terawatts of power.
Source: flickr, Oliver Svob. Solar panel, Zadar, Croatia
If a single solar panel can indeed power the world, why not construct it?
The matter is predominately an economic challenge, a matter of payback. Although one of the more cost efficient materials, silicon solar cells are still energy intensive and expensive to produce. There are many additional costs including other necessary materials such as the mounting and cabling as well as labour costs to set up the solar cell. The amount of produced energy required to compensate for the building, running and upkeep costs are not worthwhile for investors to invest in.
Additionally, the distribution of the energy world-wide as well as energy storage is inefficient; making a single solar panel an impractical solution. However, this example demonstrates that it is possible to power the world through solar and widely distributed solar panels are the answer.
Solar energy is the future sustainable energy source for the world. Reducing energy payback and making solar cells more portable is very important as well as continuing the push for better efficiency.