The use of solar energy is on the rise and many people are wondering when we’ll get to a point of being able to power the entire world using solar panels! While the timeline for that is going to be highly dependent on the uptake of solar by governments and civilians around the globe, what we can do is work out just how many solar panels we would need to power significant chunks of our society.
According to figures from the World Energy Council and the International Energy Agency, the sun’s annual potential solar energy is 1,575-49,837 exajoules. One exajoule is the equivalent of one quintillion joules. But as our world energy consumption has been measured to be around a mere 559.8 exajoules, the sun is more than capable of powering the Earth several times over!
The World Factbook estimates that the world uses over 21 trillion kWh of electricity per year. That means we use over a whopping 57 billion kWh per day. But this is only a tiny fraction of the amount of energy we receive from the sun every day, so just how many solar panels would it take to power the world?
Let’s assume that a standard solar panel can generate 1.25kWh per day (a 250-watt solar panel functioning with 5 hours of direct sunlight). To fulfil our global daily electricity usage, we would need to have at least 45.6 billion solar panels working efficiently.
|Country||Annual Electricity Consumption (kWh)||Daily Electricity Consumption (kWh)||Number Of Solar Panels Needed|
Of course, different countries will receive different amounts of sunshine per day. These numbers are also likely to be affected by the quality of solar panels that each country would be able to afford. Although, currently, it is difficult to imagine any of these countries investing the amount of money needed to install the required number of panels to match their daily electricity consumption levels.
If we take the average size of a solar panel to be 1.64㎡, we can use data for each city’s electricity consumption along with the number of sunshine hours per day to estimate the number of solar panels that would be required to power some of the world’s major cities.
|City||Square KM Needed||Number Of Solar Panels Needed|
Just as for the countries, the reality is that the actual numbers will differ from these estimates due to different climates and fluctuations in the number of sunshine hours.
Now that we know how many solar panels are needed to power cities, countries, and the whole world, let’s bring it back to more local (and more realistic) level. While we might not be on the verge of powering entire countries using solar, schools, colleges and universities are often keen to incorporate solar energy in some way.
Schools are a hive of electrical activity throughout the day, with more learning than ever now taking place online using electronic devices. Whether it’s for powering laptops in the classroom, appliances in the canteen, or hairdryers in the changing rooms, a reliable and consistent flow of electricity is crucial for running a school. But just how many solar panels would it take to power an entire school?
Let’s estimate that the average medium-sized business, such as a school, uses roughly 70kWh of electricity and gets on average 5 sunshine hours per day. If the average solar panel is able to produce 250 watts per hour, this would produce 1.25kWh per day. If we compare this to their daily usage of 70 kWh, we can work out that 56 solar panels would be required to power the school each day.