Renewable energy is the way of the future, we are told. It is inevitable. Some renewable energy advocates boldly claim that the world could be powered by renewable energy as early as 2030 – with enough government subsidies, that is. And of course, the mainstream media play their part, hyping up the virtues of solar and wind energy as the solution to climate change.
In one regard, they are quite right: in terms of generational capacity, wind and solar have grown by leaps and bounds in the last three decades (wind by 24.3% per year since 1990, solar by 46.2% per year since 1990). However, there are two questions worth asking: (i) are renewable energies making a difference, and (ii) are they sustainable?
To answer the first question: No, wind and solar energy have not made a dent in global energy consumption, despite their rapid growth. In fact, after thirty years of beefy government subsidies, wind power still meets just 0.46% of earth's total energy demands, according to data from the International Energy Agency (IEA). The data include not only electrical energy, but also energy consumed via liquid fuels for transportation, heating, cooking, etc. Solar generates even less energy. Even combined, the figures are minuscule: wind and solar energy together contribute less than 1% of Earth's energy output.
Bottom line: Renewables are not making a difference. It would be far more cost-effective and reasonable to simply invest in more energy-efficient technology. But of course, doing so would not line the pockets of billionaires like Elon Musk.
To answer the second question: Is renewable energy sustainable? Is the future wind- and solar-powered?
Looking first at wind energy: Between 2013 and 2014, again using IEA data, global energy demand grew by 2,000 terawatt-hours. In order to meet this demand, we would need to build 350,000 new 2-megawatt wind turbines – enough to entirely blanket the British Isles. For context, that is 50% moreturbines than have been built globally since the year 2000. Wind power is not the future; there is simply not enough extraditable energy. Unfortunately, better technology cannot overcome this problem: turbines can become only so efficient due to the Betz limit, which specifies how much energy can be extracted from a moving fluid. Wind turbines are very close to that physical limit.
The state of solar energy is only slightly more promising. Recent findings suggest that humanity would need to cover an equatorial region the size of Spainwith solar panels in order to generate enough electricity to meet global demand by 2030. Not only is this an enormous amount of land that could otherwise be used for agriculture, or left pristine, but it also underestimates the size of the ecological footprint, since only 20% of mankind's energy consumption takes the form of electricity. Were we to switch to electric vehicles, the area needed would be five times as large.
Even if the world agreed to take this project on, it would not be possible due to resource limitations. For example, each 1.8-square meter solar panel requires 20 grams of silver to build. Since there are 1 million square meters in a square kilometer, 11.1 tons of silver is needed per square kilometer of solar panels. Spain is 506,000 square kilometers. Covering this much space with solar panels would require 5,616,600 tons of silver. As it turns out, that is 7.2 times as muchsilver as is estimated to exist in Earth's crust. Granted, new technology could mitigate the need for silver, but this same logic applies to dozens of other minerals present in solar panels. They are simply not feasible on a large scale because they are resource-hungry.
One must also remember that such massive investments in solar panels would inevitably contribute to resource scarcity: modern electronics require many of the same minerals as do solar panels. Increased competition for a finite supply of minerals would raise the prices of our electronic goods, as well as the price of electricity. Of course, this analysis wholly ignores the many other problems with solar and wind energy, such as the problem of intermittency and the hidden systemic risks it entails.
This is not to say wind and solar energy have no uses. In some cases, they may be preferable to other types of energy. For example, in remote locations townships and homesteads can benefit greatly from local electricity production, especially since renewable energy does not require fuel. However, wind and solar energy are unlikely to underpin the global energy supply, so long as more cost-effective and efficient options remain on the table.