Temperatures in New York will be higher than in Bahrain, the release of diseases such as bubonic plague will come out of the Siberian ice, the world economy will collapse, etc. In the face of such apocalyptic predictions, can humanity switch to 100% renewable energy?
At first glance, the answer to this question seems depressingly obvious. Despite cost reductions, wind and solar energy still make up only 5.5% of global electricity. Hydropower is a much more important source of renewable energy, but its costs are rising and investments are falling.
On the other hand, over the past decade, solar photovoltaics (PV) and wind energy have been successful as sources of electricity. In some countries, solar PV are now cheaper than coal and gas. For countries such as Denmark and Scotland, it is now quite common to have situations where the equivalent of all their power comes from the wind.
Moreover, the Senate of California, a state that is close to achieving its goal of generating one-third of its energy from renewable sources, has proposed raising the target to 60% by 2030; Germany's goal is 80% by 2050. But the possibility of generating all electricity only from wind, solar and water resources is the subject of fierce debates.
In 2015, Mark Jacobson from the Stanford University claimed that, by 2050-2055, the electrical, transportation, heating and cooling American industries can be fully powered by wind, water, and sun, without changing weather conditions affecting consumers. As they noted, by abandoning the use of natural gas, biofuels, nuclear energy and stationary batteries, the country would be able to ensure a stable supply at relatively low costs.
Others take a broader view. Specialists from the Rocky Mountain Institute Research Center (Colorado, USA) dismissed the dispute about 100% renewable energy. They believe the share of eco-energy can be increased with ease, perhaps up to 80%. But in order to drastically reduce emissions, the world should focus on designing more advanced buildings and factories and using lighter materials, as well as maintaining a small share of natural gas in the structure.
Some skeptics are concerned about the economic consequences if the spread of renewable energy sources increases significantly. If we focused on the energy efficiency of solar PV and wind turbines, which represents the ratio between the amount of energy they produce and the amount of energy invested to create them, we would find out it is significantly lower than that of fossil fuels. The use of renewable energy sources to produce half of the world's electricity would leave less energy to supply other types of economic activity.
Moreover, other studies show that revenues from energy derived from fossil fuels have declined and will continue to decline as they incur additional costs associated with pollution and climate change. A high proportion of renewable energy sources may be less effective in stimulating economic growth than fossil fuels during the last century.
What about you? Do you believe in a world where all energy is ecological?
