Renewables: The Paradox
Updated: Mar 18
Modern society is utterly dependent on its use of carbon-based/fossil fuels (coal, oil and gas). Yet our consumption of these fuels means that we dump billions of tons of CO2 and other greenhouse gases into the atmosphere every year. If we do not change course the consequences will be catastrophic. Therefore, at the heart of virtually all climate change proposals such as ‘Net Zero by 2050’ is a plan to switch from fossil fuels to alternative sources of energy that do not emit greenhouse gases. These alternatives include solar, wind, hydro-electric and ocean (wave and tidal) power.
Most of these plans contain within themselves an unspoken presumption that we can simply switch to a modified way of living — for example, from gasoline-powered cars to electric vehicles — and continue our current energy-profligate lifestyle. Few ‘Net Zero’ programs call for us to make a significant cut in our material standard of living, or to live a simpler lifestyle.
The assumption that we can simply switch from fossil fuels to “green” energy sources and continue on our merry way is unrealistic. But, the fact that the transition will be much more difficult than most people think does not mean that we give up on making the switch. However, we do need to temper our expectations with engineering, project management and financial realities. It also means that we should consider the role of technology in a ‘Net Zero’, post-fossil fuel society.
In this series of posts we consider some of the difficulties the transition entails. This first post discusses the Renewables Paradox — the fact that renewables are growing much more quickly than other energy sources, but their share of the overall energy mix is declining.
At the heart of most ‘Net Zero’ programs lies a requirement that we transition from heritage, finite fossil fuel sources of energy (coal, oil and gas) to renewables. Renewable energy is, at least on a human timescale, unlimited in supply. This contrasts with finite energy sources, particularly the fossil fuels: coal, oil and gas; eventually they will either run out or become too costly to extract and process. Moreover, renewables do not emit carbon dioxide (CO2) and other greenhouse gases.
The principal renewable energy sources are:
The ocean's tides and waves
The conventional line of thinking is that we simply replace coal, oil and gas with one or all of these alternative energy sources, and we are home free. This headline from the Green Bay Press Gazette, Cheap solar helps Wisconsin utilities speed up green energy transition as support grows, epitomizes this way of thinking.
The Renewables Paradox
When it comes to the speed with which we are implementing renewables, we are making good progress, but we are also paradoxically, falling behind. This paradox can be seen in the following chart which is taken from BP’s World Energy Outlook (2020). The chart shows how energy consumption has grown in the last 25 years; it also shows the ratios between different types of fuel.
In order to interpret this chart we need to wear our strongest reading glasses, but it is worth the effort. Close inspection of the trend lines shows that,
Renewables are growing faster than other sources of energy.
The fraction of energy provided by renewals is declining.
The reason for this apparent paradox is that natural gas and coal contributed more the overall growth in energy consumption than did the renewables, even though renewables grew at a faster rate. (Another way of understanding this paradox is that a small fraction of a large number can be larger than a large fraction of a small number.)
The organization Our World in Data has developed the following chart based on the same BP source material. Once more, we see that renewables are growing much more rapidly than other energy sources but are still a small and declining fraction of the overall energy mix.
The following Table, also taken from the BP report, further illustrates the apparent paradox. (All values are in exajoules.)
The Table shows that, in the period 2018-2019, renewables grew at a much faster rate than all fossil fuels (12.3% vs. 0.7%), but the absolute increase for renewables was less than it was for all fossil fuels (3.2 vs. 3.3 exajoules).
Therefore, when someone claims that we are successfully transitioning to renewables, the answer to their statement is both “Yes and No”. Indeed, we are making a rapid transition, but renewables are not increasing their market share. The growth in renewable energy supply is not driving us toward ‘Net Zero’.
It is vital that we replace fossil fuels with alternative energy sources such as solar and wind. But we need to recognize that also need to recognize that achieving ‘Net Zero’ requires that we reduce our overall energy consumption. Referring once more to the Green Bay Press Gazette article, the writer says,
WEC Energy Group . . . have laid out plans to shut down greenhouse gas-emitting coal plants in coming years and replace them with clean solar parks and wind farms.
A more complete statement would be,
WEC Energy Group . . . have laid out plans to shut down greenhouse gas-emitting coal plants in coming years and replace them with clean solar parks and wind farms without requiring the citizens of Green Bay to cut back their energy consumption.
Based on the above analyses, this goal is not achievable.