The energy transition
Reliability of renewables One significant reason the transition to net-zero by 2050 will be a struggle is because the reliability of energy sources such as wind and solar are so inferior to conventional energy sources. Whilst oil rigs and coal factories can operate night and day, wind and solar are inherently intermittent, meaning their output fluctuates based on the availability of their wind or sunshine (WMC, 2024). This variability prevents them from providing a stable, predictable power output that traditional fossil fuel-based power plants are able to do so well. Currently, renewable options cannot offer the near 100% capacity factor (CF) that fossil fuels boast, proving that transitioning to entirely green options, is a challenge in this aspect. Capacity factor is defined as the percentage of energy generated from the theoretical maximum that a plant could generate in a year (WMC, 2024). For example, the CF of wind energy is around 33%, reflecting that wind is only producing at its maximum efficiency 33% of the time. When comparing the CF of different types of energy sources, the data can be shown in Figure 2 (Statista, 2024a).
Figure 2 – CFs of energy sources
This comparison reveals how the CF of some renewables is limited by the resource: solar, for example, will never exceed 50% per year due to the scarce hours of sunshine; some other renewables, not having this constraint, could in theory approach 100%, as is the case for nuclear. A reliable energy system preserves a balance between supply and demand, adapting to fluctuations throughout the day, at any given second. Operators of electricity grids must also quickly restore this balance in the face of a loss of a major power plant or a transmission line, and if they cannot do so quickly, large-scale power outages may occur (Nelson and Wisland, 2015). As two of the most prominent sources of
renewable energy, solar and wind, are driven by the weather, their power output is far more variable and uncertain than that of conventional power plants (Cochran et al., 2021). Therefore, conventional power plants are typically more reliant on fossil fuels, because when grid operators are assessing what is the best method of powering their grids, in terms of cost, reliability, efficiency and CF, it is the fossil fuel backed power systems that are the most attractive, thus curtailing the demand for renewable electricity (Nelson and Wisland, 2015). In relation to reliability, therefore, renewable energies are inferior to traditional methods of energy production. Importance of critical minerals in supplying the green transition Another, perhaps, overlooked problem with renewables is that to boost the infrastructure that is to replace the current fossil-fuel reliant infrastructure, the mining of critical minerals in the world will need to increase immensely. Critical minerals such as copper, lithium, nickel and cobalt are rare earth elements and have a role as essential components of many modern energy technologies such as wind turbines, electricity networks, and electric vehicles. To deliver the same levels of energy for a typical day of energy use, purely from renewable energy sources, the amount of critical minerals mined in the
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