Some Key Points
- By renewable energy for electricity generation we mean wind, solar, geothermal and biomass, hydroelectric energy is another renewable energy but this is treated separately, simply because the main data source defines things in this way.
- There are also biofuels for combustion this is covered in another metric
- Worldwide electricity demand is increasing by about 2% each year, even if we increase renewable electricity generation by 8% per year we will still be using more fossil fuel in electricity generation than now in 2040.
Figure 12.1 shows the sources of electricity generation for the world from 1985, fossil fuels are dominant, and currently renewables constitute only 8% of this and fossil fuels 64%. Figure 12.2 shows the growth in renewables since 1965, the growth rate is impressive, but can it be sustained and can it be replicated in all regions around the world.
There is a lot to do to replace fossil fuels in electricity generation with renewables, but given that power generation accounts for over ⅓ of global CO2 emissions it is an important target. Unfortunately it is not simply a case of replacing fossil fuels with renewable energy, this is what we would all like to see but it is not happening. Instead with growing population and greater demand for electrical power we are increasing the use of renewable energy and increasing the use of fossil fuels, we will probably continue to do so for at least another 20 years, in doing so our output of CO2 will continue to increase not decrease. In a fairly likely scenario given current trends (Figure 12.3), renewables substantially grow whilst the use of fossil fuels also continues to grow to meet the ever increasing demand. In a nutshell this is why we need to consider actions like carbon capture from power plants in addition to renewable energy, a multifaceted approach is essential to atmospheric CO2 reduction.
In addition as we move to electric ground transport electricity demand will increase even further but will reduce the use of fossil fuels in the internal combustion engine. On the UK grid this is a gain, as the carbon output from our grid per mile driven is lower than the carbon output of an internal combustion engine per mile driven, but on a grid solely powered by coal this is not the case.