In order to know if you’re on track you need a destination and a map. If you don’t know where you’re going, any road will take you there. As the Cheshire Cat points out to Alice.
If our destination is a world where global warming has been limited to 2.0°C, what does the map look like? And, what if we want to go further and limit warming to 1.5°C?
At least a quarter of the answer lies in how quickly we reach 100% renewable generation of our electricity. This post will describe the map, and a check to see how we’re getting on.
The Paris Target (the destination)
In December 2015, in Paris, 174 countries agreed to do whatever is necessary to limit the increase of the average global temperature of our planet to no more than 2˚C above pre-industrial levels. These countries have also agreed that ideally we should keep warming “well below 2˚C” and that they will meet every 5 years to ratchet down this target towards 1.5˚C.
An increase of 1.5˚C is the level at which the scientists at the UNFCCC have told us that “most terrestrial and marine species would be able to follow the speed of climate change; up to half of coral reefs may remain; sea level rise may remain below 1 m [39 inches]; some Arctic sea ice may remain; ocean acidification impacts would stay at moderate levels; and more scope for adaptation would exist, especially in the agricultural sector”. Many of these statements may not hold true in a 2˚C world. So, let’s focus on the 1.5˚C target.
We are already above 1˚C and to get a feel for how close we are to these limits, see this incredible animation produced by climatologist Ed Hawkins, from the University of Reading in the UK (via Climate Progress).
What do the Paris targets mean in terms of CO2 reductions? The “Feasibility of limiting warming to 1.5°C and 2°C” report by Climate Analytics has concluded that for us to limit global warming to 1.5˚C:
“Global energy and industry CO2 emissions must reach zero by around 2050″.
So, that is our challenge, and it is monumental. Total carbon neutrality of global energy AND industry. Carbon neutrality of global electricity, transport, manufacturing, construction, agriculture and more… In just over 30 years!
This article will focus on decarbonising the production of electricity. The Electricity and Heating sector is only part of the story but accounts for the largest share, 25%, of global GHG (greenhouse gas) emissions by sector. See the chart below from the IPCC (2014). In this chart, the use of electricity from the grid by industry is included in ‘Electricity and Heat Production’. Therefore, every new wind turbine, solar PV panel or wave turbine attacks this 25% chunk of the pie.
The demand for electricity is commonly split between “base load”, “intermediate load” and “peak load”. Simply, the base load tends to remain the same over a 24 hour period. The intermediate and peak loads are the reaction to increased need for electricity during the day or seasonal variation. Below is an example from two 24 hour periods in the UK in 2016, one during June (summer) and one during January (winter). You can see the continuous base load beneath the varying intermediate and peak loads above. The increase in winter is a result of the UK turning the heating on.
The importance of all this is that the different types of demand require different types of power generation technologies to match the loads. Traditionally, the base load has been met using technologies that are not easy to turn on or off and trundle away continuously throughout the year, such as coal or nuclear. The intermediate and peak loads are met with power stations that can be ‘dispatched’ easily when needed, such as natural gas.
Models constructed by several researchers and institutes agree that 100% renewable electricity grids are capable of providing for national electricity demand day and night, 365 days a year and during extreme circumstances. Each propose a combination of technologies that together, are capable of replacing the fossil fuel alternatives mentioned above. The exact mixture of generation technologies differs from study to study but the conclusion is the same regardless of which country is the focus: 100% renewable electricity grids are technically possible. See the table at the bottom of this page for examples of a few.
The studies follow a common theme. By 2050, 100% of electrical power generation is derived from a combination of technologies including wind turbines, wave turbines and solar PV. Normally, it is assumed that extra technologies must be used to provide the base load power, biomass, biofuel, nuclear or carbon capture and storage (CCS).
However, In 2009, Jacobson and Delucchi published a plan in the Scientific American that proposed a scenario in which, as early as 2030, 100% of electricity is produced solely by a combination of wind, water and sun (coined WWS). This may be the most optimistic view in research, but knowing the most ambitious path helps to put alternative pathways into perspective.
In this scenario there is no need for biomass, biofuel, nuclear or CCS which are deemed more damaging technologies. A combination of wind, water and sun can meet the intermittent, peak and baseload electricity demand. In 14 years from today, wind turbines provide 50%, concentrated solar power 20%, commercial solar plants 14%, rooftop solar photovoltaic (PV) 6%, hydroelectric plants 4%, geothermal plants 4%, wave turbines 1% and tidal turbines the final 1% of global electricity demand.
The following chart, the demand curve for a day in California, shows how WWS could potentially cope with the full range of demand without the need for nuclear, bio or CCS.
Around the world, this scenario requires:
- 3.8 million wind turbines (19000 GW)
- 49,000 concentrated solar power plants (14,700 GW)
- 40,000 solar PV plants (12,000 GW)
- 1.7 billion rooftop solar PV systems (5,100 GW)
- 900 hydroelectric plants (1170 GW)
- 720,000 wave turbines (540 GW)
- 5,350 geothermal plants (535 GW)
- 490,000 tidal turbines (490 GW)
(all GW values are installed capacity) (If you’re interested in climate solutions, you should check out the Solutions Project which was founded by Mark Jacobson, one of the two authors of this paper.)
So, how are we doing so far?
Deployment of Renewable Technologies (the map)
Let’s take a look at what’s currently installed, and the rate at which we would need to install each technology to reach the numbers set out by Jacobson and Delucchi.
My previous post described how, despite policy u-turns on subsidies from some governments, despite huge lobbying efforts to suppress renewables in some countries, and despite the collapse of some solar industries, the growth of solar power on a global scale has consistently doubled every two years for the past 15 years. Behind all of the drama is a very smooth, steep curve.
The same consistent nature is true for wind and water technologies. Since wind and solar account for 90% of generation in the 100% WWS scenario, we will focus on those.
The Map for Wind
As of 2015, we have 432 GW of installed wind capacity. This is 2.3% of Jacobson and Delucchi’s 2030 target of 19,000 GW.
However, the good news is if we maintain the rate of growth that has occurred between 2000 and 2015, we will reach 19,000 just before 2033. A slightly increased growth rate could reach the required 19,000 GW by 2030. This implies some potentially unrealistic increases in the final years (641,000 turbines installed in 2032) but even at a much slower growth rate, we could see 19,000 GW of wind power by 2040 or 2050.
The Map for Solar
As of 2015, we have 237 GW of installed solar capacity. This is 0.9% of the 2030 target of 26,700 GW.
If if keeps up its current rate of growth of 140.6% (2000-2015) solar will fly past wind and reach the 26,700 GW target by 2029. A slightly slower growth rate of 137% will see solar reach the target in 2030.
These two technologies alone account for 90% of the WWS generation. If we can follow the map and achieve these rates of construction we will practically elimate the 25% chunk of CO2 emissions from the Electricity and Heating sector. If the global car fleet switches to electric battery vehicles, the clean electricity grid will also be responsible for slashing the 14% of global CO2 emissions from the transport sector.
The trajectories for deployment of wind and solar are high. But s-curves for technology penetration are getting shorter and shorter. If these growth rates were achieved in a pre-Paris COP21 world, who’s to say the same can not be achieved in a post-Paris world with falling costs for renewables, increasing investment and far more pro-active global climate policy?
Bear in mind that the 100% WWS scenario puts almost all the responsibility on wind and solar in an attempt to achieve the cleanest possible energy mix. In reality, although it is possible that nuclear power plant installations may slow, it seems unlikely, barring a significant catastrophe, that the industry will grind to a halt any time soon. Any increase in nuclear, biomass, biofuel or CCS capacity would make up for shortfalls in installations of wind and solar.
Regardless of what we end up achieving, the purpose of this article was to present a map to our destination. Emissions reductions targets are abstract and difficult to follow. Installed capacity of wind and solar is the clearest way to keep an eye on our progress. Watch out each year for the figures for new wind and solar capacity, compare them to the projections on the graphs above, and you’ll know how well we’re doing at making the most significant technological transition since the industrial revolution.
Table 1. 100% Renewable Electricity studies, Jacobson and Delucchi (2009).