In previous blogs we have discussed the carbon budget to keep global warming to 1.5°C. There are different carbon budget models with varying outcomes. There is also the required per annum rate of greenhouse gas emission reduction to consider too. Once again there are a number of studies on this subject.
Considering these models and studies, we have devolved our target on required emissions reduction to keep global warming to 1.5°C. That is, global emissions need to be reduced to 25 gigatonnes per annum. That reduction has to happen now. Unfortunately, the current global emissions are 50 gigatonnes per annum, twice what we need them to be.
Critically, 73% of global emissions come from fossil fuel use for the provision of energy. So eliminating fossil fuel use will also allow the human species to meet a critical target. Fortunately, with wholesale electrification, it can be done, but the rate of transition has to accelerate!
Hundred percent renewable energy is feasible according to the LUT University study called “GLOBAL ENERGY SYSTEM BASED ON 100% RENEWABLE ENERGY Power, Heat, Transport and Desalination Sectors” of 2019.
The study’s report states: “Existing renewable energy potential and technologies, including storage, is capable of generating a secure energy supply at every hour throughout the year. The sustainable energy system is more efficient and cost effective than the existing system, which is based primarily on fossil fuels and nuclear. A global renewable transition is the only sustainable option for the energy sector and is compatible with the internationally adopted Paris Agreement.”
Most importantly, the report asserts that the energy transition is not a question of technical feasibility or economic viability, but one of political will. The state-of-the-art scientific modelling of the study simulates a transition to 100% renewable energy of the entire world, structured in nine major regions and 145 sub-regions on an hourly resolution of 5-year time periods from 2015 until 2050.
The modelling computes the cost-optimal mix of technologies, based on locally available renewable energy sources. By 2050, the world’s population is expected to grow from 7.2 billion in 2015 to 9.7 billion. Final energy demand is expected to grow by about 1.8% annually, driven by energy services for higher level of living standard, and is accompanied by massive energy efficiency gains.
The report asserts electrification across all energy sectors is inevitable and is more resource efficient than the current system. Its prediction is that electricity generation in 2050 will exceed four to five times that of 2015, primarily due to high electrification rates of the transport and heat sectors. Final energy fuel consumption is reduced by more than 68% from 2015 numbers, as fossil fuels are phased out completely and remaining fuels are either electricity-based or biofuels. Electricity will constitute more than 90% of the primary energy demand in 2050. This electrification results in massive energy efficiency gains when compared to a low electrification trajectory. Almost all of the renewable energy supply will come from local and regional generation.
The diagram above shows the study’s prediction that primary energy supply in the 100% renewable energy system will be covered by a mix of sources, with solar PV generating 69%, followed by wind energy (18%), biomass and waste (6%), hydro (3%) and geothermal energy (2%) by 2050. Wind energy and solar PV make up 96% of total electricity, and approximately 88% of the total energy supply, which will have a synergetic balancing effect.
A study released in November last year by researchers at the University of California (https://www.sciencedaily.com/releases/2021/11/211105134636.htm) states that wind and solar can supply more than 80 per cent of demand in many countries around the world without “crazy amounts” of storage or excess generating capacity.
The study found most of the current electricity demand in advanced, industrialised nations can be met by some combination of wind and solar power whilst acknowledging the crucial need for a range of storage and other grid balancing technologies.
The researchers found that a wind and solar power system could provide about 85 percent of the total electricity demand of the United States, and that amount could also be increased through capacity overbuilding, addition of batteries and other storage methods, and connecting with other national partners on the North American continent.
For people who fixate on the line – when wind don’t blow and the sun don’t shine – the researchers recommend building up generating capacity that exceeds annual demand, developing long-term storage capabilities and pooling resources of multiple nations, or states, where possible.
Whilst around the world, there are some definite geophysical constraints on our ability to produce net-zero carbon electricity, researchers found that it comes down to the difference between the difficult and the impossible. They found it will be hard to completely eliminate fossil fuels from the power generation mix, but the goal can be achieved when technologies, economics and socio-political will are aligned.