THE EVOLVING ENERGY MIX - PART 1

My Learnings about Energy Transition (FROM IFP SCHOOL MOOC ON ENERGY TRANSITION)

Energy is all around us. Humans for example derive energy from the food we eat. What about our electricity and our vehicles? They all need energy to function. The global consumption of energy has grown by a factor of 13 since the beginning of the industrial revolution in the 20th century; mainly driven by population growth (from 1.6 billion in 1900 to 7 billion humans today) and economic development (with a growth in GDP by a factor of 40 from 1900 till date).

There has been a lot of buzz over renewable energy in recent times in a bid to reduce the climate impact of our economic and population growth. While we have a much more diverse energy mix today than at the beginning of the industrial revolution, we still rely on fossil fuels (coal, oil, and natural gas) for more than 80% of our energy consumption.

Although renewables make a significant percentage of net capacity additions, it still only represents about 4% of the total primary energy consumption today. As prices of renewable energy continue to become more competitive, we will see a gradual shift in demand for renewable energy. But this may take several years as energy systems need heavy infrastructures and thus time to evolve.

Lastly, so far, the increase in renewable energy consumption has not led to a slow-down of demand for fossil energies. This is because we live in a world of resource addition and not substitution as the world is always more thirsty for new energy resources as a result of growing economic activities (in rapidly developing nations) and population.

The Stresses on the Energy Demand

There is no single perfect source of energy. Designing an energy policy is about finding the ideal balance between reliability, affordability, and sustainability.

Reliability: Is there enough energy for everyone?

Because solar panels, wind turbines, and batteries require rare earth elements which are only available in limited quantity, a physical limit could constrain supply someday.

Affordability:

The cost of renewables such as wind and solar has reduced drastically in recent years especially in terms of the complete cost of generating electricity over the full life cycle of these technologies.

Sustainability:

Perhaps, the most compelling reason for a shift to renewable energy is climate change. Fossil fuels constitute a bulk of today's energy consumption, leading to an accumulation of greenhouse gas emissions released during their combustion and leading to an increase in global temperatures, which will harm life on earth as we know it.

Diplomacy

In 2015, the UN convention on climate change adopted the Paris agreement to limit the rise of temperatures to well below 2 degrees Celsius above the pre-industrial level - a level considered acceptable by the Intergovernmental Panel on Climate Change (IPCC). To achieve this objective, all countries must collectively cut greenhouse gas emissions to a net-zero level by 2050. This can be done by storing any emissions underground (carbon capture) or compensating by negative emission measures such as afforestation or direct capture of co2 in the air.

The Road Towards a Sustainable Energy for All

Drivers of greenhouse gases emissions

• People

• Energy

• Economic Activity

• Carbon Content

The Kaya Equation

The Kaya equation is a simple model to assess the factors driving the growth of greenhouse gases emissions. It was named after Japanese economist, Yoichi Kaa who developed it in the 1990s. According to Kaya, the evolution of carbon emission is the product of 4 factors.

1. Carbon content - the evolution of the content of the energy we consume (CO2/energy)

2. Economic Activity - the intensity of our economic activity (energy/GDP)

3. Wealth per person - (GDP/capita)

4. Population growth

The Kaya Equation:

Carbon emissions = (carbon emissions/primary energy consumption) * (primary energy consumption/gross domestic product) * (gross domestic product/total population) * (total population)

Scenarios and Assumptions

There are many scenarios compatible with the Paris net-zero emissions goal by 2050, to be in line with the objective of limiting the growth of temperatures at +2 degrees Celsius. One scenario would be for all countries to collectively divide their emissions by 3 between now and 2050.

According to UN estimates, the global population is going to grow by 30% between now and 2050. Also, assuming that the global GDP/Capita is going to grow in the next 35 years as fast as it did in the last 35 years, then, GDP/Capita will grow by approximately 60% by 2050.

In summary, to cut global emissions by a factor of 3 in 2050 with a 30% increase in population and a 60% increase in GDP per Capita, we need to divide the other terms of the Kaya equation C02/energy or energy/GDP by more than a factor of 6!

In other words, we need to reduce every year by more than 5% the carbon content of the energy we consume or reduce the amount of energy needed to produce one unit of GDP.

Reducing Carbon Content of the Energy Mix

Lifecycle greenhouse gases emissions of electricity generation technologies

Decarbonizing the energy mix implies shifting towards less carbon-intensive energy sources

(renewables & nuclear), or abating CO2 emitted from fossil sources (with CCS).

The carbon intensity of the primary energy supply is the same today as it was 30 years ago. This is mostly due to the fast-paced economic development of Asian countries in the 2000s which was supported by intensive consumption of coal and oil.

The energy content of our GDP by contrast has decreased by about 1% per year, reflecting gains in energy efficiency. This is mostly a result of improvements in industrial processes as well as expansion of the less energy-intensive services sector in the global GDP.

Although this is still far from the -5% per year decrease of the global carbon intensity of GDP that is expected in a +2 degrees celsius compatible scenario.

Innovation towards a low carbon future

To be sustainable and limit global warming, we have to evolve and innovate on various technologies that can drastically reduce anthropogenic Co2 emissions. The most important areas are energy efficiency, and the development of renewables, together representing 80% of the Co2 abatement effort. Others include Carbon Capture and Storage, Nuclear, fuel-switching, etc.

Global anthropogenic CO2 emissions in Gt versus scenario.

The Risks on a Growing Demand for Low-Carbon Technologies Minerals

Renewable energies are produced from different sources such as wind and sun which are technically unlimited. However, the technologies used to harness these energies consume mineral resources that are finite on earth. And this is true for all low-carbon technologies. The following are the common renewable sources and the mineral resources they utilize;

• Wind turbines - neodymium, dysprosium

• Solar panels - silica, cadmium, indium

• Fuel cells - titanium

• Electric batteries - lithium, cobalt, etc.

• Catalytic converters in thermal cars - platinum, rhodium, palladium, and so on.

Power Generation in Global Energy Demand

Electricity is one of the fastest-growing final energy usages and will be for decades to come. Thus, decarbonizing electricity will be a key step towards a “well-below 2-degree world”.

The current electricity mix is dominated by fossil sources; with 65% produced from coal, natural gas, and oil while about a quarter comes from renewable sources such as hydro, wind, biomass, solar and geothermal, in that order.

Why has coal and natural gas been dominating the power generation mix?

This is because in most cases, they have proven to be reliable, flexible and economical. However, this is beginning to change. However, power plants built today generally have a 20-40 year lifespan, thus, the current mix will require a few decades to evolve.

Another major hurdle is that electricity storage cannot be easily stored economically up to now. Thus, many countries favored the flexibility of dispatchable means of generation such as nuclear and fossil fuels over variable ones such as wind and solar.

To sum up what we just talked about: electricity is an essential energy carrier for many applications. But power is CO2 intensive, it represents 20% of our energy use but is responsible for 40% of CO2 emissions. Moreover, electricity consumption is expected to grow in the future: 1 billion people still lack access to modern energy today, and global electricity needs are growing. So it is essential to decarbonize the electricity mix to mitigate the risk of climate change.