‘I would like nuclear fusion to become a practical power source. It would provide an inexhaustible supply of energy without pollution or global warming.’

– Stephen Hawking

7.1. Introduction

In preceding chapters I have addressed the existential challenges facing our planet caused by greenhouse gas emissions, as well as the extent of both global and national initiatives to mitigate these perils. I have also described some of the available tools and processes offered by Green Six Sigma and digital technology to accelerate the implementation of these initiatives. Although neither these strategies nor the wisdom of the carbon neutral target by 2050 are in doubt, it is important to note that in reality the reduction of greenhouse gas emissions can only be delivered by tackling its sources, such as power stations, factories, buildings, land usages and transport systems.

Table 1.3 in Chapter 1 indicated that the biggest source of greenhouse gas emissions is the energy sector, contributing 35% of total releases. This chapter will analyse the challenges and opportunities in this sector as well as the role of Green Six Sigma to accelerate and sustain the desired outcomes. Before I address the issues of clean energy, Table 7.1 illustrates how the share of greenhouse gas emissions by economic sector has been grouped to describe the impact of Green Six Sigma in each sector; this will be addressed in the later chapters of the book.

7.2. Guiding Factors of Clean Energy

There are a number of aspects that arise if we scrutinise articles or plans regarding Clean Energy and the shaping of its future direction. The good news is that even though the energy sector constitutes only 35% of greenhouse gas emissions it represents much more than 35% of the potential solution. This is because energy generation and supply are at the start of the greenhouse gases value chain. Industry, transport and buildings, and even agriculture, are all driven by the supply of energy.

The first guiding factor is the basic demand for power to support the energy supply of a house, city or a country. Although this demand varies according to seasonality, degree of industrialisation and the time of the day, Table 7.2 is indicative of how much power we need to support us.

The global requirement for electricity and energy is growing, and this is bearing in mind that currently some 860 million people (including 600 million in Africa) do not have access to any electricity at all.

We are highly dependent on fossil fuels (84.3% for combined oil, gas and coal) for the generation of primary power, as shown in Table 7.3.

There are positive growths for renewables and nuclear sources of primary energy but these advances are not enough to meet the carbon target of 2050. Another worrying trend is that gas consumption is also increasing.

In the UK as well, most of the primary energy is produced by fossil fuels, mainly natural gas (45%) and coal (9%). However, shares of renewables (25%) and nuclear (21%) are also relatively high.

The space required for primary power generation is also an important guiding factor. Power density is a useful metric, allowing us to understand the amount of power generated per square metre of land and water for different energy sources, as shown in Table 7.4.

In terms of the required space, power plants run by fossil fuels have a clear advantage over renewables. However, one benefit of wind turbines is that they could be installed on otherwise unusable land and water.

Then there is the small matter of the cost advantage of an installation. Detailed cost benefit analyses are beyond the scope of this book, but we can discuss some of the principles involved. Zero-carbon solutions are in general more expensive than fossil fuel power plants. When we consider the cost of the environmental damage caused by fossil fuels or the government imposed ‘carbon tax’ then renewable alternatives may seem more viable. Some protagonists of fossil fuels have suggested ‘direct air capture’ (DAC) as a feasible alternative. With DAC, emissions are blown over a device that absorbs carbon dioxide and the output is then stored for safekeeping. However, DAC is a very expensive and largely unproven technology.

A novel concept of the Green Premium is advocated by Bill Gates (2021). The Green Premium is the difference between the cost of a green solution and the alternative or existing option. There are many such Green Premiums – some for electricity from various fuels, others for cement, steel and so on. The size of the Premium depends upon, firstly, what you are replacing and, secondly, what you are substituting it with. In rare cases, a Green Premium can be negative – for example, it may be cheaper to replace your gas cooker with an electric one.

7.3. How Clean Energy Solutions Can Reduce Greenhouse Gas Emissions

The primary objective of Clean Energy solutions is to generate carbon-free electricity. We know that the key suppliers of Clean Energy are renewable sources, which are natural sources that are constantly replenished. These constitute

• Wind energy
• Solar energy
• Hydropower
• Geothermal energy
• Tidal energy
• Biomass
• Hydrogen

Nuclear energy is also a source of carbon-free electricity although the material (e.g. uranium) used in nuclear power plants is not a renewable source. Nuclear energy is considered to be an effective way of producing power without the harmful by-products emitted by fossil fuels.

If we combine the energy from renewable sources and nuclear energy we get Clean Energy without any greenhouse gas emissions. The biggest share of the 2,790 gigawatts of Clean Energy in 2019 came from hydropower (42%), as shown in Table 7.5.

The portion of hydroelectricity has been stable for several years. The share of wind and solar energy is growing while the segment of nuclear energy is in decline, especially after the ‘Great East Japan Earthquake’ in 2011. Thanks to wind and solar power, renewable energy experienced a record growth in 2019, accounting for 40% of the expansion in primary energy. This is undoubtedly a good sign for Clean Energy.

Hydropower that harnesses the strength of water is the oldest source of energy. In Ancient Greece flowing water was used to turn the wheels of flour mills. The most common type of hydroelectric plant is called an impounded facility. Here a large reservoir is created by building a dam and the flow of controlled water drives a turbine, thereby generating electricity. This natural energy source has the advantage of being more reliable than wind or solar power. Furthermore, electricity can be stored for potential use at a time of peak demand. In another type of plant, called a diversion plant, a series of canals are used to channel a flowing river towards the turbines. A third type of operation, called a pumped storage facility, is where the plant collects energy produced from renewable sources by pumping water uphill from a pool at a lower level to a reservoir situated at a higher point. When a greater demand for electricity occurs, water from the reservoir is released to turn the turbines.

Table 7.6 shows ranking in the hydropower capacity of the top five countries.

Wind is a plentiful source of Clean Energy. It captures the natural airstream in our environment and converts the wind motion into electricity by using wind turbines. The spinning blades of these wind turbines are connected to electromagnetic generators that create electricity. This electricity is then fed into the national grid. However, there are some locations better suited for wind power than others. In general, wind speeds are higher near the coast and offshore as there are fewer obstructions. A group of large structures of wind turbines, called wind farms, are familiar sights both in the outskirts of towns and also at sea. There are also some domestic or ‘off grid’ wind energy generation systems available.

The main advantages of wind energy are that it is a clean renewable form of power and has low operational and maintenance costs. However, as the wind speed varies both throughout the day and on an annual basis, wind energy presents an intermittency issue for the power grid. Fortunately, reliable storage systems, including battery storage, compressed air storage and pump storage are now available. The price of wind energy is declining and the share of renewable energy by wind is increasing.

Table 7.7 shows ranking in the wind power capacity of the top five countries.

Like wind, sunlight is one of our most abundant and freely available resources. Solar energy is absorbed in specially designed and manufactured solar panels to generate electricity directly. Solar panels are made out of photovoltaic cells (or PV cells) that convert the Sun's energy into electricity. A single PV cell can produce typically around 0.58 volts. PV cells are sandwiched between layers of silicon. When hit by photons from sunlight each layer creates an electric field that creates the direct current (DC) needed to produce electricity. This current is then passed through an inverter to convert it into an alternating current (AC), which then can be connected to the National Grid or used by a building with solar panels. Solar energy is carbon free and renewable and thus has many benefits, including its diverse applications for generating both electricity and heat, as well as its low maintenance costs. However, there are also disadvantages, such as the initial high cost, weather dependency and storage expenses.

Table 7.8 shows ranking in the solar power capacity of the top five countries.

Nuclear power is controversial with environmental activists primarily for the risks of radioactive waste storage and disposal that it poses. However, it is the only carbon-free energy source that reliably delivers electricity throughout every season almost anywhere in the world. The process of obtaining energy by splitting the atom is known as nuclear fission. The released energy is capable of generating steam and can then be used to turn a turbine and thus produce electricity. The most commonly used fuel for fission is uranium. In theory, fission power offers the exciting prospect of an almost inexhaustible source of energy for future generations. Nuclear fuels (uranium and plutonium) can be used to create nuclear weapons as well as nuclear reactors. Hence, only nations that are part of the Nuclear Non-Proliferation Treaty (NPT) are allowed to import nuclear fuels. In spite of the possible risks of radioactive wastes and misuse of nuclear fuels, nuclear energy has been found to be the cheapest and most continuously available path towards the goal of achieving the net-zero carbon target.

China is often criticised as a leading emitter of greenhouse gases. However, the above data shows that in fact the country ranks first in global terms in renewable power generation (hydro, wind and solar) and is in third place for the generation of nuclear power.

Having discussed the opportunities and challenges of clean energy initiatives in our battle against climate change, it is useful to describe a few well-known clean energy plants as case studies for successful clean energy endeavours.

One of the most famous renewable projects is the Three Gorges Dam in China, the largest hydroelectric dam in the world. Almost 100 years after it was envisioned and following two decades of construction the dam became operational in 2012. Built across the Yangtze River in western China the construction is 185 metres high and stretches over a length of 2 km. The reported cost of the project was £17 billion, but the efficacy of its operations is clear. The water flows over 32 turbines capable of producing 700 MW of power. It is providing 1.7% of China's electricity, reducing carbon dioxide emissions by 10 million tonnes every year.

Walney Offshore Windfarm is located off the coast of Cumbria, England, and is the largest wind energy provider in the world. It was built at a cost of £1.6 billion and began generating power from the beginning of 2011. The farm, stretching over 145 square km, has a total of 189 wind turbines, each standing 190 metres high. It has a total capacity of 600 MW, which is enough to power 600,000 homes.

A further interesting example can be found in the Ivanpah Solar Electric Generating system, located in the Mojave Desert of Southern California, which is the largest solar energy facility in the world. The scheme was created jointly by Bechtel and BrightSource Energy with a total investment of £2.4 billion and began operations in 2013. About 300,000 large (10 ft × 7 ft) mirrors (called heliostats) are digitally controlled to reflect sunlight to 140 metre towers fitted with solar panels. The concentrated sunlight heats water stored at the top of the three towers to create steam for turbines. The three plants together can produce 392 MW of electricity, sufficient to power 140,000 homes.

The largest nuclear plant in the world is the Kashiwazaki-Kariwa plant in Japan. It is owned by the Tokyo Electric Power Company (TEPCO) and has a gross installed capacity of 8,200 MW. It has seven boiling water reactors (BWR) and all units became fully operational from 1997. However, activities at the plant stopped in May 2012 following the Fukushima nuclear disaster. New safety guidelines from the Japan Nuclear Regulatory Authority are being implemented and all reactors of the plant are expected to be operational again from 2022.

7.4. How Six Sigma Is Helping Clean Energy Initiatives

There are good applications of Six Sigma and Lean Six Sigma in the renewable energy sector, especially in wind energy. However, Six Sigma projects seem to be almost non-existent with no mention of them in the published papers related to hydropower nuclear power plants. There are some academic publications on Six Sigma applications in thermal power plants (Kharub et al., 2018). The following case examples illustrate how Six Sigma can help in the renewable energy sector to save money and achieve sustainable improvements.

7.5. How Green Six Sigma Can Help Clean Energy Initiatives Further

There is strong evidence of the application of Six Sigma/Lean Six Sigma methodology in solar power and wind power initiatives. Six Sigma has also been applied in thermal power plants. However, there is little testimony regarding Six Sigma methodology in hydropower and nuclear power projects.

Green Six Sigma should be very effective in all new Clean Energy projects, whether they are for hydropower, solar power, wind energy or nuclear plants. The existing clean energy installations, especially hydropower and nuclear plants, should consider proactively the application of the Green Six Sigma approach. The case example of Vestas India clearly demonstrates that a modest investment to develop employees even up to the basic Yellow Belt level can deliver big savings and sustainable processes.

The distinctive additional contributions of Green Six Sigma include:

• A comprehensive performance management system supported by a periodic self-assessment to monitor and sustain performance levels. (See Chapter 4.)
• A regular senior management review (e.g. Sales and Operations Planning) to include Green Six Sigma projects. (See Chapter 4.)
• Application of carbon footprint tools and software. (See Chapters 5 and 6.)
• Application of Material Flow Account. (See Chapter 5.)

7.6. Summary

We know that the energy sector is the top contributor of greenhouse gas emissions and its mitigation will come from all Clean Energy initiatives including nuclear energy. There is evidence of good progress within the realm of wind energy initiatives, with the solar energy sector coming close behind. Although natural gas is the least of the carbon polluters amongst fossil fuels, the faster growth in natural gas consumption is not promising with regard to attaining the net-zero carbon target. The big advantage of nuclear energy sources is that they can deliver more electricity day and night without interruption. Therefore, greater national efforts should be focussed on developing the field of nuclear energy.

This chapter has dealt with four main sources of Clean Energy, but there are of course other energy supplies. One example would be geothermal, using deep underground hot rocks. High-pressure water can be pumped down into these rocks and the water with absorbed heat comes out from another hole; in turn this can spin a turbine to generate electricity. Another example is hydrogen, which serves as a key ingredient of fuel cell batteries. We can use the intermittent supply of electricity from solar or wind farms to create hydrogen and then put hydrogen in fuel cells to generate electricity on demand.

Green Six Sigma is not a silver bullet to solve all Clean Energy demands. However, it can play a significant role in accelerating the initiatives at power plants and renewable farms as well as being instrumental in sustaining improved processes and environmental targets.