Coal

On the world scale coal provides 23% of its energy. Of that, 69% is devoted to generating electricity. Reserves of coal are estimated to be 560 billion tonnes,4 which would be sufficient for the next 160 years at current rates of extraction. According to the IEA, annual consumption will increase from the present ~2.5 billion tonnes to ~3.95 billion by 2020. This would reduce the life expectancy of coal to 123 years. However, there will probably be a considerable increase in the use of coal to compensate for the gradual demise of oil and gas. Gasification and liquefaction for transport fuel would also make big inroads into reserves. Altogether these could lead to reserves being exhausted well before 2100. In 2004 the world's consumption of coal rose by 6.3% with ~75% of the increase due to China.

The US and Canada plan for over 500 new-coal fired plants which will last 30 years. China is planning to build 300 coal-fired power stations and expects to treble the capacity of its coal-fired plants by 2020. Its coal reserves have a high sulphur content. Over the next 25 years coal-fired plants will emit more CO2 in their lifetime than the total pollution from coal burning in the last 250 years.

China is rapidly approaching superpower status and by 2040 will have overtaken the USA in economic strength and the west will have to adjust to this, all assuming that climate change has not in the meantime wrought catastrophic social and economic damage throughout the world.

Despite its high carbon intensity, coal is being promoted as a zero carbon fuel for the future. One strategy is to liquefy its CO2 and bury it in extinct oil wells. Another is to gasify coal to produce methane which would be reformed to produce hydrogen to power fuel cells. A third method of CO2 sequestration is to capture it from fossil fuel power plants and feed it to bioreactors. These are plastic cylinders containing algae which is converted via sunlight and water into biofuels (see 'From smokestack to gas tank', New Scientist, 7 October, 2006, p. 28).

Superficially it might be concluded that the depletion of fossil fuel reserves can only help the transition to renewable technologies. On the basis of the present rate of adoption of renewable energy generation it is highly probable that installed renewable resources will not be nearly sufficient to cope with the economic tensions arising from the increasingly bitter competition for the dwindling reserves of gas and oil. On the other hand, using fossil fuels to exhaustion would increase global temperature by ~13°C leading to catastrophic climate consequences.5

At the same time it is an inescapable fact that the majority of cultures are wedded to the idea of economic development. Humans are teleological creatures, that is, programmed to seek and achieve goals. For most individuals and states the goal is increasing wealth and security, especially security of energy. A realistic scenario for the future should take account of this fact despite the protests of those who consider the idea of sustainable development to be the ultimate oxymoron.

It is pointless mapping a future which takes no account of the realities of human nature like the desire at least to maintain a present standard of living and the ability to be in denial about unpalatable predictions. That is why it is logical to assume that world economic growth will

Table 16.1 Progressive rate of increase in carbon neutral energy to 2100

Year

%

Total energy (EJ)

Carbon neutral energy (EJ)

2020

20

11.8 (281 mtoe)

2.36 (56.2 mtoe)

2030

30

13.0 (310 mtoe)

3.9 (93.0 mtoe)

2050

50

15.9 (379 mtoe)

7.95 (189.5 mtoe)

2100

80

26.2 (623 mtoe)

20.96 (498.4 mtoe)

Table 16.2

The pace of renewables uptake assuming 80% by 2050

Year

%

Total energy (EJ)

Carbon neutral energy (EJ)

2020

30

11.8 (281 mtoe)

3.5 (84.3 mtoe)

2030

50

13.0 (310 mtoe)

6.5 (155 mtoe)

2050

80

15.9 (379 mtoe)

12.7 (303 mtoe)

2100

80

26.2 (623 mtoe)

20.96 (498.4 mtoe)

continue until at least to the end of the century. In this case we have to indicate the kind of pressure which will fall on the renewable technologies if catastrophic climate change is to be avoided.

A UK scenario of goals for renewable energy capacity will give an insight into the scale of the problem on the world stage. Assuming a net 1% per year growth in energy demand within 2-3% economic growth and a progressive percentage increase in the ratio of carbon neutral energy to conventional energy the situation that emerges is shown in Table 16.1. This assumes 80% from renewables by 2100.

Starting from the UK energy consumption of 233mtoe or 8.75 EJ of energy in 2002 and incrementing at a net 1% per year, total energy predictions and renewable energy targets to 2100 would be as Table 16.1.

It is possible that, with the uncertainties now being revealed, the pace of global warming will be significantly faster than that assumed in the above 20-30-50-80 scenario. In that case the rate of contribution by carbon neutral energy might have to be accelerated to achieve 80% by 2050 (Table 16.2).

Since the contribution from carbon neutral sources in 2100 will need to be well over twice the total energy expended in the UK in 2004 the question is: has the UK got the capacity to produce this amount of carbon neutral energy?

Figure 16.4 illustrates the possible spread of renewable technologies that will be needed to meet the 1%/year primary energy growth rate to 2100 under the WEC scenario. Anything above the 1% is achieved through energy efficiency gains.

The distribution of the different technologies in exajoules is:

Bioenergy

3.3

Marine energy

5.0

PV and solar thermal

3.05

Wind

2.05

Hydro

1.0

Heat pumps, Stirling CHP etc

1.0

Coal with CO2 sequestration

5.56

Total

20.96 EJ

Bioenergy (energy corps, agricultural and municipal waste)

l/VV| Hydro including small-scale and micro-hydro

IvWuvm .. . . . . , „ . H-j^aF&l Heat pumps, Stirling CHP, domestic fuel

IWXWYI Marine energy (tidal stream, rise and fall, wave) ^

Bioenergy (energy corps, agricultural and municipal waste)

l/VV| Hydro including small-scale and micro-hydro

IvWuvm .. . . . . , „ . H-j^aF&l Heat pumps, Stirling CHP, domestic fuel

IWXWYI Marine energy (tidal stream, rise and fall, wave) ^

Photovoltaics and solar thermal

Coal with CO2 sequestration

Wind (onshore and offshore)

B Nuclear

Figure 16.4 Suggested distribution of the 80% carbon neutral energy needed in the UK by 2100 based on the World Energy Council estimate of growth

The above scenario is based on World Energy Council predictions of global growth. It presents an unrealistic and impracticable picture for the UK. Closer to probability is the European Union's estimate for UK total energy growth which predicts it rising from ~240 mtoe or ~9exa-joules per year to about 270 mtoe or 11.3 exajoules towards the middle of the century. Figure 16.5 depicts the scale of the challenge facing energy suppliers getting close to meeting the UK's declared target of 60% carbon neutral energy by 2050 and 80% by 2100. Under this scenario renewables will be called upon to provide 5 exajoules or 119 mtoe per year by 2050 and 9 exajoules or 218.2 mtoe by 2100. At the level currently under discussion, nuclear power would make a minor impact, if any, on the final requirement from genuinely renewable technologies.

EJs mtoe

Bioenergy

1.5

37.7

Marine energy

2.0

47.6

PV and solar thermal

1.5

37.7

Wind

1.0

23.8

Hydro

0.5

11.9

Heat pumps, Stirling CHP etc

0.5

11.9

Coal with CO2 sequestration

2.0

47.6

Total

9.00

218.2

Figure 16.5 Renewables requirement under EU energy consumption scenario for the UK. It is assumed that, after 2050, energy demand will be level and economic growth achieved through energy efficiency gains

To produce this amount of energy will require a generating capacity from renewables of around 162 GW, which represents 90% of the total energy capacity for the UK, including transport, for 2003.

However, things become less formidable if there is a significant reduction on the demand side. A genuinely sustainable future is only feasible if there is a concerted assault on the CO2 derived from both the demand and supply sides. Figure 16.6 offers one scenario which assumes that the built environment and transport could realize substantial reductions in demand by 2100, amounting to nearly one-third of total consumption (see Fig. 16.6).

It is challenging but achievable remembering that the UK is especially favoured in the potential to extract energy from its marine resources as indicated in Chapter 11.

In July 2005 the leaders of the three main UK parties entered into an agreement on a strategy to combat terrorism. It was felt to be too important a subject to be undermined by the adversarial politics of Parliament. Earlier, the Government Chief Scientist, Sir David Kind, got universal coverage for his opinion that climate change was an even greater threat than terrorism. Why then can there not be a cross-party consensus on robust strategies to deal with global warming and climate change? Only by removing the risk of electoral penalties will the UK and other democracies be prepared to take the radical actions needed to stabilize CO2 emissions at a level which will keep the climate within tolerable limits.

There is no doubt that the UK has the natural assets to enable it to be fossil-fuel free in meeting purely its electricity needs by 2030. However, this would require an immediate policy decision by the government to make a quantum leap in its investment in renewable technologies, especially the range of opportunities offered by the tides. This calls for a twin-track strategy.

On the one hand small-scale distributed generation should be vigorously promoted with government subsidies along the lines of the German Renewable Energy Law. Domestic scale heat and power technologies are developing fast and could transform the profile of energy.

On the other hand in parallel there should be development of high-energy intensity or extensive coverage renewables that can deliver base load power to gigawatt level. This mainly concerns tidal power and bioenergy. Neither will take off without substantial government investment. The first step is an integrated energy policy driven by a dedicated government department. The UK government has yet to perceive that energy is at the heart of both its climate change policy and its economic security.

In October 2005 the former UK Energy Minister, Brian Wilson, made a plea for the government to be the driving force behind energy policy rather than leaving the energy future in the hands of the market. He asserted that there must be a new Department of Energy with its own Secretary of State 'who has a clear mandate to promote an agreed policy'. The intention behind this book has been to show that there has never been a time when this has been more urgent. The UK has no more than 5 years in which to change its mindset on energy.

Solar Power Sensation V2

Solar Power Sensation V2

This is a product all about solar power. Within this product you will get 24 videos, 5 guides, reviews and much more. This product is great for affiliate marketers who is trying to market products all about alternative energy.

Get My Free Ebook


Post a comment