Energy revolution: The future is not what it used to be

(1)

1

The Dies Natalis lecture

Energy Revolution: the future is not what it used to be prof.dr.ir. Tim van der Hagen

It is 2007 and I would like to welcome you back. In the next 25 minutes I hope to convince you of the enormity of the challenge we face, but also to share with you the opportunities that lie ahead. TU Delft has named sustainable energy a primary focus of our research programmes. The sciences will have to make an important contribution to developing affordable sustainable energy sources. Together with water management, this is probably the greatest challenge we will face in the next hundred years.

The problem

In recent decades our Earth has been subject to a shock wave of population growth. The pace of population growth is quickening. We’ve gone from just a few hundred million at the beginning of the first millennium A.D. to more than six and a half billion people now. Soon there will be nine billion of us.

In physics, we generally apply a step function to these kinds of curves. And suddenly there were humans: nine billion of them! One and a half billion people have no access to safe drinking water and/or electricity. Two and a half billion people use brushwood and rubbish as their daily source of energy for heating and cooking. Things are going to change, that much is certain.

At this rate of population growth, the demand for energy will increase enormously in the decades to come, especially when you consider the increasing numbers of people living in relative prosperity. Billions of Chinese and Indians are well within their rights to demand their fair share of energy. This means that worldwide energy use will at least double in the course of this century.

The International Energy Agency predicts in its most recent World Energy Outlook 2006 a growth of 53% in world energy demand in the next 25 years. 70% of the growth will occur in developing countries, including China and India. The latter countries alone account for one-third of the world’s population. The level of CO2 emissions will grow a

bit faster, since more coal will be used for the generation of electricity. It is estimated that around fifteen thousand billion euros will need to be invested in the energy sector. That is 15 times a million times a million euros. 15 times the costs of the Iraqi war … Fossil fuels are still plentiful. Nevertheless, the possible application rate of those fuels will be unable to keep pace with growing demand. Furthermore, their unequal

(2)

2

The media shout it at us every day: the number one problem with burning fossil fuels is the carbon dioxide that is released into the atmosphere. No one knows for sure if these extra emissions really will cause the disaster that Al Gore predicts, but I for one would rather not take the risk.

The green curve on this graph shows how atmospheric CO2 levels have fluctuated over

the last 160 thousand years. During all that time the concentration of this greenhouse gas was never as high as it is today. If we take extreme measures, we will attain a CO2

level at the end of this century that is twice as high as the concentration before the Industrial Revolution. If we wait, the concentration might even rise to three times the pre-industrial level. The causal connection between CO2 variations and the

simultaneously fluctuating red temperature curve is clear. However, we are still unable to determine which is cause and which is effect.

Most would likely agree that the future is not coming up all roses and daffodils. Earth’s surface temperatures have been climbing since about the year 1900. The increase has become more pronounced since the 1970s. The temperature is currently nearly one degree higher than the average over the past one thousand years. The

Intergovernmental Panel on Climate Change forecasts an average temperature for the end of this century of 1.5 to 5.8 degrees higher than the average for the period between 1960 and 1990.

Last year, Nicholas Stern, one of the world’s leading economists, outlined the potential worldwide consequences of a global rise in temperature. Powerful effects can be

expected with a rise of just one degree. An increase of five degrees means that many large cities will be threatened by seawater. Reason would seem to caution against taking that ominous, apocalyptic risk. I would rather have my grandchildren laugh at me for being over-cautious than accuse me of lack of foresight.

This graph shows the rise in carbon emissions, expressed in billions of tons per year. If we fail to do anything to change this trend, the tremendous growth in energy use will cause the dotted red line to rise still further.

How can we keep CO2 emissions constant in the face of increasing energy demand?

We can’t really deny people their prosperity or hamper them in their development. Energy use is expected to double in the next 50 years. In real terms, this means that we must somehow find a way to avoid releasing seven billion extra tons of carbon per year into the atmosphere. That is 125 times the current total of carbon dioxide

emissions in the Netherlands. And that only means that we will have stabilised emissions in 50 years’ time. We will not have reduced them.

The options

Let’s divide the amount of carbon emissions that we want to prevent into seven portions of one billion tons each. Here are the options for reducing emissions by one billion tons per year.

Saving energy seems like the easiest way, but what does it really mean? Make all cars worldwide twice as fuel efficient,

(3)

3

fit all buildings with the most modern and energy-efficient installations. Enhance and improve today’s large-scale energy sources:

triple the number of nuclear power plants,

capture all the CO2 emitted by 800 coal-fired power plants and store it.

Make greater use of renewable energy:

increase the amount of solar energy produced by a factor of seven hundred, increase the amount of wind energy produced by a factor of fifty,

use fifty times as much biomass for transportation fuel as compared to today. Each of these options requires a Herculean effort and we need to achieve seven of them to continue to meet the demand for energy while keeping CO2 emissions constant

for the immediate future. Don’t let armchair scientists blow smoke into your eyes by telling you that energy savings or wind turbines alone will be enough. The Industrial Revolution is now behind us. We are about to embark on the Energy Revolution!

Solar energy

The sun is a nuclear fusion reactor situated at a safe distance from the Earth. The amount of solar energy that reaches the Earth’s surface every hour is the same as mankind’s worldwide energy need every year. With the exception of nuclear energy, nearly all our current energy sources are in fact converted solar energy.

The high price of solar cells has restricted their use. At present, they produce no more than 0.01% (one hundredth of one percent) of the world’s electricity. Nevertheless their application experiences a tremendous growth of 35% per year. If we want to maintain that rate of growth the kilowatt-hour price will have to drop considerably. In 25 years’ time, the proportion of photovoltaic energy could then rise to … 1.7%. But it could really take off once the electricity generation price approaches that of fossil and nuclear electricity. In the most optimistic case we could use solar energy to produce 30% of our electricity in 2050, provided that there is no delay in giving science what it needs to make this enormous growth a reality.

TU Delft is developing thin films, which will likely become very important in the next ten years. Further, we are working on revolutionary designs for the long term. Thin films contain 300 times less silicon than currently available solar panels made with expensive crystalline silicon. Far lower processing temperatures are required for amorphous silicon in thin layers. This means that the layers can be applied to flexible materials that can be distributed worldwide with greater ease. In the Netherlands it currently takes four to five years for a solar panel to recover the energy required for its own production. That period is cut in half by thin layer systems. Delft has the

(4)

4

Solar cells are currently made from extremely pure, and therefore expensive, semi-conducting materials such as silicon. Research has shown that making the active areas of the solar cell out of extremely small particles (nanocomposites) means that cheaper materials of lower purity can be used (including titanium oxide, an ingredient in

toothpaste and latex). Research has also been done into nanostructuring to increase the efficiency of silicon-based thin layer solar cells. There is currently great hope that inexpensive, organic materials (plastics) can be used to convert light into free charge carriers.

Wind is also a type of solar energy. The power-generating capacity of wind turbines has increased 100-fold in the past 20 years. Wind energy is now literally becoming visible. It requires large-scale investments and it has a great impact on power

distribution systems. Wind turbines are the largest rotating machines on the planet. An Airbus A380 aircraft would easily fit within the span of the blades.

Today’s maximum diameter of 120 metres (generating capacity of 5 MW) will grow to a diameter of 250 metres, enough for 20 MW. The average operating capacity of just three of these modern turbines would be enough to provide electricity to all households in the city of Delft. These gargantuan installations will be situated in offshore wind parks with capacities of 500 to 1000 MW.

Wind energy

TU Delft is a world player when it comes to wind technology. There’s a little bit of Delft know-how in every wind turbine, anywhere in the world. Our grasp of aerodynamics, materials, production processes and control systems is not yet sufficient to enable us to build an efficient 20 MW turbine. Material properties simply won’t allow these machines to be scaled up indefinitely. New materials and new combinations of materials will be required for these giants, and new production processes too. New, subtle control systems will have to be developed for distributed blade control.

Solar and wind energy are a great promise for the time to come. To give solar energy a chance to come into its own and to become a mature energy source, while keeping the society running, we will have to continue using other energy sources for decades. We will be faced with large-scale reliance on fossil fuel and nuclear energy.

Nuclear energy

Nuclear power is currently the most important source of electricity in Europe. Nuclear energy can be utilised on a large scale, is CO2-free and safe. This very week, the

European Commission issued its World Energy Technology Outlook - 2050, in which it predicts a global increase in the use of nuclear energy with at least 450%. That would result in a total nuclear capacity of more than 3500 times that of the Borselle nuclear power plant. The disadvantage of nuclear energy lies in the production of radioactive waste. The amount of waste involved is exceptionally small – just a few cubic metres per power plant per year – and it cleans itself up through the process of radioactive decay. Nevertheless many perceive the lengthy process of decay as problematic. New fast breeder reactors are currently in development which will address that

(5)

5

Another advantage that can be gained by using fast breeder reactors is that they not only produce electricity, but also convert the non-fissile part of uranium into fissionable material. Uranium ore can then be used 100 times more efficiently than in current nuclear reactors.

With regards to sustainability, fast breeder reactors are a necessity: less and shorter-lived waste and far more thorough raw materials use. In the Netherlands, TU Delft and NRG in Petten are conducting international research into the development of safe, economically viable, fast breeder reactors.

Clean fossil

Fossil fuel will remain the other large scale energy source for a long time. Rather than curtailing CO2 emissions from fossil fuels, we can capture them during the burning

process and store them indefinitely. This is what is meant by ‘clean fossil’. There is space in depleted gas and oil fields, in coal layers and in deep saltwater reservoirs. An even cleverer option would be to use the pressure provided by CO₂_{to aid in gas and oil} extraction. A great deal of large-scale research is needed to make capturing and

storing CO2 economical and energetically feasible. Safety and societal support also play

a role that should not be taken lightly. Stop and consider the fact that the mass of CO₂ that a coal-fired power plant releases into the atmosphere is three times more than the mass of the coal that went into the plant. If your 60 litre petrol tank is empty, that means you’ve put 160 kg of CO₂ into the atmosphere.

Hydrogen

Until now, I have talked about electricity production only. Fuels for transport will be needed as well. Here, hydrogen might be a good candidate. Delft is participating in Stanford University’s prestigious Global Climate & Energy Project. The purpose of this programme is to develop a highly efficient hydrogen production process. A porous ceramic membrane is being developed which combines the production of hydrogen from water and methane while separating the hydrogen produced. Still, fossil methane is used here, but the CO2 produced can be stored away, which is impossible when fossil

fuels are burnt in the car.

The next question is how to store hydrogen. Earlier I mentioned gas hydrates, which hold large reserves of natural gas deep beneath the oceans. Delft scientists came up with the idea that hydrogen atoms could be stored in those ice cages. By adding a specific molecule, tetrahydrofuran, our researchers were able to reduce the required pressure from 2500 bar to a more easily manageable 80 bar. Furthermore, the storage capacity of the ice could be doubled by introducing yet another molecule. The

application is simple: a reduction in pressure releases hydrogen, which produces electricity in a fuel cell. All that remains in the car’s fuel tank is water.

Energy storage

(6)

6

Various groups are engaged in fundamental research into functional materials for

better batteries and for practical hydrogen storage. That research looks into all kinds of light, porous materials including metal hydrides and metal networks. Nanostructuring facilitates higher energy densities and a shorter battery charge and discharge time. Radiation from the Delft nuclear research reactor is being used to probe those materials to see how the charge carriers (lithium and hydrogen) behave.

Turn a threat into an opportunity

Ladies and gentlemen, I could continue for a while but time and your patience are limited.

We need to strive for scientific breakthroughs in many of the areas I have mentioned. I have shown you some of the current developments at the Delft University of

Technology.

Fortunately, researchers from the three technical universities have joined forces in the 3TU federation. On a national level, scientists have recently established NODE, the Dutch Research Platform on Sustainable Energy Supply, to combine their efforts. Together we can establish the scientific backbone for future developments in one of the most important economic sectors of all.

The Netherlands is one of the most sensitive areas in the world when it comes to rising sea levels. However, the country also possesses top-level institutes, some of the

world’s major energy companies and the ambitious port of Rotterdam, which signed Bill Clinton’s contract to reduce its CO2 emissions by 50%.

If we act now, the Netherlands can position itself in the spotlights and turn a threat into an opportunity.

(7)

1

Energy revolution:

the future is not what it used to be

Tim van der Hagen

165

165 th

th

_Dies

_Natalis

January 12, 2007

(8)

(9)

(10)

4

W

orld

energy demand

Source: International Energy Agency 2006

now 2004

‘tomorrow’ 2030

15,000 billion euros

investments needed

in the energy sector

+ 53 %

the

(11)

5

Proved oil reserves at end 2005

Source: BP Statistical Review of World Energy 2006

dependence on

the Middle East

the

(12)

6

The last 160,000 years

(from ice cores)

and the next 100 years

Time (thousands

of years)

160

120

80

40 Now

–10

0

10

100

200

300

400

500

600

700 CO

₂

in 2100

(with business as usual)

(13)

7

Temperature

earth surface

variations

from the year 1000 up to 2100

Source: IPCC

greenhouse effect ?

the

(14)

8

Stabilizing CO

₂

emission:

action needed

stabilization triangle:

cut emissions by

7 Gton/year

Source: Carbon Mitigation Initiative; www.princeton.edu

billions of tons carbon

emitted per year

(15)

9

How to avoid 7 x 1

Gton

carbon emission/year?

here are the options (1

Gton

/year each)

Source: Carbon Mitigation Initiative; www.princeton.edu

Double the fuel

economy of the

world’s cars

Half the number of

car kilometers

Use the best

efficiency practices

in all residential and

commercial buildings

Savings

Nuclear power:

Triple the number of

nuclear power plants

Clean Fossil:

Capture and store carbon from

800 coal electric power plants

‘Transition’

ready by

2050?

50 x today's wind energy

Wind energy:

Biofuels:

50 x more ethanol production

Solar cells:

700 x the current capacity

(16)

10

Time is pressing …

(17)

(18)

12

Solar PV

the future scenario?

increase

w.r.t. 2005

% of world

electricity

€ct/kWh

% annual

growth

(19)

13

Solar PV at the TU Delft

crystalline silicium

thin films new materials

• highly efficient cells

• very cheap cells

- organic materials (“plastic”)

- TiO

₂

(tooth paste, latex)

• goal: 10% of current € / kWh

• 300 times less silicium

• price and energy cost / 2

(20)

(21)

15

largest turbine blade (61.5 m)

Wind

(22)

16

in 2020:

a 20 MW, 250 m diameter

wind power station?

blades with distributed control

Wind

(23)

17

erts

101 102 103 104 105 106 102 103 104 105 106 107 108 109 R a di ot ox ic it y ( S v )

Storage time (a)

Actinides Fiss Prods Ore

Radiotoxicity

/ Sv

fission products

250,000

years

actinides

1000-fold reduction of rad. waste lifetime !

• ‘Actinides’ (heavy elements)

are responsible for the long

lifetime of radioactive waste

• Fast

reactors can fission

these actinides

Nuclear fission

reduction of the lifetime of radioactive waste

250 years

(24)

18

better use of uranium fuel

thermal

reactors use

< 1%

of the uranium

fast

reactors use up to

100%

of the uranium

100-fold better usage of uranium ore !

238

239

92 U

+ →

n

92 U

→

93 Np

→

94 Pu

conversion to fissile material:

Nuclear fission

(25)

19

Sources: Lynn Orr, Stanford University; Dan McGee, Alberta Geological Survey

Clean fossil

options for geologic storage of CO

₂

CO₂dissolved in formation water CO₂plume

• Oil and gas reservoirs:

enhanced oil and gas recovery

• Coal beds:

adsorbed CO

₂

replaces

adsorbed CH

₄

• Deep formations

(26)

20

Macroporous Support

(α-Al

₂

O

₃

)

Nano-structured Layer

Atomic Layer Deposition (ALD)

(<0.32 nm)

Intermediate Porous Layer

Sol-Gel (2-3 nm)

Reaction catalyst

Membrane reactors for production

and separation of hydrogen

hydrogen

(27)

21

hydrogen & lithium

Goals:

• high storage capacity / kg, m

3 _{and €}

• rapid and reversible storage

• close to ambient conditions

• safe

Energy storage

light metal

hydrides

metal organic

frameworks

hydrogen

clathrates

catalysts

(28)

22

80 bar

hydrogen clusters

pure H

₂

hydrate

stable H

₂

+ THF hydrate

Florusse, L.J., Peters, C.J., Schoonman, J., Hester, K.C., Koh, C.A., Dec. S.F., Marsh, K.N.,

Sloan, E.D., Science, 306 (2004) 469-471.

tetrahydrofuran

Energy storage

in ice crystals

2500 bar

(29)

23

Energy revolution:

we better start

we better start today

today

!

Dutch Research Platform on Sustainable Energy Supply

(30)

24

Special thanks to:

Ineke Boneschansker

Hans Bruining

Chris Hellinga

Erik Kelder

Roel van de

Krol

Paul de Krom

Gijs

van Kuik

Fokko

Mulder

Cor Peters

Wilfred van Rooijen

Diederik

Samsom

Joop Schoonman

Laurens Siebbeles

Roelf van Til

Marnix

(31)

1

Energy revolution:

the future is not what it used to be

Tim van der Hagen

165

165 th

th

_Dies

_Natalis

January 12, 2007

(32)

(33)

(34)

4

W

orld

energy demand

Source: International Energy Agency 2006

now 2004

‘tomorrow’ 2030

15,000 billion euros

investments needed

in the energy sector

+ 53 %

the

(35)

5

Proved oil reserves at end 2005

Source: BP Statistical Review of World Energy 2006

dependence on

the Middle East

the

(36)

6

The last 160,000 years

(from ice cores)

and the next 100 years

Time (thousands

of years)

160

120

80

40 Now

–10

0

10

100

200

300

400

500

600

700 CO

₂

in 2100

(with business as usual)

(37)

7

Temperature

earth surface

variations

from the year 1000 up to 2100

Source: IPCC

greenhouse effect ?

the

(38)

8

Stabilizing CO

₂

emission:

action needed

stabilization triangle:

cut emissions by

7 Gton/year

Source: Carbon Mitigation Initiative; www.princeton.edu

billions of tons carbon

emitted per year

(39)

9

How to avoid 7 x 1

Gton

carbon emission/year?

here are the options (1

Gton

/year each)

Source: Carbon Mitigation Initiative; www.princeton.edu

Double the fuel

economy of the

world’s cars

Half the number of

car kilometers

Use the best

efficiency practices

in all residential and

commercial buildings

Savings

Nuclear power:

Triple the number of

nuclear power plants

Clean Fossil:

Capture and store carbon from

800 coal electric power plants

‘Transition’

ready by

2050?

50 x today's wind energy

Wind energy:

Biofuels:

50 x more ethanol production

Solar cells:

700 x the current capacity

(40)

10

Time is pressing …

(41)

(42)

12

Solar PV

the future scenario?

increase

w.r.t. 2005

% of world

electricity

€ct/kWh

% annual

growth

(43)

13

Solar PV at the TU Delft

crystalline silicium

thin films new materials

• highly efficient cells

• very cheap cells

- organic materials (“plastic”)

- TiO

₂

(tooth paste, latex)

• goal: 10% of current € / kWh

• 300 times less silicium

• price and energy cost / 2

(44)

(45)

15

largest turbine blade (61.5 m)

Wind

(46)

16

in 2020:

a 20 MW, 250 m diameter

wind power station?

blades with distributed control

Wind

(47)

17

erts

101 102 103 104 105 106 102 103 104 105 106 107 108 109 R a di ot ox ic it y ( S v )

Storage time (a)

Actinides Fiss Prods Ore

Radiotoxicity

/ Sv

fission products

250,000

years

actinides

1000-fold reduction of rad. waste lifetime !

• ‘Actinides’ (heavy elements)

are responsible for the long

lifetime of radioactive waste

• Fast

reactors can fission

these actinides

Nuclear fission

reduction of the lifetime of radioactive waste

250 years

(48)

18

better use of uranium fuel

thermal

reactors use

< 1%

of the uranium

fast

reactors use up to

100%

of the uranium

100-fold better usage of uranium ore !

238

239

92 U

+ →

n

92 U

→

93 Np

→

94 Pu

conversion to fissile material:

Nuclear fission

(49)

19

Sources: Lynn Orr, Stanford University; Dan McGee, Alberta Geological Survey

Clean fossil

options for geologic storage of CO

₂

CO₂dissolved in formation water CO₂plume

• Oil and gas reservoirs:

enhanced oil and gas recovery

• Coal beds:

adsorbed CO

₂

replaces

adsorbed CH

₄

• Deep formations

(50)

20

Macroporous Support

(α-Al

₂

O

₃

)

Nano-structured Layer

Atomic Layer Deposition (ALD)

(<0.32 nm)

Intermediate Porous Layer

Sol-Gel (2-3 nm)

Reaction catalyst

Membrane reactors for production

and separation of hydrogen

hydrogen

(51)

21

hydrogen & lithium

Goals:

• high storage capacity / kg, m

3 _{and €}

• rapid and reversible storage

• close to ambient conditions

• safe

Energy storage

light metal

hydrides

metal organic

frameworks

hydrogen

clathrates

catalysts

(52)

22

80 bar

hydrogen clusters

pure H

₂

hydrate

stable H

₂

+ THF hydrate

Florusse, L.J., Peters, C.J., Schoonman, J., Hester, K.C., Koh, C.A., Dec. S.F., Marsh, K.N.,

Sloan, E.D., Science, 306 (2004) 469-471.

tetrahydrofuran

Energy storage

in ice crystals

2500 bar

(53)

23

Energy revolution:

we better start

we better start today

today

!

Dutch Research Platform on Sustainable Energy Supply

(54)

24