Davd Howarth's course, University of Cambridge — April 2015

Why climate change action is difficult, and how we can make a difference


Part 0: Climate Science

Part 1: Climate change action – understanding the scale required

Part 2: The importance of innovation

Part 3: Why making good energy policy is difficult


David MacKay FRS
   
Department of Engineering
University of Cambridge
Former Chief Scientific Advisor
Department of Energy and Climate Change
United Kingdom Government


Davd Howarth's course, University of Cambridge — April 2015

Sustainable Energy – without the hot air


David MacKay FRS

Department of Engineering
University of Cambridge

Former Chief Scientific Advisor
Department of Energy and Climate Change
United Kingdom Government


   

One lane of cars

60 miles per hour
 
30 miles per gallon
1200 litres of biofuel per hectare per year
80 metres car-spacing

One lane of cars

60 miles per hour
30 miles per gallon
1200 litres of biofuel per hectare per year
80 metres car-spacing

= 8 kilometres wide

This book is free online


www.withouthotair.com

This book is free online


www.withouthotair.com

Climate science

The size of future climate change depends on cumulative emissions


DECC/Met Office, adapted from IPCC 5th Assessment Report (2013)

What pause?


skepticalscience.com



Temperature data, corrected for the ENSO effects Source: Real Climate

Global warming has not stopped

Global-mean surface temperature 1880-2013 (NASA GISS data)
Grey line shows annual values, the blue line a LOESS smooth
Jos Hagelaars / realclimate.org
^ Sea level 100m lower than today

Summer of 2003

The size of future climate change depends on cumulative emissions


DECC/Met Office, adapted from IPCC 5th Assessment Report (2013)

Why climate change action is difficult

1. Emission rate must drop to zero

2. The '2°C'* budget is roughly half gone

* NB, climate sensitivity is still uncertain

Energy arithmetic

A rough guide to sustainable energy

No millions, billions, or trillions

Make quantities comprehensible and comparable

Do calculations per person, to one significant figure

Energy unit: kWh

Power: 1 kWh per day ≈ 40 W



  

Examples

  • one lightbulb for 24 h - 1 kWh
  • food - 3 kWh / day (*)
  • bath - 5 kWh (*)
  • litre of petrol - 10 kWh
  • aluminium can - 0.6 kWh

Drive a car 100 km per day...

80 kWh per day

Run this North-American house

80 kWh per day

Fly London to Los Angeles and back, once per year...

26 kWh per day

June 2007

         

'If every London household unplugged their mobile phone chargers when not in use,
we could save 31,000 tonnes of CO2 and 7.75m per year.'

Numbers

Energy saved by
switching off for one day
= Energy used by
driving an average car for
one second
0.5 W × 86,400 s = 40,000 W × 1 s

Numbers

Energy saved by
switching off for one day
= Energy used by
driving an average car for
one second
0.5 W × 86,400 s = 40,000 W × 1 s
0.01 kWh
Transport
Heating
Electricity



UK energy consumption:

125 kWh per day
per person


and more,
if we take
into account imports







90% fossil fuels

A rough guide to sustainable energy

No millions, billions, or trillions

Make quantities comprehensible and comparable

Do calculations per person, to one significant figure

Energy unit: kWh

Power: 1 kWh per day ≈ 40 W



  

Examples

  • one lightbulb for 24 h - 1 kWh
  • food - 3 kWh / day (*)
  • bath - 5 kWh (*)
  • litre of petrol - 10 kWh
  • aluminium can - 0.6 kWh

Population density: square metres per person

UK:4000 m2 per person
250 people per sq km

Power per unit area: W per square metre

(point size shows land area)

Photo provided by the University of Illinois

Plant power per unit area


* assumes genetic modification, fertilizer application, and irrigation
For sources, see D J C MacKay (2008) Sustainable Energy - without the hot air

Powers per unit area of British wind farms, v farm size


20 W/m2


Data and photo by Jonathan Kimmitt - 25 sq m of panels

Bavaria Solar Park: 5 W/m2
www.powerlight.com

3.8 W/m2
Photo by Robert Hargraves
Data from www.allearthrenewables.com

14 W/m2
www.stirlingenergy.com

Andasol, Spain

10 W/m2

RWE.com

PS10, Solucar

5 W/m2


Photo by afloresm
Ivanpah CA: 377 MW capacity
1079 GWh/y (123 MW)
  from 14.2 km2 of land
Power per unit area: 8.7 W/m2
Kagoshima: 70 MW capacity
expected load factor 12.8%.
1.04 km2 of land
Power per unit area: 8.6 W/m2
Solana AZ: 280 MW capacity
944 GWh/year (108 MW)
  from 12.6 km2 of land
Power per unit area: 8.6 W/m2

All renewables are diffuse

Wind 2.5 W/m2
Plants 0.5 W/m2
Solar PV panels 5–20 W/m2
Tidal pools 3 W/m2
Tidal stream 8 W/m2
Rain-water (highlands) 0.24 W/m2
Concentrating solar power (desert)      15–20 W/m2

   Fission: 1000 W/m2   

A consultation exercise in full swing




Demand-side options – Transport


Have small frontal area per person
Have small weight per person
Go slowly
Go steadily
Convert energy
    efficiently


We need a plan that adds up!



We need a plan that adds up —





... every month, every day, and every hour!
Electricity, gas, and transport demand; and fictional wind (assuming 33 GW of capacity), all on the same vertical scale.

Why climate change action is difficult

3. People are unaware of the scale of action required to decarbonize the energy system

4. and they've been misled by myths

The 2050 Calculator



2050-calculator-tool.decc.gov.uk
2050.edp.pt
www.wbc2050.be
www.wbc2050.be
china-cn.2050calculator.net
2050.sejong.ac.kr

The Global Calculator - globalcalculator.org

Why climate change action is difficult

5. Most low-carbon technologies are either expensive, today

6. ... or they have front-loaded costs

Part 2

Innovation support is crucial

What we need for most 2050 pathways

lots of low-carbon deployment

and innovation to drive down costs

What we need for most 2050 pathways

Amazing insulation


Thermablok

and cheap building-retrofit

Electric vehicles

  • batteries
  • capacitors
  • light-weighting
  • fly-wheels

Smart meters and smart controls that induce behaviour change

What we need for most 2050 pathways

Heat pumps that work

What we need for most 2050 pathways

Cheaper wind, especially offshore

2benergy.com
Makani Power
Makani Power

What we need for most 2050 pathways

Biomass-to-good stuff

Waste-to-good stuff

What we need for most 2050 pathways

Proliferation-resistant, safe, low-waste nuclear power

Jules Horowitz materials test reactor

What we need for most 2050 pathways

Carbon capture and storage at scale


NET Power, LLC

What we need for most 2050 pathways

Smart grids, DSR

Interconnectors

Energy storage

Dinorwig - 10 GWh energy; 2 GW maximum power

Energy storage

What we need for most 2050 pathways, in the long term

Carbon dioxide removal technologies

What we need for most 2050 pathways


Backup plans


  • eg, in case low-cost electric vehicles don't materialise
    • hydrogen, ammonia

  • in case sustainable bioenergy can't be delivered
    • air-fuel synthesis

  • or in case climate sensitivity turns out on the big side
    • geoengineering research

What the world needs for 2050


Solar power

Deep geothermal

What we need for most 2050 pathways

Public and political support for a numerate approach

An ever-improving energy model for each country

Innovation support to drive down costs

Well-trained engineers

Why climate change action is difficult

7. Making good energy policies is difficult


Why DECC's work is difficult –
Reflections on 5 years in the Department of Energy and Climate Change


David MacKay FRS

Department of Engineering
University of Cambridge

Former Chief Scientific Advisor
Department of Energy and Climate Change


 

Why DECC's work is difficult

Multiple misaligned objectives

Wishful thinking

Lack of evidence

The 2050 Calculator



2050-calculator-tool.decc.gov.uk

"Renewable" target misaligned with primary energy-saving and emissions reduction


- example 1

Which is more valuable?


1 cup of boiling water and nine cups of ice-cold water

or


10 cups of water at 10 °C?


[The quantities of heat are identical]

The value of heat depends on its temperature

Standards for Heat-pump Installations

Chris Wickins and the Microgeneration Certification Scheme Heat-pump Working Group

"Renewable" target misaligned with primary energy-saving and emissions reduction

- example 2

Source: IPCC

Policies

  • Renewable transport fuel obligation
  • Renewable obligation
  • Renewable heat incentive
  • International negotiations: prevention of deforestation


Vancouver to Immingham: 8888 nautical miles

(skip to pv example)

Could bioenergy be in tension with climate-change action?

"BEaC"

more about BEaC [see also Amsterdam talk]


Using these assumptions, and assuming all harvested wood goes to power station
Area required for 30 M odt/y of pellets, delivering roughly 35 TWh/y:
about 40,000-50,000 km2 (two Wales)

"Renewable" target misaligned with energy security and with value-for-money

 
Electricity price in pounds per MWh

(skip to ivc example)

www.energy-charts.de

(skip to ivc example)

Electricity production in Germany: Week 29

Graphs: B Burger, Fraunhofer ISE; data: EEX Transparency Platform

(skip to ivc example)

Electricity production in Germany: Week 25

Graphs: B Burger, Fraunhofer ISE; data: EEX Transparency Platform

(skip to ivc example)

GB Electricity Supply, June 2012

(skip to ivc example)

Lowest demand in Summer, 2012

Source: National Grid 2013

simulation of 40 GW of solar capacity in the UK
clear-sky, partially sunny, overcast: 1, 0.547, 0.1

Renewable target in conflict with energy efficiency

Impington Village College

Why climate change action is difficult

(at least, while low-carbon technologies are more expensive than fossil fuels)


8. The atmosphere is a commons


9. Solutions must be fair

Negotiate a carbon price

or a carbon price mechanism

giving a predictable price
and with compensation for poorer people


NOT caps.
NOT cap and trade.
 

Why negotiating a price can yield a better outcome





See also carbon-price.com

This book is free online


www.withouthotair.com

Spare slides





Keeping energy demand and supply in balance

Electricity, gas, and transport demand; and fictional wind (assuming 33 GW of capacity), all on the same vertical scale.

How subsidies are often set

The "50th percentile" method for setting subsidies The "50th percentile" method for setting subsidies The "50th percentile" method for setting subsidies
The "50th percentile" method for setting subsidies

PV efficiencies

2012 2013 2014
J M Martinez-Duart
"Photovoltaics firmly moving to the terawatt scale"
March 2013

Electricity storage costs

Storage costs - assume $125 per kWh [optimistic?]

installed June 2011 — cost $12M ($28 per average watt)


Solar system cost: $28k per average kW;
(to compete, aiming perhaps for $10k per average kW?)

To keep 1 kW going for 12 hours of darkness, need 12 kWh of storage, which costs an extra $1.5k
To keep 1 kW going for 5 dull days, need 120 kWh of storage, which costs an extra $15k
So, for PV to deliver cost-competitive reliable electricity in a sometimes-cloudy location, we need two cost breakthroughs!

From "Solar energy in the context of energy use, energy transportation, and energy storage"
by David MacKay (2013)

This book is free online


www.withouthotair.com

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