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

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

## Part 3: Why making good energy policy is difficult

David MacKay FRS

Department of Engineering
University of Cambridge
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

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

## The size of future climate change depends on cumulative emissions

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

# Energy arithmetic

## A rough guide to sustainable energy

### 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

80 kWh per day

80 kWh per day

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

### 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

## Demand-side options – Transport

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

## 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

## 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

# What we need for most 2050 pathways

## What we need for most 2050 pathways

Thermablok

### Electric vehicles

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

## What we need for most 2050 pathways

### Cheaper wind, especially offshore

2benergy.com
Makani Power
 Makani Power

## What we need for most 2050 pathways

### Waste-to-good stuff

• what are the best uses of biomass?

## 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

### Energy storage

 Dinorwig - 10 GWh energy; 2 GW maximum power

## 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

# Why climate change action 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

Department of Energy and Climate Change

# Why DECC's work is difficult

## The 2050 Calculator

2050-calculator-tool.decc.gov.uk

- 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

- 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

## "BEaC"

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:

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

 Electricity price in pounds per MWh

www.energy-charts.de

Electricity production in Germany: Week 29

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

Electricity production in Germany: Week 25

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

## 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)

NOT caps.

## 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

## this presentation was written in HTML using: Christian Steinruecken's 'slides.css' and 'slides.js'

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