A reality check on renewables
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0:00 - 0:03When the Industrial Revolution started,
-
0:03 - 0:07the amount of carbon sitting
underneath Britain in the form of coal -
0:08 - 0:11was as big as the amount of carbon
sitting under Saudi Arabia -
0:11 - 0:12in the form of oil.
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0:13 - 0:16This carbon powered
the Industrial Revolution, -
0:16 - 0:18it put the "Great" in Great Britain,
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0:18 - 0:21and led to Britain's temporary
world domination. -
0:22 - 0:27And then, in 1918,
coal production in Britain peaked, -
0:27 - 0:28and has declined ever since.
-
0:29 - 0:33In due course, Britain started using
oil and gas from the North Sea, -
0:33 - 0:35and in the year 2000,
-
0:35 - 0:39oil and gas production
from the North Sea also peaked, -
0:39 - 0:41and they're now on the decline.
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0:42 - 0:45These observations about the finiteness
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0:45 - 0:49of easily accessible, local,
secure fossil fuels, -
0:49 - 0:52is a motivation for saying,
"Well, what's next? -
0:53 - 0:55What is life after fossil fuels
going to be like? -
0:55 - 0:59Shouldn't we be thinking hard
about how to get off fossil fuels?" -
0:59 - 1:02Another motivation,
of course, is climate change. -
1:02 - 1:05And when people talk
about life after fossil fuels -
1:05 - 1:07and climate change action,
-
1:07 - 1:09I think there's a lot of fluff,
-
1:09 - 1:12a lot of greenwash,
a lot of misleading advertising, -
1:12 - 1:17and I feel a duty as a physicist to try
to guide people around the claptrap -
1:17 - 1:20and help people understand the actions
that really make a difference, -
1:21 - 1:23and to focus on ideas that do add up.
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1:25 - 1:27Let me illustrate this
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1:27 - 1:30with what physicists call
a back-of-envelope calculation. -
1:30 - 1:32We love back-of-envelope calculations.
-
1:32 - 1:34You ask a question,
write down some numbers, -
1:34 - 1:35and get an answer.
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1:35 - 1:39It may not be very accurate,
but it may make you say, "Hmm." -
1:39 - 1:40So here's a question:
-
1:40 - 1:43Imagine if we said, "Oh yes,
we can get off fossil fuels. -
1:43 - 1:45We'll use biofuels. Problem solved.
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1:45 - 1:47Transport ... We don't need oil anymore."
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1:47 - 1:54Well, what if we grew
the biofuels for a road -
1:54 - 1:57on the grass verge
at the edge of the road? -
1:57 - 2:01How wide would the verge
have to be for that to work out? -
2:02 - 2:03OK, so let's put in some numbers.
-
2:03 - 2:06Let's have our cars go
at 60 miles per hour. -
2:06 - 2:08Let's say they do 30 miles per gallon.
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2:08 - 2:11That's the European average for new cars.
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2:11 - 2:13Let's say the productivity
of biofuel plantations -
2:13 - 2:16is 1,200 liters of biofuel
per hectare per year. -
2:16 - 2:19That's true of European biofuels.
-
2:19 - 2:23And let's imagine the cars are spaced
80 meters apart from each other, -
2:23 - 2:25and they're perpetually
going along this road. -
2:25 - 2:27The length of the road doesn't matter,
-
2:27 - 2:30because the longer the road,
the more biofuel plantation. -
2:30 - 2:31What do we do with these numbers?
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2:31 - 2:35Take the first number, divide by the other
three, and get eight kilometers. -
2:35 - 2:37And that's the answer.
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2:37 - 2:39That's how wide the plantation
would have to be, -
2:39 - 2:41given these assumptions.
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2:41 - 2:44And maybe that makes you say, "Hmm.
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2:44 - 2:46Maybe this isn't going
to be quite so easy." -
2:48 - 2:50And it might make you think,
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2:51 - 2:53perhaps there's an issue to do with areas.
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2:53 - 2:57And in this talk, I'd like to talk
about land areas, and ask: -
2:57 - 2:59Is there an issue about areas?
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2:59 - 3:03The answer is going to be yes,
but it depends which country you are in. -
3:03 - 3:05So let's start in the United Kingdom,
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3:05 - 3:08since that's where we are today.
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3:08 - 3:10The energy consumption
of the United Kingdom, -
3:10 - 3:14the total energy consumption --
not just transport, but everything -- -
3:15 - 3:16I like to quantify it in lightbulbs.
-
3:16 - 3:20It's as if we've all got
125 lightbulbs on all the time, -
3:20 - 3:24125 kilowatt-hours per day per person
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3:24 - 3:26is the energy consumption of the UK.
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3:27 - 3:29So there's 40 lightbulbs'
worth for transport, -
3:29 - 3:3140 lightbulbs' worth for heating,
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3:31 - 3:34and 40 lightbulbs' worth
for making electricity, -
3:34 - 3:36and other things are relatively small,
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3:36 - 3:38compared to those three big fish.
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3:38 - 3:41It's actually a bigger footprint
if we take into account -
3:41 - 3:45the embodied energy in the stuff
we import into our country as well. -
3:45 - 3:49And 90 percent of this energy, today,
still comes from fossil fuels, -
3:49 - 3:53and 10 percent, only, from other,
greener -- possibly greener -- sources, -
3:53 - 3:55like nuclear power and renewables.
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3:56 - 3:58So.
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3:58 - 3:59That's the UK.
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3:59 - 4:04The population density of the UK
is 250 people per square kilometer. -
4:04 - 4:07I'm now going to show you other countries
by these same two measures. -
4:07 - 4:10On the vertical axis, I'm going
to show you how many lightbulbs -- -
4:11 - 4:13what our energy consumption per person is.
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4:13 - 4:15We're at 125 lightbulbs per person,
-
4:15 - 4:19and that little blue dot there
is showing you the land area -
4:19 - 4:20of the United Kingdom.
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4:20 - 4:23The population density
is on the horizontal axis, -
4:23 - 4:26and we're 250 people per square kilometer.
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4:26 - 4:29Let's add European countries in blue,
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4:29 - 4:31and you can see there's quite a variety.
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4:31 - 4:34I should emphasize,
both of these axes are logarithmic; -
4:34 - 4:37as you go from one gray bar
to the next gray bar, -
4:37 - 4:39you're going up a factor of 10.
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4:40 - 4:42Next, let's add Asia in red,
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4:42 - 4:44the Middle East and North Africa in green,
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4:45 - 4:48sub-Saharan Africa in blue,
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4:49 - 4:51black is South America,
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4:52 - 4:54purple is Central America,
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4:55 - 4:58and then in pukey-yellow,
we have North America, -
4:58 - 5:00Australia and New Zealand.
-
5:00 - 5:03You can see the great diversity
of population densities -
5:03 - 5:06and of per capita consumptions.
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5:06 - 5:09Countries are different from each other.
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5:09 - 5:12Top left, we have Canada and Australia,
with enormous land areas, -
5:12 - 5:17very high per capita consumption --
200 or 300 lightbulbs per person -- -
5:17 - 5:20and very low population densities.
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5:20 - 5:23Top right: Bahrain has
the same energy consumption -
5:24 - 5:25per person, roughly, as Canada --
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5:26 - 5:28over 300 lightbulbs per person,
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5:28 - 5:31but their population density
is a factor of 300 times greater, -
5:31 - 5:331,000 people per square kilometer.
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5:33 - 5:38Bottom right: Bangladesh has
the same population density as Bahrain, -
5:38 - 5:40but consumes 100 times less per person.
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5:41 - 5:44Bottom left: well, there's no one.
-
5:44 - 5:46But there used to be
a whole load of people. -
5:46 - 5:48Here's another message from this diagram.
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5:48 - 5:51I've added on little blue tails
behind Sudan, Libya, -
5:51 - 5:53China, India, Bangladesh.
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5:53 - 5:55That's 15 years of progress.
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5:55 - 5:57Where were they 15 years ago,
and where are they now? -
5:57 - 5:59And the message is,
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5:59 - 6:01most countries are going to the right,
and they're going up. -
6:01 - 6:04Up and to the right:
bigger population density -
6:04 - 6:06and higher per capita consumption.
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6:06 - 6:10So, we may be off in the top
right-hand corner, slightly unusual, -
6:10 - 6:12the United Kingdom accompanied by Germany,
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6:12 - 6:14Japan, South Korea, the Netherlands,
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6:14 - 6:16and a bunch of other
slightly odd countries, -
6:16 - 6:21but many other countries are coming
up and to the right to join us. -
6:21 - 6:23So we're a picture, if you like,
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6:23 - 6:25of what the future energy consumption
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6:25 - 6:28might be looking
like in other countries, too. -
6:29 - 6:32I've also added in this diagram
now some pink lines -
6:32 - 6:34that go down and to the right.
-
6:34 - 6:38Those are lines of equal
power consumption per unit area, -
6:38 - 6:40which I measure in watts per square meter.
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6:40 - 6:44So, for example, the middle line there,
0.1 watts per square meter, -
6:44 - 6:48is the energy consumption
per unit area of Saudi Arabia, -
6:48 - 6:52Norway, Mexico in purple,
and Bangladesh 15 years ago. -
6:53 - 6:56Half of the world's population
lives in countries -
6:56 - 6:58that are already above that line.
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7:00 - 7:05The United Kingdom is consuming
1.25 watts per square meter. -
7:05 - 7:08So is Germany, and Japan
is consuming a bit more. -
7:09 - 7:13So, let's now say why this is relevant.
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7:13 - 7:15Why is it relevant?
-
7:15 - 7:17Well, we can measure
renewables in the same units -
7:18 - 7:20and other forms of power
production in the same units. -
7:21 - 7:23Renewables is one of the leading ideas
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7:23 - 7:27for how we could get off
our 90 percent fossil-fuel habit. -
7:28 - 7:29So here come some renewables.
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7:29 - 7:32Energy crops deliver
half a watt per square meter -
7:32 - 7:33in European climates.
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7:35 - 7:36What does that mean?
-
7:36 - 7:38You might have anticipated that result,
-
7:38 - 7:41given what I told you about the biofuel
plantation a moment ago. -
7:41 - 7:44Well, we consume 1.25 watts
per square meter. -
7:44 - 7:45What this means is,
-
7:45 - 7:49even if you covered the whole
of the United Kingdom with energy crops, -
7:49 - 7:52you couldn't match
today's energy consumption. -
7:53 - 7:56Wind power produces a bit more --
2.5 watts per square meter. -
7:56 - 8:01But that's only twice as big
as 1.25 watts per square meter. -
8:01 - 8:05So that means if you wanted, literally,
to produce total energy consumption -
8:05 - 8:07in all forms, on average, from wind farms,
-
8:07 - 8:10you need wind farms
half the area of the UK. -
8:12 - 8:15I've got data to back up
all these assertions, by the way. -
8:16 - 8:18Next, let's look at solar power.
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8:18 - 8:20Solar panels, when you put them on a roof,
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8:20 - 8:24deliver about 20 watts
per square meter in England. -
8:26 - 8:28If you really want to get
a lot from solar panels, -
8:28 - 8:31you need to adopt the traditional
Bavarian farming method, -
8:31 - 8:32where you leap off the roof,
-
8:33 - 8:35and coat the countryside
with solar panels, too. -
8:35 - 8:38Solar parks, because of the gaps
between the panels, deliver less. -
8:38 - 8:42They deliver about 5 watts
per square meter of land area. -
8:42 - 8:45And here's a solar park
in Vermont, with real data, -
8:45 - 8:48delivering 4.2 watts per square meter.
-
8:48 - 8:51Remember where we are,
1.25 watts per square meter, -
8:51 - 8:54wind farms 2.5, solar parks about five.
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8:55 - 8:58So whichever of those renewables you pick,
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8:58 - 9:02the message is, whatever mix
of those renewables you're using, -
9:02 - 9:04if you want to power the UK on them,
-
9:04 - 9:06you're going to need
to cover something like -
9:06 - 9:0920 percent or 25 percent of the country
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9:09 - 9:11with those renewables.
-
9:11 - 9:15I'm not saying that's a bad idea;
we just need to understand the numbers. -
9:15 - 9:17I'm absolutely not anti-renewables.
I love renewables. -
9:17 - 9:19But I'm also pro-arithmetic.
-
9:19 - 9:21(Laughter)
-
9:21 - 9:25Concentrating solar power in deserts
delivers larger powers per unit area, -
9:25 - 9:27because you don't have
the problem of clouds. -
9:27 - 9:30So, this facility delivers
14 watts per square meter; -
9:30 - 9:32this one 10 watts per square meter;
-
9:32 - 9:35and this one in Spain,
5 watts per square meter. -
9:35 - 9:37Being generous
to concentrating solar power, -
9:37 - 9:41I think it's perfectly credible it could
deliver 20 watts per square meter. -
9:41 - 9:42So that's nice.
-
9:42 - 9:45Of course, Britain
doesn't have any deserts. -
9:45 - 9:46Yet.
-
9:46 - 9:48(Laughter)
-
9:48 - 9:50So here's a summary so far:
-
9:51 - 9:54All renewables, much
as I love them, are diffuse. -
9:54 - 9:56They all have a small power per unit area,
-
9:56 - 9:58and we have to live with that fact.
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9:58 - 10:04And that means, if you do want renewables
to make a substantial difference -
10:04 - 10:05for a country like the United Kingdom
-
10:05 - 10:07on the scale of today's consumption,
-
10:08 - 10:12you need to be imagining renewable
facilities that are country-sized. -
10:12 - 10:13Not the entire country,
-
10:13 - 10:17but a fraction of the country,
a substantial fraction. -
10:18 - 10:20There are other options
for generating power as well, -
10:20 - 10:22which don't involve fossil fuels.
-
10:22 - 10:25So there's nuclear power,
and on this ordinance survey map, -
10:25 - 10:29you can see there's a Sizewell B
inside a blue square kilometer. -
10:29 - 10:31That's one gigawatt in a square kilometer,
-
10:31 - 10:33which works out to 1,000 watts
per square meter. -
10:33 - 10:36So by this particular metric,
-
10:36 - 10:41nuclear power isn't
as intrusive as renewables. -
10:41 - 10:43Of course, other metrics matter, too,
-
10:43 - 10:46and nuclear power has
all sorts of popularity problems. -
10:47 - 10:49But the same goes for renewables as well.
-
10:49 - 10:52Here's a photograph of a consultation
exercise in full swing -
10:52 - 10:55in the little town of Penicuik
just outside Edinburgh, -
10:55 - 10:57and you can see the children
of Penicuik celebrating -
10:57 - 10:59the burning of the effigy of the windmill.
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11:00 - 11:01So --
-
11:01 - 11:02(Laughter)
-
11:02 - 11:03People are anti-everything,
-
11:03 - 11:06and we've got to keep
all the options on the table. -
11:06 - 11:10What can a country like the UK
do on the supply side? -
11:10 - 11:13Well, the options are,
I'd say, these three: -
11:13 - 11:14power renewables,
-
11:14 - 11:18and recognizing that they need
to be close to country-sized; -
11:18 - 11:19other people's renewables,
-
11:19 - 11:21so we could go back and talk very politely
-
11:21 - 11:24to the people in the top left-hand side
of the diagram and say, -
11:24 - 11:27"Uh, we don't want
renewables in our backyard, -
11:27 - 11:29but, um, please could we put
them in yours instead?" -
11:29 - 11:31And that's a serious option.
-
11:31 - 11:35It's a way for the world
to handle this issue. -
11:35 - 11:39So countries like Australia,
Russia, Libya, Kazakhstan, -
11:39 - 11:42could be our best friends
for renewable production. -
11:43 - 11:45And a third option is nuclear power.
-
11:45 - 11:48So that's some supply-side options.
-
11:48 - 11:51In addition to the supply levers
that we can push -- -
11:51 - 11:53and remember, we need large amounts,
-
11:53 - 11:57because at the moment, we get 90 percent
of our energy from fossil fuels -- -
11:57 - 11:58in addition to those levers,
-
11:58 - 12:01we could talk about other ways
of solving this issue. -
12:01 - 12:04Namely, we could reduce demand,
and that means reducing population -- -
12:04 - 12:06I'm not sure how to do that --
-
12:06 - 12:09or reducing per capita consumption.
-
12:09 - 12:12So let's talk about three more big levers
-
12:12 - 12:14that could really help
on the consumption side. -
12:14 - 12:15First, transport.
-
12:15 - 12:17Here are the physics principles
-
12:17 - 12:20that tell you how to reduce
the energy consumption of transport. -
12:20 - 12:22People often say,
"Technology can answer everything. -
12:22 - 12:25We can make vehicles
that are 100 times more efficient." -
12:25 - 12:27And that's almost true. Let me show you.
-
12:27 - 12:30The energy consumption
of this typical tank here -
12:30 - 12:33is 80 kilowatt hours
per hundred person kilometers. -
12:33 - 12:37That's the average European car.
-
12:37 - 12:38Eighty kilowatt hours.
-
12:39 - 12:41Can we make something 100 times better
-
12:41 - 12:43by applying the physics
principles I just listed? -
12:43 - 12:45Yes. Here it is. It's the bicycle.
-
12:45 - 12:47It's 80 times better
in energy consumption, -
12:47 - 12:50and it's powered by biofuel, by Weetabix.
-
12:50 - 12:52(Laughter)
-
12:52 - 12:54And there are other options in between,
-
12:54 - 12:56because maybe the lady
in the tank would say, -
12:56 - 12:59"No, that's a lifestyle change.
Don't change my lifestyle, please." -
12:59 - 13:03We could persuade her to take a train,
still a lot more efficient than a car, -
13:03 - 13:04but that might be a lifestyle change.
-
13:04 - 13:06Or there's the EcoCAR, top-left.
-
13:06 - 13:10It comfortably accommodates one teenager
and it's shorter than a traffic cone, -
13:10 - 13:12and it's almost as efficient as a bicycle,
-
13:12 - 13:15as long as you drive it
at 15 miles per hour. -
13:15 - 13:18In between, perhaps
some more realistic options -
13:18 - 13:21on the transport lever
are electric vehicles, -
13:21 - 13:23so electric bikes
and electric cars in the middle, -
13:23 - 13:28perhaps four times as energy efficient
as the standard petrol-powered tank. -
13:29 - 13:31Next, there's the heating lever.
-
13:31 - 13:34Heating is a third of our energy
consumption in Britain, -
13:34 - 13:36and quite a lot of that
is going into homes -
13:36 - 13:38and other buildings,
-
13:38 - 13:40doing space heating and water heating.
-
13:40 - 13:42So here's a typical crappy British house.
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13:42 - 13:45It's my house, with a Ferrari out front.
-
13:45 - 13:46(Laughter)
-
13:46 - 13:47What can we do to it?
-
13:47 - 13:51Well, the laws of physics
are written up there, -
13:51 - 13:56which describe how the power
consumption for heating -
13:56 - 13:58is driven by the things you can control.
-
13:58 - 14:01The things you can control
are the temperature difference -
14:01 - 14:03between the inside and the outside.
-
14:03 - 14:05There's this remarkable technology
called a thermostat: -
14:05 - 14:07you grasp it, rotate it to the left,
-
14:07 - 14:09and your energy consumption
in the home will decrease. -
14:10 - 14:13I've tried it. It works.
Some people call it a lifestyle change. -
14:13 - 14:14(Laughter)
-
14:14 - 14:17You can also get the fluff men
in to reduce the leakiness -
14:17 - 14:20of your building -- put fluff
in the walls, fluff in the roof, -
14:20 - 14:22a new front door, and so forth.
-
14:23 - 14:26The sad truth is,
this will save you money. -
14:26 - 14:27That's not sad, that's good.
-
14:27 - 14:29But the sad truth is,
-
14:29 - 14:32it'll only get about 25 percent
of the leakiness of your building -
14:32 - 14:35if you do these things,
which are good ideas. -
14:35 - 14:38If you really want to get a bit closer
to Swedish building standards -
14:38 - 14:40with a crappy house like this,
-
14:40 - 14:43you need to be putting
external insulation on the building, -
14:43 - 14:45as shown by this block of flats in London.
-
14:47 - 14:50You can also deliver heat
more efficiently using heat pumps, -
14:50 - 14:53which use a smaller bit
of high-grade energy like electricity -
14:53 - 14:56to move heat from your garden
into your house. -
14:57 - 14:59The third demand-side option
I want to talk about, -
14:59 - 15:02the third way to reduce energy
consumption is: read your meters. -
15:02 - 15:04People talk a lot about smart meters,
-
15:04 - 15:05but you can do it yourself.
-
15:05 - 15:07Use your own eyes and be smart.
-
15:07 - 15:11Read your meter, and if you're anything
like me, it'll change your life. -
15:11 - 15:13Here's a graph I made.
-
15:13 - 15:15I was writing a book
about sustainable energy, -
15:15 - 15:16and a friend asked me,
-
15:16 - 15:18"How much energy do you use at home?"
-
15:18 - 15:20I was embarrassed; I didn't actually know.
-
15:20 - 15:22And so I started reading
the meter every week. -
15:22 - 15:26The old meter readings are shown
in the top half of the graph, -
15:26 - 15:28and then 2007 is shown
in green at the bottom. -
15:28 - 15:30That was when I was reading
the meter every week. -
15:30 - 15:32And my life changed,
-
15:32 - 15:35because I started doing experiments
and seeing what made a difference. -
15:35 - 15:36My gas consumption plummeted,
-
15:36 - 15:39because I started tinkering
with the thermostat -
15:39 - 15:40and the timing on the heating system,
-
15:40 - 15:43and I knocked more than half
off my gas bills. -
15:43 - 15:46There's a similar story
for my electricity consumption, -
15:46 - 15:49where switching off the DVD
players, the stereos, -
15:49 - 15:52the computer peripherals
that were on all the time, -
15:52 - 15:54and just switching them on
when I needed them, -
15:54 - 15:57knocked another third
off my electricity bills, too. -
15:58 - 16:00So we need a plan that adds up.
-
16:00 - 16:03I've described for you six big levers.
-
16:03 - 16:04We need big action,
-
16:04 - 16:06because we get 90 percent
of our energy from fossil fuels, -
16:07 - 16:11and so you need to push hard
on most, if not all, of these levers. -
16:11 - 16:14Most of these levers
have popularity problems, -
16:14 - 16:17and if there is a lever
you don't like the use of, -
16:17 - 16:21well, please do bear in mind
that means you need even stronger effort -
16:21 - 16:23on the other levers.
-
16:23 - 16:27So I'm a strong advocate
of having grown-up conversations -
16:27 - 16:29that are based on numbers and facts.
-
16:29 - 16:33And I want to close with this map
that just visualizes for you -
16:33 - 16:36the requirement of land and so forth
-
16:36 - 16:39in order to get just
16 lightbulbs per person -
16:39 - 16:42from four of the big possible sources.
-
16:42 - 16:46So, if you wanted to get 16 lightbulbs --
-
16:46 - 16:50remember, today our total energy
consumption is 125 lightbulbs' worth -- -
16:50 - 16:52if you wanted 16 from wind,
-
16:52 - 16:55this map visualizes a solution for the UK.
-
16:55 - 16:59It's got 160 wind farms,
each 100 square kilometers in size, -
16:59 - 17:03and that would be a twentyfold increase
over today's amount of wind. -
17:03 - 17:06Nuclear power:
to get 16 lightbulbs per person, -
17:06 - 17:09you'd need two gigawatts
at each of the purple dots on the map. -
17:09 - 17:13That's a fourfold increase
over today's levels of nuclear power. -
17:14 - 17:17Biomass: to get 16 lightbulbs per person,
-
17:17 - 17:21you'd need a land area something
like three and a half Wales' worth, -
17:22 - 17:24either in our country,
or in someone else's country, -
17:24 - 17:26possibly Ireland, possibly somewhere else.
-
17:26 - 17:28(Laughter)
-
17:28 - 17:29And a fourth supply-side option:
-
17:29 - 17:32concentrating solar power
in other people's deserts. -
17:33 - 17:35If you wanted to get 16 lightbulbs' worth,
-
17:35 - 17:38then we're talking
about these eight hexagons -
17:38 - 17:39down at the bottom right.
-
17:39 - 17:44The total area of those hexagons
is two Greater London's worth -
17:44 - 17:46of someone else's Sahara,
-
17:46 - 17:49and you'll need power lines
all the way across Spain and France -
17:49 - 17:52to bring the power
from the Sahara to Surrey. -
17:53 - 17:54(Laughter)
-
17:54 - 17:55We need a plan that adds up.
-
17:56 - 17:59We need to stop shouting
and start talking. -
18:00 - 18:04And if we can have
a grown-up conversation, -
18:04 - 18:07make a plan that adds up and get building,
-
18:07 - 18:10maybe this low-carbon revolution
will actually be fun. -
18:10 - 18:12Thank you very much for listening.
-
18:12 - 18:14(Applause)
- Title:
- A reality check on renewables
- Speaker:
- David MacKay
- Description:
-
How much land mass would renewables need to power a nation like the UK? An entire country's worth. In this pragmatic talk, David MacKay tours the basic mathematics that show worrying limitations on our sustainable energy options and explains why we should pursue them anyway. (Filmed at TEDxWarwick.)
- Video Language:
- English
- Team:
- closed TED
- Project:
- TEDTalks
- Duration:
- 18:35
Krystian Aparta commented on English subtitles for A reality check on renewables | ||
Krystian Aparta edited English subtitles for A reality check on renewables | ||
Krystian Aparta edited English subtitles for A reality check on renewables | ||
Thu-Huong Ha edited English subtitles for A reality check on renewables | ||
Thu-Huong Ha approved English subtitles for A reality check on renewables | ||
Thu-Huong Ha edited English subtitles for A reality check on renewables | ||
Morton Bast accepted English subtitles for A reality check on renewables | ||
Morton Bast edited English subtitles for A reality check on renewables |
Krystian Aparta
The English transcript was updated on 12/16/2016.