Living on other countries renewables

Whether the Mediterranean becomes an area of cooperation or confrontation in the 21st century will be of strategic importance to our common security.

Joschka Fischer, German Foreign Minister, February 2004

We've found that it's hard to get off fossil fuels by living on our own re-newables. Nuclear has its problems too. So what else can we do? Well, how about living on someone else's renewables? (Not that we have any entitlement to someone else's renewables, of course, but perhaps they might be interested in selling them to us.)

Most of the resources for living sustainably are related to land area: if you want to use solar panels, you need land to put them on; if you want to grow crops, you need land again. Jared Diamond, in his book Collapse, observes that, while many factors contribute to the collapse of civilizations, a common feature of all collapses is that the human population density became too great.

Places like Britain and Europe are in a pickle because they have large population densities, and all the available renewables are diffuse - they have small power density (table 25.1). When looking for help, we should look to countries that have three things: a) low population density; b) large area; and c) a renewable power supply with high power density.

Power per unit land or water area

Wind

2W/m:

0ffshore wind

3W/m:

Tidal pools

3W/m:

Tidal stream

6W/m:

Solar PV panels

5-20 W/m:

Plants

0.5 W/ m:

Rain-water

(highlands)

0.24 W/m:

Hydroelectric

facility

11 W/m:

Solar chimney

0.1 W/m:

Concentrating solar

power (desert)

15 W/m:

Table 25.1. Renewable facilities have to be country-sized because all renewables are so diffuse.

Region

Population

Area (km2)

Density (persons per km2)

Area per person (m2)

Libya

5 760 000

1750 000

3

305 000

Kazakhstan

15100 000

2 710 000

6

178 000

Saudi Arabia

26 400 000

1 960 000

13

74200

Algeria

32 500 000

2 380 000

14

73 200

Sudan

40100 000

2 500 000

16

62 300

World

6 440 000 000

148 000 000

43

23 100

Scotland

5 050 000

78 700

64

15 500

European Union

496 000 000

4330 000

115

8 720

Wales

2 910 000

20 700

140

7110

United Kingdom

59 500 000

244000

243

4110

England

49 600 000

130 000

380

2 630

Table 25.2 highlights some countries that fit the bill. Libya's population density, for example, is 70 times smaller than Britain's, and its area is 7 times bigger. Other large, area-rich, countries are Kazakhstan, Saudi Arabia, Algeria, and Sudan.

Table 25.2. Some regions, ordered from small to large population density. See p338 for more population densities.

Table 25.2 highlights some countries that fit the bill. Libya's population density, for example, is 70 times smaller than Britain's, and its area is 7 times bigger. Other large, area-rich, countries are Kazakhstan, Saudi Arabia, Algeria, and Sudan.

In all these countries, I think the most promising renewable is solar power, concentrating solar power in particular, which uses mirrors or lenses to focus sunlight. Concentrating solar power stations come in several flavours, arranging their moving mirrors in various geometries, and putting various power conversion technologies at the focus - Stirling engines, pressurized water, or molten salt, for example - but they all deliver fairly similar average powers per unit area, in the ballpark of 15 W/m2.

A technology that adds up

"All the world's power could be provided by a square 100 km by 100 km in the Sahara." Is this true? Concentrating solar power in deserts delivers an average power per unit land area of roughly 15W/m2. So, allowing no space for anything else in such a square, the power delivered would be 150 GW. This is not the same as current world power consumption. It's not even near current world electricity consumption, which is 2000 GW. World power consumption today is 15000GW. So the correct statement about power from the Sahara is that today's consumption could be provided by a 1000 km by 1000 km square in the desert, completely filled with concentrating solar power. That's four times the area of the UK. And if we are interested in living in an equitable world, we should presumably aim to supply more than today's consumption. To supply every person in the world with an average European's power consumption (125 kWh/d), the area required would be two 1000 km by 1000 km squares in the desert.

Fortunately, the Sahara is not the only desert, so maybe it's more relevant to chop the world into smaller regions, and ask what area is needed in each region's local desert. So, focusing on Europe, "what area is required in the North Sahara to supply everyone in Europe and North Africa with an average European's power consumption? Taking the population of Europe and North Africa to be 1 billion, the area required drops to 340 000 km2, which corresponds to a square 600 km by 600 km. This area is equal to one Germany, to 1.4 United Kingdoms, or to 16 Waleses.

The UK's share of this 16-Wales area would be one Wales: a 145 km by 145 km square in the Sahara would provide all the UK's current primary energy consumption. These squares are shown in figure 25.5. Notice that while the yellow square may look "little" compared with Africa, it does have the same area as Germany.

Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

Get My Free Ebook


Post a comment