RESULTS ON ENERGY DEMAND

Having defined the boundaries of our scenarios ^- the population assumptions, the economic growth rates, and the seven world regions ^- we now turn to interior detail, the purpose of the MEDEE model, described briefly in Figure 8 and in more detail in Lapillone (1978). (Figure 7 showed its position in the overall model set.) Basically we had to go through a detailed accounting of energy end uses in the various sectors, such as transportation, industry, or household. For instance, we had to identify what room temperatures will be appropriate in India by the year 2000. Of course, these are assump- tions but in any exercise like this one, such assumptions must be made. It is crucial to make them explicit and to document them. We have done this at several levels: in a book for the general reader, in a comprehensive technical report, and, at a more detailed level, in a series of research reports and working papers.*

In developing the demand figures, we assumed substantial energy conservation.

Thus a clear, qualitative result of the overall analysis is that, without energy conservation,

*Energy Systems Program Group of the International Institute for Applied Systems Analysis, Wolf Hifele, Program Leader (1981) Energy in a Finite World: Volume 1. Paths t o a Sustainable Future;

Volume 2. A Global Systems Analysis. Cambridge, Massachusetts: Ballinger. Volume 1 is the book for the general reader, Volume 2 is the comprehensive technical report; the latter provides detailed listings of the supporting literature.

Putting the Results o f t h e IIASA Energy Systems Program t o Work

FIGURE 8 The MEDEE approach. (MEDEE stands for Moddle dlEvolution de la Demand dlEnergie.)

v I

it just cannot be done. The issue is not whether to pursue energy conservation, but rather how much energy conservation must be realized.

I do not want to go into the details of the analysis here, but I do want to show you growth over the next 50 years. In the High scenario the increase is a little higher.

The numbers for Region I1 (SU/EE) are not arbitrary numbers. They were cal- culated in close cooperation with the Academy of Sciences of the USSR in Moscow, and we therefore consider them reliable and realistic: 8.57 kW/cap in 2030 in the High scenario and 6.15 kW/cap in the Low scenario.

SUBSTITUTABLE FINAL ENERGY DEMAND

TABLE 2 Final (commercial) energy consumption per capita for the High and Low scenarios from 1975 to 2030 (kilowatt-years per year per capita, abbreviated in the text as kW/cap).

IIASA

5 8 W. Hafele Of special note is the situation in Region V (Af/SEA), where the consumption level currently is only 0.18 kW/cap for commercial energy (see Table 2). However, there is necessarily consumption of noncommercial energy on top of this, some 0.3 kW/cap Office, thus incorporating the wisdom and judgment of people from the region.

In Region IV (LA), where current consumption is only 0.8 kW/cap, we see in Table 2 that the High-scenario 2030 consumption level is approximately 3.3 kW/cap, exceeding the average consumption in Region 111 (WEIJANZ) in 1975. This comparison reflects the high expectations and the highexpected growth rates for Latin America; it pro- vides a yardstick for considering the distribution of energy consumption over the regions.

Turning to aggregate primary energy consumption, we find in Table 3 a current rate of 8.2 terawatt-years per year (TW-yr/yr) for the world as a whole. (One TW-yr/yr is a large energy unit; it equals roughly a billion tons of coal per year or 14 million barrels TABLE 3 Primary (commercial) energy consumption by IIASA regions for the High and Low scenar- ios from 1975 to 2030 (terawatt-years per year).

IIASA

aColumns may not sum to totals because of rounding.

b~ncludes 0.21 TW-yrlyr of bunkers ^- fuel used in international shipments of fuel.

of oil per day, which is greater than Saudi Arabia's current possible production rate.) Most of the 8.2 TW-yr/yr goes to Regions I, 11, and 111, with only a minor fraction going to the four other regions.

In the High scenario, where primary energy consumption in 2030 reaches 36 TW-yr/

yr, the assumed higher growth rates are associated with the additional benefits of innova- tion and support for equalizing social differences. Thus, by 2030 Regions I (NA), I1 (SU/EE), and 111 (WEIJANZ) account for a much smaller share of the global primary energy consumption than they did in 1975. In the Low scenario, where primary energy consumption reaches 22 TW-yr/yr in 2030, the trend toward equalization across regions can also be seen, although it is less pronounced than in the High scenario. The two num- bers 36 TW-yr/yr and 22 TW-yr/yr are not meant to represent extremes in either direc- tion, but rather are assumed to cover a middle ground. Still, their magnitudes indicate that an increase in energy supply by a factor of around three or four will be required over the next 50 years.

Putting the Results o f the IIASA Energy Systems Program t o Work 5 9 ENERGY RESOURCES

It is on the basis of energy demand, then, that we have to contemplate the supply problem. Do we have enough energy resources, particularly fossil resources? Typically, the answer is, "yes and no." Originally, when I was more naive, I thought that looking into the resource problem would not be too difficult and that the numbers would be well established. Not so: it proved to be a most complex problem. And our fundamental concern was to look at the problem in terms of the right categories - not the traditional ones, but those of tomorrow. Table 4 illustrates my point. According to traditional TABLE 4 Global energy resources and their costs (terawatt-years).

- -- - - - - - -- - - - . -

NOTES: Cost categories represent estimates of costs either at or below the stated volume of recover- able resources (in constant 1975 US$).

For coal - category 1: 253, and category 2: 25-503 per metric ton of coal equivalent.

For oil and natural gas - category 1: 12$, category 2: 12-203, and category 3: 20-25$ per barrel o f oil equivalent.

wisdom, 1000 TW-yr is a very good indication of global fossil resources, and it is con- sistent with the 1091 TW-yr shown in the table as the global total of what may bereferred to as conventional fossil resources. Furthermore, the 560 TW-yr of category 1 coal listed in the table equal some 600 billion tons of coal equivalent (tce), essentially the conven- tional component of coal resources as, for instance, reported at the Detroit World Energy Conference (WEC 1974). The same can be said for oil, with 264 TW-yr, and gas, with 267 TW-yr. But when one goes to higher-cost categories - and here I mean not only monetary costs, but also environmental-impact and social-difficulty costs - one gains additional resources amounting to a threefold increase: that is, not 1000, but 3000 TW-yr is the more appropriate figure. However, this does not mean that the additional resources have the same nature as the first 1000 TW-yr. The difficulties that accompany category 2 and 3 resources are significant, and I shall return to them later. And, of course, there is the key question: how do we use these 3000 TW-yr most intelligently, if at all?

We looked, not only into fossil resources, but also into alternatives for supplying energy, and Table 5 gives a brief summary of them. In the case of the renewables, it is important to realize that, while wood, for instance, may have an infinite potential, there is a finite limit constraining the possible annual production level: some 2.5 TW-yr/yr is a good figure. When all the renewables are added, within appropriate limits, they total about 6 TW-yr/yr, and certainly do not exceed 14 TW-yr/yr, a large ^- but not very large - number. Oil and gas production is limited to 8 to 12 TW-yr/yr with a question mark, and, to recognize even greater uncertainty, the production potential for coal is listed as 10 to 14 TW-yr/yr with two question marks.

The case of nuclear energy requires a more detailed discussion. If we continue to use only burners, the total resource that we can exploit is only 300 TW-yr - much smaller

W. Hafele

TABLE 5 Alternatives to fossil resources for supplying energy:

resources and production potentials. description is, of course, a simplification, but it captures the essential points of a nuclear future based solely on burners.

However, if breeders are introduced, the most efficient possible energy strategy would lead to a nuclear-energy production level by 2030 of 17 TW-yr/yr, which could

The situation for solar energy is also noteworthy. For the localized, decentralized use of solar power, which Table 5 labels "soft," it is difficult to conceive of more than 1 or 2 TW-yr/yr, although the resource is indeed essentially infinite. The other category of solar power that Table 5 shows is "hard" solar, a classification perhaps best typified by a large centralized facility located in the Sahara Desert. In the final analysis, produc- tion in this category could be very large. Still, the hard-solar option takes time, and it will be difficult to bring to reality. To expect more than 2 to 3 TW-yr/yr by the year 2030 would be unrealistic. Again it is time, and not resources, that is the principal con- straint during at least the next 50 years.