## Implications of the Lunar Solar Power System

Between 1960 and 1986, the total electric energy, Ee, (y), used every year, measured in TWe-y, was an excellent index of the annual GWP in trillions of dollars (T\$e(y)) in a given year "y" (Starr, 1990; Criswell, 1997). Equation (1) presents this empirical relation. Equation (1) includes the annual increase in productivity of energy (Eff(y) = 1%/y). The maximum cost of 1500 TWe-y of energy delivered by the LSP System between 2000 and 2100 is estimated to be 300 T\$.

T\$e (y) = 2.2 T\$ + [10.5 T\$/TWe-y] X Ee(y) X Eff(y) - 300T\$/(100 y) (1)

A new electric power system is initiated in 2000. Capacity builds to 20 TWe by 2050 and then remains at 20 TWe capacity until 2100. The new power system delivers 1510 TWe-y over the 21st century. Applying Equation (1) to this profile predicts an integral net GWP ~25 800 T\$ by 2100. Assume the growth in world population presented in Table 9.1. These relations predict a global per capita income of —30000 \$/y-person in 2050 as a result of the acceleration of global electrification. By 2100, global per capita income is —38000 \$/y-person because of the 1%/y growth in economic productivity of a unit of electric energy. The electric power capacity of the new system, and the net new wealth it produces, could be further increased for users on the Earth and in space.

These gains are enormous in total GWP compared to Case A2 of Nakicenovic et al. (1998). Refer to Table 9.1. The all-electric world supplied by the LSP system has —2.5 times greater economic gain and retains enormous reserves of fossil and nuclear fuels. Also, there is no additional contamination of the atmosphere or Earth.

Case A2 assumes that aggressive use of oil, natural gas, and especially coal will not degrade the environment and that costs of environmental remediation, health effects, and pollution control will all be low. However, it is not obvious this should be so. During the 1990s the world per capita income remained near 4000 \$/y-person. There was little growth in the Developing Countries because of increases in population and recessions. Without a major new source of clean and lower-cost commercial energy it will be very difficult to increase per capita income in the Developing Nations. Suppose per capita income remains at 4000 \$/y-person throughout the 21st century. The integral of gross world product will be —4000 T\$ or only 2.2 times the total energy costs for Case A2 in Table 9.1. Over the 21st century the LSP System offers the possibility of economic gains —80 to 900 times energy costs.

Enormous attention is directed to discovering and promoting "sustainable" sources of energy and seeking more efficient means of utilizing conventional commercial and renewable energy. However, there are clear limits to the conventional options. Over 4 billion of Earth's nearly 6 billion people are poor in both wealth and energy. Their existence depends primarily on new net energy taken from the biosphere. This energy is harvested as wood, grass, grain, live stock from the land, fish from the seas, and in many other direct and indirect products. The biosphere incorporates each year approximately 100 TWt-y of solar energy in the form of new net plant mass (algae, trees, grass, etc.). It is estimated that humanity now directly extracts — 5% of that new energy and disturbs a much greater fraction of the natural cycles of power through the biosphere. People divert almost 50% of the new solar photosynthetic energy from its natural cycles through the biosphere. Humankind now collects and uses approximately 50% of all the rainwater that falls on accessible regions of the continents. Given the continuing growth of human population, most of the fresh water used by humans will be obtained through desalination (Ehrlich and Roughgarden, 1987; Rees and Wachernagel, 1994).

Human economic prosperity is possibly now using 6 kWt/person. In the next century an LSP supplying —2 to 3 kWe/person will enable at least an equal level of prosperity with no major use of biosphere resources. For a population of 10 billion people this corresponds to 2000 to 3000 TWe-y, of electric energy per century (Goeller and Weinberg, 1976; Criswell, 1998, 1994, 1993). Much more energy might be desirable and can be made available.

It is widely recognized that the lack of affordable and environmentally benign commercial energy limits the wealth available to the majority of the human population (WEC, 1993, 1998, 2000). However, there is almost no discussion of how to provide the enormous quantities of quality commercial energy needed for an "energy-rich" world population. The carbon curve of Figure 9.1 depicts the cumulative depletion of terrestrial fossil thermal energy by a prosperous human population in terawatt-y of thermal energy. There is approximately 4000 to 6000 TWt-y of economically accessible fossil fuels. Thus, the fossil energy use stops around 2100 when the prosperous world consumes the fossil fuels. Economically available uranium and thorium can provide only the order of 250 TWt-y of energy. Fission breeder reactors would provide adequate energy for centuries once seawater is tapped for uranium and thorium. However, given the political opposition, health and safety risks, and economic uncertainty of nuclear power at the end of the 20th century, it is unlikely that nuclear fission will become the dominant source of power within the biosphere by 2050.

The LSP System is recommended for consideration by technical, national, and international panels and scientists active in lunar research (NASA, 1989; Stafford, 1991; ESA, 1995; ILEWG, 1997; Sullivan and McKay, 1991; Spudis, 1996). An LSP System scaled to enable global energy prosperity by 2050 can, between 2050 and 2070, stop the depletion of terrestrial resources and bring net new non-polluting energy into the biosphere. People can become independent of the biosphere for material needs and have excess energy to nurture the biosphere. The boundaries of routine human activities will be extended beyond the Earth to the Moon, and a two-planet economy will be established.