International Trends in Renewable Energy,
Applications and Policies
National Solar Energy Day 2000
April 10, 2000
Donald W. Aitken, Ph.D.
Senior Staff Scientist
The Union of Concerned Scientists
The developed and industrial world is powered primarily by nonrenewable fossil
fuel resources. There is continual conjecture as to when these might be depleted. It is
generally agreed that oil will be depleted, at least from an economic standpoint, within
the first half of this century, for we shall soon have a meeting of increasing global
demand for oil with decreasing oil production capacity. Other fossil resources, however,
in particular coal, probably have significantly longer lives.
International pressures to curtail the burning of these fossil fuel resources long
before they are depleted, however, are arising from other physical and economic grounds.
Fossil fuel burning is the dominant source of "Greenhouse Gas" emissions into the
earth's environment, unbalancing the flows of solar and reradiated energy to and from the
surface of the earth. The physical result will be an alteration to the global climate, as the
earth seeks to redistribute the energy according to changing conditions.
Projections suggest extremely expensive potential consequence from these
changes, including possible major loss of low-lying lands and seacoast areas, and likely
shifts of rainfall away from many areas presently crucial for the growth of food,
especially in developing countries. Projections also suggest possible increases in major
atmospheric disturbances, such as storms, hurricanes and floods. The result is growing
international pressure to change energy policies away from the use of fossil fuels, well
before they are physically "used up". These pressures may also be expressed in direct
future economic charges (carbon taxes), which will also alter energy resource economics.
The alternatives that work within the earth's natural balance of energy resources
and flows are the so-called "renewable energy resources", consisting of hydroelectric
potential, wind flows, radiant and thermal solar energy, geothermal energy, and energy
derived from plant matter which itself converts the incident solar energy ("biomass").
Each day the earth converts incident solar energy into these resources (save for
geothermal) at a rate that is about 15,000 times greater than the requirements of all
nations today, bathing the Earth each day with energy equivalent to ten times the energy
stored over all history in the form of fossil resources - and tomorrow these massive
resources will again be renewed.
To capitalize on these naturally available energy resources, new technologies for
capturing these energies have been developed, and are continuing to be refined. But they
are already sufficiently reliable that the real policy task for nations today is to generate
ever-growing markets for them, and to use these markets to reduce costs and yield new
industries and job creation. Policies differ among nations, but the goal of at least those
that are taking the imminent global energy transition seriously is to progressively increase
the share of energy and power offered to society from renewable energy resources, often
according to long-range strategic timetables.
The potential for achieving an eventual transition away from fossil energy
resources to the renewable energy resources is such that it is no longer a technical
question, but rather a policy decision for governments. This requires firm goals to be set
by governments, along with market inducements such as tax credits or other financial
incentives in these early days of large scale application.
This presentation will trace some of the global forces leading to pressures on
governments to adopt new renewable energy policies. It will describe the various
renewable energy technologies, and show particular kinds of applications for them. A
stress will be placed on "building-integrated" renewable energy technologies because of
the great convenience and local economic benefit of placing the energy resource at the
site of demand and use. Differences between policies will be discussed.