Renewable energy is frequently viewed as part of the future solution to reducing emissions of carbon dioxide from the combustion of fossil fuels. In fact, the United Nation's Intergovernmental Panel on Climate Change (IPCC), the International Institute for Applied Systems Analysis (IIASA) and the World Energy Council (WEC), as well as Shell Oil's renowned scenario developers have all developed scenarios that present futures for the 21st century in which much, if not most, world primary energy is derived from renewable energy (see Figure 5.9). Moreover, these scenarios are not considered to be outlying scenarios by their developers. The Shell "Sustained Growth Scenario" was essentially Shell's business-as-usual scenario when developed in the mid-1990s (Kassler, 1994). Perhaps more remarkable, the IPCC "Coal-Intensive Scenario" from the Second Assessment Report6 (SAR) shows non-hydro renewables contributing 60% of all worldwide primary energy use by 2100 (IPCC, 1996).
Inasmuch as these scenarios also presume continued growth of world economies and of energy markets, an increase in the market share for renewables is an even larger increase in the absolute amount of energy provided. In the Shell "Sustained Growth" scenario, the contribution from non-hydro renewable energy by 2100 is more than 50% larger than today's total world energy use. Similarly, in the IPCC scenarios, the non-hydro renewables contribution is larger than today's total world primary energy consumption.
6 The IPCC Third Assessment Report was undergoing review at the time this chapter was written.
Of course, such scenarios are fraught with uncertainties in their estimation and difficulties in their actual evolution. These include the role that climate change will play in market evolution, the price and availability of fossil fuels as the 21st century progresses, evolving technologies - both renewables and conventional, the extent of and access to renewable energy resources, and the infrastructure developments required to shift energy markets to renewable energy. The authors are usually careful to point out that scenarios are not forecasts, but planning tools that help to prepare us for change by outlining different possible futures.
The infrastructure required to attain these levels of renewable energy deployment will take many years to develop. For example, current world production of photovoltaic modules in 1999 is estimated to be about 170 MW annually (Energetics, 1999). Were this production increased by 25% for each of the next 30 years, annual production would increase to 137 GW by 2030, and total installations (assuming no retirements) from 2000 forward would be about 686 GW. At a 20% capacity factor, this world photovoltaic capacity would displace about 196 GW of coal capacity operating at a 70% capacity factor, or 12% of the world's coal capacity today. Thus, even with such aggressive growth, by 2030, the photovoltaic contribution to carbon emissions reductions is relatively modest. However, under such a growth scenario, by 2030 photovoltaics will begin making more substantial contributions, not only because the infrastructure will have developed, but also because industry will have learned how to bring the costs down. Based on historical cost improvements of 18% for each doubling in market installations (REPP, 2000), under the above scenario of 25% annual growth in production, costs will decrease by a factor of about 5 by 2030.7 This would position photovoltaic technology for even faster market penetration and greater substitution for fossil fuels and their carbon emissions.
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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.