restrictions (e.g., terrain, weather, environmental conditions, ecological limitations, cultural issues, etc.). As technologies and methodologies for defining the technical potential of a renewable resource improve over time, uncertainties in assessments are reduced and confidence in the results increases.
Economic potential is expressed as a supply curve showing the quantity of a resource available at a specific cost. Methodologies for calculating the economic potential of a renewable resource have variable degrees of complexity by source and include considerations of energy, environmental, economic, existing and new infrastructure, and social factors.2 When sustainability factors are included, economic potentials can be refined into a “sustainable potential” for a specific region. Sustainability factors can be local, national, or international (e.g., changes in land use caused directly or indirectly by the expansion of energy or other economic activity [see Chapter 4]).
Regional potential assessments include the potential of multiple resources in a geographic area (multiple inventories in a certain region). A regional potential assessment can be combined with geographic information of the existing infrastructure (e.g., conventional electricity generation and transmission) and economic information to support integrated resource planning and development for policy makers, industry, and project developers. As costs for renewable energy technologies come down, regions with lower quality wind and solar resources may be able to reassess their economic potential.
Most renewable electricity generation must be located near the source of the renewable energy flux (i.e., the rate of energy transfer through a unit area). This means that even if a source does not contribute significantly to total (national) electricity generation, it could still provide a substantial contribution to regional power generation (NAS/NAE/NRC, 2010a). Biomass, for example, can be stored and made available to meet specific demand, although there are limitations to this, including the distance the biomass can be economically transported and the ability of the power generation technologies to cycle on or off (i.e., to meet peak or intermittent demand).
In the following sections, advances in quantitative characterizations of wind, solar, and biomass, with examples of technical and economic potentials, are highlighted. Some information on geothermal and hydrokinetic energy is also provided. Table 1-1 from the previous chapter can be used as a reference point in drawing comparisons to present installed capacity (in GW) and electrical generation (in terawatt hours [TWh]) in the United States and China.
The Intergovernmental Panel on Climate Change defines economic potential as: “The portion of the technical potential for GHG emissions reductions or energy-efficiency improvements that could be achieved cost-effectively in the absence of market barriers. The achievement of the economic potential requires additional policies and measures to break down market barriers.” Available online at http://www.gcrio.org/ipcc/techrepI/appendixe.html.