The Power of Renewables Opportunities and Challenges for China and the United States (2010) / Chapter Skim
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3 Technology Readiness
3 Technology Readiness
Pages 63-88
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From page 63... ...
. "All-in" cost analysis should include all items required to reliably serve customer load with the generation resource, such as: the direct capital and operating costs of the renewable generation resource; costs for required transmission; and costs of other incremental resources required to integrate the renewable generation resource into the overall grid system (e.g., balancing services or backup generation)
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From page 64... ...
Status of Technology Many of the negative perceptions about wind power are based on earlygeneration wind turbines. Modern turbines have technological improvements to control low-voltage ride-through and output/ramp rate and provide volt-amperereactive support.
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From page 65... ...
. China is interested in offshore wind development but faces the additional hurdle of deploying wind turbines that are resilient to typhoons and other severe weather events, because their most abundant offshore wind resources are in coastal areas prone to typhoons.
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From page 66... ...
Likely breakthroughs in wind technology are more for offshore wind turbines that must be resistant to the harsh marine environment and extreme weather events.
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From page 67... ...
Advanced materials Rotors Improved structural-aero design Active controls +35/+25/+10 -6/-3/+3 Passive controls Higher tip speed/lower acoustics Reduced Energy Reduced blade soiling losses Losses and Improved Damage-tolerant sensors +7/+5/0 0/0/0 Availability Robust control systems Prognostic maintenance Drivetrain (Gearboxes Fewer gear stages or directand Generators and drive Power Electronics) Medium-/low-speed generators Distributed gearbox topologies Permanent-magnet +8/+4/0 -11/-6/+1 generators Medium-voltage equipment Advanced gear tooth profiles New circuit topologies New semiconductor devices New materials (gallium arsenide [GaAs]
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From page 68... ...
cells represent the largest share of the commercial thin film market, but thin films can also be made with amorphous silicon or "CIGS cells" so-called because they use Copper, Indium, Gallium, and Selenide as their semiconductor metals. Some of the most efficient solar cells are multi-junction CIGS cells.
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From page 69... ...
Se2 UNSW UNSW Stanford Percent Efficiency (14x conc.) FhG-ISE Georgia Spire 20.4% UNSW Tech 20 Georgia 20.0% Sharp ARCO Tech NREL NREL Varian NREL NREL NREL NREL Westinghouse 16.7% 16 University No.
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From page 70... ...
China's trade surplus of PV cells suggests that having access to the international export market is an important factor in its renewable energy strategy. In order to establish a domestic market for PV deployment, China established a PV power concession program in 2010, including 13 PV power station projects ranging in size from 20-30 MW each and 280 MW in total, all in the northwest FIGURE 3-3 Production of photovoltaics in the world, 2000–2009.
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From page 71... ...
Thin-film technologies are also high throughput and have a continuous production rate, and some technologies require lower temperatures for processing (and thus lower energy inputs)
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From page 72... ...
Organic cells, for example, which can be about 10 times thinner than thin-film solar cells, present opportunities for lower costs because they have low-cost constituent elements, require less material, include materials with high-conversion efficiency, and can be manufactured with high-volume production techniques. It is interesting to note that reductions in deployment costs could also result from streamlining deployment by capturing efficiencies related to large-scale deployment or from producing lower cost structures that support solar panels (commonly referred to as the balance-of-system and sometimes comprising 50 percent of total costs)
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From page 73... ...
. Status of Technology The parabolic trough combined with a conventional Rankine cycle uses concave mirrors to focus direct-beam radiation on a linear receiver containing synthetic oil.
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From page 74... ...
In terms of specific components, cost reductions are anticipated for increasing the reflector size of the concentrator (heliostat or dish) , low-cost structures, better optics, and high-accuracy tracking.
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From page 75... ...
Co-location and size matching are also characteristic of biomass power plants operated on black liquor, the lignin-rich by-product of fiber extraction from wood. Co-fired power plants for which coal is the primary fuel source and solid biomass is the secondary source are relatively large, and therefore enjoy higher efficiencies.
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From page 76... ...
, and 18 MW biomass gasification. The costs for power generated at these plants is typically not competitive with coal-fired power, but it is worth noting that between 30 and 50 percent of the costs of biomass power generation are in the transportation and storage of biomass feedstocks.
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From page 77... ...
By contrast, electricity generation from biogas has developed rapidly in China since 2005. Of the 173 MW of installed capacity noted above, 79 MW make use of waste streams from light industries (e.g., breweries and distilleries, paper mills)
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From page 78... ...
The world's overall installed geothermal power capacity is 10,500 MW, which generates about 70,000 GWh of electricity worldwide. The United States has the largest installed geothermal energy capacity and represents nearly onethird of global geothermal power generation capacity.
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From page 79... ...
Technology is not a major barrier to the development of conventional hydrothermal resources, but improvements in drilling and power conversion technolo gies could lead to cost reductions and more reliable systems. There are many ways in which EGS technology can by improved and better understood.
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From page 80... ...
of the roughly 80,000 existing dams in the United States are presently used to generate electricity (NHA, 2010)
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From page 81... ...
Although this is not likely to lead to the removal of major generating facilities, it could impede plans for substantial additions to hydropower stations. In China, despite the potential for several hundred GW of additional hydropower capacity, there are similar concerns about the impacts of large-scale projects.
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From page 82... ...
Energy Storage Energy storage is a rapidly changing space in which new technologies are moving into the commercial arena. Storage technologies are valuable to electrical power systems regardless of the generation resource, but they provide specific attributes that are especially important for systems with large shares of wind and solar.
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From page 83... ...
. High-power approaches for multiple-hour energy storage include pumped hydropower, compressed air, some types of batteries, and devices that convert electricity into chemical fuels, such as hydrogen.
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From page 84... ...
Lead-acid batteries are used in China by the hundreds of thousands for distributed grid-connected systems and to support wind and PV power generation in remote areas. Alternatives to conventional batteries are flow batteries and regenerative bat teries.
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From page 85... ...
Additionally, the momentum provided by these responsive resources will provide a more reliable grid capable of smoothing the output of an increasing number of volatile generation resources.
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From page 86... ...
This could be especially useful in systems with large wind loads in the evening -- devices (e.g., dishwashers) could be programmed to operate only when sufficient wind power is available.
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From page 87... ...
China is now moving ahead of the United States in terms of offshore wind development and has plans to begin deploying next-generation 5 MW wind turbines. Readily available information on these developments could enhance technology evolution and make renewable technologies more accessible globally, especially in developing nations.
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From page 88... ...
Both countries have experience with pumped hydro and are currently investigating options to create additional capacity, which could directly benefit large wind and solar farms. The United States could also work with China to develop and demonstrate a compressed air energy storage system (CAES)
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