The Power of Renewables: Opportunities and Challenges for China and the United States (2010)

In 2007, the Intergovernmental Panel on Climate Change said that "climate system's warming is clear" and "Most of the global mean temperature rise observed since the mid-20th century is due to human- Actually measured concentration is ". Given these and other important issues of climate change, both the United States and China have taken major steps to address carbon dioxide and other greenhouse gas emissions, and include new regulations We are taking further measures.

In the United States where fuel is used directly, electricity production is the largest carbon dioxide emission source, exceeding 3 billion tons in 2007, accounting for over 40% of total energy related emissions. In China, the carbon dioxide emissions in the electricity sector in 2007 are estimated at 1 billion metric tons, accounting for nearly half of the country's total emissions.

Renewable energy technology has significant advantages in reducing carbon dioxide and other greenhouse gas emissions compared to fossil fuel based power generation. Furthermore, as shown in Figure 4-2, all types of renewable energy generation generate significantly more life-cycle greenhouse gas emissions (expressed as CO2, expressed as CO2e) than conventional coal and natural gas plants It is expected to reduce. Supplementing the results shown in Figure 4-2, the LCA of the photovoltaic power generation tower in Appendix B estimates that the emission of greenhouse gases is 32 g CO2e / kWh.

Renewable energy is less advantageous if carbon recovery and storage are included in fossil fuel power plants, or where energy storage systems (such as battery storage, compressed air storage, pumped storage, etc.) are included as part of renewable energy . Energy system (Denholm and Kulcinski, 2003). Also remember that there are some important opportunities to improve energy conversion efficiency and reduce the need for certain renewable energy technologies, especially fossil fuels for the production and transportation of photovoltaics.

It is difficult to estimate greenhouse gas emissions from specific renewable technologies. For example, bioenergy emissions vary depending on the raw materials used and the assumptions made. In the case of biomass from cultivated raw materials, the majority of bioenergy CO2e values ​​range from 15 to 52 g CO2e / kWh (excluding emissions associated with initial land conversion) (NAS / NAE / NRC, 2010a). The negative CO2e value shown in Figure 4-2 reflects an estimate based on the assumption that waste that decomposes to produce CO2 and methane otherwise would be used as a feedstock (Spath and Mann, 2004). When carbon recovery and storage are added to the bioenergy system, the CO2 conversion value also decreases sharply.

Likewise, estimates of greenhouse gas emissions from hydroelectric power will vary depending on what is included in LCA. Although not reflected in Figure 4-2, some studies showed that the first flood of biomass releases large amounts of carbon dioxide and methane when the hydropower reservoir is full (see, eg, Gagnon and van de Vate, 1997). These emissions depend on the density of the biomass and the size of the reservoir.

Hydropower is currently the largest producer of renewable energy in the United States. In 2010, the total power generation of the country accounted for 6.2% of the total power generation of the country, accounting for 60.2% of the total US renewable energy. America is the world's fourth largest hydroelectric power generation country. After China, Canada, Brazil. Grand Coulee Dam is the fifth largest hydropower plant in the world. There are several biggest solar farms in the world in the United States. Solar Star is a 579 MW (MWAC) farm near Rosamund, California. Desert Sunlight Solar Farm is a 550 MW solar power plant located in Riverside County, California, in Topaz Solar Farm, a 550 MW solar power plant located in Obispo County, San Luis California. The total generation capacity of the solar thermal SEGS plant group in the Mojave Desert is 354 MW.

From a political point of view, China is challenging America as the world's superpower. China's GDP growth rate is the 14th (accounting for 6% of the US growth rate of 6.7%), second only to the US, second only to the US. By the way, I know that GDP is not necessarily the best indicator of economic power or potential, but for our purposes it is enough to explain the economic situation of the world China. Withdrawing from the partnership in the Pacific Rim region is the greatest benefit for the United States and it is clear that China will benefit by filling the vacuum. With massive workforce and relaxed supervision, China can quickly and effectively use new economic opportunities. One example is the approach to renewable energy. It is reported that environmental consciousness is not known, China is currently the world's largest renewable energy investor