Renewable hydropower

Renewable hydropower has long provided a significant contribution to the U.S. energy supply. Today, hydropower is competitive with other forms of conventionally generated electricity. 

Link Transit, in Wenatchee, Washington, will acquire up to 10 electric trolley buses manufactured by Ebus with Altairnano nLTO batteries as well as two quick-charge stations powered by renewable hydropower. 

There are many benefits for using hydro resources to produce electricity. First, hydropower is a renewable resource oil, natural gas, and coal reserves may be depleted over time. Second, hydro resources are indigenous. A country that has developed its hydroelectric resources does not have to depend on other nations for its electricity hydroelectricity secures a country s access to energy supplies. Third, hydroelectricity is environmentally friendly. It does not emit greenhouse gases, and hydroelectric dams can be used to control floods, divert water for irrigation purposes, and improve navigation on a river. 

Hydro-electricity is the most developed renewable resource worldwide, even if it has to face social and environmental barriers [29]. In fact societal preferences are difficult to predict, while hydro-sites are often difficult to reach, which results in high transmission and capital investment costs. These are difficult to be accepted by private power companies. The global economic hydropower potential ranges between 7000 and 9000 TWh per year. Particularly mral communities without electricity appear to be convenient for small (<10 MWe), mini- (<1 MWe), and micro- (<100 kWe) scale hydro schemes. They have low environmental impacts, and generation costs are around 6-12 c/kWh. Emissions of GHG linked with hydro-electricity operation are due to flooding of land upstream of a dam that can imply a loss of biological carbon stocks and can produce methane emissions due to vegetation decomposition. 

Other studies suggest that only 17% of Iceland s renewable energy has been developed. This renewable electricity has been estimated at up to 50 million MWh per year for hydropower and geothermal. This represents six times the current renewable energy capacity. 

Renewable electricity (RES-E) Electricity generated from renewable non-fossil energy sources, i.e., wind, solar, geothermal, wave, tidal, hydropower, biomass, landfill gas, sewage treatment plant gas and biogas (this corresponds to the definition in Directive 2001/77/EC on renewables, Article 2). 

In Norway and Romania, hydrogen production and export is in direct competition with electricity transmission via high-voltage direct-current lines (HVDC). This solution is particularly attractive because hydropower is a non-fluctuating renewable energy source and does not destabilise the grid, as, for example, wind or solar power do. 

Renewable energy sonrces such as wind, solar, biomass and hydropower are important today, and they will be important in the future. Table 1.1 shows the global primary energy consnmption as shares of 10.2 gigatons of oil equivalent (Gtoe) by energy sonrce in 2002 (UNDP, 2004). 

Considering observations from the last 30 years, oil has been losing share, gas has been growing, coal has been coming dowrt, while nuclear and hydropower are both constant at abont 6%. Renewables still make a minor contribution to world s energy market. 

The water in rivers and streams can be captured and turned into hydropower (HP), also called hydroelectric power. HP currently provides about 17% of the world s electricity supply, virtually all of Norway s electricity and more than 40% of the electricity nsed in developing countries. However, there is great potential in hydropower worldwide. Norway produces more than 99% of its electricity with hydropower. New Zealand nses hydropower for 75% of its electricity. HP provides more than 97% of all electricity generated by renewable sources. Other sources, biomass, geothermal, solar and wind account for less than 3% of renewable electricity production. When the electricity share of total energy consumption is considered, the increase becomes even more dramatic. 

Wave power, tidal power, municipal solid waste, gas from animal wastes (biogas), landfill, peat energy and ocean thermal energy conversion (OTEC) are the other renewable energy sources (RES). Water energy sources are hydropower, tidal and wave technologies. 

After the law passed, the political debate about the sustainable management of hydropower came to a standstill. The law could only be applied in the context of a renewal of the water use licenses. In Switzerland these licenses typically run over 80 years and therefore no major changes in operation could be expected before the year 2020. Furthermore, the deregulation of electricity markets begun to shape expectations in Switzerland. This new market order put pressure on hydropower operators to reduce cost and to act as competitive firms. Environmental requirements were considered as a direct threat to economic survival of the plants. 

Well-to-wheel thermodynamic efficiencies for (a) crude to regular vehicle (b) crude to hybrid vehicle (c) natural gas to all-electric vehicle (this efficiency increases to 74 respectively 80% for electricity from hydropower or renewable resources) (d) natural gas conversion to H2 and natural gas conversion to electricity followed by electrolysis to H2- Conv Conversion M motor HM hybrid B battery eM electric motor FC fuel cell. Routes a and b do not allow for the capture of C02. (From Marisvensson, A. et al., Energy, 32,437,2006.)... 

Web Address wwwl.eere.energy.gov/windandhydro The Wind Hydropower Technologies Program of the Office of Energy Efficiency and Renewable... 

---