Biomass energy is a source of energy. （renewable / non-renewable)

Renewable energy sources can be replenished in a short period of time. The five renewable sources used most often include hydropower (water), solar, wind, geothermal, and biomass. Renewable energy's impact on the world's energy picture is significant. Many important events have occurred during the history of using renewable sources to generate electricity--but the overall consumption from renewable energy sources has declined by about 15 percent from their I996 peak to about 6 quads in 2005.

The use of renewable energy is not new. Five generations (125 years) ago, wood supplied up to 90 percent of our energy needs. Due to the convenience and low prices of fossil fuels, wood use has fallen. Now, the biomass which would normally present a disposal problem is converted into electricity (e.g., manufacturing wastes, rice hulls, and black liquor from paper production).

Historically, low fossil fuel prices, especially for natural gas, have made growth difficult for renewable fuels. The deregulation and restructuring of the electric power industry could have a major impact on renewable energy consumption. Demands for cheaper power in the short term would likely decrease demand for renewable energy, while preferences for renewables included in some versions of proposed electricity restructuring legislation would breathe new life into this industry.

Use of renewables in the United States is not currently expected to approach that of the major fuels, and due to their limitatious (e.g., their intermittent nature-cloudy days have no solar gain, quiet days mean no wind blows to drive wind turbines, dams are primarily for flood control, so hydroelectricity production varies as dams' water levels change), renewables may never provide "the" answer to all energy problems. Around the world, renewable energy is proving to be of great value.

In 2005, about 6.1 Quadrillion Btu (Quads) of U.S. energy came from renewable fuels. Each of the energy sources we use is measured, purchased, and sold in a different form. Many units of measurement are used to measure the energy we use each day.

From 1996 to 2005, the trend of the consumption from renewable energy was ______.

A．increasing

B．decreasing

C．irregular

D．not mentioned

作业题1 Primary energy（一次能源 ）means those which exists in the natural world in extant form ,including fossil energy (coal, petroleum, natural gas ), nuclear fuel, renewable energy (solar energy, wind energy, geothermal energy（地热能）, tidal energy（潮汐能）). Secondary energy （二次能源 ） means those which are processed and transformed from primary energy for the sake of improving the energy utilization efficiency or protecting the environment, such as electric power, town gas, coke, diesel oil, gasoline, kerosene（煤油）. 请大家明晰什么是一次能源，什么是二次能源 请大家讨论： Which belong to the primary energy ? Kerosene Wind energy BFG(Blast Furnace Gas （焦炉煤气）) LPG(Liquefied Petroleum Gas) Biomass Energy

A、NO2

B、SO2

C、CO2

D、--