Hydroelectric Pros Flood control. Electricity wo/ghg or pollutants. Reservoir for drinking water & irrigation. Cons Reservoir floods terrestrial areas = loss of habitat & re- location of people. Anadromous & catandromous fish migrations are blocked. Sediment collects behind the dam instead of downstream for nutrients. Loss of white water, cool water and sediment downstream.

Wind Wind is free wo/ghg/polution. Land underneath can be used for farming etc. Can be scaled upward for more power. Cons Requires adequate wind speed. Some people object to their looks. Bird kills Noise sometimes. Wind doesn’t always blow & at present time it is too expensive to store the power. Sometime located away from the grid.

Geothermal Pros Free heat from the earth’s hot rocks that heats ground water. Cons Only certain areas of heat are easy to access. Some gas pollutants. If sited near National Parks it can destroy geysers etc.

Solar Pros Free, clean energy. Can use existing rooftops or land in deserts to install the panels. Simple to use passive heating. Cons Sun doesn’t always shine; battery or other storage mechanisms are not fully developed or too expensive. High priced.

Biomass Pros Can be sustainable if re- planted as fast as it is used. Potential to provide energy for ½ the planet. CO2 given off is equal to what is taken in by photosynthesis. Cons Currently is unsustainable. Deforestation Flooding/landslides/soil erosion. Inefficient when turned into fuel; both the process and the mileage.

Sun connection Solar Passive: Sun shine warms room or rock structures. Active: sun’s energy is used to produce electrons directly OR solar energy is circulated by pumps throughout homes/businesses.

Sun connection Biomass Plants take in light energy either directly through the sun or indirectly through electric energy created by burning plants or fossil fuels. Plants use the sun’s energy in the process of photosynthesis to build biomass which stores the energy in a chemical form.

Sun connection Wind energy Wind is caused by the uneven heating of the earth causes pressure differences. High pressure flows toward low pressure creating winds.

Sun connection Hydroelectricity Sun warms bodies of water for evaporation. Water is moved by the wind (explanation on previous slide** you must include this**) onto land and to areas when gravity then moves it downhill.

Nuclear Power Uranium 238 is split (nuclear fission) by high speed neutrons. The fission causes heat & more neutrons to be released. To control the reaction, neutron absorbing rods called control rods are lowered into the nuclear core area. These rods are made of Boron or other neutron absorbing materials. Nuclear waste is first stored in pools of circulating water for at least 10 years. Then the rods are placed into casks for storage on site. This is because we still do not have an approved waste storage site. Yucca Mtn. was built for this purpose but politically has been a non-starter.