Concentrated Solar Power:

This technology basically takes the energy from the sun to heat water and produce steam.  This steam is used to spin a turbine and generate electricity.  There is a few types of concentrate solar power forms: Troughs, Tower Systems, and Stirling Dishes. 

Concentrated Solar Power (CSP) systems are not to be confused with Photovoltaic Cells/Panels, which can be plopped on rooftops.  CSP is generally land intensive and able to generate substantial amounts of energy.  Tower Systems are more attractive than Trough or Stirling Dish systems because of the higher temperatures the Tower System can raise the water too thus providing a higher efficiency.   


  • A CSP can be located in remote locations (aka deserts).  For example, Ivanpah is a Tower System CSP system currently being built in California Mojave Desert (  
  • No need for import or mining of fossil fuels such as coal to generate electricity.
  • No CO2 emissions generated from electricity production.
  • No air pollutants produced. 


  • Potential threat to desert wildlife.
  • Capital intensive: requires government incentives such as tax credits.
  • Connectivity to grid: need transmission lines in remote areas.
  • Only produces electricity when the sun is out. 

CSP: Tower System

CSP Tower System

CSP: Stirling Dishes

Stirling Dishes

CSP: Trough

CSP Trough System

Hydro Power:

This technology uses the potential energy of water to generate electricity: Damns.  Water generally runs through a penstock or pipe, which then spins a turbine to produce electricity.  There are generally “low head” or small dams and big dams, such as Hoover Dam. 


  • Low head small dams do not require a large reservoir that can gobble up surrounding land thus altering natural habitat.
  • Low head small dams are less likely to kill small fish.
  • Low head small dams maintain the river morphology – does not alter current.
  • Low head small dams are cheaper to install and manufacture. 
  • No CO2 emissions from electricity generation.


  • Large dams are capital intensive.
  • Require careful planning and permitting.
  • Large dams alter natural habitat and landscape. 

Large dam: Hoover Dam

Large Dam: Hoover Dam

"Low head" small dam

Low head small dam

Wind Energy:

This technology essentially harnesses the energy from the wind to spin a turbine to generate electricity. 

Capacity Factor: this is the percentage of the MegaWatts installed actually produced.  Example: a wind farm has a 20% capacity factor – this means that 80% of the time the blades are not spinning.  High capacity factors are favored for wind farms. 


  • No CO2 emissions from generation.
  • No pollutants that cause acid rain or smog.
  • No water requirement.
  • Arguable most economic new green electricity source.
  • Technology improving for blade design – greater efficiencies. 
  • Can be installed in farmlands: dual land-use. 


  • Intermittent generation: no constant generation – unpredictable. 
  • Noise pollution. 
  • Impact on landscape. 
  • Connectivity to grid: need transmission lines in remote areas. 

Wind farm:

Wind farm(102047)