IDS2935 Exam 2 Review

- 30% of Iceland's electricity is from geothermal energy - used for heating and hot water to > 90% of buildings (distinct heating), deicing of roads in wintertime

Describe Iceland's geothermal energy: -What % of electricity comes from geothermal energy? -What is it used for?

- 6 million square feet (1/3 of downtown) is heated by geothermal water -Since 1870 naturally hot water has been used to heat Idaho -Geothermal energy is used primarily for heating, but also electricity, although limited

Describe Idaho's geothermal energy: -How many square feet are heated by geothermal water? -Since when has naturally hot water been used to heat? -What else is it used for?

- more predictable than wave power -higher range = higher potential

Describe tidal power as an energy source.

- waves form as the wind blows over an open water surface - 64% of US utility scale electricity could come from wave power -wave power pilot projects around the world

How do waves form? What % of US utility scale electricity generation could be covered by wave power? Large-scale or pilot projects?

- keep it cool (using backup power supply) - shut it down before storm hits - outer walls are very strong (reinforced concrete / steel)

How do you prepare a nuclear powerplant for a storm?

- 42000 GW -oil drilling and fracking techniques used to get heat - expected to remain for billions of years to come

How hot is the heat flowing from the Earth? How is it retrieved?How long is it expected to remain?

1. water flows from upper to lower elevation through penstock pipe, causing change in potential energy 2. dams with turbines and generators collect water to convert potential to mechanic potential energy 3. water current turns turbine (prime mover) which turns shaft connected to wire coil/magnet, creating electric AC current 4. hydroelectric generator converts mechanical energy into electricity

How is hydropower generated?

Moving air rotates blades attached to generator shaft in machine cabin "nacelle", which contains the electrical generator which converts the rotational energy into electrical energy

How is wind power converted to electricity?

6 kw

How much energy does a single wind turbine produce?

Very much 2010: 2.5% 2021: 10%

How much have wind turbines grown in popularity?

-grey: fossil fuels -blue: fossil fuels with carbon capture -green: renewable energy -yellow: solar power -pink: nuclear power

Hydrogen color meanings: grey: blue: green: yellow: pink:

6% of US energy is generated by hydropower 15% of global energy is generated by hydropower

What % of electricity is generated by hydropower?

Subsidies

What are money incentives from the government to support the development of electricity?

+ minimal impact on environment + cheap when in use + no greenhouse gas emissions - "flickering" effects - noisy - interfere with radio/tv signals - bird impacts

What are pros and cons of wind turbines?

- expensive - US lacks materials to generate it (arsenic, gallium in China, Russia)

What are some negatives of solar power?

1. Norway 2. Brazil

What are the #1 and #2 countries of hydropower generation?

-limited funding -harsh environment wears out tech and infrastructure -environmental impact

What are the challenges of wave power?

wood - 17.1 MJ/kg crude oil - 41.9 MJ/kg hydrogen - 142.0

What are the energy densities of wood, crude oil, and hydrogen?

Pros: + renewable energy + no greenhouse gas emissions + storage of water Cons: -flooding

What are the pros and cons of hydropower?

Pros: + symbol of China's technological and economic progress + replaces 30 million tons of coal + reduces flood potential on Yangtze River Cons: -forced thousands of villages to relocate -jobs promised did not materialize -changed silt/river flow --> damage -pH / acidity change -unstable reservoir --> 150 geological events

What are the pros and cons of the Three Gorges Dam?

Pros: + renewable + availability + uses waste + versatile Cons: - emits CO2 - removes vegetation that absorbs CO2 - takes time to renew - deforestation

What are the pros and cons of using biomass for power?

-burnt - steam engine -converted into heat/natural gas (compost) -methane gas from landfill -biofuel

What are the uses of biomass?

-oil (Venezuela, Saudi Arabia) -coal -nuclear power -natural gas -non - renewable, increasing prices, limited availability 70% of the world's electricity

What are traditional energy sources? What % of the world's electricity?

- US peak oil in 1970s - world peak oil in 21st century - global coal reserves will last until 2150

What did Hubbert (1956) write about peak oil?

November 1333: 3000 deaths caused by flooding "the sinfulness of man" November 1966: 33 deaths caused by extreme flooding due to 22ft rainfall and energy company opened floodgates of dam. 15 museums and 18 churches flooded. saved by "Angeli del Fango" - mud angels

What happened in 14th century Florence? and again in 1966?

2008: the world's first operational wave power generator was built 5 km off the coast of Portugal installed capacity: 2.25 MW

What happened in 2008 for wave power?

-during photosynthesis, carbon is captured from the air -consumption of biopower releases the carbon stored in vegetation

What happens during photosynthesis? What about the consumption of biopower?

-oil rigs shut down -natural gas transported through underground pipelines (can operate in an emergency) -crews on standby to repair power grid

What happens to oil rigs, natural gas, and power grids during a storm?

- may need cover to protect from debris - most can withstand < 140 mph winds

What happens to solar panels during a storm?

-shift gears as wind speeds increase -change angle of wings -can withstand wind speeds < 42.5 m/s (94 mph) before it is cut off

What happens to wind turbines during a storm?

the sun

What is Earth's primary source of energy?

rotation of the nose around the vertical axis

What is a yaw, used in the yaw-orientation system?

- 1.3% of US electricity but 5% of energy - organic matter used as fuel. comes from forest debris, agricultural waste, animal manure, energy crops

What is biomass? What % of US energy and electricity?

harnesses heat from the sun to provide electricity for large power stations (STEAM ENGINE)

What is concentrating solar power?

- the use of energy from the Earth's thermal interior to produce electricity - .4% of Earth's electricity is geothermal

What is geothermal energy? What % of the Earth's electricity is geothermal?

configuration of two water reservoirs at different elevations that can generate power as water moves down from one to the other Daytime: water flows downhill through turbine, producing electricity Nighttime: water pumped uphill reservoir for tomorrow

What is pumped hydro storage?

converts sunlight to electricity for businesses and homes (SOLAR PANELS)

What is solar photovoltaic technology?

energy return on energy investment -oil 1930 = highest -coal 2005 = 2nd highest

What is sustainability?

US

What is the #1 geothermal country by installed capacity?

Wind Power (9.6% of US energy, 2021)

What is the #1 source of renewable energy?

Itaipu, Brazil

What is the #2 hydropower source?

hydropower

What is the cheapest energy source in the US?

-Renewable energy - energy sources that renew themselves (wind, water, sun), free fuel, less CO2 emissions, less dependence on other countries - sustainable energy - fulfills the energy requirement and leaves resources for future generations - not all renewables = sustainable!!!!

What is the difference between renewable energy vs sustainable energy?

Ivanpah Solar Power Facility -located in Mojave Desert, California -392 mw -3500 acres -largest in the world when built in 2014

What is the largest solar power facility in the US?

Three Gorges Dam in China

What is the largest source of hydropower?

- largest: Bay of Fundy, Canada - France: La Rance Tidal Power Station, 1966, installed capacity: 240 mw, tidal range of 8.2 m, capacity factor: 40%

What is the largest tidal range in the world? What about tidal power in France?

hydrogen

What is the most abundant chemical in the universe, THE solution to replace fossil fuels, expensive, and colorless but given different colors based on how it's produced?

Offshore wind

What is the most expensive energy source in the US?

hydropower

What is the oldest form of renewable energy production?

large river with mountains / hills

What is the perfect setting for hydropower?

5-10x rotor diameter

What is the spacing for a wind farm?

levelized cost - $$$$: offshore wind, concentrated solar - $ - hydropower, coal, natural gas

What is the total cost of operating a powerplant over its lifetime?

I Low wind speed = little to no power II Medium wind speed = meaningful power III High wind speed = maximum power Cut-out speed = dangerous wind speeds (hurricane/tornadoes) shut down the turbine

What is the wind power curve?

-Denmark gets > 45% of electricity from wind - pioneered commercial windpower in 1970s -very flat country -July 9, 2015: wind power produced 140% of nation's demand

What is the wind power situation in Denmark? (How much electricity do they get from wind, when did it start, why, and what happened July 9 2015)

Capacity factor 59.3% (1928, Albert Betz)

What is wind power measured by? What is the max. % for wind power?

Hydropower

What type of energy are the 6 largest power plants?

Northwest / Northeast Grand Coulee Dam and Hoover Dam

Where can hydropower be found in the US?

along plate boundaries

Where does geologic activity mostly occur?

US: Alta Wind Energy Center, California, US (1458 MW, 600 turbines, capacity factor 23.5%) Globally: Gansu Wind Farm Project, Gobi Desert, China (7965+ MW, goal: 20K MW, mini projects)

Where is the largest wind farm in the US? Globally?

Persia, 900 AD for mills and sails

Where was wind energy first used?

1. USA (Iowa, Nebraska, Illinois) 2. Brazil

Which country is #1 in biofuel production? #2?

Greeks (waterwheels grinding wheat into flour)

Who was the first to use hydropower?

Risk: flooding, loss of life, no power production Solution: evacuate water to make room for rainfall

Why are hydropower dams a risk during a storm and what is the solution?

+ wind currents are smoother and stronger offshore + not in sight + no mountains to block wind - cost of transporting large heavy turbine parts - difficult to build infrastructure - increased maintenance

Why does current technology favor offshore wind farms? What are the negatives of offshore wind farms?

renewables

____________ get more subsidies than any other energy source.