Electrical Energy in California and beyond…

          US Energy usage by energy type Where our electricity comes from in US and in California Electricity Demand in California and projected future demands from:   Population increase Electric plug-in vehicles Renewable vs. non-renewable energy sources History of using Oil and Gas Problems associated with fossil fuels      Oil Natural Gas Coal Infrastructure Geosequestration – i.e. Clean Coal Renewable sources and new technologies:         Solar Hydrogen and Fuel Cells Wind Hydro Biomass and Digesters Co-generation Geo-thermal Nuclear What is the Power Grid and Deregulation of the Power Grid Choosing Green power – what does it mean How Photovoltaics (PV) work and opportunities with electing solar power

What energy source is most commonly used for electricity generation in the US?

Energy Sources for Electricity

http://www.flexibleenergy.

com

http://www.ecoworld.com

Year: 2000

Summary of last slide:

  Europeans and Americans are very productive. Do you think this might have anything to do with Technology?

But…..

Americans are wasteful with resources How could technology address energy waste and why haven’t engineers attacked this problem?

Besides meeting demands, there are environmental issues related to worldwide energy consumption: Keeling Curve:

CO 2 is a greenhouse gas Greenhouse gases absorb the earth’s infrared radiation: water vapor carbon dioxide methane ozone nitrous oxide

Photosynthesis consumes CO 2 while combustion of hydrocarbons produces CO 2 (Ethane) 2C 2 H 6 (Propane) C 3 H 8 (Wood/sugar)C 6 H (gas) 1 C 7 H 16 12 + 7 O 2 + 5 O O 6 + 6 O 2 + 22 O 2 2    4 CO 2 3 CO 2 + 6 H 2 O + 4 H 2 O  6 CO 2 7 CO 2 + 6 H + 8 H 2 0 2 O

Scientist attribute rising CO 2 and temperatures to human activities:

There isn’t a natural catastrophe that we can look to as the cause of rising CO

2

levels

Clean Coal – what are we hearing?

 Develop and Deploy Clean Coal Technology  The U.S. needs to advance its research on clean, alternative energy sources like solar, wind and clean coal, while at the same time recommitting itself to expanding the use of nuclear power.

http://www.podcastingnews.com

What is Coal?

    Fossil Fuel – takes millions of years to form Coal came from plant matter that got buried under tons of rock and ancient seas and “cooked” underground The US has 25% of the world’s supply of coal Coal is mined in 26 states

Millions of years worth of stored Carbon is released in 150 years

Coal has been burned for 2000+ years, however it was the Industrial Revolution that dramatically increased the use of coal.

http://www.fossil.energy.gov

Burning Coal

C 10 H 2 + O 2  H 2 0 + CO 2 2C 10 H 2 + 210 2  2H 2 0 + 20CO 2 A lot of Carbon Dioxide is produced and it is emitted from the smoke stack in a un concentrated form.

What is Clean Coal?

   Removal of pollutant Sulfur Dioxide, SO 2 Sulfur Dioxide causes Acid Rain Today “Clean Coal” also means sequestering the CO 2

1.

2.

3.

4.

5.

6.

Sequestering the CO

2

from Coal

CO 2 CO 2 has to be concentrated has to be transported to where it will be buried underground CO 2 liquid then has to be compressed into a A 1000 meter deep hole has to be dug CO 2 then can be injected into the hole Hole this must be monitored for 1000’s of years to ensure there are no leaks.

How much energy does it take to perform these six steps?

20% of the energy produced from burning coal would be needed just to compress the CO 2

How much land is needed to store the compressed CO 2 from coal power plants?

12 cubic miles of CO 2 would have to be pumped into the earth every day if all coal plants used geo-sequestration.

PG&E :

Sources for Electricity Generation 47% 20% 16% Natural Gas * Nuclear Hydro 15% 2% Renewable Coal 1% Other California gets 31% of its energy from renewable sources.

* http://fossil.energy.gov/programs/gasregulation/analyses/Frequently_Asked_Questions.html#Q3

Renewable Energy Resources:

     Solar Thermal Electric Photovoltaics (PV) Landfill Gas Wind Fuel Cells (using Renewable Fuels)         Biomass Hydroelectric Geothermal Electric Municipal Solid Waste Anaerobic Digestion Tidal Energy Wave Energy Ocean Thermal

Non-Renewable Energy Sources:      Coal Natural Gas Oil Other Carbon products mined from the ground Uranium for Nuclear Power plants (this is not a fossil fuel) Fossil Fuels are formed from the buried remains of plants and animals that lived millions of years ago

How is electricity made?

  A fluid working on a turbine Generator http://www.solarschools.ne

http://currentenergy.lbl.gov/ca/index.php

33,000 MWatts was California’s Peak Electricity Demand on December 1, 2005 but…   Peak electricity demands occur on hot summer days. California’s highest peak demand was 52,863 megawatts and occurred July 10, 2002.

Peak demand is growing at about 2.4 percent per year, roughly the equivalent of three new 500-megawatt power plants.

http://www.cpuc.ca.gov

Solar Energy – Using sun’s radiation to heat water and air.

 Most readily available source of energy  Use sun’s radiation to heat a fluid.

Solar Thermal Power Plants

A highly curved mirror called a parabolic trough focuses the sunlight on a pipe running down a central point above the curve of the mirror. The mirror focuses the sunlight on the pipe, and it gets so hot that it can heat synthetic oil within the pipe. Heat is extracted from the oil to boil water into steam. That steam can then be used to turn a turbine to make electricity. 25% of electricity is still made with natural gas as gas is the backup power source.

Boulder City, Nevada

Solar Tower Power Plants      Solar II Uses molten salt as a method of storing heat.

Can produce power 24 hrs/day.

10 MW Retired in 1999

Sunlight is reflected off 1,800 mirrors circling the tall tower. The mirrors are called heliostats and turn to face the sun all day long. http://www.solarpaces.org/solar_tower.pdf

Using sunlight to create electricity using photovoltaics (PV):   Sunlight hits a sandwich of doped silicon. Electrons are knocked out of their orbits. The electron flow provides the current, and the cell's electric field creates a voltage .

PV was developed In the 1950’s for Powering Satellites.

Wind Power

  California has over 13,000 wind turbines 95% of turbines are at:    Altamont Pass Tehachapi (east of Bakersfield) San Gorgonio, Palm Springs Traditionally wind mills were used to Pump water or grind grains.

Wind Turbines usually produce about 50 to 300 kilowatts of electricity each

Hydro-Power

  The state of Washington leads the nation in hydroelectricity.

About 87 percent of the electricity made in Washington state is produced by hydroelectric facilities. Lake Shasta Dam, CA

Hetch Hetchy Dams     Operated by SFPUC 380 MW of power SF has the largest unfiltered water supply on the west coast.

The Dam led to creation of the Sierra Club by John Muir Built 1913 Hetch Hetchy filled Prior to filling the Hetch Hetchy valley.

Pro’s and Con’s            California has 386 hydro plants 14,116 MW of capacity Renewable and clean Recreation Water storage Can be used to pump water during non peak hours as a means of storing gravitational potential energy for use later when demand rises.

Animals displaced and fish migration disturbed.

Loss of land and wilderness Change in hydrology and rivers Increase landslides, erosion, and sediment.

Dam has limited life span

Geothermal

     Using the earth’s heat energy to produce electricity.

California’s Geyser facility is the largest geothermal electricity producer in the world Need to locate a “hot spot” 50X fewer emissions that fossil fuel powered plants.

Geothermal accounts for 2,800 MW of capacity in the United States Geysers plant Near Sonoma 850 megawatts capacity

Using geothermal heat pumps to pre-heat water Hidden Villa Farm and Youth Hostel – Los Altos Hills

Biomass Power Plants

   Biomass is the combustion of plant derived waste materials into electricity California has more Biomass power plants than any other state with 29 plants and a capacity of 588 MW.

Materials consumed are:  Ag waste, construction waste, forest thinning, orchard removal, urban waste, and other wood type waste that would otherwise go into landfills or get burned.

Biomass

  Controlled boilers reduce emissions compared to open burning.

Heat energy is used to produce electricity.

Colmac Energy – Riverside County. 47 MW

How do Photovoltaics (PV) work?   A is n-type Si (e.g. Phosphorus) B is p-type Si (e.g. Boron)

P-Type dopants N-Type dopants

Just at the junction the electrons and holes mix, creating a an electric field (voltage) separating the two sides. This voltage allows electrons to flow up but not down.

The solar cell is acting like a diode; current flows in one direction only.

http://www.specmat.com/pn%20junction.jpg

http://www.specmat.com/Solar%20Cell%20Description.jpg

A – glass coating B – contact grid C – Antireflective coating D – N-type Si E – P-type Si

http://www.specmat.com

http://www.wcubed.com/solar/solar_photovoltaics.htm

PV System with Batteries It is for the safety of line workers that PV system inverters are engineered to shut down when they do not receive input of matching voltage from the grid.

This system can be taken off the grid.

PV System without battery back-up.

All power is lost if grid goes down because there is no battery back up.

Utility Meter spins backwards when PV panel produces more than home power needs. Size of PV array is not critical since homeowner has security of being tied to the grid.

Net-Metering    Under net-metering, excess electricity produced by the PV panels will spin the existing home electricity meter backwards.

This provides the customer with full retail value for all the electricity produced. The customer is billed only for the net energy period. consumed during the billing Benefits: required.

Use the existing meter and no batteries

    The Energy Policy Act of 2005 requires electric public utilities (e.g. PG&E) to offer net-metering to customers.

Prior to this, utilities only had to pay wholesale prices for energy produced, thus there was little incentive.

If you produce more than you consume on average, the utility is NOT required to pay you.

Some utilities will pay for the excess.

Success of a technology often is impacted by policy.

Time-of-Use Net Metering These are special Time-of Use meters that keep track of WHEN you draw power from the grid and WHEN you supply power to the grid.

Time-of-Use agreements mean you pay more for power during peak times and you also receive larger credits if you generate an excess of power during peak times.

This system is beneficial if you generate an excess at peak times.

www.elsterelectricity.com

Design your PV system

    Estimate needs Determine electricity demands Assess start-up costs Calculate cost-recovery time A good resource is: http://www.realgoodssolar.com/

Electing Green Power

"Energy derived from green sources is not specifically delivered to the customers who choose it, but to the power grid, which displaces power that would have otherwise been produced from traditional [fossil fuel] generating sources." (Source: Stan Wise, Georgia PSC Commissioner)

What can Engineers do about the Energy Crisis?