2 energy situation

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High Energy Society:

Why do we care about energy? High Energy Society

I am very energy conscious?:

I am very energy conscious? Strongly Agree Agree Neutral Disagree Strongly Disagree

People should be able to use as much energy as they can afford.:

People should be able to use as much energy as they can afford. Strongly Agree Agree Neutral Disagree Strongly Disagree

The vehicle I most like to drive or want to drive on a regular basis is…:

The vehicle I most like to drive or want to drive on a regular basis is… SUV, Van or Minivan Hybrid Car or SUV High Performance Sports Car Conventional 4 door sedan Compact Car

What is Energy:

What is Energy We will look at the “Physics” definition in a bit, but essentially, it is the ability to make something move. Experiment: Stand up and start doing deep knee bends at a rate of about 1 per second. You are working (using energy) at a rate of approximately 100 W.

Energy and Power:

Energy and Power A watt is a measure of the rate of energy used as opposed to the total amount of energy. It would take the same amount of energy to do 10 deep knee bends in 10 min as it would in 10 sec, but by doing it in 10 sec, you use energy at a faster rate.

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The rate of using energy is called POWER. Something that is powerful uses a lot of energy quickly. Power = Energy/Time This is a Rate Equation (More soon.) Common Unit of Power is a Kilowatt =kW = 1000 W

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Energy = (Power)x(Time) Common Unit of Energy= kW-h (Kilowatt-hour) 1 kW-h is the amount of energy you would use if you consume energy at the rate of 1 kW for 1 hr. (10 people doing deep knee bends for an hour.)

Other Units of Energy/Power:

Other Units of Energy/Power 1 kWh = 3 600 000 joules (J) 1 Btu = 1055 J 1Calorie = 4186 J 1hp =746 Watts

What do we care about energy?:

What do we care about energy? The bottom line is that using energy is strongly correlated to standard of living (as measured by GDP per capita). For most of history, we could rely on our own body or animals to do work. This is a few hundred watts of power at most.

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Today in the US, we consume energy at a rate of 10kW per person. You may think of this as having 100 “energy servants” doing work for you 24/7.

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2007 Report: Dust to Dust: The Energy Cost of New Vehicles From Concept to Disposal http://cnwmr.com/nss-folder/automotiveenergy/DUST%20PDF%20VERSION.pdf

World Population

World Population

World Population

Energy use is directly tied to GDP:

Energy use is directly tied to GDP The GDP of a country is defined as the market value of all final goods and services produced within a country in a given period of time. It is also considered the sum of value added at every stage of production of all final goods and services produced within a country in a given period of time. GDP = consumption + investment + (government spending) + (exports − imports) GDP per capita (US \$)

US Per Capita Energy Use 1870-1990:

US Per Capita Energy Use 1870-1990

We are doing better on a GDP per kWh basis.:

We are doing better on a GDP per kWh basis. Energy intensity is a measure of the energy efficiency of a nation's economy. It is calculated as units of energy per unit of GDP. * High energy intensities indicate a high price or cost of converting energy into GDP. * Low energy intensity indicates a lower price or cost of converting energy into GDP.

US Energy Production and Consumption:

US Energy Production and Consumption How Large is a Quadrillion BTU? It's about equal to the amount of energy in 45 million tons of coal, or 1 trillion cubic feet of natural gas, or 170 million barrels of crude oil. In 1988, total world energy consumption was about 1 quad every 26 hours. To make this a bit less abstract, 45 million tons of coal would be a pile 10 feet thick, one mile wide and about 3.3 miles long. At 60 mph, it would take about 9 minutes to drive around the pile. In terms of electricity, 1 quad is equal to 293 gigawatt-hours.

Where does our energy come from? Approx. 85% from fossil fuel :

Where does our energy come from? Approx. 85% from fossil fuel

Exajoules?

Oil Supply and Demand:

Oil Supply and Demand

How Much Is There?:

How Much Is There? Proven Reserves: Resource that we know is there AND we can extract it at current prices with current technology. We can increase Proven Reserves by 1) Finding new reserves. 2) Improvements in technology 3) Changes in economic conditions

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Note: We never totally extract all of the energy, it just becomes too difficult to recover after a while. Unproven Reserves: We think that it is there based on testing/experience. OR We know that it is there, but it is too expensive to extract with current technology/economics.

How Long Will It Last ?:

How Long Will It Last ? Simplest analysis (Rate Equation) If we know (or can guess) how much we started with (Q) and we know the rate we are using it (R) and how much we have already used (Qu)

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This is really a bad approximation because it does not take into account changes in rate of use. The demand for energy has been constantly increasing, so the rate equation time is probably too long, but still interesting.

Exponential Growth:

Exponential Growth Amount of growth depends on the rate of change of the amount with time. Time Amount

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Year Amount Interest Total 0 \$1000 \$100 \$1100 1 \$1100 \$110 \$1210 2 \$1210 \$121 \$1331 3 \$1331 \$133 \$1464 4 \$1464 \$146 \$1610 5 \$1610 \$161 \$1771 6 \$1771 \$177 \$1948 7 \$1948 \$195 \$2143 8 \$2143 Note: Money had just about doubled after 7 years. If we had just added \$100 per year (constant rate) we would have only had \$1700 after 7 years. Financial Example: Start with \$1000 and have it gain interest at 10% per year.

Doubling Time:

Doubling Time In general, if our percentage growth per unit time is P (%/unit time) then the time for our initial quantity to double is DT where: DT=70%/P Example: If P=10%/year then DT = (70/10)years =7 years

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Between 1960 and 1970, US energy consumption grew by 4.5%/yr. This would mean energy use would double in only 70/4.5 =15.5 years! With a constant rate if we double our reserves, we double their expected life. With exponential growth, doubling reserves will only add a short amount of time. Obviously exponential growth in energy demand CANNOT go on for very long.

Is It Really Exponential?:

Is It Really Exponential? Prices Matter An important lesson from history is that energy prices matter a lot. Before 1973, US energy consumption appeared to be growing exponentially at a rate of more than 4% per year. An exponential growth curve fit the data superbly well: in statistical terms, the R2 was 0.976 and the standard error of the estimated growth rate was 0.1%. These statistics imply that energy growth should have been between 4 % and 4.5 % for many years to come. However, that turned out to be very, very wrong.

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The graph below compares the exponential forecast (based on data from 1947-1973) with what actually happened. The exponential model predicted 88 quads more energy consumption in 2003 than there actually was, an error of 89% (186 quads predicted vs. 98 quads of actual consumption). The simple exponential growth model looked good during the period before 1973 because energy prices were low and relatively stable. When prices rose sharply, demand dropped as energy users (especially in industry) began conserving energy.

Hubbert Analysis:

Hubbert Analysis Works for just about any natural resource. (Not just fossil fuels) Initially a new resource shows a period of rapid growth. Easy to find, new markets, etc. As high quality, easy to find resources are depleted, production will peak and then decline.

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Production will have a “Bell Shaped” Curve.

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In the 1950’s, Hubbert predicted that the US oil production would peak in the 1970’s….It did. Current models predict world oil production will peak in 5-20 years…watch out! Much more when we get to each fossil fuel source. 