Much of modern civilization has been based on converting the internal energy of fossil fuels, into electricity, and then eventually "useful work".
There is nothing sacred about Oil, except for maybe the ease with which we empty our wallets for it.
Sooner or later -- hopefully sooner -- modern civilization has to find suitable replacements for fossil fuels, which can also been converted into electricity, and perfectly capable of performing that same "useful work".
President Obama in the State of the Union speech, set out some serious goals to continue to move America toward switching over to energy sources of the future:
Obama’s Clean Energy Plan for an America Built to Last:
How to Use Less, Save More, and Put People Back to Work
by Daniel J. Weiss, Center for American Progress -- January 25, 2012
Renewable energy: Creating clean jobs
[...]
Under this administration the use of renewable electricity has nearly doubled. And in 2011 the United States invested more money in clean energy than China.
To maintain this momentum the president called for the development of 10 gigawatts of renewable electricity on public lands. This goal is within reach. At the end of 2011, the Department of the Interior had approved:
25 major renewable energy projects on public lands. When constructed, the projects are expected to create nearly 12,000 construction and operational jobs and produce nearly 6,200 megawatts of energy, enough to power 2.2 million American homes.
[...]
Another tool to increase the generation of clean electricity and create jobs is the president’s proposal to “pass clean energy tax credits.” Congress should extend the production tax credit for wind energy, which expires at the end of 2012. It effectively reduces the cost of wind power by 2.2 cents per kilowatt-hour. Without an extension 37,000 well-paying jobs are at risk because investments in wind projects will decline.
With all the mentions of megawatts, gigawatts, and kilowatt-hours, it got me thinking ... it may be time for a crash course on some basic Energy Physics ...
How much "work" could that be?
Anytime I'm trying to understand how stuff works, I first go to one of my favorite sites:
howstuffworks.com ... and then go from there.
How Force, Power, Torque and Energy Work
by Karim Nice, howstuffworks.com
What is Mass?
Generally, mass is defined as the measure of how much matter an object or body contains -- the total number of subatomic particles (electrons, protons and neutrons) in the object. If you multiply your mass by the pull of Earth's gravity, you get your weight.
[...]
Mass is important for calculating how quickly things accelerate when we apply a force to them. What determines how fast a car can accelerate? You probably know that your car accelerates slower if it has five adults in it than if it has just one.
Mass, Force, Acceleration -- wow we did just jump into the thick of it.
"Trust the Force, Folks" -- No, that other Force ...
howstuffworks.com
What is Force?
One type of force that everyone is familiar with is weight. This is the amount of force that the Earth exerts on you.
[...]
When you step on a bathroom scale, you exert a force on the scale. The force you apply to the scale compresses a spring, which moves the needle. When you throw a baseball, you apply a force to the ball, which makes it speed up.
[...]
Force causes acceleration. If you apply a force to a toy car (for example, by pushing on it with your hand), it will start to move. This may sound simple, but it is a very important fact.
Autos? Auto's don't do "work" do they?
Well they don't call it the "internal combustion engine" for nothing.
howstuffworks.com
Forces on a car
[...]
When the car begins to accelerate, some new forces come into play. The rear wheels exert a force against the ground in a horizontal direction; this makes the car start to accelerate. When the car is moving slowly, almost all of the force goes into accelerating the car. The car resists this acceleration with a force that is equal to its mass multiplied by its acceleration.
[...]
Eventually, the car will reach its top speed, the point at which it cannot accelerate any more. At this point, the driving force is equal to the aerodynamic drag, and no force is left over to accelerate the car.
Autos, and Trucks, and Trains, Ships, and Planes -- they have all "driven" much of the growth of the 19th and 20th Century. They were the Engines that got us here.
Moving stuff, takes work.
howstuffworks.com
What is Work?
The work we are talking about here is work in the physics sense. Not home work, or chores, or your job or any other type of work. It is good old mechanical work.
Work is simply the application of a force over a distance [...]
Work is energy that has been used. When you do work, you use energy. But sometimes the energy you use can be recovered. [...]
Useful Work takes Energy, check. Cars do useful work, check.
But, I always wondered why cars were rated by "Horse Power" ... and how much that was, anyways?
howstuffworks.com
What is Power?
Power is a measure of how quickly work can be done. [...]
The SI unit for power is the Watt.
{The English unit for power is -- Horsepower (hp). 1 HP = 0.746 kW }
[...]
An interesting way to figure out how much power you can output is to see how quickly you can run up a flight of stairs.
1. Measure the height of a set of stairs that takes you up about three stories.
2. Time yourself while you run up the stairs as quickly as possible.
3. Divide the height of the stairs by the time it took you to ascend them. This will give you your speed.
For instance, if it took you 15 seconds to run up 10 meters, then your speed was 0.66 m/s (only your speed in the vertical direction is important). Now you need to figure out how much force you exerted over those 10 meters, and since the only thing you hauled up the stairs was yourself, this force is equal to your weight. To get the amount of power you output, multiply your weight by your speed.
Power (W) = (height of stairs (m) / Time to climb (s) ) * weight (N)
Power (hp) = [(height of stairs (ft) / Time to climb (s) ) * weight (lb)] / 550
I always wondered why we have so many dang stairs too. Who thought of that one?
Did they know what an energy drain all those stairs would eventually be? Whew, makes me tired just thinking about it.
howstuffworks.com
What is Energy?
[...]
If power is like the strength of a weightlifter, energy is like his endurance. Energy is a measure of how long we can sustain the output of power, or how much work we can do. Power is the rate at which we do the work.
[...]
Potential energy is waiting to be converted into power. Gasoline in a fuel tank, food in your stomach, [... are] examples of potential energy.
The human body is a type of energy-conversion device. It converts food into power, which can be used to do work. A car engine converts gasoline into power, which can also be used to do work.
OK, how much "useful work" is found in that very abundant natural resource known as "Sunlight"?
Look around, it's everywhere. Unlike like those very well-buried sources of fossil fuel.
Power Density of Solar Radiation
The Physics Factbook™
Manica Piputbundit -- 1998, edited by Glenn Elert
The sun is the source of heat and energy for the earth. The solar output on the earth is called the power density. The power density of the sun's radiation on the surface of the earth is approximately 1.4 kW / m2.
[1.4 kilo-Watts per square-meter of surface area, the sunlight strikes.
Or about 1 Horsepower unit of power per square-meter of surface area. ]
The Basic Facts and Information about Sunlight
[...]
The solar power density at the equator on a bright day at noon is about 1000 watts per square meter. This value is called the "standard sun". It is used in the industry for rating efficiency and peak power output of PV panels.
[...]
The net amount of the sunlight received during a day varies significantly with geographical locations and the weather patterns. To calculate the average amount of electricity a residential PV system can generate, you need to know the characteristic called insolation (INcoming SOLar radiATION). Insolation levels represent an average solar energy density and are usually expressed in kilowatt-hours per square meter per day (kW-hr/m2/day), or as an amount of equivalent hours of "standard sun" 1000 W/sq.m
Advantages
The 89 PW of sunlight reaching the Earth's surface [Petawatts] is plentiful -- almost 6,000 times more than the 15 TW equivalent of average power consumed by humans [Terawatts].[62]
Additionally, solar electric generation has the highest power density (global mean of 170 W/m²) among renewable energies.[62]
OK, so there's 6000 times more power in "free" sunlight -- than all us modern human consume, check.
OK, so far so good. But how about some "benchmarks" on what all these gazillion-watt units of power, really mean out in the real world?
Orders of magnitude (power)
wikipedia.org
This page lists examples of the power in watts produced by various sources of energy. They are grouped by orders of magnitude:
[... some selected examples ... ]
W = Watt [or 1 watt]
4 W – tech: the power consumption of an incandescent night light
14 W – tech: the power consumption of a typical household compact fluorescent light bulb
60 W – tech: the power consumption of a typical household incandescent light bulb
120 W – tech: power output of 1 m2 solar panel in full sunlight (approx. 12% efficiency), at sea level
130 W – tech: peak power consumption of a Pentium 4 CPU
500 W – biomed: power output (useful work plus heat) of a person working hard physically
745.7 W – units: 1 horsepower
750 W – astro: approximately the amount of sunshine falling on a square metre of the Earth's surface on a clear day in March for northern temperate latitudes
KW = Kilowatt (10^3 watts) [or 1,000 watts]
1.1 kW – tech: power of a microwave oven
2.4 kW (21,283 kWh/year) – geo: average power consumption per person worldwide in 2008[8]
10.0 kW (87,216 kWh/year) – average power consumption per person in the United States in 2008[8]
16–32 kW – eco: average photosynthetic power output per square kilometer of land[9]
26 MW – tech: peak power output of the reactor of a Los Angeles-class nuclear submarine
75 MW – tech: maximum power output of one GE90 jet engine as installed on the Boeing 777
140 MW – tech: average power consumption of a Boeing 747 passenger aircraft
MW = Megawatt (10^6 watts) [or 1,000,000 watts]
1.3 MW – tech: power output of P-51 Mustang fighter aircraft
1.5 MW – tech: peak power output of GE's standard wind turbine
3 MW – tech: mechanical power output of a diesel locomotive
GW = Gigawatt (10^9 watts) [or 1,000,000,000 watts]
2.074 GW – tech: peak power generation of Hoover Dam
4.116 GW – tech: installed capacity of Kendal Power Station, the world's largest coal-fired power plant.
12.7 GW – geo: average electrical power consumption of Norway in 1998
18.3 GW – tech: current electrical power generation of the Three Gorges Dam, the world's largest hydroelectric power plant of any type.
55 GW – tech peak daily electrical power consumption of Great Britain in November 2008.[14]
74 GW – tech: total installed wind turbine capacity at end of 2006.[15]
190 GW – tech: average power consumption of the first stage of the Saturn V rocket
TW = Terawatt (10^12 watts) [or 1,000,000,000,000 watts]
3.34 TW – geo: average total (gas, electricity, etc.) power consumption of the US in 2005[17]
16 TW – geo: average total power consumption of the human world in 2010
44 TW – geo: average total heat flux from Earth's interior[18]
75 TW – eco: global net primary production (= biomass production) via photosynthesis[citation needed]
50 to 200 TW – weather: rate of heat energy release by a hurricane
PW = Petawatt (10^15 watts) [or 1,000,000,000,000,000 watts]
1.4 PW – geo: estimated heat flux transported by the Gulf Stream.
4 PW – geo: estimated total heat flux transported by Earth's atmosphere and oceans away from the equator towards the poles.
174.0 PW – astro: total power received by Earth from the Sun
SOOOO ... when President Obama calls for "the development of 10 Gigawatts of renewable electricity on public lands"
-- it is approximately equal to "average electrical power consumption of Norway in 1998".
It's a start. We still have a long ways to go to catch up with China's Clean Enegry Gigawatt goals though:
China to add over 2.0 GW solar power capacity in 2011
Reuters, Beijing -- Nov 11, 2011
(Reuters) - New solar power capacity in China, the world's top energy user, may quadruple from last year to more than 2.0 gigawatts (GW) this year, an official of the research arm of the National Development and Research Commission (NDRC) said on Friday.
[...]
The government has raised its installed solar capacity target for 2020 to 50 GW, up from the previous goal of 20 GW, state media have quoted Li as saying.
Like I said, 10 GW, it's a start. And it is a sizable chunk of "useful work" too.
Maybe we can start retiring some of those 19th & 20th century modes of conveyance, eh?
Switching to Clean Energy kind of sounds like a lot of work -- a lot of useful work.