Hello,
The following monologue is part of an analysis I have done regarding our petroleum usage and how we, as individuals may ameliorate it. It is geared toward Americans but if you feel you are using more petroleum (or fossil energy) than you would like, you may avail yourself of this analysis. I have put the first two parts on this blog. Encouraging comments will result in more sections being added, so, please feel free to comment. If you wish to work on this project, let me know. Co-intelligence rocks!
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The Petroleum Patch
(A first level analysis)
Humans use a lot of petroleum; over 84 million barrels a day. People of the United States used the lions share in 2004 at around 20.5 million barrels a day. That amounts to around 3 gallons of oil per person per day. That amount includes products made from oil as well as energy feed stocks. The remainder of the world is trying to catch up with the U.S. in development status, thereby requiring a larger amount of petroleum. Many of the world problems today result in part from the availability of petroleum including climate change, offensive actions in the pursuit of oil, production constraints,…the list goes on.
Many people who live in a developed society find it very difficult to live without oil and other fossil fuels. We are at a loss when the power goes out, or impatient on those rare occasions when there are lines at the gas pump. We spend much time working to maintain the trappings of personal civilization. Americans work harder than any other society, even the Japanese, to keep our standard of living at its current level.
For those of us who feel or know there is a better way to live, this program is set up to wean us off the current level of petroleum consumption. Using the current flow of oil, we can set up better ways of living that require less oil. That is why I have dubbed this work the Petroleum Patch. It uses bits of oil to ameliorate our use of it; much as a nicotine patch is said to decrease a person’s need for nicotine over time. We will use a combination of mathematics, economics, and fun ideas to get over the OIL ADDICTION!!
Americans, taking the lion’s share of oil are in the best position to wean off it. We have the energy throughput to make great and profound changes to our society using this energy but we have to act quickly. There are very specific steps required to walk away from this addiction. First, we must recognize our need. Then, the following steps apply:
Recognize the depth of our need (how much oil we use as individuals)
Determine how we use this resource
Look for more intelligent ways to use this resource
Find replacements for oil (social, cultural, infrastructural, and technical)
Iterate steps 2 – 4
In 2004 the average American used 3 gallons of oil per day. Of course some of us used less and some more, but collectively, that was the norm. In 2003, on average, Americans used 338.6 million BTU’s per person or 3.57 x 1011 Joules (that’s a BIG number). So, the first question is, with all this energy available for each of us, are we using this energy to its optimal effect?
According to the EIA, in 2004 each American (including those that didn’t drive) burned 1.53 gallons per day of gasoline. Each American would therefore use 20.24 Million Joules of energy (in gasoline consumption) per day (hefty).
So the following questions present themselves.
Is this energy being used at its most optimum?
What amount of this represents petroleum consumption?
How can we use the current levels of consumption to decrease that level?
What feedback mechanisms can be created to decrease oil consumption?
Let’s take each question in order.
Is this energy being used at its most optimum?
Nature uses feedback mechanisms and vertical integration (trophic organization) to use energy at various scales. Most activity occurs at microscopic levels and an incident “packet” of energy will move upwards and downwards through both trophic levels and biotic scales.
Corollary questions we may ask are related to the optimal human condition. Do all humans benefit from this large use of energy? Equitably? How does this energy re-enter the Earth Sphere once we are finished with it? Once we define what it means to “benefit” from the energy, we can answer the first question. Clearly, given the gap between poor and rich, the use is hardly equitable. The entry of this energy to the Earth sphere manifests itself as global climate disruption. In terms of climate stabilization, the way we use this energy is not in keeping with laws of nature.
What amount of this energy represents petroleum consumption?
In 2004 we used 7.5 Billion Barrels in the US. That comes out to 25 Barrels/person/per day. Of course, these are collective figures, not individual figures. How many Btu’s is that? 1 barrel = 5.8 million Btu’s. Ergo; 25 barrels = 145,000,000 Btu’s (per person per year).
Now, let’s look at the way we use this resource.
Energy used to make other energy available
Energy used to keep milk cold in the supermarket until we arrive to pick it up
Energy used to transport raspberries from Chile to NY restaurants
Energy used to take timber to Japan and to return finished lumber or furniture to the U.S.
Energy used to create balloons for our birthdays
Energy used to support the accountant who keeps track of the sales of balloons
Energy used to keep city lights on, even when no one is there is see by them
The list goes on and on and on and on…
How is this energy represented financially in our life?
Subsidies – we pay the government to make certain operations “economic”
Taxes – the money we give to the government for its operations
Sales – the money we use to pay for goods and services
Donations – money we pay to non-profits or organizations that we support
Money that is in our direct control goes to sales and donations. Some donations can take the place of taxes. So, the choices we make when buying or donating have a large effect on what our energy footprint is. Taxes have an effect on what is done for us (or in our name) by the government but there is less control of the way they are spent. That is most controlled by who we put into political office and how much pressure we put on them to address certain issues. Subsidies are currently (and largely) out of our control and sometimes beyond our knowledge. This is money that goes out of the government offices and into the pockets of “whomever.” “Whomever” usually turns out to be large companies and corporations because they can convince legislators that this expenditure is critical to economic health of the nation (or the next election). The average person does not have this clout but we can gain it by grouping together and hiring an advocate to speak on our behalf. So, lets look more closely at financial energy flows as listed above and see where analysis leads us.
Sales
What we spend our money on has direct bearing on our independence or interdependence. There is also the matter of temporal dynamics. Will the money we spend now benefit us in 5 years time? 20 years time? 50 years time? If I have 25 gallons of crude oil, per day, at my disposal, how will the energy stored in that crude be best used so as to benefit myself (and my community) 50 years down the road? And, if that amount of energy decreased, how can I make up for it.
There are three options to address the last issue.
Find another source of energy
Use less energy with technical conservation measures
Change habits to decrease energy use
If the time element is of concern, use the oil that you have to create energy sources that will last longer than the oil itself. Let’s start by looking at a typical solar panel.
Part 1 Solar Electricity
Basically 1 sq meter is approximately 10 sq ft.
10 sq ft supports 100 watts of PV
100 sq ft of panel yields approximately 1 kW
so 10 sq meters yields about 1 kW of PV
The efficiency of the PV is typically around 14-15%
Therefore, the total real Wattage is 150 Watts of power.
Using tables available from NOAA and NREL that show sun hours by the hour for various degrees of tilt of a panel we find that for northern U.S., the daily annual average is about 3.5 sun hours per day (about 5 hours in summer and 2 hours in winter).
And so we calculate:
3.5 * 365 * peak Watts = Annual Watts
3.5 * 365 * 150W = 191 Kwh/year
Now,
1kWh = 3413 Btu
so the total Btu output of the modules… before the efficiency losses from various hardware and other conversions along the way as we use the electricity... is
3413 * 191 = 651,883 Btu per year (about 652 kBtu’s per year) or 0.1124 bbl
Photovoltaic Efficiency is based on a number of factors and include angle of tilt toward the sun, solar tracking, ambient temperature (PV arrays work better in colder temperatures), and clarity of atmosphere.
It takes 2 – 6 years of solar activity to create the amount of energy that went into production of the solar panel. To keep life simple, let’s say that after 4 years, all energy is net. The typical solar panel will last around 20 years. So, for 16 years you are creating net energy. This information will be used later in the program.
Now remember, we use 20.5 M-Btu’s per day. That included internalized amounts from your refrigerator and HVAC and externalized amounts like the cappuccino maker at your favorite café (which is just waiting for your daily arrival) and the roads that you might use at any given time.. In one year we use 145 M-Btu’s. That’s 121 billion Btu’s. So, based upon the calculations given above, we have the following. With 10 m2 of PV array producing 4.5 M-Btu’s per year, how much oil does that represent? In 1 gallon of oil there is 138,000 Btu’s (there are 42 gallons of oil in a barrel). Crunching the numbers gives us around 32 gallons of oil or 0.75 barrels. A summary is below.
Daily Use: 397,260 Btu’s
Yearly Use: 145 M-Btu’s
PV Supply: 4.5 M-Btu’s/yr
Balance: 145 M-Btu’s – 4.5 M-Btu’s = 140.5 M-Btu’s/yr (don’t worry – we’ll get there)
Balance w/ 50 m2 PV: 122.5 M-Btu’s/yr
Part II Solar Water Heater
Let’s add a solar water heater. Heating water is a major energy consumer.
The calculations for energy conversion are the same as above. Therefore, if we use a 100 m2 collector, we arrive at the following values:
Eff. = 25% – 45% (we’ll use 30%)
Area = 10 m2
Nominal Btu’s = 12,700,000 Btu’s/yr
Real Btu’s = 38,100,000 Btu’s/yr (3.81 M-Btu’s/yr)
But what does that give us?
It takes 1 Btu of energy to heat 1 pound of water 1 degree Fahrenheit.
1 Pound of water = .125 gallons
A 120 gallon water tank holds 960 pounds of water (water weighs 8 lb/gal)
To raise one tank of water 1° F, we would need 960 Btu’s of energy
To raise one tank of water from room temperature to 120° F we would make the following calculation:
(50° F) x 960 Btu’s = 48,000 Btu’s of energy
One 10 m2 solar panel would give us the following:
(3.81 M-Btu’s / 48,000 Btu’s) = 79 (that’s the number of tanks of water we could heat)
79 x 120 = 9,525 gallons of water @ 120° F per year
The DOE (Dept. of Energy) website states that American household hot water use, in 2001, was 15,800,000 Btu’s per year for hot water (15.8 M-Btu’s).
So, if we need 15.8 M-Btu’s per year and we are collecting 3.81 M-Btu’s per year we have a shortfall of 11.99 M-Btu’s per year. We have two options: Add more panel or decrease usage. Adding enough panel would require 5 x the area or 50 m2 (that’s an area of 5 m x 10 m or 15 ft x 30 ft)
Summary
Daily Use: 335,616.44 Btu’s
Yearly Use: 122.5 M-Btu’s
Solar H2O: 3.81 M-Btu’s/yr
Balance/m2: 122.5 M-Btu’s – 3.81 M = 118.69 M-Btu’s (better and better)
Balance w/ 100 m2 of panel: 84.4 Btu’s/yr
Part III Space Heating
In 2001, an American household used 47.1 M-Btu’s for the year . In petroleum usage that would be:
(M-Btu’s) x (Barrels/Btu) = 47.1 M-Btu’s x (1/(1700 kWh x 3413 Btu’s) = 8.12 bbl per year per household.
Let’s look at three ways to replace that energy source: Wood, Passive Solar, and active Solar.
Wood
In places with an adequate supply this is an excellent option. For analyses sake, let’s use a typical wood stove.
First, wood has an energy content of 18 M-Btu’s per cord . The average house built last year was around 2400 ft2 . 54.9 M-Btu’s were used in 2001 for a house of 2400 ft2 for space heating.
Therefore, 3.05 cords of wood for a stove of 100% efficiency or 4.5 cords at the standard efficiency of 70% will produce 54.9 M-Btu’s. Now we have to factor in the energy needed to build a wood stove. For a cast iron stove, the iron has a process energy of 14,891 Btu/lb. If the stove is 400 lbs in weight, the stove will take roughly 6.0 M-Btu’s of energy to build. If the stove lasts 20 years intact, the embodied energy/per year will be 300,000 Btu’s per year. Add the energy to cut the wood: 1.85 M-Btu, and we get 2.15 M-Btu’s. We must subtract this number from the energy liberated in operating the stove. That will give a final answer of 52.75 M-Btu’s generated per year.
Now let’s use a tile stove. Tile stoves are more popular in Europe but slowly gaining popularity in the U.S. Common bricks have an embodied energy content of about 13,570 Btu’s/kg . A tile stove has around 36,093 Cubic Inches of material. That is 1,337 yd3. Some of it is brick, some is concrete. 1 common brick is 53.61 in3. We can start the analysis at 50% for each material. So, brick will total 18,046 in3. Now we need to convert cubic inches to Kilo-grams. For that we need the density in kg/in3. Let’s start with converting kg to pounds. 1 kg = 2.2 lbs. Common brick has a density of 120 lbs/ft3. Multiply 120 by 2.2 and 1 ft by 27 (33)to get the final value. That is 264 kg/27 in3 or 9.77 kg/in3.
So, multiply density by total mass and we get 176,309 kg of brick.
Now for the concrete.
Concrete has a density of 148 lbs/ft3 or 12.05 kg/in3
Ergo, density is 12.06 kg/in3
If there is 18,046 in3 of concrete, then we will have 217,621 kg of concrete. Concrete has an embodied energy of 817, 600 Btu’s / ton. 1 Ton = 907.18 kg.
Ebrick = 176,309 kg * 13,570 Btu/kg = 2.346 x 109 Btu’s = 2,346 M-Btu’s
Econcrete 217,621 kg * 901.25 Btu/kg = 196.13 M-Btu’s
Add the embodied brick and concrete energies together:
2,346 M-Btu + 196.13 M-Btu = 2,542.13 M-Btu.
Divide this energy by the lifespan of the stove: 28.25/90 = 0.3138 Btu’s / yr
Heat Output = 6500 Btu per hour per 30 lbs of wood. Hard Wood density averages around 680 kg/m3. That is 42.45 lbs/ft3. The volume of 30 lbs of wood therefore is
30 lbs/42.45 lbs/ft3 = 0.70 ft3 or 0.0262 yd3 (an average value) and
1 cord of wood = 128 ft3 or 4.74 yd3
1 Cord of wood = 18 M-Btu’s and 4.74 yd3 ergo,
There are 5,433.6 lbs / cord so,
If I put 30 lbs of wood into a tile stove per 24 hour period, I will have enough fuel for 181.12 days or enough wood for 6 months.
The total energy output in that time period is 6500 Btu/hour/day x 181.12 days.
Total then for the year, where the year only has 6 months of heating needed, is
28.255 M-Btu’s (call that 28 M-Btu’s for a years supply of space heating).
Calculation for cutting the wood = 411,428 Btu’s/cord
Add to embodied energy of stove: Total = 411,428 Btu
Subtract the embodied energy/year from this amount and we get
28 M-Btu’s – 411,428 Btu’s = 27.59 M-Btu’s / yr (good deal, eh?)
Subtract from total heat needed: 54.9 – 27.69 = 27.01 M-Btu’s per year as the remaining need. Consider that the energy GAP. We can fill in that GAP by using Passive Solar heating.
Passive Solar Space Heat
A properly positioned double-glazed window will net about 70,000 Btu’s per square foot per day of sunlight.
Now we need to determine the embodied energy per square foot of a window used in collection. Let’s choose a window 4 ft x 6 ft. The thickness of the glass is 0.25” and therefore the volume of the window glass is 864 in3.
Window glass will last at least 10 – 15 years (we will use 13 in our calculations).
Glass has an embodied energy of 31.5 MJ/kg. Its density is 2580 kg/m3.
864 in3 = 0.014158423 cubic meters.
So, the embodied energy in MJ is (31.5MJ/kg)(2580 kg/m3)( 0.014158423 m3) = 1,150 MJ = about 1.1 M-Btu’s. Of course, this is for the glass itself. If we add in transportation, the embodied energy will increase.
The window is 24 square feet or 87.78 m2. Therefore, the Btu’s produced in one year will be 24.5 M-Btu’s. This is for one double-paned 4ft x 6ft pane of clear glass. Now we need the efficiency of the glass and how much energy will be retransmitted at night or in cloudy weather. For that, we use the U-Value (opposite the R-Value for insulation). For clear windows, the value is 0.46 and for low-E is about 0.25. The U-Value is measured in Btu/hr-sq ft-°F or W/m2K and that is Btu’s per hour-square foot-degree Fahrenheit. Therefore, a window that is Low-E and has an U-Value of 0.25 is losing 0.25 Btu/hr-sq ft-°F.
If we take averages of U.S. temperatures to be 57.44, we can determine how many Btu’s are escaping through the window.
Btu’s / hr = (U-Value)(Area)(Tinside - Toutside ) = (0.25)(24)(75 – 57.44) = 105.36 Btu’s / hr
Because we are using averages, let’s assume the window is losing this amount at all times of the day. Sometimes it will be less, sometimes more. The total for a year will be 922,954 Btu’s. We need to subtract this from Btu production. That gives us 23.6 M-Btu’s of energy transference.
Dividing embodied energy by Btu’s generated per day of sunlight, the result will be 0.0467 years or about 2 weeks or about half a month. That is the time needed to pay off the energy of production. This number will rise as we include the frame in embodied energy costs.
So, after 2 weeks, the energy received by the window is net. Therefore, in 13 years, we will generate (23.84 M-Btu’s/yr)(12.5) = 300 M-Btu’s.
Summary
Yearly Use: 122.5 M-Btu’s
Annual Space Heat Use: 47.1 M-Btu’s
Balance w/ Wood Heat: 122.5 M-Btu’s – 27.69 M-Btu’s = 94.81 M-Btu’s
Balance w/ Passive Solar: 94.81 M-Btu’s – 23.84 M-Btu’s = 70.97 M-Btu’s
Onward…