This era in history may be remembered as the "Peak Age", a brief time when nearly all materials used to power and create our society reach the maximum extraction and production potential. Past this point, all of these resources become increasingly difficult to extract until they are no longer economically viable resources to be using. There are hundreds of examples of resources, currently embedded in our industrial society, which have reached their peak in the 50 years surrounding 2010, but the one which will most impact our society is petroleum.

The goal of living for 100 days without oil is to understand the extent of our dependance on oil in American society today. Specifically, how it will affect my life, as a 25 year-oil living in Minneapolis, MN. By using myself as a metric I can take a close and conscious look at where oil dependance occurs in all aspects of our daily lives : How we transport ourselves from one place to another, what we eat, how much waste we create, how water is cleaned and transported, where oil is used as; an energy resource, in conventional medicine and for hygiene and how oil affects how we entertain ourselves and communicate with others. By demonstrating how someone would be forced to live without using any oil resources, outlining both what the sacrifices will be as well as the benefits, we can can identify the many systems which will have to be re-designed in a world without cheap oil, and explore a new way of living in which we live in an energy balance.


(At the bottom of this page is a link to my version of a flow diagram of 'Where Petroleum Exists in Our Daily Lives' (using information from the Energy Information Administration-Annual Energy Review 2008 fig 5.0 Petroleum flow) click and zoom to enlarge)


Tuesday, September 28, 2010

DAY 43_MPG vs GPM (GARBAGE TRUCK ENERGY)

26 September 2010

How much energy is used to take out the trash?

I decided not to create any waste for this project mostly to see if it was possible, but have recently been looking into just how much energy it takes for a garbage truck to haul your trash away once a week.  A little background on Minneapolis (Hennepin County's) waste system from the city website(http://www.ci.minneapolis.mn.us/solid-waste/garbage.asp):

"None of your garbage goes into a landfill. City of Minneapolis garbage goes to the Hennepin Energy Resource Co. (HERC).
Located in downtown Minneapolis, the HERC facility uses mass burn technology to convert 365,000 tons of garbage a year into electricity that is sold to Xcel Energy, Inc."

This waste-to-energy facility is located in downtown Minneapolis, just 2.1 miles from my house.  While it may seem strange that Minneapolis burns all its waste near the most densely populated area of the city, this is a convenient location for the facility because it can more efficiently distribute the steam (heat energy) which is being created by HERC.  While the facility is extremely close to where I live, the main problem lies in how garbage gets there -garbage trucks.  As this article outlines (http://www.informinc.org/pr_ggt.php), garbage trucks have some serious fuel efficiency issues:

"The study found that garbage trucks are among the oldest, least fuel-efficient, and most polluting fleet vehicles in the United States:
  • There are more than twice as many garbage trucks in the US (179,000) as there are urban transit buses (82,600). The garbage truck fleet includes refuse and recycling collection vehicles as well as transfer trucks.
  • Forty-one percent of garbage trucks in use are more than 10 years old, nearing the end of their lifetime (12 to14 years), and performing at reduced efficiencies.
  • Garbage trucks use more fuel than any other type of vehicle – averaging 8,600 gallons per year – except for tractor-trailers and transit buses (which use 11,500 gallons and 10,800 gallons on average per year, respectively).
  • Garbage trucks in the US consume approximately 1 billion gallons of diesel fuel annually and get the lowest fuel efficiency (2.8 miles per gallon) of any vehicle type. Transit buses, single-unit heavy-duty trucks, and tractor-trailers get 2.9, 7.0, and 6.1 miles per gallon, respectively.
  • Diesel garbage trucks are a major source of air pollution, including smog-forming compounds, particulate matter, and toxic chemical constituents. While heavy-duty diesel-powered vehicles, including garbage trucks, make up only 7 percent of vehicles on the road, they contribute 69 percent of on-road fine particulate pollution and 40 percent of nitrogen oxide emissions.
  • Diesel garbage trucks are notoriously loud, generating noise levels of up to 100 decibels, which can cause serious hearing damage. Garbage truck operators, as well as those living along garbage truck routes, are affected by this noise.
Trying to crunch some numbers to get the # of gallons used to get from my house to the facility I realized that 2.8 miles per gallon = 2.8 gallons per mile.  Wait, why don't we use GPM instead of MPG?  Wouldn't it be interesting to be able to calculate exactly how many gallons of gas you use for each trip you take (or on a long vacation?).  It turns out, that the term MPG is an easy way to confuse consumers. according to this article (http://www.mpgillusion.com/2009/02/overveiw-of-gpm.html):

"MPG tricks people's perceptions. Replacing a car that gets 14 MPG with a car that gets 17 MPG saves as much gas for a given distance as replacing a car that gets 33 MPG with a car that gets 50 MPG (about 1 gallon per hundred miles--see this table). MPG obscures the value of removing the most inefficient cars. As the GPM table shows, a 14 to 20 MPG improvement saves twice as much gas as a 33 to 50 MPG improvement:"

MPG = miles per gallon
GPHM = gallons per hundred miles
MPGGPHM
1010
119
12.58
147
16.56
205
254
333
502
1001

More information on this at http://www.mpgillusion.com/"

A few conversions from wikipedia:

1 barrel of crude oil (42 gallons) makes 19.5 gallons of gasoline (other products are made from the barrel as well)

1 gallon of gasoline = 132 MJ = 36.6 kWh

Garbage trucks = 2.8 MPG = GPM
2.8 GPM x 2.1 (miles from my house to the HERC) = 5.88 gallons of gas

Multiplying 5.88 gallons of gas x 36.6 (kWh in a gallon of gasoline) I found that 215.2 kWh of energy are used in the garbage truck's 2.1 mile trip from my house to the waste facility. Whoala. A few comparisons, our house uses about 140 kWh of energy a month (that's 3 people).  Check your energy bill, this is probably pretty close to the amount of energy most small homes use in a whole month!  Granted, the truck makes many stops, so it isn't just MY garbage that is being picked up on the truck. For example, if the truck was on a 10 mile round-trip route which served 50 houses, the energy use per house would be 20.49 kWh (((2.8 MPG x10 miles)/50 houses) x 36.6 kWh)). I have had trouble finding data about garbage routes and number of homes served by each truck.  Updates on these numbers as I find more data...

But just for a moment I would like to consider how much energy would have to be dedicated for garbage hauling each day if I were to be using this service.  215.2 kWh divided by 7 days (garbage picked up once a week) = 30.7 kWh per day.  My energy budget is 5kWh/day.  (Again this number comes from my 'share' of the average solar energy that lands on my roof each day). This means that if I were to consider having garbage trucks haul my garbage away, and dedicated my ENTIRE energy budget towards it, I would only have enough energy to have garbage hauled every 43 days (215.2 kWh per load/5 kWh energy budget per day).  While there is no way I could dedicate my entire energy budget to garbage hauling, picking up garbage once a month doesn't actually seem that unreasonable.  As mentioned in earlier posts, while it is almost impossible to not accumulate ANY waste, it is certainly possible to minimize waste dramatically.  There are only a few items that I continually collect (milk lids, glass wine bottles, twisty ties).  Most of these things are actually recyclable (but I'm not recycling in this project due to energy requirements as well).  I won't have any problem collecting waste in the 14 gallon (2.5'x2'x2') plastic tub I am using now over the 100 days.  This means that I would really only need garbage to be picked up every 3 months or so. 

Below is a graphic describing the garbage energy use and flows (click to enlarge in a new window):

waste energy flows (click to enlarge)