Paper versus Polystyrene Cups - Again

Posted by Max Dunn Tue, 28 Apr 2009 21:47:25 GMT | no comments

Many organization are looking for ways to reduce their garbage and increase composting of the disposable cups. However, it turns out that the styrofoam (also known as extruded polystyrene foam or XPS) versus paper question is more difficult than it first appears.

One big problem is that the coating on the paper cups which keeps it from leaking also makes it difficult to recycle or compost. And the cups themselves contain very little recycled paper.

An old study from Science shows that on almost every count, except cooling water and biodegradability, the styrofoam cups are more eco-friendly.

A newer study also concludes that to process the raw materials about six times as much steam, 13 times as much electric power, and twice as much cooling water are consumed to produce the paper cup as compared to the styrofoam cup.

The same study found that landfill disposal of the two items under dry conditions will occupy similar landfill volumes after compaction and neither will decompose much. Under wet conditions, styrofoam will not readily degrade but may help other materials to do so, while the paper will decompose giving off methane, a significant greenhouse gas.

Another possibility is to recycle the styrofoam cups, although this is hard to find. There are mail in recycling centers in Redwood City and Hayward that take them and Imagine Surfboards makes surfboards out of used styrofoam cups.

It is too bad that there isn’t an easy solution to making disposable cups more eco-friendly.

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A Real Market for Negawatts!

Posted by Max Dunn Fri, 27 Mar 2009 13:47:19 GMT | no comments

Negawatts is term coined by Amory Lovins to describe “negative watts” or conservation. It makes sense – instead of constantly building power plants to add more megawatts to the grid, why not let people bid on saving power through negawatts? That’s what New England’s independent system operator started doing last year.

In its Forward Capacity Market, the ISO projects how much power the region will need three years ahead and then runs a descending-clock auction for the right to provide it. The ISO doesn’t care whether it gets its power from increased production of megawatts or from conservation through negawatts. Result: money saved in power plants and wires, more stable electricity bills, and a homegrown incubator for getting bright green ideas off the drawing board.

(Source: Wired Magazine Trade – Electricity Like Pork Bellies)

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Wind, Water and Sun Best Energy Alternatives

Posted by Max Dunn Thu, 19 Mar 2009 19:31:25 GMT | no comments

A recent study by Mark Jacobson at Stanford ranks clean energy options and found that wind was by far the most promising. The best to worst electric power sources Jacobson found were:

  1. Wind power
  2. Concentrated solar power
  3. Geothermal power
  4. Tidal power
  5. Solar photovoltaic
  6. Wave power
  7. Hydroelectric power
  8. Nuclear/coal with carbon capture

Jacobson also comes down hard on biofuels, “Biofuels are the most damaging choice we could make in our efforts to move away from using fossil fuels.” He added, “Ethanol-based biofuels will actually cause more harm to human health, wildlife, water supply and land use than current fossil fuels.”

(Reference: Wind, water and sun beat other energy alternatives, study finds)

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Electric Generation Costs

Posted by Max Dunn Thu, 19 Mar 2009 03:38:23 GMT | no comments

What does it cost to build a new electric power plant? Here is a graph that shows this:


However, you do need to adjust this for utililization, since nuclear operates about 90% of the time, while solar operates only about 20% of the time:

(Source: What does Sustainability Mean for Energy?)

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Coal Tax Needed

Posted by Max Dunn Fri, 27 Feb 2009 04:03:36 GMT | no comments

I just went to an interesting talk about distributed solar and found out that prices of solar PV panels are dropping dramatically. Soon, PV will be about $4 per watt installed (in large installations) which works out to about $0.17 per kWh.

By comparison, coal-fired electricity sells for about $0.05 per kWh. This includes about $0.02 for the coal itself ($2.15 per MMBtu and 1 MMBTU produces about 100 kWh) and $0.03 for all other expenses.

Adding in a $30 per ton CO2 tax would add about $0.03 per kWh to this price, (coal produces about 2 lbs of CO2 per kWh) for a total of $0.08 per kWh.

So even with a CO2 tax, coal electricity will still be half the cost of PV.

Therefore, for coal electricity to cost about the same as PV electricity, a tax of 400% would need to be added to coal!

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Electric Power Plant Cost Comparison

Posted by Max Dunn Wed, 25 Feb 2009 00:54:16 GMT | 2 comments

While looking for the external costs of coal, I ran into a great table that shows how much it costs to build and run various types of electric power plants.

It is interesting to note that while a convention coal plant costs much less to build than a solar thermal plant, the coal plant costs more to maintain so over 30 years, the total costs would be equal.

Power plant costs

Table 1: Specification of electric power technologies used in GMM model. All costs are given in $(1998). The progress ratio (pr) is the rate at which the cost declines each time the cumulative production doubles. The data presented in the table comes from various sources: IIASA MESSAGE model database, literature reviews. Characteristics of technologies with CO2 removal are adopted from [8].

(Reference: Internalisation of external cost in the power generation sector)

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The True Cost of Gas

Posted by Max Dunn Wed, 28 Jan 2009 01:44:29 GMT | 1 comment

The price we pay for a gallon of gas at the pump doesn’t include all the costs associated with it, like environmental costs and tax subsidies. One older study found that if we included all of these, we would be paying and extra $5 to $14 per gallon!

However, if we look at just the cost spent on military defense of oil in the Persian Gulf, it would be less than this.

One rough estimate would be to assume that 15% of the $430 billion DoD budget was spent on defending our oil interests in the Persian Gulf. Spread over the 142 billion gallons of gas we use each year, it works out to $0.46 per gallon.

Of course the hard number to determine is how much of the military budget goes to just protecting oil in the Persian Gulf. The $65 billion seems to fall in the middle range of what is spent on that region, but there is a lot of differences in opinion over how much spending would be reduced if we didn’t need to protect the oil there.

Here are some of the studies and what they determined we would need to add to the price of a gallon of gas to cover the cost of protecting oil in the Persian Gulf:

So don’t assume the price you pay at the pump is the true cost of gasoline. There are a lot more costs hidden away in making that gasoline available and in the environmental problems it causes that you pay for elsewhere.

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Climate Change Recalculated - Saul Griffith

Posted by Max Dunn Sun, 18 Jan 2009 06:45:00 GMT | no comments

On January 16th, the Long Now Foundation sponsored a very interesting talk at Fort Mason by Saul Griffith entitled “Climate Change Recalculated”.

Saul first went through a calculation of his energy usage. However, he did it in a different way – instead of using energy (kilo-watt-hours or kWh) he used continuous power expended (kilo-watts or kW) because this made it easier to add up and compare.

After adding up all his plane trips, driving, food, energy usage and embodied energy in the stuff he buys (which accounts for 1/4 of his energy use), he calculated that he used 18kW. By comparison, a person in Qatar uses 27kW but the average person in the US uses 11kW and the global average is 2.2kW. So he uses a lot more than the average American and way more than the global average. So he decided to shoot for 2.2kW and see how he would have to change his life.

First, he would be able to fly to the East Coast only once per year, and fly to Australia only once every 5 years. He would need to have a car that got 100 MPG, and then could only drive 20 miles per day. He could eat meat only once a week and would need to buy 1/10 of the stuff he does now and make it last 10 times longer. He isn’t quite there yet but has cut down on his travel and the stuff he buys and now is using only 12kW. Interestingly, this has also increased his quality of life. For instance, he isn’t traveling as much so is spending more time with his family.

Next he talked about climate change and what would be necessary to hold CO2 to 450 ppm. Humanity currently uses 16TW (tera-watts or 10^12 watts or a million-million watts) and in order to hold the CO2 limit, we can only burn 3TW of fossil fuels. Since 1.5TW already comes from renewable resources we would need an additional 11.5TW from new renewable sources. To meet this, we would need to produce 2TW of power each year for the next 25 years (not sure how he got this from the 11.5TW figure?), and this would require installing:

  • Photovoltaic: 100 m2 per second
  • Solar thermal: 50 m2 per second
  • Wind: one every 5 or 6 seconds
  • Nuclear: one new plant every 3 weeks

This is a lot! However, if GM and Ford stopped making cars and started making just wind turbines, they could meet the goal of creating a wind turbine every 5 seconds.

Summary: We need to reduce the power we all use – which we can do but is not easy. We also need to dramatically increase the amount of renewable power production – which we can do but it won’t be easy.

(For more details, see Climate Change Recalculated)

The next by the Long Now Foundation is Social Collapse Best Practices on February 13th and features Dmitry Orlov who witnessed the collapse of the Soviet Union and how it survived and applies these insights into how the US might not be able to cope as well with a similar collapse. Should be interesting too!

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Military Cost of Oil

Posted by Max Dunn Tue, 02 Dec 2008 16:56:34 GMT | no comments

It is well known that a large part of our military expenses goes to protecting the flow of oil from the Persian Gulf. What has not been as clear is the actual cost of this protection. However a recent study sheds some light on this hidden expense.

In this study, Mark Delucchi of the Institute of Transportation Studies at UC Davis estimates that American taxpayers spent between $27 billion and $73 billion in 2004 (which was the most recent year data was available) for military protection of US oil interests in the Persian Gulf region.

While this is a huge number by itself, it works out to only $0.03 to $0.15 cents per gallon of gas for motor vehicle use.

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Paper versus Polystyrene Cups

Posted by Max Dunn Fri, 21 Nov 2008 15:57:22 GMT | no comments

I just finished my Sustainable Design class in the Stanford Continuing Studies program taught by Mark Martin. It was a really interesting, well taught class and I learned a lot.

One of the main points that Mark made was that it is difficult to tell how eco-friendly a product is without a in-depth study. As an example, he had us discuss which we thought was more eco-friendly: paper or polystyrene coffee cups. (Polystyrene is sometimes called Styrofoam or Polyfoam.) We all pretty much all agreed that paper cups were better, and then Mark showed us this study:

On almost every count, except cooling water and biodegradability, the polystyrene cups are more eco-friendly.

In a more recent study polystyrene was also found to be better:

In raw material requirements the paper cup required about 2.5 times its finished weight of raw wood and about the same hydrocarbon fueling requirement as is needed for the polystyrene foam cup. To process the raw materials about six times as much steam, 13 times as much electric power, and twice as much cooling water are consumed to produce the paper cup as compared to the polystyrene foam cup. Emission rates to air are similar and to water are generally higher for the paper cup.

Another interesting ramification this study pointed out is that in a wet landfill, the polystyrene will remain stable while the paper will decompose giving off methane gas and contributing to the instability of the land surface.

This just goes to prove what Mark taught in this class – it isn’t always obvious which products are eco-friendly.

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