Feb 28, 2009

Paper vs. Plastic?: BYOB

Bring Your Own Bag for Shopping. Original bag picture from buffaloreuse.wnymedia.net

What bag is the best? paper or plastic? My answer: Bring Your Own Bag !

From a public policy perspective, the recent NY plan to tax plastic bags is a one-sided approach to the problem. This is because plastic bags consume less water to produce compared to paper bags. Additionally, some studies indicate that paper bags do not decompose in landfills. Here is a link to a life cycle analysis comparing paper vs. plastic bags. Therefore, any policy that taxes plastic bag use (indirectly) provides incentives for retailers to use paper bags, which when not recycled are not significantly better for the environment.
Most arguments for the use of plastic bags indicate that recycling is environmentally responsible. After discussing this with my friends, I also think that reusing old bags is also a good way to eliminate waste. For example: Today, at the grocery, I asked the cashier not to bag my items because I already had plastic bags in my car. I simply transferred the items to the plastic bags and will continue to have a handful of plastic bags in my car to cover for any contingencies.

Therefore, I think that the argument should not be about paper vs. plastic. Rather, the discussion should be about how we could better reuse and recycle both bags. Let us know in the comments how you plan to reduce your plastic & paper waste.


Feb 23, 2009

Surface Radiation Calculations

Basic system thermodynamics revisited (click image to view full size)
A colleague of mine emailed me an article (pdf link) containing the above figure. The author Ashworth (2008) contends among many things that the radiation energy balance shown in the figure above is wrong, and that it violates 1st and 2nd law of thermodynamics. I am writing this post to show that Ashworth is completely off base on that point and is not even close to interpreting the above figure correctly. I am not able to decipher any 2nd law implications from the figure though.
I don't have clear arguments or time right now for the all graphs of CO2/warming shown subjectively. It could go either way.

But first, imo, the author does not even know how to define a system for performing energy balances. Because of this he does not know how to add the necessary terms to achieve a 1st law energy balance. Clearly, if you look at the total energy balance, the incoming and outgoing solar radiation fluxes at the outer boundary of the atmosphere add up fine (342 coming in and 107+235 going out at the atmosphere level, from space).

This author is forgetting the fact that the earth is round and receives radiation at different times throughout the day and radiates it back. Consequently it is possible to radiate 390 (+ 78+24 also shown in the image) because earth is also getting back radiation of 324 apart from the 168.
Further if you do a surface balance that also adds up fine. See image of my excel calculation below.

The original paper from which they obtain the Fig 8 is here (pdf) where towards the end the authors clearly put forward the errors etc in the model and still clearly show that an energy balance has been achieved. Further the Ashworth "paper" is written like an opinion piece and (gasp) and shows lack of simple mathematical concepts.

But the bigger issue with anthropogenic CO2 related global warming is not the average daily solar fluxes, it is the release of the chemical energy trapped for millions of years in carbon bonds. The resulting CO2 release into the atmosphere is what is being considered as a precursor to global climate changes.

I should add at this point, my personal view on the subject of global warming and climate change is still not firmed up. I am merely an advocate for efficient use of resources, irrespective of whether they are carbon based or not. But what really bothers me sometimes is people pointing fingers at others, but making similar mistakes themselves.


Feb 17, 2009

Game-changing clean energy technologies?

During my recent Ph.D. defense, one of the questions was whether there were any potentially game-changing energy technologies out there, and I put the question to our audience. What do you think are the potential game-changers? There are a multitude of good ideas, and to (mis)quote Chairman Mao, we should "let a thousand ideas bloom".
For one, I can think of a cross between the Reva and the Nano. Tom Friedman talks of a hybrid solar-electric car in India which derives 10% of its energy consumption using PV panels. Something like this, would not only alleviate pressure on oil imports (for both India and China), but also be cheap enough to make a realistic difference.


Feb 4, 2009

MIT Clean Energy Competition

The MIT (Masschusetts Institute of Technology) Clean Energy Entrepreneurship Competition for the year 2009 opens tomorrow (Feb 5 2009). It is open to full time students in the US. (However, non students can be part of the team as long as at least one of the team members is a student at a US university) [rules] Deadline for submissions is Feb 16 2009.
More information about the competition can also be found on the facebook group. Excerpts from the competition website:
The MIT Clean Energy Prize is a student business plan competition open to all full time students in the US. Over $500,000 in cash and other prizes will be awarded to the grand prize winning team, and to category winners.

Grand prize: $200,000 cash prize (sponsored by NSTAR and the US Department of Energy) plus legal advice and support to help launch successful businesses.

Categories: Biomass, Clean Hydrocarbons, Energy Efficiency, Renewables, and Transportation.

More information about the categories can be found under sponsor information and other locations on the CEP website.

Past year's winners included FloDesign wind turbine, Covalent solar and Catalyzed combustion technologies.

Note: A separate business competition that is held annually at MIT is the 100K Entreprenuership competition.


Feb 2, 2009

Energy ads: Superbowl XLIII

Here are a couple of GE ads from the Superbowl
Wind energy:

Smartgrid technologies:

GE is working with a handful of utility companies (Duke Energy etc.) to promote smartgrid technologies. I also came across the supposedly eco-friendly Steelers superbowl t-shirt, made from organic cotton. Apart from this, I do not see how selling this t-shirt would be eco-friendly..


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