Archives for the month of: January, 2012

Energy was certainly on the agenda during President Obama’s 2012 State of the Union Address. “This country needs an all-out, all-of-the-above strategy that develops every available source of American energy,” he stated, while opening up the energy discussion.

His strategy includes exploiting America’s limited oil reserves and also expanding natural gas extraction. However, with commendable foresight, he acknowledged that these resources are finite and emphasized the need to continue government support of clean energy technologies like wind and solar while removing support from the already prosperous oil industry.

“We’ve subsidized oil companies for a century. That’s long enough,” he stated. “It’s time to end the taxpayer giveaways to an industry that rarely has been more profitable, and double-down on a clean energy industry that never has been more promising. Pass clean energy tax credits.”

To justify the subsidization of clean energy, President Obama used natural gas extraction as an example. He stated that “…it was public research dollars, over the course of 30 years, that helped develop the technologies to extract all this natural gas out of shale rock –- reminding us that government support is critical in helping businesses get new energy ideas off the ground.”

Furthermore, he encouraged citizens to think long-term, noting the example of natural gas as proof that “…the payoffs on these public investments don’t always come right away. Some technologies don’t pan out; some companies fail.”

This is no doubt an allusion to the highly publicized failure of the government subsidized solar module manufacturer Solyndra. It is clear from the president’s statement that he sees such failures as inevitable on the road of technological development and he is certainly correct.

Despite this failure, he remains unperturbed, pledging not to “…walk away from the promise of clean energy.”

-Erik Janssen

(Engineering Physics, MASc, Year 2 at McMaster University)

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A full transcription of his address can be found at:

http://www.nytimes.com/interactive/2012/01/24/us/politics/state-of-the-union-2012-video-transcript.html

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Humanity is consuming more and more energy every year and, since much of the world depends on fossil fuel based resources, our total carbon emissions continue to climb as well. In the effort to curb this trend, energy conservation is imperative. One area where conservation efforts can make a particularly large impact is in our nation’s buildings where 40% of our national energy expenditure is consumed. [1] This is a powerful motivation to construct buildings that are more energy efficient. Researchers from the National Research Council (NRC) are attempting to do just that with a promising new technology called the vacuum insulated panel (VIP).

It is important to digress somewhat here.  What does it mean to make a building more energy efficient? Well, we have to actively heat and cool our buildings. In other words, we continually supply energy so as to maintain a constant temperature. If we need to supply it constantly then that means we must be losing it somewhere.  The energy expended to heat or cool a structure is lost through the walls, windows, floor, roof, etc. An “energy efficient” building would lose less.

This is what insulation does. It helps to maintain the difference between the interior and exterior temperature by slowing the rate of heat transfer between them thus requiring less energy to heat and cool the structure. The best insulation possible is a vacuum. This is because heat needs some medium through which to travel and a vacuum is essentially the absence of a medium. Everyone knows that a thermos can keep liquids hot for a long time and this is the reason why. It is insulated with a vacuum (in actuality it would not be a perfect vacuum).

This is the same idea behind VIPs. They are constructed from an open nano-porous material that is strong enough to remain intact under atmospheric pressure. The air is evacuated from the panel and then the whole thing is sealed in a gas barrier to prevent any air infiltration. It is essentially a portable, rigid container that holds a vacuum. In terms of performance it blows the competitors away.

Cross-section of a VIP

Cross-section of a VIP: The core is made from a porous material. (Picture from ref.)

The ability of a material to prevent heat loss is given by its R-value per unit thickness. Familiar insulation materials like mineral fibre or cellulose are less than R-5 per inch. VIPs can achieve R-values as high as R-60 per inch. This is incredibly high and anyone in the building industry would be very skeptical of such a number. However, that’s just the power of a vacuum.

So why haven’t we seen the widespread proliferation of this wonder-material? There are several reasons. Cost is the most prohibitive factor. VIPs are currently more expensive than the alternatives. However, the researchers at the NRC claim that once economies of scale kick in the cost will come down considerably. Another major issue is  uncertainty in the long-term performance of VIPs. The research has yet to establish how this technology degrades over time. They are certainly less robust than convention materials, as a single pinhole in the gas barrier will compromise the vacuum.  Nevertheless, it is a very promising technology and perhaps not too far away from more widespread adoption.

For the NRC paper on VIPs  see:

Mukhopadhyaya P., M.K. Kumaran, F. Ping and N. Normandin. Use of vacuum insulation panel in building envelope construction: advantages and challenges. May 2011. NRC-53942.

http://www.nrc-cnrc.gc.ca/obj/irc/doc/pubs/nrcc53942.pdf

-Erik Janssen

(Engineering Physics, MASc, Year 2 at McMaster University)


[1] Mukhopadhyaya et al.

Researchers at the University of Notre Dame are working on a novel one-coat solar cell paint that they claim is “sun-believable.” The concept may seem strange; ie. a solar cell that you can just paint onto a surface, really? When we think solar cell, the image comes to mind of a bluish-coloured square of rigid silicon lined with metal contact fingers and certainly not a bucket of Benjamin Moore’s “Burnt Sienna” with eggshell finish.  However, in both appearance and physical application, this solar cell paint may have more in common with the latter than the former.

So what does one do with solar cell paint? Paint it on your car or maybe your house? What about bus terminals, fire hydrants, public buildings, etc.? The possibilities seem endless but perhaps we are getting ahead of ourselves here. The researchers claim that this is just the sort of “transformative” technology that is necessary to bring solar energy generation into the realm of economic viability but it doesn’t appear as though they are speculating as to how this paint could be applied outside the realm of familiar solar cell/module processing.

The benefit of solar cell paint for standard solar cell processing seems to be that it uses relatively cheap materials and is straightforward to apply. It really is just painted onto a conductive surface in one coat with a brush, followed by a relatively low-temperature heat treatment. It’s that simple. The downside is that the efficiency of this solar paint is currently quite low (around 1%). However, that may just be indicative of the fact that there is still plenty left to optimize.

We’ll see where the technology goes but with a growing interest in solar-integrated green-buildings it seems at least somewhat possible that solar paint may have some role to play in tomorrow’s structures. We already have solar shingles… is solar paint the natural step forward?

(For a proper explanation of how this solar cell paint works please visit the original article: “Sun-Believable Solar Paint. A Transformative One-Step Approach for Designing Nanocrystalline Solar Cells.” Matthew P. Genovese, Ian V. Lightcap, and Prashant V. Kamat. ACS Nano (2011).)

-Erik Janssen

(Engineering Physics, MASc, Year 2 at McMaster University)

What are the top three things that most people hate about winter? The average list would probably look like this: (1) it’s cold, (2) it’s dark and (3) the driving conditions are terrible.

The cold and darkness are things we just need to accept. They are a consequence of the Earth’s tilt and our country’s latitude, neither of which are going to change.   However, one American inventor has come up with an eyebrow-raising  solution which he hopes will tackle the problem of icy winter road conditions…. and it also generates electricity.

At first glance, the invention proposed by Scott Brusnaw, an electrical engineer, seems to be a logistical nightmare. He suggests we turn our road systems into large solar photovoltaic (PV) installations integrated with LEDs, sensors, heating elements and other electronic devices to essentially create a “smart-road.”

According to his vision the road is a constructed of glass and is rugged enough to protect all the electronic components. It produces electricity, monitors road conditions, displays signals to drivers and it even heats itself to keep clear of snow and ice.

The benefit of using the road system as a power plant seems to be that it could turn an already existing structure into something with dramatically increased functionality and thereby potentially lessen land-use and construction costs associated with photovoltaics.

That is the basic concept. It may not be the first time someone has envisioned it. However, this case is unique in that now Brusnaw has been given the funding to actually try out a prototype of his design in a parking lot in his hometown in Idaho.

Will it result in a potentially game-changing technology? Is it doomed to failure? We’ll wait for the results but in the meantime one can’t help but both skeptical and intrigued by where such a technology could lead.

(Original article can be found at: http://www.theglobeandmail.com/report-on-business/commentary/neil-reynolds/no-more-snowplows-or-icy-roads/article2287667/ )

-Erik Janssen

(Engineering Physics, MASc, Year 2 at McMaster University)