These are videos I've stumbled upon about interesting renewable tech while researching for the blog. Some new, some old, some strange. Enjoy!
The Gulf Stream and Its Link to Climate Change
Professor Jennifer Francis of the Institute of Marine and Coastal Sciences at Rutgers University explains how the gulf stream has recently been slowed at times and how that relates to global extreme temperatures. -added 6/9/2013
Solar Updraft Tower
Solar updraft technology is completely passive, relying only on the temperature differential between hot desert and high altitudes to pull wind through the tower. Low costs and zero inputs make this a very promising technology just coming to market. -added 12/12/2012
Gemasolar: 24hr Solar
Thermal solar in Spain stores heat in molten salts to keep it running 15 hours after sundown. An exciting and upcoming technology shown clearly with excellent and simple graphics. -added 10/15/2012
Thermal solar is a cutting edge way of doing the old-fashioned chore of boiling water to push a turbine. The Gemasolar plant in Spain's Andalucia province differentiates itself by storing heat in molten salt to keep the turbine going at full speed 15 hours after sundown. This almost completely eliminates what is probably the biggest drawback of solar: its intermittency.
Summary
A very cool and upcoming technology shown clearly with excellent, simple explanatory graphics.
Here are some TED Talks related to green energy that I found interesting. Click in to the link to see a full breakdown of each talk and watch the video.
David MacKay: A Reality Check on Renewables
This theorist and computer scientist puts in perspective the amount of land we would need to devote to renewable energy to satisfy our energy needs.
Donald Sadoway: The missing link to renewable energy
MIT's Donald Sadoway gives an interesting sermon on one potential future for large energy grid storage, liquid metal batteries, with great delivery and comic effect.
Donald Sadoway, a chemist at MIT and entrepreneur, does a good job drumming up interest in this technology. Although not entirely an original concept, he frames the liquid metal battery as his own creation and explains how it can be easily scaled and used for grid energy storage to offset the intermittency of renewable energies such as solar and wind. He hits on a lot of points and explains the battery well, but fails to put it in context in the market. The only characteristics that decide whether this battery will successfully change the game as he predicts are price and energy density. He mentions that it is "designed to the market price point", but does not elaborate on this at all in comparison with the lithium ion competitors that currently rule the world. If you look around the web, there are hints that they may be cheaper and have more capacity, but mostly in relation to the currently in-development "cold" liquid-metal version for use in electric vehicles. See more about these batteries.
Summary
All in all it's an interesting topic from a good speaker with too little context. Enjoy!
Although he breaks fusion power down quite well for the average non-nuclear physicist, the rest of the video is relatively uninformative. He basically says that we need it, and soon (and we don't mind blowing up France in the process). As always, fusion is referred to as "about 30 years away", but what I didn't know and found very interesting is that we have actually created fusion reactions in the past.
JET labs created a fusion reaction in 1997, but it is not explained clearly how this is not capable of providing energy in the form of a power plant. The French fusion reactor ITER that is currently in development is, according to their wikipedia page, is on track to produce 500 megawatts of fusion power from a 50 megawatt input by 2019, but only for a short burst. This seems like a great ratio, but the 500 megawatts of fusion power cannot be directly translated into electricity, and in the case of this experiment will just be dissipated by heating water to steam.
The final step in the process will be to make DEMO, an actual demonstration of fusion power being converted into electricity using the thermal energy produced to turn turbines. DEMO will attempt to produce 2000 megawatts of fusion power continuously, translating into a measly 2-4 megawatts of electric power by the 2030's.
The final step will be to create PROTO, a commercial demonstration of fusion power, by sometime around 2050.
What is most interesting about this is that it seems the process is already underway, the main issues have been ironed out, and all that remains is basically just building it. Unfortunately, he didn't mention anything about this in the speech.
ITER's website has a lot of information on fusion and shows clearly where they are in the building process.
Summary
He is right to say that fusion would be great, but with very little relevant information about when it will be useful and what the current pitfalls are the speech falls flat.
TED talks can sometimes be very high-minded with little substance or application, which is why I particularly liked this one. David MacKay delves right into the fact that fossil fuels can already be discounted as a permanent solution, and we have to pick its replacement(s) carefully.
He takes on some popular energy sources, such as biofuel and wind, and shows that to continue life at our first world level we'd basically have to be surrounded by wind farms or have our own biofuel farm. Although this may sound shortsighted with the technology constantly moving forward, it puts into light the reality of how much we expend and the limited land available for production.
My only problem with this speech is it getting sidetracked by ways to reduce consumption. I do agree that this is important, but pick a topic and run with it.
Summary
Although the silence surrounding his jokes can be a bit unnerving, David MacKay does a great job breaking down a very important aspect of converting the world economy to renewable energy sources: land use and the efficiency of each green technology.
