22. The Tracked Energy - Harvesting Energy from beneath the tracks.

Don't know if the Japanese have thought of this already,(besides I am tired of researching to see if this is already done in the Shinkansen while I struggle to meet my daily quota ;) ) but I am sure that there is a lot of vibrational energy beneath the tracks and sleepers allowing for a harvesting setup that independently provides some chance of recovery.

After trying to look up energy recovery through hydrodynamic damping, I thought piezo maybe the way to go and found this piezo-generator very useful for a back of the envelop calculation!

http://www.piezo.com/prodproto4EHkit.html

Extract :
Piezo Energy Harvesting Circuit
The self powered Piezo Energy Harvesting Circuit collects intermittent or continuous energy input from the piezo generator and efficiently stores their associated energy in an on-board capacitor bank. During the charging process, the capacitor voltage is continuously monitored. When it reaches 5.2V the module output is enabled to supply power to an external (user) load. At this point 55 mJ of energy are available. When generator energy input is high, the output voltage remains ON continuously. Capacitor voltage is clamped at 6.8V. If external power demand exceeds generation, the output voltage decreases. When the output voltage drops to 3.1V, power to the load is switched OFF and is not turned on again until the capacitor bank has been recharged to 5.2V. The circuit accepts input voltages from 0V to ±500V AC or DC and input currents to 400 mA.

So what will a possible system look like if  more energy is to be harvested - 

and how much energy is available ?

Here's a back of the envelop calculation - 

The piezo is about 3 inches (7.62 cms) , which allows us to lay 13123 pieces per km, which means about 9.8 (say 10) million pieces below the entire track length (presumed here to be 750 kms including the maintenance and shunting yards). Multiply this by 4 (because you will have at least 4 rails for 2 tracks one going up and the other down) you have 40 million pieces capable of generating-

40 million x 55 mJ = 2,200 million mJ or 2,200 Mega Joules

Now, Joules per second is Watts , so the potential is 2200 Megawatts!!! or am I dreaming again with my time integrals?

Ah! I know my wise friends will scream "cost", like the proverbial Faust, as they would have scrolled to the bottom of the above link and found the cost per piece for a quantity of 100 pcs to be $ 349, and adding another $50 for the system we round to say $ 400 then, we have $ 160 Million as investment for harvesting this energy!!

My experience with component level costing tells me that this price should fall to 1/2 or even 1/3 of the price indicated at 100 pcs when production is ramped to a million pieces and more importantly it is "Make in India" - I know one company that is capable of this in India, but are they watching, its anybody's guess.

In the end, this need not be under the track, it can be under the sleepers, it can be under the thrust pads of the bearings on some of the pillars and also, it can be thoroughly tested to full implementation before the second leg of the bullet train is operationalised anywhere in India or the world!

13. Energy in the Wake - Use of micro-mini windmills

Being a student of Visvesvaraya (National Institute of Technology), the thought of harnessing energy at a micro level never ceases to amaze me!

Therefore like the idiot that I am I thought I could fill my quota of the day by looking at regenerative braking only to be prevented by a decades old presentation on "High-Speed Rolling Stock- Japan", where curves are presented of how much energy is recovered !!

Refer link for details -
High Speed Rolling Stock - Japan

Tough guys, these Japanese, I say!

So I prayed to Lord Visveswarayya, and lo and behold is the idea of the day -

At 320 kmph , average speed there should be enough wind velocity in the wake of every bullet train to harness the energy in into a 5-50 KW wind turbine (the wind velocity is going to be huge!!) like the one shown below-

( i didn't get better picture in Images section of Google for my idea, but I think you will get the drift! the actual configuration will be longer, shorter and more like an aeroplane turbine!!)

Putting one turbine at every length +10 meters of a train and with a train passing every 15 minutes, we are looking at some generation potential - i would think about 0.5-5 MW capacity and i could be off by orders of magnitude.(I am very bad at these phasor calculations where one needs to integrate areas under peak capacities and zero capacities over defined time intervals!!)

Very small capacity in terms of teh gigawatt plans of the nation, but with eddy dissipation and staggered configurations, this will keep a host of engineers busy studying the aerodynamic profiles in the immediate wake with a lateral shift of say 1-3 meters!!

11. Water Conservation - Re-cycling cleaning water during maintenance

Given that we already have talked about the toilets being airplane like, we would presume that the trains would be washed everyday!

Naturally, one presumes that all water would be re-cyclable, because we do not expected sewage spill anywhere on the lines.

Also the storm water drains would gradient themselves into natural aquifers around the maintenance depots marked in the map taken from Wikipedia below!

Should we set a metric for recycling the amount of water used in cleaning for the entire project at 99%, so that apart from evaporation losses we don't lose treated water to inefficiency and also safeguard ourselves during drought times !! 

8. Windows - What should they be made of ?

In August 2015, I had written an email to friends and my erstwhile organisation about some exciting developments in the field of solar cell materials.

I think the opportunity to use such a material on the window of the bullet train is too good a opportunity to miss given that this area is going to be exposed to sun quite a lot!

Please read the note written then and imagine for yourself how this would play when such material is used in the windows.

Energy from renewables

Also see a comparison of costs of fossils fuel consumption in the referred spreadsheet which is also linked here for your review!

Sample calculations on renewables