GENeco, an “organic waste solutions” specialist (AKA sewage treatment) company in the UK is bringing something new to the green table: a human-powered car.  The Bio-Bug is a VW Beetle converted to run on Compressed Natural Gas (CNG) which is a lot like Liquefied Natural Gas (LNG) only, well, less compressed as it remains in a harder-to-contain gaseous form rather than the denser and more commonly used liquid form.  Presumably the choice was made because the hardware to convert natural gas into LNG requires a cooling phase and more expensive equipment.  In any event, the Bio-Bug is essentially run on methane gas.  And where does that gas come from?  In this case it’s from cleaned-up leftovers from the Avonmouth sewage treatment plant of Wessex Water.

You see the Avonmouth plant normally produces CNG from sewage waste, which powers its “digesters” through a combination of electrical power and heat generated from, you guessed it, burning off the CNG surplus from the sewage.  It’s a brilliant idea as methane is a far more powerful greenhouse gas than carbon dioxide so should not be released into the atmosphere.  Burning it, turning it into carbon gasses instead, is far less harmful to our environment.  So using it in any way is a big plus, and where can you get more methane than from organic waste?  It’s not a new concept and in fact it’s a new trend to convert livestock farms to methane power.  But it’s nice to see it in action wherever possible and a sewage treatment plant is certainly a good place to use the technology.  Especially when there’s enough produced to also generate electricity to sell back to the grid, as is the case in Avonmouth.

But the thing is, even with all of that, Avonmouth still has a surplus of methane biogas, which would normally just be burned off before releasing it into the atmosphere to break down the methane into less damaging carbon gasses.  And that’s where GENeco has stepped in with their Bio-Bug.  With a little cleaning up of the excess CO2 naturally found in the biogas, the methane is converted into a cleaner burning fuel fit for automotive use.  And the Volkswagon Beetle, converted to run on CNG, is just the kind of vehicle to use it.

GENeco Bio-Bug - a human-waste powered car

Which all sounds brilliant and green!  It’s a great way to convert waste into a renewable resource, right?

Well, with a few caveats.  The first being that this isn’t really a carbon-free system.  It’s a good use of carbon that would otherwise be released into the atmosphere, carbon-shifting I guess you could call it.  It is not however carbon free.

The second caveat, one could simply replace the CNG cleansing and distribution with more electricity production for recharging electric cars, or even used to generate hydrogen from hydrocarbons through steam reforming to power hydrogen cars.  There are green paths here that are more synergistic with the modern green automotive trends that can be done at a big facility where as the typical farm cannot.

And the third caveat, and perhaps one of significant note, is that this is a process that does not equate to one car per household.  No.  It takes approximately seventy households to produce the quantity of CNG needed for one Bio-Bug.  It won’t work for every household to run their daily automotive needs, but it could be used in the fleet vehicles needed in the running of any facility.

So clearly, this is not a magic pill that could solve all of the world’s problems.  It is however a very interesting and creative approach to better utilizing the resources available to us, even (if not especially) the ones that we consider to be useless waste.  The smarter that we can innovate with these under-utilized resources, the better off our planet will be.  And the more intriguing the solutions are now, the more advanced and opportunities to replicate or even improve upon them will be in our future.  Sometimes being green isn’t just about the perfect zero-sum product, but about more efficiency with what we have.  If there’s one thing that we have a lot of, it’s poo.  So brown is the new green, and innovatively trapping, collecting, and utilizing methane gas will make for a better tomorrow, no matter how silly it might seem to drive a poo-powered car.

Some German and Australian scientists have been working on a project to revolutionize renewable resources.  They have found a way to make synthetic “natural gas” from carbon dioxide (CO2), water, and electricity, much in the same way hydrogen can be produced from water.  Dr Michael Specht of the Zentrum für Sonnenenergie- und Wasserstoff-Forschung (Solar energy and Waterstuff [Hydrogen] Research center – ZSW) explains:

“Our demonstration system in Stuttgart splits water using electrolysis. The result is hydrogen and oxygen.  A chemical reaction of hydrogen with carbon dioxide generates methane – and that is nothing other than natural gas, produced synthetically.”

And the process they currently use will supposedly will scale up remarkably well.  Plans are to create a double-digit megawatt-range unit by 2012 to prove that it really can be done, and to provide homes with synthetic natural gas.

Brilliant!

Err … maybe.

The thought behind it is that electricity is a somewhat wasteful system as during lulls in usage the generation has no useful way to store large amounts of energy for when the peak usage times hit.  This is especially a hindrance to renewable green sources of electricity like wind and solar where peaks of energy production rely upon the timetable of Mother Nature and not upon peak usages by mankind.  Where as converting electricity into natural gas allows one to store a lot of energy created during lulls to take the load off during peaks.

Colleague Dr Michael Sterner explains, “Surplus wind and solar energy can be stored in this manner. During times of high wind speeds, wind turbines generate more power than is currently needed. This surplus energy is being more frequently reflected at the power exchange market through negative electricity prices.”

Plus there are other theoretical benefits, like the ability to modify vehicles to run on Liquid Natural Gas (LNG) which is just a compressed form of natural gas that turns it from a gaseous state to a liquid state.

Which is all well and good.  In theory.

One might want to remind the world that we can however already do this with hydrogen.

And then there’s the conversion efficiency, which is only 60% efficient.  Where as processes like just pumping water up higher into a dam to store as potential energy for a hydroelectric plant are more than 70% efficient.

But the largest concern would be that according to the Environmental Protection Agency (EPA) methane gas has a Global Warming Potential (GWP) of 21, meaning that methane is twenty one times more effective as a greenhouse gas than carbon dioxide (CO2).  So while proponents of synthetic  natural gas try to tell you that their methods are carbon-neutral, thus not harming our environment any more than it is saving it, this is not necessarily the case.  Any of their synthetic natural gas going up up and away is far more damaging to the environment than CO2.  Where as hydrogen isn’t.

But then one of the main problems with hydrogen is that, being the smallest atom, it escapes easily from systems that try to hold or transport it.  Where as methane, a much larger molecule, has no such problems.

So then, is it really such a great idea?  Yes, potentially, it holds a lot of interesting promise.  But then so does generating hydrogen from electrolysis.  Where as, potentially, it also holds a number of potential concerns, where as generating hydrogen from electrolysis doesn’t.

It’s certainly something to think about, and goes to show that when we put our heads to it, we can come up with all manner of interesting solutions to any problem.  And that it is likely a combination of efforts that will solve the world’s woes and not any one singular invention or ingenuity.

If you’ve been wondering where our solar cells are and why they’re not just everywhere yet as the green revolution churns onward, there’s a reason for that.  So far their construction still requires all manner of expensive rare materials such as silicon and cadmium.  And because of the way that they’re manufactured, silicon panels grown in vacuum, they’re just plain expensive to produce.  So as much as we’d like to see a solar renaissance, where we finally go from wow to now, it’s just not happening.

But all that may change.

Researchers at IBM think that they’ve hit the next best thing since sliced silicon: “High-Efficiency Solar Cell with Earth-Abundant Liquid-Processed Absorber”  It’s a completely new take on producing solar cells, based primarily on more “earth-abundant” materials such as copper, zinc, tin, selenium, and sulfur in a chalcogenide compound.  In fact, unlike silicon-based photovoltaics which have to be grown in a vacuum, these materials can just be sprayed on.  They’re applied in a slurry state, so spraying, dunking, printing, spin-coating, or what have you can be done to apply them to the solar cells.  So not only are the materials more friendly and available, but they’re applied in a process that is much cheaper and easier to manufacture.  And because they’re basically painted on, they can be applied to all sorts of shapes that would cause traditional solar panels to shatter if attempted.  The next paint job on your car or house might be “High-Efficiency Solar Cell with Earth-Abundant Liquid-Processed Absorber”.

The only downside is that so far the efficiency rate is only around 9.6 percent.  That’s a bit shy of today’s silicon-based photovoltaic efficiency between 10 and 15 percent.  Though researchers do like to point out that the technology is still in an early phase and efficiency may improve as the process is refined.  And still, for the price and theoretical availability, what one lacks in efficiency one can easily make up for in volume.

But Big Blue isn’t the only horse in this race.  Researchers from the California Institute of Technology in Pasadena have made their own headway in a new photovoltaic direction: silicon wires.

In a new paper published in Nature Materials entitled “Enhanced absorption and carrier collection in Si wire arrays for photovoltaic applications” is described an entirely new process of solar absorption using arrays of 1mm thick silicon wires to create a flexible polymer.  This is a markedly different direction from the normal use of silicon in solar panels.  It uses far less material, a mere 1 percent of the silicon needed for traditional solar panels.  And yet in spite of the incredible reduction in the amount of silicon used (or perhaps because of it) panels made from these silicon wires have been measured at 17 percent efficiency, blowing away the competition.

What’s more, the bundles of silicon wires absorb solar energy “over a broad range of incidence angles“, meaning that they don’t need to be adjusted for optimum absorption nearly as often as traditional solar panels.

And just as amazing, because these panels are made from bundles of silicon wires, they’re flexible.  So not only are they much less likely to be damaged from things that would normally ruin the traditional brittle silicon panels, it’s a technology that would be easy to adapt to locales that aren’t traditionally flat, such as car roofs, or even the curtains in your window!

With the incredible savings and improvements in manufacturing that each of these new solar technologies offer, we just one day may find photovoltaic solar panels common building materials available to every home.  And with the flexibility that they offer, solar energy just may make the jump from small electronics and home panels to … everything and anything.  What a wonderful world it would be.

Researchers at Rochester University in New York have found a nifty and easy way to improve the incandescent lightbulb.  All that it takes, actually, is a quick zap (a femtosecond-long pulse) with an extremely high energy laser.  The burst of intense light travels through the glass of the bulb and into the tungsten filament (that wire that makes the light happen) causing a complex series of nano-scale and micro-scale structures to form on the surface of the filament.  This makes the filament more efficient, on an order of approximately 40%.

The handy thing is, any production facility could easily add this extra lasering step into their manufacturing line, automating the efficiency improvement with nary an effort.

The less-than-stellar problem is however that not only have greener compact-fluorescent lightbulbs been around forever now, practically replacing all incandescent use in many businesses and homes, but even LED lightbulbs with a much higher order of magnitude in energy savings, yet at a price point similar to compact fluorescents.  One wonders then where the actual benefit of these new green incandescents may be.

Still, there are a lot of people slow to uptake on the greener lightbulbs.  So if green incandescents can reach the shelves at the same price as the energy-wasting incandescents, the technology possibly could still do quite a lot of good.

As I explained before, while electric cars may be the green machine of the future, it is the battery technology that keeps them from replacing standard gasoline automobiles today.  Well, the battery, or the hydrogen fuel cell, which is actually just another type of battery – the same as a lithium-ion battery – to power an all-electric car.  The only difference is that hydrogen fuel cells are “recharged” by adding back in the spent hydrogen where as normal batteries are recharged by adding back in the spent electricity.

The thing is, while we have electrical lines, well, everywhere … we really don’t have hydrogen recharging stations much of, well, anywhere.  In the US they’re pretty much all in California, which is rather inconvenient if you want to own a hydrogen fuel cell car in Wisconsin.  And even if the technology can all be worked out and commercialized in the near future, it is this lack of an infrastructure that really puts hydrogen in last place in the green race.  Even the Obama Administration is now on that page.

So what is a green car manufacturer to do?

Develop better batteries!

Enter two new contenders for better batteries, adding options 4 and 5 to the superbattery list:

Option 4 – Lithium-Sulfur Batteries:

The first is Scion Power Corporation and their Lithium-Sulfur (Li-S) battery technology.  They’ve been puttering around with the idea for a while now.  In theory it holds great potential as it has a much higher energy density (stores more power in the same size battery) than the standard old lithium-ion technology we’ve been using forever.  Their last generation Li-S batteries can hold 350 WH/Kg.  Their newest generation Li-S bring the density up to 450 WH/Kg.  (Compared to Li-ion’s storage capacity of 150 to 200 WH/Kg.)  As you can see on their webpage, when packed into a Toyota RAV4 EV, using the exact same volume for their Li-S battery pack as the Li-ion battery pack they replace and less than half of the weight, they can expand the measly Li-ion’s 27kWh battery capacity to 70kWh with Li-S.  This takes the electric range from 81 miles to a whopping 226 miles!

The downside?

Scion Power Corporation has been having difficulty with the recharge cycles, able to only squeeze out 150 to 200 recharges before the batteries become useless.  To that end, they’ve gone into a partnership with BASF to co-develop the Li-S battery, hoping that BASF’s chemical expertise can uncover a way to the expand battery life in a commercial production line of Li-S batteries.  How soon this partnership can crack the battery life problems is anyone’s guess, but the Li-S technology holds great promise.

Option 5 – The St Andrews Air (STAIR) or Lithium-Oxygen (Li-O) Batteries:

Across the pond in Scotland at the great St Andrews University, Professor Peter Bruce and his team of geniuses had a brilliant idea.  Rather than load a battery full of every chemical needed for the discharge-recharge process, why not use a re-agent readily available in nearly every environment?  And so they sought out to use oxygen as the re-agent, saving loads of weight from the battery, thereby creating the Lithium-Oxygen (Li-O) battery.

As the Li-O battery discharges the lithium ions from the electrolyte combine with drawn in oxygen to form Li₂O₂.  And as the battery is recharged, the lithium ions free the oxygen molecules back into the air.  And so, because of this use of oxygen from the air instead of extra chemicals in the battery, the power density is astounding.  The in-lab estimates for the technology are around 3050 WH/Kg, nearly 20 times the storage capacity of a Lithium-ion battery.

The technology does, of course, have a few minor caveats.  In that it takes in oxygen to work, this would not exactly be suitable battery technology for space use, or likely even submarine use.  (Vehicles would however be fine.)  And because it puts out concentrated oxygen as the batteries recharge, it might be a bit dangerous without good ventilation.  It’d be a shame if your shiny new electric car blew up because it had filled with concentrated oxygen, a highly ignitable and explosive invisible vapor.  But, again, simple ventilation to circulate the air would save the day.

The other dilemma for the Li-O superbattery is that it only exists in a labratory so far.  Commercialization could easily take another five years.  But the potential in energy density is so astounding compared to the standard Li-ion batteries that we use now that I don’t see where anyone would have a problem jumping onto this idea to make it happen.  Where electric cars using Li-ion batteries could have ranges of 200 miles per charge, electric cars based on Li-O batteries could have ranges of 4000 miles per charge.  That would right solve anyone’s range limitation problems with an electric car.

Conclusion:

As time marches on it is becoming more and more clear that not only are hydrogen fuel cell cars becoming a pipe-dream for electric cars, but that new battery technologies may well far exceed any potential that hydrogen fuel cells could ever offer the automobile.  The potential to create an electric car that really can recharge in the time it takes you to fill a gas tank is there.  As is the potential for an electric car that fan far outdistance a petrol or diesel car between refills/recharges.  And, of course, electricity is cheaper and less polluting than fossil fuels and readily available anywhere you go.  As the enthusiasts, universities, and goverments push harder and harder to advance battery technologies in an effort to go green the nails keep pounding into the coffins of both hydrogen fuel cell and petrol-powered vehicles.  The superbattery is now just around the corner.  Are you ready?