Recent Comments:
Lane splitting in California - for or against? {Autoblog Green}
Mar 18th 2008 11:24AM Riding and lane-splitting furthers my pro-environmentalist and motor-enthusiast interests.
2008 Shell Eco-marathon coming in April; will anyone best 1902 mpg? {Autoblog Green}
Feb 29th 2008 2:11PM "harvick"
CarChip E/X: a great gadget to teach green driving {Autoblog Green}
Sep 18th 2007 5:43PM acceleration and speeding, sure: but what does braking - either hard or soft - have to do with fuel economy (assuming you don't accomplish your deceleration by downshifting)?
The Chrysler Patriot hybrid drive Le Mans racer from the mid-90s {Autoblog Green}
Aug 7th 2007 7:43PM I believe this series hybrid concept of a turbine/ICE genset with flywheel power storage and some battery energy storage remains the best design for the efficient use of fuel (or as a PHEV: just add more batteries). Given more recent advances in flywheel magnetic bearings, composites, and controllers there is no reason this propulsion system cannot be inexpensively mass-produced as it uses no exotic materials (as the Rosen brothers tried to point out). It is certainly the most efficient means to recapture brake energy and provide superior acceleration, and it is relatively light and compact and extremely low maintenance. Sadly, it seems only a couple of DARPA projects may currently be working toward development of this system, although perhaps Formula One's kenetic energy recapture rule adoption may spur practical applications.
Reader Essay: The Origins of Power - cellulosic ethanol vs. solar {Autoblog Green}
Jun 25th 2007 2:01PM I appreciate the article, which works to quantify a fairly obvious observation: purpose-built devices (here, solar energy collectors) are more efficient than non-purpose-built devices (here, plants). But for a complete analysis, raw energy production is not the end as 3 factors must be considered: 1. producer capital cost; 2. user capital cost; 3. secondary impact.
Producer capital cost includes land use, system creation, and infrastructure. Re land use, non-algae biomass requires the use of arable (if sometimes marginal) land, while solar may be placed in non-arable land - advantage, solar. System creation in very labor intensive for both, but more so for solar: on the other hand, while droughts will diminish biomass, regular natural events (major storms, etc.) will destroy solar - advantage, biomass. Re infrastructure, we would need biomass refineries but have existing liquid fuel distribution, while for solar we would need greatly improved grids - advantage, neither.
User capital cost is simpler to analyze: for biomass we use existing and improving vehicles, but for solar/electrical there are no sufficient stores of known battery raw materials (lead, nickel, lithium, zinc) to provide for hundreds of millions of battery-powered cars, and electrolysis-hydrogen-fuel cells would be tremendously expensive - huge advantage, biomass.
As for secondary impact, regarding biomass consider the use of arable land, water usage if irrigation is necessary, the disruption of ecosystems, and the production of oxygen, while for solar consider the disruption of ecosystems, the need for metal raw materials, and the perfectly carbon-neutral nature - advantage, neither.
In sum, both biomass and solar would require a great deal and commitment and capital, but for solar the deal-breaker is the lack of batteries. (While I have long been an advocate of flywheels, they would work wonderfully in hybrid-electric vehicles for power storage but they are not sufficient for energy storage.) Therefore, biomass cellulosic ethanol (switchgrass, poplar, whatever grows happily) and algae biodiesel, to be run in efficient hybrid-electric vehicles, is the way to go unless/until there is a heretofore unknown remarkable breakthrough in portable electrical energy storage.
