While EV Battery Costs Decline, Repurposing Adds Life

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Cleantechnica has heartening news from the Bloomberg New Energy Finance report.  Battery prices for electric vehicles, a key factor thus far in keeping electric cars more expensive to buy than smoggier alternatives, are dropping, and somewhat quickly. “According to an April 2012 Bloomberg New Energy Finance report, the average price of batteries used in electric vehicles dropped 14% from Q1 2011 to Q1 2012. ‘The average price of an EV battery at the end of Q1 2012 was $689 per kilowatt hour, compared to $800 per kilowatt hour in 2011, according to that report. “Compared to 2009, prices were down approximately 30%. “By 2030, BNEF projects battery prices will fall to $150/kWh (in 2012 dollars).” The report explains, “Electric vehicles such as the Mitsubishi Motor iMiEV, Nissan Leaf or Tesla Model S require between 16 and 85kWh of storage, with a total cost of $11,200 and $34,000, or around 25% of the total cost of the vehicle.  Battery pack prices for plug-in hybrid vehicles such …

How Green was GFC Electricity?

Dean Sigler Diesel Powerplants, Electric Powerplants, GFC, Sustainable Aviation 2 Comments

The blog received several comments about the relative energy use of electric aircraft, and how NASA and the CAFE Foundation might have overstated the efficiency and low emissions for the electric aircraft in the competition. Reader Robert Swanson thought the conversion between kilowatt hours and gasoline created a discrepancy. “The discrepancy in performance of gasoline and electric powered aircraft is due to an absurd conversion factor between kWh and gallons of gasoline.  The conversion should be calculated from the number of gallons of gasoline consumed by the engine driving the generator used to charge the batteries.” Steven Crow added this objection.  “Even after reading the relevant pdf’s, it is far from clear to me how CAFE computed ‘mileage’ for the electric aircraft. The right way of doing it is clear enough: base the mileage on the fossil fuel used to charge the batteries.  Electric motors and batteries are not subject to Carnot efficiency limitations.  They can seem to be nearly …

CAFE News: Comparing Apples, Bananas, Oranges and Doughnuts

Dean Sigler Electric Powerplants, GFC, Sustainable Aviation Leave a Comment

One of the problems facing judges in the July Green Flight Challenge the CAFE Foundation is managing for NASA is that of determining fairly who gets the best fuel mileage.  Since “fuel” in this case can be traditional aviation gasoline, bio-diesel, electricity from batteries or solar panels, or some other energy storage medium, wildly different energy densities have to be taken into account. If TSA “freedom feels” seem intrusive, the scrutiny applied to GFC entrants and their craft will be even more onerous.  Aircraft will be impounded once inspected and registered, and the only contact pilots may have with their planes before taking off will be to “top off” their fuel tanks or batteries just before the start of their flight – all under constant monitoring. The widely and wildly differing energy densities for the different forms of motive power require careful definition of energy equivalencies.  One pound of gasoline, for instance, equals about 20,000 BTU, or 5.8 kilowatt hours, …