Today, Tuesday, Gary and I joined Boomer at "Driving Mobility 4" the 4th annual advanced transportation symposium held at UCI. Biggest disappointment: Almost no questions taken from audience. What I found interesting/important:
Fast Charging: EVgo spokeswoman reported their net cost of electricity for some 400 evGo fast chargers stations has been $2/kWh, due to demand charges and low usage at many of these stations. However, recent inceases in usage (more kWh) has reduced this to $1/kWh. Bills have been introduced in CA state legislature to create special demand-free tariffs for public fast chargers.
There was no acknowledgement of the leadership Tesla has shown in this area. Of course their demand chargers are high, but their utilization is much higher, so the demand charge per kWh is much less. They have the efficiency of sharing 2 hoses per charger, with a slow charging car near full balanced with a fast charging car near empty, and large groups of chargers, now as high as 18 stalls in one location. In rural areas with low utilization, they have installed batteries to smooth out the demand.
RNG: Renewable natural gas, basically bio-gas. By capturing methane from manure, etc, that would otherwise be vented to the atmosphere, and cleaning it up to pipeline standards, this fuel can claim a negative carbon footprint. A company in Hemet, that has large contracts for collecting household garbage is building a big digester facility to produce RNG. A company backed by T Boone Pickens has built many truck fueling stations across the country to facilitate the conversion of the truck fleet from diesel to methane, which can be either natural gas or RNG.
Fuel Cells/Hydrogen: Honda reported on their Clarity, which now has 3 versions: all-electric, natural gas, or hydrogen fuel cells. The electric version, just introduced this Spring, has a range of only 80 miles.
First Element Fuel, a company building hydrogen fueling stations, reported that they are abandoning high pressure gaseous H2 in favor of liquid H2. The development of affordable, light-weight 5000 psi tanks made GH2 practical, but it has problems: the dispensing station must have refrigeration to mitigate the heat buildup as the high-pressure tank in your car fills, and there is lots of residual gas left in the dispensing tank. They didn't mention the safety issue of the very high pressure. The cost is high, $30/kg.
Boomer asked me: doesn't the physics say that more energy is required to liquify H2 than just compress it? Yes, of course, but there are inefficiencies. The boiling point of liquid hydrogen at one atmosphere is -297 C, 24 K. From DOE, sparing lots of interesting details:
DOE Technology Validation Project data for compression from on-site H2 production is 1.7 to 6.4 kWh/kgH2. The minimum theoretical energy to liquefy hydrogen from ambient (300 K, 1.01 bar) conditions is 3.3 kWh/kg LH2 or 3.9 kWh/kg LH2 with conversion to para-LH2 (which is standard practice).
Actual liquefaction energy requirements are substantially higher, typically 10-13 kWh/kg LH2, depending on the size of the liquefaction operation [5,6]. Novel liquefaction methods such as an active magnetic regenerative liquefier may require as little as 7 kWh/kg LH2
LH2 production benefits from the existing large volumes necessary to support the space program, with costs of $3/kg. Similar dramatic improvements in very well insulated LH2 tank technology now make LH2 practical for cars, It is easy to pump the liquid without high pressure. Counter-intuitive, but no refrigeration needed at the dispensary station. One downside they did not mention: eventually the pricey LH2 you filled your tank with is going to boil off if you let it sit in your garage. A refrigerator that operates at these temperatures would be very expensive. Most low-temperature physics labs that work with liquid helium just buy it as it boils off because it is too difficult to refrigerate.
The session on Autonomous Vehicles was disappointing, because the speakers were only doing Connected Vehicles. They talked about smart signals that would talk to cars and buses, and perhaps getting cities to invest in this gradually, a few corridors at a time, but I heard no cost estimates. SPAT is buzzword, transportation's.org, Transformational Mobility System is UCI buzzword. Obviously big infrastructure opportunity here, if anyone in Washington cares, but the speakers were expecting local and state support.
Fianally, two very young looking dudes (UCI students) talked about their entry in the HyperLoop competition. They got points for doing air levitation like Musk proposed, vs others using magnetic levitation which has eddy field losses. UCI is building their own test track so their entry in the competition coming up will have been tested.
LEAF Ocean Blue SL, "100 % Electric" decals, Delivered June 3, 2011
Sold June 2014 27K miles, 18% capacity loss, 1 bar, 5.0 mi/kWh.
Solar 4.6 KW DC with both string and micro-inverters.