The numbers are in, the report is out: Haters still wrong. (pdf)
In a previous post, I noted the (bogus) talking point that “electric vehicles just trade tailpipes for smokestacks.” But the math is clear. Electric drive is such an efficient way to roll that overall energy use is way down versus a gasser. And by “gasser,” I’ll include Diesels, since overall Diesel efficiency (pump-to-wheels net yield) is just ~20%, with ~14% for Otto-cycle (gasoline), versus 60-80% for electrics.
To pile on further, the grid isn’t as dirty as it used to be, and getting better every year (including this one). EVs aren’t “coal burners”, since for 2012, coal as a portion of the national power grid kept falling, going below 40%. Major fractions of the grid portfolio are natural gas, nuclear, and hydroelectric dams.
Installed Capacity % of Total Capacity
Coal 337.31 GW 29.17%
Natural Gas 491.82 42.48
Nuclear 107.01 9.24
Oil 41.32 3.57
Water 98.12 8.47
Wind 57.53 4.97
Biomass 15 1.30
Geothermal Steam 3.7 0.32
Solar 3.9 0.34
Waste Heat 0.69 0.06
Other 1.04 0.09
Total 1157.86 100.00
FERC industry report for Dec. 2012
There’s been a lot of talk about natural gas, since fracking has led to low prices and lots of new gas-turbine generators. And yet, the fastest growth for 2012 was in wind- again. For multiple years now, installation of wind turbines has outpaced every other additional source of electricity. That’s right, even with all the natural-gas hype, it still didn’t catch windpower’s growth rate.
Wait a minute- who messed up a standard 3-prong?
The cross-compatible NEMA 6-20R can accept a 6-15 or 6-20 plug, for currents of 15 amperes or 20A, respectively. This is exactly how a NEMA 5-20R has a T-shaped slot, for both 5-15P and 5-20P. NEMA 6 runs at 240 volts, however, not 120V. To keep people from frying things trying to jam in 5-x plugs, a 6-15P has two horizontal blades. The 6-20P, then, has one vertical (left), one horizontal.
So the currents are the same between NEMA 5 and 6, but voltage doubles. Power then doubles, at 2.88 kW, sustained (6-15) or 3.84 kW sustained (6-20). An electric car, charging overnight (say, 9 hours) would then fill a 23-35 kWh battery pack, for 68-150 miles of range. Since cars (but not my Zero) prefer 240V, this is a fine standard, as long as it’s common and widespread. So where do we find 6-x outlets?
These sockets are sometimes found in small shops, including home workshops, but the killer app turned out to be… motels, SCORE! The heater/AC units in the average motel are juuust powerful enough to ditch NEMA 5 for more power, and NEMA 6 worked nicely. Like a dryer, a dual HVAC unit can draw serious power for heating elements, which merits 240V. EV enthusiasts have run cords from their rooms; a motorcycle might even be wheeled into a ground-level room.
Yes, winter is upon us. The white stuff is falling, and the coarser white stuff is too. I’ve laid up the Zero for the season. No special accommodations are necessary; the EV battery will sit there just like a regular bike’s battery. If the winter turns out to be long, then it would be good to top up the battery sometime mid-season, just like a conventional, lead-acid car/moto battery. The one caveat here is that we’re told not to charge a freezing battery. The manual says freezing, which one would assume to be 32 F. I’ve also heard 20 F; I don’t intend to push it either way. There’ll be at least one day, even in midwinter, where the air temperature is obviously and consistently above freezing. If I really want to be sure, I can bring it inside, or at least roll the bike up to the dryer vent. (This freezing thing wasn’t a problem, even pre-salt. The pack retains heat from riding, then warms slightly in charging. So I would plug in when I got home even at 31 F or 19 F or whatever.)
Not snow… not salt grains…
Growing up in the Midwest, some people had “salt cars.” Old but functional cars for use in winter, while their nice one stayed salt- and slushball-free. You don’t see that as much, with modern materials. The thought crossed my mind again, though. Right now I’m split between public transportation, and biking/hoofing it. But my bicycles are due for a good amount of annoying work, and flu season is supposed to be brutal. So…?
For winter-only purposes, an electric car doesn’t really make sense. Having a battery pack sit unused (Summer or Winter, or whatever) is throwing money away. If you’ve spent the extra money upfront, that pack needs to be rolling, to earn its keep via fuel savings. Not using it enough means not saving. What about… ethanol, propane, or natural gas? Continue reading
Another significant anniversary: the Mars Exploration Rover-B (“Opportunity”) has been on that cold planet for ten years now– count ’em, a decade. That’s especially significant when you consider the mission was 90 days. Count ’em, the rover has outlived its design by more than a factor of 40. By “its design,” I technically mean the failure criteria; most people privately guessed the rover would last at least 91 days. But if it didn’t, someone would be penalized, after an investigation of some sort. You can think of 90 days as the rover “warranty.” Cars typically keep on going right past their warranty expirations… two or three times.
You may be asking about that other rover. Spirit (MER-A) is long frozen, though well past its mission criteria. It lasted over five years- no slacker by any standard. The Martian nights cause freeze-thaw cycles, which are bad for electrical connections and poorly-designed mechanisms. On shorter scales, one big freeze may pop something. Spirit, stuck in a sand patch and unable to bask in a Sun-facing direction, simply lost something over the Martian winter. This is despite RHUs (Radioisotope Heater Units). Many spacecraft carry little pellets of radioactive metal. Heat from the radioactivity pretty much guarantees a little thermal power. In this case, the RHUs simply couldn’t keep up.
And yet, both Spirit and Opportunity succeeded outright, and in principle. We flattered them with an imitation, MSL. A smarter, sharper, more incisive rover. And its bigger body should retain heat better through temperature swings; the mission location (Gale Crater) seems to have milder temperatures anyway, possibly due to a bowl shape retaining heat. One project member estimates over a decade of mission, perhaps fourteen years. Of course, that would still include stationary operations, if the electronics survive but the wheels grind still or something. Let’s find us a something.
When the standard for dryer plugs was revised in the ’90s, another connector besides NEMA 14-30 emerged: NEMA 14-50 for electric stoves/ranges, replacing NEMA 10-50. Cooking can reach higher temperatures, so that standard was given more current. As NEMA 5-20 is more powerful than 5-15, so too is -50 versus -30 (the current rating, in amperes). Yet, the pinouts look broadly similar, hence the “14” stays.
This is it- the most powerful outlet preinstalled in homes, possibly including your kitchen right now. Bonus: RVs often have refrigerators, ovens, etc., or just a lot of little stuff. The 14-50 is thus seen in RV parks, giving shore power to the bigger models. That’s right- this powerful, standard connector is already along our highways, including (especially!) rural roads. There are over 10,000 RV parks, making them the focus of cross-country EV trips.
14-50 boasts both 240 volts (reducing transmission and charging losses versus 120V) and high current (50A peak, but 40A sustained is more relevant to us). All told, this is 9.6 kW sustained, or over six times more power than household 5-15 (120V x 12A, or 1.44 kW sustained). Few electric vehicles can even take this; most top out at 6.6 or even 3.3 kW. But if yours can, an eight-hour overnight charge for a car (3-5 miles per kWh) means 210-380 miles of driving. Assuming your pack doesn’t “fill” in just two or three hours, that is.
Two quick notes. I mentioned that BMW was known for their engine prowess, and is not taking electrification lightly. I also mentioned that North American dryer plugs can actually give more power (5.7-7.2 kW) than many car chargers can intake (often just 3.3 kW). Well, what does Honda have to say? Here, Honda is usually known for sensible, well-built cars in the “bread-and-butter” segments. In its home market, though, Toyota and Nissan are the big boys, while Honda is the stepchild. Its reputation is largely based on advanced technologies; Toyota is considered the quality leader.
For its electrification efforts, Honda is a little behind, but far from out. First is the Fit EV, an electrified compact in the manner of the Ford Focus EV. Like that conversion, the Fit EV is aimed squarely at the Nissan Leaf… at least, in California only. Only a few hundred EVs will be offered, and as leases, not outright sales. It’s pretty clear that Honda is putting in a baseline effort to meet California pollution laws- i. e., the Fit EV is a “compliance car.” And yet, the car has a 6.6 kW charger. With a similar pack size to the Leaf and Focus, that 6.6 kW will fully charge a Fit in about four hours. When you have no backup engine, nor swappable batteries, chargers are your only lifeline. The Fit, unlike most Leafs, does not have a Level 3 (Fast DC) charging capability. So that one onboard, AC charger is 6.6 kW, to reduce the situations where it’s the bottleneck. Continue reading
I said in the last Roundup that TT-30 was too similar to dryer outlets. Dryer sockets which offer more power, and are also widely installed already. Accidentally forcing in a TT-30 plug can then fry your equipment. Hmmm, widely installed and lots of power… why not recharge EVs with the dryer sockets instead?
The US had the NEMA 10-30 standard (left) for electric dryers, then went to 14-30. A part of that was the resemblance to TT-30. But mostly, 10-30 (sometimes listed as “3-prong”) saved metal during World War II shortages. Instead of a neutral line, the two live lines dump their power to the ground line. Not using a neutral saves copper; several yards, at a hefty gauge, in most homes being built, was a whole lotta copper. NEMA 14-30 (“4-prong”) restored a neutral, and is in homes built after about 1996, or old homes that retrofitted.
Both of these dryer receptacles are 240V, which I don’t need but cars like. It’s split-phase 240, so you can get 120V if you want. Just like the power company’s service to a house, two live AC wires are used, in mirror-image phases. The ground is defined as being halfway between AC phases. Thus, using either live will yield 120V relative to the ground. But when using both lives, they act as +120V and -120V relative to each other. This was done so dryers could run heaters at the more-efficient 240V, while still using standard, cheap 120V lights and controls. Electric vehicles can use 240V directly, to reduce losses, or tap 120V as that’s plenty of voltage in my case. Continue reading