Sunday, March 9, 2014

A New Hope--Electric Buses

We need more than electric cars--we need electric trucks and buses as well.  So the news that South Korea has unveiled an electric bus is very welcomed.  Read about it here, and check out the photo below:

The bus only goes 52 miles on a charge, but it can re-charge in 30 minutes, so that could work with a few morning bus runs, a recharge, and then some afternoon runs.

What's more, California is now starting to use electric school buses, as described in this article on Climate Progress.   See photo below.

The buses have a range of 80 - 100 miles, and are funded, in part, by the California Air Resources Board.  Progress!

Saturday, February 15, 2014

Drastic Cuts in Carbon Pollution Needed by 2030

Why We Need to Cut Carbon Emissions by 80% by 2030
Below is an argument that we should aim for an 80% reduction in all carbon pollution in California by 2030.  This is consistent with the Sierra Club resolution calling for 80% reduction in carbon emissions from the electricity generation sector by 2030, but this proposal would apply to all sources of greenhouse gases as well as electricity generation.

Here's why:

The leading scientific study on climate change comes from the Intergovernmental Panel on Climate Change (IPCC).  The IPCC report contends that, in order to have a 66% chance of limiting the warming to 2°C, the total carbon emitted by humans  must be less than 800 gigatonnes (GtC).  (page 20) The report also states that 531 GtC have been emitted since 1880.  This means that the carbon pollution budget is 269 GtC. 

According to the EPA graph below, the world is now emitting about 32 gigatonnes of CO2 per year.  This is equivalent to 8.7 GtC per year.1  Assuming the world emitted at least 8 billion tonnes since the IPCC report was written, and if we continue emitting CO2 and other carbon pollution at the current rate, we will expend our carbon budget in 261/8.7 = 30 years.  Unfortunately, the graph shows that annual emissions are rapidly increasing, so, if that continues, the budget will be used up in less than 30 years.

Fig. 1:  Global CO2 Emissions per Year

So what should our goal be in terms of CO2 reductions?  If the world starts now to cut CO2 and does so continuously, the 261 gigatonnes must be cut to zero in 60 years in order to have a 66% chance of avoiding 2˚ global warming.  A graph of this is shown below:

Figure 2:  Optimistic Carbon Emissions Reduction Plan

If we want to set a global goal for 2050, the graph shows that we earthlings need to lower our current emissions from 8.7 gigatonnes per year to 3.3 gigatonnes by 2050.  This is a 62% reduction.

However, there are several reasons why we in California should aim for bigger cuts than this:

1. The EPA table in Figure 1 shows that carbon pollution is increasing, not decreasing.  So for the next few years, until this can be stopped, we will be using up our carbon pollution budget faster than the above calculations allow.  Therefore, we should aim for bigger cuts than the straight line graph shows.  In fact, if it takes 10 years for the world to begin decreasing carbon pollution, then we will have to completely eliminate carbon emissions by 2050, instead of 2074 as suggested by Figure 2.

2. California should lead the way.  The rest of the world is very likely to move more slowly than California.  We have the technology and the resources to do this much faster, and we should be a model to everyone else.

3.  A 33% chance of climate catastrophe is hardly reassuring.  If you were told that an airplane had a 33% chance of crashing, would you get on board?  We should cut fossil fuels asap!

4.  Plus, we in the advanced industrial societies are the main cause of all this carbon pollution.  In 1970 there were as many cars in Los Angeles as there were on the entire continent of Africa! It is our responsibility to clean up our mess.

Given all this, an 80% cut in CO2 by 2030 would be a much better goal for California than the present goal of 80% below 1990 levels by 2050.  The current state goal needs to be vigorously defended, but it also needs to be improved upon.

As I've argued throughout this blog, we need to convert to 100% electric vehicles running on 100% renewable energy by 2030 if we are to have any chance of avoiding climate catastrophe.

1The molecular weight of carbon is 12, while oxygen is 16.  So when you add two oxygens to a carbon the weight of CO2 is 44.  In other words, burning one pound of carbon creates 44/12 = 3.67 pounds of CO2.  So the annual production of 32 billion tonnes of CO2 equals 32/3.67 = 8.7 GtC.

Saturday, January 18, 2014

Three years on solar power and our electric car

As luck would have it, we hit 50,000 miles on our Volt on January 11, 2014, exactly three years after we bought her.  So, once again, I have to sheepishly report that we drove too much!  A long road trip to the Southwest accounts for most of extra mileage, plus more  errands, appointments, meetings, . . .  we promise to cut back in 2014!
              2011                2012                2013                  Totals
Miles Driven 12,711 16,768 20,521 50,000
Gallons of gas 129 188 251 568
Miles per gallon 98 89 84 88
Miles on electricity      7,900 (62%)        9,827 (59%)    11,734 (56%)      29,461 (59%)

We did have two maintenance issues this year—we replaced the tires and the windshield wipers!  Actually the warning light came on one time, and I took it to the dealer; they found the problem, which was minor, and fixed it under the warranty.

The 50,000 mile mark is significant, since the Climate Central report, which was critical of electric vehicles, based its argument on an expected life of 50,000 miles for the batteries.  So far I have not seen any deterioration of the battery.  E.g. this morning, after charging overnight, the mileage estimate for the batter was 37 miles, which is pretty normal for our car.  A more likely battery life is well over 100,000 miles.

How about the solar panels?  Today is the three year anniversary of the start up of our solar panels.  I took a reading and found that our current total is now 12,954 kilowatt hours (kwh), which means that the panels produced 4,304 kwh in 2013. (subtracting last year's amount) This is actually more than in 2012—maybe because it almost NEVER rained in 2013, so there was a lot of sun.  The 4304 is 1.5% less than the 2011 production, so this is in line with an expected 20% drop in power production over 20 years.

Did we save money with solar power and electric car?

Absolutely!  We just received our PG&E "true up" bill for our annual electric charges.  See figure below.  The meter shows a net reading of 2,310 kwh for the year.  Since the solar panels produced 4,304 kwh for the year, we used a total of 6,614 kwh.  Our total PG&E electric bill was their minimum charge--$5.91 x 12 months = $71 for the year.  Our solar panels cost $12,000 and are financed at a 3.5% annual rate for an annual cost of $653.  So our total electric bill plus solar finance cost for the year was $724.  Dividing that by 6,614 kwh gives a cost of 10.9 cents per kwh.  This is less than the U.S. average of 12.3 cents per kwh and well below the California average of 15.4 cents/kwh. 

Even if we add the cost of our house's electrical upgrade--$3,500—that only brings the kwh cost up to 13.8 cents per kwh.  Using this number we saved 1.6 cents/kwh x 6,617 = $106 for the year compared to average PG&E utility rates.

So there is some savings with the electricity, but the real savings is in gas.  At 3.2 miles per kwh, we used 11,734 miles/3.2 miles per kwh = 3,667 kwh.  With almost all of this being charged at the low off-peak rate of about 6 cents/kwh (adding fixed charges) the cost of driving on electricity was $220.  With our old Honda, which got 25 miles per gallon, which is also the current U.S. average, and a cost per gallon of $3.75, the cost of driving on gasoline would have been 11,734/25 mpg = 469 gallons x $3.75 = $1,760.  So we saved $1,760 - $220 = $1540 in addition to the $106 we saved on the electricity.

Of course we did have to finance the car, which was expensive, but a savings of $1646 is more than enough to pay for the additional cost of the Volt over a similar gasoline car.  And, as noted here, the cost of electric cars keeps coming down, making them a better deal all the time.

Even more good news

If you look at our annual electricity usage in the figure below, you'll see that we used a net (total electricity used minus solar electricity generated) of 670 kwh in December.  This is a lot higher than the 448 kwh net in December, 2012 or the 292 kwh in December, 2011.  The reason for the extra usage this year is that in each of the last two years our total charge for electricity was well under the minimum charge.  In 2011 we could have consumed an additional $70 in electricity without additional charge.  In 2012, we could have consumed $122 more in electricity without charge.  So, in 2013, we added an electric heater to warm our bedroom, hallway, and bathroom every winter morning before 7 AM, which is when the electric time-of-use rate goes up.  For the year we were still $37 under the minimum, so we'll keep using that electric heater through the next few months—for free!

So 2013 was a great year to be driving an electric car with solar power.  As I've said in previous years, the main regret I have is that we are still using too much gasoline.  If we could buy a low carbon gas substitute—e.g. algae based biofuel—I would be happy to pay whatever it costs.

PS--also just for the record: GM sold 23,094 Volts in 2013 compared to 23,461 Volts in 2012.  However, electric vehicle sales overall nearly doubled in 2013 as many new models came on line.  There were more than 90,000 EVs sold in 2013.

Sunday, January 5, 2014

Put on your gas math

Climate crisis gas math

In the climate crisis, we all need to grasp our gas math to help us keep breathing.

The bottom line is the main hypothesis of this blog:  electric cars running on renewable energy can help us meet California's goal of reducing greenhouse gases 80% below 1990 levels by 2050.  Actually, 2050 is too late; we need to cut greenhouse gases ASAP.

California's goal is to cut greenhouse gases to less than 100 MMT (million metric tonnes) of CO2 per year by 2050.  That would be about 2 MT (metric tonnes)per person (assuming 50 million people in California in 2050).  Half of California's CO2 currently comes from petroleum, so the goal is 1 metric ton per person from petroleum, i.e. driving.

Can we do this with internal combustion engine (ICE) vehicles?

One metric ton weighs 2200 lbs.  One gallon of gas creates 25 lbs of CO2 (counting extraction and refining).  Therefore, we should burn no more than 2200/25 = 88 gallons of gas per year.  If we drive an average of 12,000 miles per year, that would mean we need to average 136 miles per gallon (12,000/88), for an ICE vehicle.  This does not include the CO2 created in producing the vehicle.  Counting these emissions, the average car (25 mpg) emits about 1.1 lb per mile (500 g/mile), or 13,200 pounds per year = 6 metric tons.    So we really need cars that get 13,200 / 88 = 150 mpg.

Side note to re-state calculation above:   the average car consumes 12000 miles / 25 mpg = 480 gallons of gas per year.  480 gallons x 25 lbs/gallon = 12,000 pounds of gasoline plus 1,200 pounds CO2 to account for manufacture of the car = 13,200 pounds.
 New EPA standards call for 54.5 mpg by 2025.  This would cut the CO2 by more than 1/2—down to about 3 tons per car per year, but still not close to 1 ton.  Reaching 1 ton may be possible for an ICE car, but a lot of new technology would still be required. 

Alternatively, assuming an average of 50 mpg, the one ton goal could be reached by reducing vehicle miles traveled (VMT) by 2/3.  The trips could be replaced  with transit and bicycles and walking. But, because transit, bikes, and walking only operate effectively in a high density environment, this would require rebuilding all of California's cities to higher transit-friendly density, with the exception of already-dense locations such as downtown San Francisco.  Alternatively, perhaps Skype and similar technologies will reduce the number of trips.  Indeed the rapid increase of vehicle miles traveled that has occurred over the 20th Century has stopped in recent years (see graph below).  Whether there will be an actual drop in VMT remains to be seen.  Certainly tele-commuting and more transactions handled online, higher density land use, improved transit, improved bicycle facilities, and improved pedestrian facilities are all important to helping reduce the miles driven.  But it is highly unlikely that such massive changes can occur fast enough to stop climate catastrophe.
Total Vehicle Miles Traveled
Vehicle miles traveled (in millions) has declined slightly since 2005.  Source:

 Electric cars to the rescue?

For an electric car powered by solar or other renewable energy, the technology is mostly here already to reach the equivalent of 150 mpg, 1 tonne of CO2 per year.  An EV powered by solar power creates about 119 g/mile  for manufacture of the car, the batteries, and the solar panels.  This is  119 g/mile ÷ 454 g/lb = .26 lbs / mile.  For 12000 miles that would be 12000 x .26 = 3,120 lbs = 1.4 metric tons.  So instead of needing to reduce CO2 from 6 tons per year, or even 3 tons, to one ton, an EV running on renewable energy needs to reduce CO2 from 1.4 tons to 1 ton.

To get to 1 ton per person it would be necessary to reduce the 119 g/mile produced in manufacturing the car, the batteries, and the solar panels, or reduce the miles driven per person.  Each of these is a realistic possibility. 

 If the car only goes 8,500 miles per year, the total emissions would be 1 ton. If two people share the car, and it goes 12,000 miles, it would emit 0.7 tons per person, well below the goal.

If the emissions were reduced to 80 g/mile, the emissions for 12,000 miles would be 80/454 x 12,000 = 2,115 lbs., i.e. below the 1 metric ton goal.  This could be accomplished by more efficiency in the production process, use of lighter materials, more recycling of materials. . . Or it could be accomplished by extending the life of the batteries and vehicle.  The 119 g/mile number assumes a vehicle/battery life of 120,000 miles.  If the car and batteries last 240,000 miles, the g/mile would be reduced by 1/2, i.e. 60 g/mile.  Also, wind turbines have a lower carbon footprint than solar panels, so this would also reduce the emissions from electric vehicles.

Reduction of miles driven can be accomplished by a fee on miles driven over a certain amount, say 10,000.  All of the items listed previously relating to ICE vehicles--tele-commuting and more transactions handled online, higher density land use, improved transit, improved bicycle facilities, and improved pedestrian facilities—can also help keep the transportation-related CO2 under one ton per person.  Since electric vehicles powered by renewable energy already bring us close to 1 ton per person, the reductions in vehicle miles traveled based on these land use and planning changes are more feasible than in the case of ICE vehicles.

All in all, getting to 1 ton of CO2 per person is quite achievable if the State moves away from ICE vehicles, or those ICE vehicles are much more efficient than current technologies.  In either case the total gasoline consumed in California would drop drastically.  In the case of electric vehicles, there would be practically no need for gasoline.  If ICE vehicles become efficient enough to meet California's CO2 reduction goals, gas consumption would fall by 80%.  This would be sufficient to close most of California's 18 refineries unless they are allowed to export oil without any cap (which AB32, California's Global Warming cap and trade law allows.)

This raises the question of what happens to those displaced workers (estimated 4,000 but needs checking)  The answer is that installing solar panels, building wind turbines, updating electrical systems, and these types of jobs will far surpass the refineries in job creation.  Refinery workers should be given training in the new fields of work and given priority in hiring.

One technical issue facing electric vehicles is the need for quick charging stations for interstate trips and long trips within California.  Current EV ranges of 80 or so miles are clearly inadequate for most travelers, even with fast charging.  The Tesla range of 300 miles is much more reasonable for long trips, and Tesla's fast charging network may provide the answer here.  Trailers with extra batteries that can be swapped easily at drop-off/pick-up locations is another solution to this problem.

The cost of EVs is commonly cited as an obstacle, but EV prices are dropping steadily.  With tax credits the Chevy Spark price is now $17,450, i.e. about the same as an ICE car but far superior in handling, acceleration, and gas savings.  Another  financial obstacle is lack of 240 volt wiring and outlets in many older homes and in apartments.  This is a case where subsidies and low cost loans would be highly cost effective and beneficial.
 Per Capita Vehicle Miles Traveled
Note:  per capita vehicle miles traveled has dropped more than total VMT due to increases in population.

Sunday, December 29, 2013

Plugging in on the road

Wherever we stay, we ask the motel staff if it is OK to plug in for the night. We usually offer to pay, but no one has taken us up on it yet (the Volt full charge is 11 kilowatt hours, about $1.50 worth of electricity depending on the rates).  It's also a good idea to ask for the "wet floor" warning sign so no one trips over your cord.  I know the Volt owners manual says not to use an extension cord, but we bought a heavy duty 15 amp rated cord, and have never had any problems using it.

Here's a photo of our recent stay at the La Quinta Inn in Bakersfield, CA:

Friday, November 29, 2013

Who's winning--EVs vs ICEVs?

Today I toured the San Francisco International Auto show to compare electric vehicles (EVs) with the Internal combustion engine vehicles (ICEVs) on display there.  Of course, all the new cars look shiny, comfy, powerful, and sleek, so from appearances sake, I'm not much of a judge.  Fortunately, each car has an EPA sticker that gives the mileage rating and also gives the Manufacturer's Suggested Retail Price (MSRP).   From that I made a couple of tables (with rounded numbers).  I surely missed many vehicles, but I think I got pretty much of a feel for the new cars on the market.

Table 1 compares cars that looked (to me) more or less like the Chevy Volt that we own.  Table 2 compares smaller cars that look more like the Chevy Spark, which I test drove last week.  I didn't compare larger cars to the extended range EV Cadillac, but that would be an interesting task for another day.

Table 1 shows that I saw four cars that were less expensive than the Chevy Volt taking the cost of the vehicle and the cost of gasoline into account.  These were the Dodge Dart, Nissan Sentra, Honda Civic, and Hyundai Elantra.   Although these cars are less expensive, I doubt that they can compare to the Volt's smooth, quiet ride, low maintenance costs, and extremely fast take-off.  And, of course, all that carbon pollution should have a price for destroying the planet.

Table 1
Cost Comparison Chevy Volt and various similar cars
Make/Model      MPG             MSRP                                            
Chevy Volt
37 mpg on generator; assume 2/3 miles on electric
36,000 minus 9,000 rebate
annual gas savings for Volt*
Annual savings (cost) for purchase price**
Total Annual savings
Years to break even
Dodge Dart
Dodge Charger (a bit bigger)

Fiat Trekking

Mazda 4 door

Mazda 5 door

Acura (a bit bigger)

BMW active hybrid

Toyota Prius

Ford  C-Max hybrid

Nissan Sentra
Honda Civic
Honda Civic Navi

Kia Optima hybrid


Subaru WRX

Chevy Malibu

Chevy Cruze

Hyundai Elantra
Assuming 12,000 miles driven per year; cost of gas = $3.70 per gallon
*The cost for gas for the Volt assumes 8,000 miles on electricity at 3 cents per mile (10cents/kwh ÷ 3.3 miles/kwh) = $240; 4000 miles on gas at 10cents per mile ($3.70 per gallon/37 mpg) = $400; total = $640 per year
**Financing cost assumes 4% interest loan for 5 years.  Capital Recovery Factor = .225

Table 2 shows that, among small cars like the Spark EV, only the Toyota Yaris can compete on total cost of the vehicle plus gasoline.  This assumes that the Spark is used for commuting and local errands with its range of about 90 miles.  As in the case of the Volt, the price difference does not take into account maintenance savings, the smooth, quiet ride, zippy performance, or environmental benefits of an EV. 

Table 2
Comparisons for Chevy Spark EV
Chevy Spark EV
28000 minus $10000 in rebates
cost savings on gas
Annual savings (cost) for purchase price**
Total Annual savings
VW Beetle
Fiat Sport Hatchback
Toyota Yaris
Hyundai Accent
Assuming 10,000 miles driven per year, cost of gas $3.70 per gallon.  Cost for Spark = 3 cents per mile. $300.  Financing costs same as Table 1.

I also saw three all-electric models in addition to the Spark.  They were all larger, sized like the Volt, and would make an excellent choice for a second car if you feel the Spark is too small.  They were the Focus Electric--$37,000, the Nissan Leaf--$36,000, and the Honda FiT-EV--$37,000.  BMW also had an EV on display that has an optional extended range EV backup generator like the Volt, but it won't be available until the Spring of 2014, so there were no price details.

I couldn't help but chuckle at the SF Chronicle's coverage of the auto show.  They featured an article headlined "The internal combustion engine isn't dead yet".  The negative nature of the headline reminded me of Richard Nixon's proclamation, "I'm not a crook."  All people heard was the word "crook".  Hopefully all people will hear about ICE's is the word "dead".

Conclusion:  Save money and save the planet--make your next car an EV!