Saturday, March 7, 2015

How Clean are EVs?--Good News from GREET

How clean are electric vehicles (EVs)?  I've been trying to answer this for a few years, using various sources and changing numbers.  The answer has always been that EVs charged with renewable energy are very clean--about 80% cleaner than Internal Combustion Engine Vehicles (ICEVs) when taking the full life cycle costs of manufacture of the vehicle, batteries, fuel, recycling, etc. into account.

One problem with the calculations has been that I've had to use varying sources, so there is a danger that I could be comparing  apples to oranges if the methodologies of the various sources are different.

With this in mind I decided to take a close look at what I feel is the most authoritative source--The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation Model (GREET). GREET was updated in October, 2014, so I was hoping that I could find all the necessary data in this one source.  And I was very pleased to find out that not only did GREET have all the numbers I was looking for, but their most recent numbers are better than ever for EVs.

Table 1 gives a look at the latest GREET numbers comparing EVs to ICEVs.   The bottom line is that an EV powered by a combination of wind and sun, based on the GREET numbers reduces emissions by 87%--WOW!

Table 1.
                         Greenhouse Gas (GHG) Emission comparison of ICEVs and EVs (grams per mile)
Type of Vehicle—
ICEV—internal combustion engine vehicle
EV—all electric
Vehicle components, assembly, batteries, fluids, demolition, recycle1
Well to wheel delivery of energy source
Operation of the vehicle
EV—US mix

The sources of this data are two GREET spreadsheets--GREET1 and GREET2, plus a supplemental report, also prepared by GREET: "Life-Cycle Analysis Results for Geothermal Systems in Comparison to Other Power Systems:  Part II"  The GREET spreadsheets can be downloaded from the GREET website here.  The supplemental report can be found here.  Specific locations of data are shown in the footnotes below.

1GREET2, Vehi_sum tab, table 2:

2 GREET1, Results tab, 2.  Well-to-Wheels Energy Consumption, Water Consumption, and Emissions: per mile and per mmBtu (also GREET1, Vehicles tab, Table 3 Per-Mile Fuel Consumption and Emissions of Vehicle Operations)

3 GREET1, Results Tab, Electric Vehicle.  This table shows 21 g/mi feedstock and 221 g/mi fuel for a total of 242 g/mi. 

4Using the GREET1, Input tab, Item 10—Electric Generation; select Mix for Transportation and Use--No. 12 for CA Mix.  Then click on Results or the Results Tab.  The table for EVs now shows 21 g/mi for Feedstock and 130 g/mi for Fuel with a rounded total of 152 g/mi.   

5See the GREET publication:  "Life-Cycle Analysis Results for Geothermal Systems in Comparison to Other Power Systems:  Part II", Table A2. (see below). The table shows that production of wind power emits 9 g/kwh (÷ 2.6 mi/kwh = 3.5 g/mile) and that solar PVs emit 35.8 g/kwh ÷ 2.6 mi/kwh = 14 g/mi.  It is also worth noting that Table A2 also shows lower g/mile numbers for solar generated with concentrated solar power projects, so the PV numbers are conservatively high.

6calculated using 23.4 mpg = .043 gal/mi.  40 mpg = .025 gal/mile.  (.025/.043) x 89 = 50g/mi for well to wheel emissions and  (.025/.043) x 370 = 216 g/mi  for operations emissions.  Adding the emissions for manufacture and disposal of the vehicle gives 46 + 50 + 216 = 312 g/mi

One important factor in these numbers is that GREET maintains that EV batteries are likely to last the full life of a vehicle, which they estimate at 160,000 miles.  This means that the greenhouse gases produced by manufacture of the batteries can be spread over those 160,000 miles, which gives a lower grams/mile of GHGs than others such as Climate Central have contended.

I do have one small quibble with GREET.  GREET uses 2.6 mi/kwh for EVs, which is quite a bit less than the 3.2 mi/kwh that I get with the Chevy Volt, and less than the 3.4 mi/kwh apparently being used by the Union of Concerned Scientists.  I did learn that the GREET data being used to calculate the 2.6 mi/kwh figure is three years old and is due to be revised upward soon.

But all in all, the numbers from GREET do allow a "one stop shopping" approach to the question of "How clean are EVs?"  I really appreciate their research, their scientific approach, and their data.



Tuesday, February 3, 2015

Gas prices, Electric Cars, and Global Warming

With gas prices the lowest that they've been in 10 years, should we all be cheering? 
Of course, it is good for people to save money on gas.  But in the big picture, cheap gas is a big problem.  Even if gas were free, the scientific fact is that we have to leave most fossil fuels in the ground if we want to avoid climate catastrophe.  This is the conclusion of the comprehensive scientific report by the Intergovernmental Panel on Climate Change (IPCC) as shown in their graphic below, which shows that we only have 275 Gigatonnes of carbon  (1 GtC = 1 billion tonnes of carbon) that can be emitted before we exceed the 2 degree C temperature increase that could be catastrophic for agriculture, rising oceans, mass extinctions, and other disasters.   Note that 275 GtC (1 tonne = 2200 lbs = 1.1 US ton) equals 1008 Gigatonnes of CO2 (GtCO2).  Since we are now emitting the equivalent (taking into account all greenhouse gases) of over 40 GtCO2 per year, that means we will exceed our carbon budget in 25 years unless we drastically reduce greenhouse gasses.  Yikes!

So if people respond to lower gas prices by buying more internal combustion engine vehicles, we are simply stepping on the gas to go over the climate cliff. 
Unfortunately, the market is not sending people the proper signals about the danger of gasoline combustion.  This is where government needs to step in with

·         education campaigns such as warning labels on gas pumps,

·         prices on carbon much greater than the $13 per tonne currently in California,

·         programs to reduce vehicle miles traveled—e.g. ride sharing, transit, bikes, transit-oriented development

·         programs to encourage electrification of transportation—electric vehicles, buses, trucks, trains, ships

·         conversion of all electricity to renewable sources—solar, wind, hydro, and others

 Let's get busy folks!  One way to start, if you are in California, is to come to the March forReal Climate Leadership this Saturday, February 7 at noon in Oakland, CA.  And join us for a relaxing time at the after-party at La Peña—3105 Shattuck in Berkeley, 4 – 9:30 pm.


Sunday, January 18, 2015

Four year report--solar power and electric car--2011-2014

Four year report—Jan 18, 2014
It's been another good year for our solar power and electric car. It has been four years since we bought our Chevy Volt and our solar panels in January, 2011.  Below is a look at how we are doing:

The car:  In 2014, 23 drove 15,905 miles, which was well under the 2013 total of 20,521, but about the average for our four years.  We did drive to San Diego twice, but other than that, we didn't have any long road trips.  This is why our miles per gallon was the highest yet--120 mpgs, and 69% of our miles were on electricity, compared to an average of 61%. 
Here are the details:
Miles Driven
Gallons of gas
Miles per gallon
Miles on electricity

The Solar Panels:  This year we added an electric heater to take the morning chill out of our bedroom in January/February.  We did this because we had extra electricity in all other years, and could use that without increasing our PG&E bill.  And it worked!  This year we ended up with a total electricity bill of $23.26 for the year, rather than a non-refundable surplus of $50-100 like we've had in previous years.  The PG&E meter shows that we used 2,523 kwh.  Adding that to the 4116 kwh from the solar gives us 6,639 kwh for both the solar net metering and the PG&E grid.  This is almost the same as last year's 6,614 kwh, in spite of adding the heater.   But the PG&E total of 2,523 is 213 kwh above the 2,310 from PG&E last year.  This 213 kwh is mostly due to the drop in solar production from 4304 to 4116 kwh.

Solar power production--our 3.2 kilowatt rooftop system (18 panels)
First installed 1/18/2011
Reading on annual anniversary
total produced

Discussion:  The 6% drop for the solar panels in 4 years is higher than expected 1% per year.  We will keep an eye on this next year to see if there is another large drop.
The car batteries appear to be as good as new.  Today the mileage indicator said that the range with a full charge is 39 miles.  This indicates that there has been no deterioration of the batteries, since it equal or above all the mileage indicator estimates with each new charge.


Thursday, November 27, 2014

Fox News Takes on 350 Bay Area/Solar Power Electric Cars--You Decide Who Won

I had a rare opportunity to talk about solar power and electric cars on Fox Business News on Nov 25. 

They mostly wanted to make fun of Berkeley's proposal to put climate change labels on gas pumps, but it did provide an opportunity to make some broader points.  Here's the 3 minute interview--you can decide who came out on top.

On the same day, the San Francisco Environment Commission voted to approve a label, possibly something like the one pictured below.  This will go to the San Francisco Board of Supervisors early next year (graphic by Raymond Pajek, 350 Bay Area Beyond the Pump team).

Wednesday, October 29, 2014

California Air Resources Board Leads the Way for Electric Vehicles

California is leading the electric vehicle revolution.  This outstanding achievement was on display at the California Air Resource Board (CARB) October 23 meeting  that included a Zero Emission Vehicle (ZEV) Showcase with 20 models of EVs and Fuel Cell Vehicles for public viewing (see figure below).  The six hour meeting included many excellent presentations about CARB's Advanced Clean Cars Program and lots of lively discussion about how to promote Zero Emission Vehicles.


The entire meeting is available online here (from this site, click on Webcast,  then click on California Air Resources Board, and select the October 23, 2014 meeting)  I watched most of it online, and found it spellbinding!  I was very impressed with CARB staff and Board members--they really have done their homework and understand the numbers.  They sparred with the automakers and stood their ground (although the automakers themselves were supportive of the ZEV program, which is noteworthy compared to previous decades of resistance.)  ​Environmental  and health organizations were also well represented supporting the CARB efforts;  groups appearing included the Union of Concerned Scientists,  the American Lung Association,  the Sierra Club's Beyond Oil campaign,  and the Natural Resources Defense Council.

Some highlights (for me):

*      CARB chair Mary Nichols told it like it is:

". . .we know from our own assessment of where we're trying to get by 2030--100% of the vehicles sold in California had better be essentially zero emission vehicles, looked at on a life cycle basis, and by the time we get to 2050, we've got to change the whole fleet."

This is exactly the reality that needs to sink in to all policy makers and the general public.  I would argue that we need to move even faster (see final point in this post), but I welcome this message.

·         The automakers (GM, Ford, Toyota, and Honda among others) recommended some reduction of the ZEV program requirements, arguing that the market for EVs on the East Coast is weaker than California.   In response, during the lunch break, David Cash from the Massachusetts EPA called a few auto dealers in MA posing as a buyer.  He said that they told him that they didn't have EVs in stock and didn't seem to know anything about them.  He argued that the automakers themselves are not marketing EVs aggressively.


*    Along similar lines, UC Davis researcher Eric Cahill reported that car salespeople provide very little support for EV buyers.  They don't understand electricity rates, charging options, tax credits, and all the real advantages of EVs.


* The long meeting was mostly a lovefest of supporters of GHG reductions.  However, the open testimony period had two opponents--Tupper Hall from Western States Petroleum Association (WSPA) requested a delay to California's cap and trade law (AB32), which will go into effect for gasoline Jan 1.  He was followed by Bill McKinney of the California Driver's Alliance who presented 115,000 petition signatures against AB32's "Hidden Gas Tax".  He argued that there has been "no real dialogue" on the issue.  Mary Nichols responded that 12 hearings and workshops were held with wide publicity.  Board member John Goia said, ". . .this idea that there's not notice to the public just seems ridiculous."  He argued that "the price of gasoline is very volatile, and is due to many factors--the world market, supply, demand, maintenance,. . ." 

Personally, I do think we need to be ready to defend AB32 from the likely backlash against gas price increases.  Fortunately, gas prices right now are fairly low, so a 10 cent increase would still be well below the average price of the past few years.  Still, I would expect WSPA to mount a ballot measure on this.


* David Reichmuth of the Union of Concerned Scientists applauded CARB's ZEV program which he said has been "instrumental in promoting new technology".  Indeed, I looked at CARB's tutorial on ZEVsproduced in 2009, and found today's ZEV program to be very much on target with its goals and vision.  The good news is that "All vehicle manufacturers subject to the ZEV Regulation are in compliance through model year 2013."   (source--CARB) 

One positive result of the CARB program has been the car buyer's Environmental Performance Label (see figure below).  Providing consumer information is comparable to the recent efforts of San Francisco and Berkeley to  put warning labels on gas pumps themselves (I'll blog more on this soon)

·         The gains in EVs in California over the past few years are exponential as shown in the graph below.  It shows that ZEVs and Plug-in Hybrid Electric Vehicle (PHEVs) sales have grown to over 3% of California's auto sales, with sales distributed among 11 automakers (22 automakers involved in overall program).  If CARB can keep up its efforts, along with support from the auto industry, activists and environmentalists, the future looks electric!

Apart from the points raised at the meeting, I appreciate the following points from the CARB website:

*  ZEV mass commercialization is essential in meeting California’s long term GHG, air
quality, and petroleum independence goals and stressing that "ZEVs still need to be mandated".
California Projected Impacts from climate change:

75% loss in snow pack

1-2 foot sea level rise

70 more extreme heat days/year

80% more ‘likely ozone’ days

55% more large forest fires

Twice the drought years

One Note of Caution


Just so the CARB staff and Board don't get complacent (actually I didn't sense that they were), I would like to conclude by pointing out that the California goal of reducing greenhouse gases (GHGs) from the 1990 level by 80% is misleading.  This reduction is a global requirement.  If California and the U.S. only cut GHGs by 80%, we would still emit about 3-4 metric tons (MT) per person per year.  If China were to cut its GHGs by 80%, they would only emit about 1 MT per person per year.  If India cuts 80%, they would be well under one MT.  Clearly, this is not an equitable solution.  Since the 1990 level of global emissions was about 40 billion MTs, an 80% reduction would allow emission of about 8 billion MTs.  Dividing this equally among the 9 billion people likely to be living on earth in 2050, we get about one MT per person.  Therefore, the only socially just transition would be for everyone in the world to cut to about 1 MT per person.


Since light duty vehicles make up about 59% of transportation emissions in the U.S., which in turn make up about 38% of all California emissions, this means that the goal for California's light duty vehicles should be around 0.38 x 0.59 = 0.224 x 1 MT = 224 kg per person per year.  Given California's average vehicle miles traveled per person of around 7,600 miles per capita and average emissions for a standard ICE vehicle are 536 g/mile, current emissions in California are around 4.1 MT per capita. To reduce that to 224 kg will require about a 95% reduction in GHGs, not an 80% reduction.  It will be important for activists and environmentalists to push legislators to adopt this goal.  For right now the 80% goal is a good one, but we should not fool ourselves into thinking it is enough.







Wednesday, September 17, 2014

People's Climate March/People's Climate Rally

The planet is burning!  Mobilize now for solar power, electric cars, 100% renewable energy, and an end to fossil fuels.  Clean air, millions of jobs, and a climate we can count on--it's a win, win, win.

Plan A--Go to New York!  Be part of the largest climate mobilization in US history.  Sunday, September 21--Sign up here

Plan B--If you are in the San Francisco Bay Area come to the Northern California People's Climate Rally in Oakland at Lake Merritt.  Sunday, Sept 21, 2 - 5 pm.  More details here.

Plan C--Join one of the 2350 (and counting) other events around the world.  Find one near you here.

Sunday, July 20, 2014

How Clean Are Electric Cars?

I often hear the argument that manufacture of an electric car requires so much energy that it negates the savings from driving the car.  The table below shows that this is false.  Manufacture of an electric vehicle (EV) does require more energy than an internal combustion engine vehicle (ICEV), but the operation of the car more than makes up for this.  For example, an EV running on wind energy reduces greenhouse gases by 79%. 
The numbers below include the full well to wheel greenhouse gas emissions for ICEVs as well as the emissions in battery production, and production of solar panels/wind turbines for EVs.  For full details on the calculation and source of these numbers, please see my earlier blog post here.
Lifetime greenhouse gases from car manufacture plus operation

                                                      Car Manufacture               Operation of car                      Total
Internal combustion engine veh. (ICEV)
Electric Vehicle (EV) on average US grid
EV on solar energy
EV on wind energy