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This is part three of a three-part series exploring the environmental lifecycle analysis completed by Divergent. It will get into some technical detail, but is intended for anyone who has an interest in total system environmental and health damages for manufacturing.

Before reading this section, please read our lifecycle analysis overview, Part 1, and Part 2.

Modeling philosophy: change as few variables as possible

There are obviously many ways to create and modify models. Thankfully, by using GREET and AP2, we were able to leverage decades of existing work. These peer-reviewed, published, and transparent models have inputs, calculations, and outputs that have been highly vetted.

When modifying an existing model, it behooves the modeler to make as few changes as possible. That is the philosophy we used at Divergent when making modifications to include our vehicles in the existing models. By reducing changes, you’re reducing chances for error and reducing the number of assertions you need to make. It’s also easier to delineate the full set of changes you made so that others can review and understand your work.

Similarities and differences between our analysis and NAS analysis

We based our modeling on the method used in the 2009 report by the National Academy of Science (NAS), Hidden Costs of Energy: Unpriced Consequences of Energy Production and Use. They used GREET for lifecycle emissions calculations and APEEP (the predecessor to AP2) for health and environmental system damage cost calculations.

We used updated versions of those same two models, GREET and AP2. The models have not fundamentally changed in structure since 2009, though some of the content has been updated with more recent calculations (e.g., the environmental cost of CO2 emissions).

We updated GREET to include modern electric vehicles with 85 kWh batteries and to also include the Divergent vehicles, both compressed natural gas (CNG) and gasoline.

cents per vmt graph-1

Delineation of variable changes

In keeping with the modeling philosophy above, we limited the set of changes in the GREET model to only those changes necessary to include modern EVs and our Divergent vehicles. We used the existing lightweight car vehicle type in GREET and modified it to suit the Divergent Blade. No changes were made to AP2, as it takes inputs from GREET. Below is a table delineating the exact changes we made.

That’s all. By limiting the number of changes, we have a strong and defensible modeling technique. Divergent vehicles drastically reduce the environmental and health damages compared to existing, traditional vehicle manufacturing. Keep in mind that we modeled the Divergent Blade, a 0-60 in 2.5 seconds 700 horsepower supercar. We can expect that future Divergent vehicles will have even lower total system damage numbers.


Thank you for joining us in our mission to reduce the environmental impact of automobile manufacturing. We hope this blog series has been informative, and welcome your thoughts and comments in the space below.

This is part two of a three-part series exploring the environmental lifecycle analysis completed by Divergent. It will get into some technical detail, but is intended for anyone who has an interest in total system environmental and health damages for manufacturing.

Before reading this section, please read our lifecycle analysis overview and Part 1 of this series.

Introduction to AP2

In Part 1, we introduced the Argonne National Lab’s GREET model. Developed over the last 20 years, it is a complicated and deep model that outputs greenhouse gas and particulate emissions.

AP2, formerly called APEEP, is a model developed by Nicholas Muller, Associate Professor of Economics at Middlebury College and Visiting Associate Professor at Carnegie Mellon University. AP2 takes the outputs from GREET and translates them into a dollar figure – the environmental and human health cost of those emissions.

From the AP2 website: “The Air Pollution Emission Experiments and Policy analysis (APEEP) model is an integrated assessment model that links emissions of air pollution to exposures, physical effects, and monetary damages in the contiguous United States. The model has been used in many peer-reviewed publications,” including a paper in Science in August 2014.

For example, in our recent analysis of various vehicle types, AP2 received a total CO2 count from GREET for the manufacture and operation of a vehicle. AP2 translated this CO2 count to an environmental and health system damage cost for the lifetime of the vehicle. To standardize this number, we then divided the cost across the total miles that car will be driven in its lifetime (estimated to be 160,000 miles per vehicle). The output from AP2 is then a cents (US dollars) per vehicle mile traveled (VMT).

History of GREET + AP2

The 2009 National Academy of Sciences report “Hidden Costs of Energy: Unpriced Consequences of Energy Production and Use” used this same dual-model approach, connecting GREET and APEEP to show the combined damages. This report was one of the first to show the full lifecycle emissions of various types of vehicles and their environmental and health system cost. It revealed costs that were previously hidden, bringing into question some of the policies and trends in vehicle manufacturing.

This report was one of the founding inspirations for Divergent. Seeing this report, we believed we could and should do better: build a more environmentally sustainable car.

Connections between the GREET and AP2

GREET and AP2 have a fairly simple point of connection. We analyzed six vehicle types:

  1. Gasoline (25 mpg)
  2. Hybrid gasoline (40 mpg)
  3. Plug-in electric car (85 kWh)
  4. Plug-in electric SUV (85 kWh)
  5. Divergent compressed natural gas
  6. Divergent gasoline

For each of these vehicles, we used GREET to calculate greenhouse gas and particulate emissions over the lifetime of the vehicle, both for manufacture and operation. The chart below shows the conceptual connections between the models.

GREET and AP2 connections

We then used the outputs from GREET as inputs to AP2. The table below shows the most important outputs from GREET.

table of outputs from GREET

Using AP2, costs for each of the various pollutants were calculated and then tabulated. We also include the cost of the greenhouse gases directly, estimated by the US government at $39 per ton of CO2 equivalent.

table of outputs from AP2

The Vehicle production, Fuel production, and Operation lines under the Health Damages (per VMT) are the numbers that are used in the graph below.

cents per vmt graph

What’s next in this series?

In the next (and last) posting in this series, we’ll discuss the input variables to GREET, as well as our philosophy of changing as few of those variables as possible.

Although 97% of scientists agree that climate change is a real and present danger, the U.S. government has not been treating it as an emergency. Quite the opposite; our political bodies seem strangely reticent to act. Moreover, despite being a matter of facts, figures, and rising tides, there is a strong partisan divide. The canned answer is that humans are simply too short-sighted, selfish, and greedy. Yet people have mobilized before (with both citizens and companies rationing during WWII, for instance), and further, we are currently facing austerity measures in the form of cuts to many public programs, including schooling. We are already making sacrifices.

So why are we failing to act on climate change?

While Divergent is by no means a political group, understanding the world of politics surrounding climate change is important to our mission. We aim to improve the planet by making incredible products. Our technology will be implemented by those people best equipped to make positive changes.


In Naomi Klein’s book, This Changes Everything: Capitalism vs. The Climate, she unpacks some of the thornier realities underlying the environmental movement. The underlying thesis: in order to effectively battle global warming, we have to majorly restructure our current societal set-up. This would involve confronting big corporations and big money individuals, empowering disenfranchised countries and peoples, and letting the needs of the environment and local economies trump free market capitalism. In other words, when conservatives argue that the green movement’s hidden agenda is wealth distribution, they are only half wrong. According to Klein successful programs would require the privileged few to relinquish some of their power.

For those who won’t acknowledge the failures of our current laissez-fare system, there are many reasons to deny climate change. Some deniers accept that it may be getting warmer, but denigrate rash action and insist that our small emissions problem may be curbed by gradual, system-sanctioned means. Emissions restriction policies are too often rendered immediately moot by the doctrine of continual GDP growth and by the fact that corporations can easily buy their way out, game the market, or otherwise avoid penalties. Serious change is needed, Klein maintains.

Even green groups have fallen into the trap of inadvertently working to uphold the interests of corporations. While the 60s and 70s saw everything from the Clean Air Act (1963) to the Resource Conservation and Recovery Act (1976), Ronald Reagan’s presidency ushered in an ideological shift. Accustomed to being political insiders, activists scrambled to continue as such. As a result, coal and oil companies now sponsor the most important summits of many groups, which in turn invest their own wealth in these same players. In one particularly egregious conflict of interest, the Texas City Prairie Preserve ended up drilling for oil on its own property despite the decline and eventual die off of the bird it was trying to protect.

Siphoning off responsibility to benevolent billionaires and scientists developing high tech fixes is also no good. Just as no corporation wants to limit its business, no billionaire wants to lose money. Meanwhile, high tech fixes are extremely high risk. For instance, an initiative to block out the sun by simulating the activity of a volcano would interrupt the Asian and African summer monsoons. The resulting draughts would effect billions of people. The winner? Wealthy westerners who could buy their way out of any problems.

Luckily not all hope is lost. While top-down environmentalism is floundering, grassroots movements are gaining traction. “Blockadias” or areas involved in direct resistance are cropping up everywhere from Greece to Inner Mongolia. Typically, response from governments and corporations in such cases is brutal. For instance, the Nigerian government reacted to protests by torturing residents and razing villages; in one instance soldiers conducted lethal raids using a helicopter taken from a Chevron operation. However, the number and effectiveness of protests is growing as citizens gain knowledge and corporations are forced to expand their reach to include places with more political power.

While many local protestors may not have much political experience, the feel connected to their land and often view it as essential to their way of life. Meanwhile, a coalfield worker Klein interviewed said he trained himself to think of the Powder River Basin as “another planet” that he could raid without consequence. Coalitions of rights-rich-but-cash-poor people are teaming up with (relatively) cash-rich-but-rights-poor people to effect change. Aboriginals are finding help from the green movement; treaties against land contamination are now being upheld more regularly. Despite minimal government assistance, local people are winning victories.

Klein presents her arguments in a compelling way, peppering hard facts with personal anecdotes. Her descriptions of the plight of ordinary people faced with climate change are at turns heartbreaking and inspiring. Divergent believes that its technology can contribute to this local, personal green movement, leading to a more even playing field for anyone concerned about their land and their way of life.

This is part one of a three-part series exploring the environmental lifecycle analysis completed by Divergent. It will get into some technical detail, but is intended for anyone who has an interest in total system environmental and health damages for manufacturing.

Before reading this section, please read our lifecycle analysis overview, which sets the context for the discussion here.


My name is Nick Hofmeister. I have a computer science degree from Northwestern and an MBA from MIT. I’ve worked in fairly diverse industries, starting at Microsoft, followed by Bain & Co., an algae biofuels company, and three biotech/software startups I’ve founded. Over the years, my teams and I have raised about $260 million for early stage companies. I started making environmental analyses about 7 years ago to demonstrate the lifecycle value of a fuel made directly from a photosynthetic plant.

Why do we care about lifecycle analyses?

Around 2 billion cars have been built over the last 115 years; twice that number will be built over the next 35-40 years (Emmott, Stephen, Ten Billion, p. 95, New York, New York: Random House, Second Edition, 2014). The environmental and health impacts will be enormous. The automotive industry has $9 trillion a year in revenue and employs 11 million people.  And that doesn’t include oil & gas, a $4 trillion industry employing another 1.3 million people. These giants greatly affect the world’s material flows and all the consequences thereof. Unfortunately, very little has changed in the manufacture and use of vehicles in the last 100 years – our cars are getting bigger, heavier, and often less efficient at using energy. At Divergent, we intend to change this trajectory.


There are many types of environmental analyses, and they vary in both scope and kind. For this discussion, we are focused on environmental lifecycle analyses. Lifecycle analysis follows the path of an object through a system for its full lifetime, looking at its environmental impact at each stage of life. Lifecycle analyses can be performed on cars, toasters, a strawberry, or even a human being.

The exact scope of a lifecycle analysis is one of the trickiest questions: which parts of the life cycle do you include, and which not? For the strawberry, do you include the cost of making its fertilizer, the cost of its transportation to the grocery store, the cost of its disposal (e.g., the green tops, the rotten berries), and the cost of its packaging? The total cost of environmental and health system damages varies widely depending on the scope.

The gold standard in vehicles – GREET

In vehicles, thankfully, the Argonne National Lab has set the gold standard through a model called GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation Model). The first use of GREET was in 1995, and it has been peer- and industry-reviewed very thoroughly in the intervening 20 years. The scope of this model is quite wide – it looks at both vehicle operation and manufacture (vehicle cycle) and fuel manufacture and use (fuel cycle). It is also quite deep, capturing emissions down to the extraction and manufacture of materials (e.g., aluminum, lithium), as described in the image below:


The Argonne GREET model was also used for the 2009 National Academy of Sciences report “Hidden Costs of Energy: Unpriced Consequences of Energy Production and Use”, mentioned in the introductory article of this series).

What is the scope of GREET?

This model is very detailed and robust. It contains more than 100 fuel production pathways, such as corn ethanol, gasoline from algae, and cellulosic ethanol from switchgrass. It contains more than 70 different vehicle types, from a standard gasoline car, to an electric car, to a lightweight compressed natural gas vehicle.

GREET also looks backward into the manufacture of a vehicle quite deeply. As an example, consider the chassis of a vehicle. In GREET, even the transmission system (i.e., gearbox) is broken down into 8 major material types, each of which is accounted for separately in the model:  steel, copper, cast iron, magnesium, wrought aluminum, cast aluminum, average plastic, and rubber.

This level of detail, both in breadth and in depth, is necessary to create an accurate picture of the emissions of the vehicle across both its manufacture and its operation.

Inputs and outputs

GREET is free and publicly available for download. It is also, essentially, open source: if you download the Excel version, you can change any variable in the system that you wish.


However, to reduce the complexity in the model and variations in the answers, there are a limited number of inputs that are commonly changed. These include:

  1. Vehicle type
  2. Fuel type
  3. Total weight
  4. Balance of materials

Vehicle type has options such as standard internal combustion gasoline vehicle, electric vehicle, and lightweight compressed natural gas vehicle. Fuel type is tied with vehicle type, but there are many variations for each vehicle type. For example, an electric vehicle can use only electricity, but that could be electricity from the U.S. National Grid or from a coal-heavy region like the Midwest. A gasoline vehicle can use fuel with 15% corn ethanol or 5% cellulosic ethanol.

Total weight is a high-level, summarized factor that greatly affects the outcome of the GREET model. A Tesla Model S weighs approximately 4,700 pounds: every foot traveled by that vehicle is a result of moving 4,700 pounds of material. And at least 4,700 pounds of material needed to be manufactured in order to make the car (in reality, due to wasted materials, it is much more than that). In contrast, the Divergent Blade is 1,400 pounds, which makes it easier to move and easier to manufacture from an environmental standpoint.


There is also a common set of outputs created by GREET, showing the emissions of a vehicle across both its fuel cycle and its vehicle cycle. These are calculated on an energy/mile or grams/mile basis, depending on the output. Here are the most common outputs:

  1. Total energy
  2. Fossil fuels
  3. Coal
  4. Natural gas
  5. Petroleum
  6. Water consumption
  7. CO2 (VOC, CO, CO2)
  8. CH4
  9. N2O
  10. Total greenhouse gases (GHG)
  11. Volatile organic compounds (VOC)
  12. CO
  13. NOx
  14. Particulate matter large (PM10)
  15. Particulate matter small (PM2.5)
  16. SOx
  17. Black carbon (BC)
  18. Organic carbon (OC)

If you look at the examples included in GREET, it’s worth noting that a gasoline car uses a fair amount of natural gas. Why? Natural gas is used to make electricity, and electricity is used to make the materials that comprise a gasoline car and is used for its assembly. An electric vehicle typically uses a fair amount of coal, since coal is a major factor in the U.S. electricity grid.

What’s next in this series?

In the next posting in this series, we’ll discuss AP2 (formerly known as APEEP), which translates the output of GREET into environmental and health system damages.

We had a terrific response to the keynote speech at the Solid Conference at the end of June. You can watch the full video of Kevin’s speech here.

We also wanted to make the presentation available as a downloadable pdf, available here. It contains all the visuals, overlaid with some of the narrative from the speech.

DM Solid Keynote 2015 Standalone v03

Antonia Czinger

When my father told me about his idea for Divergent, I felt more than supportive: I felt inspired and driven to help him succeed. My father has had more than one ambitious project over the years, but this was the first time I felt that his idea wasn’t just cool but could work to make the world a better place in a radical way, both for humans and the other creatures who share it.

As someone with a basic affinity for breathing and real love for flora and fauna, the environment has always been important to me. In fact, when I was a child, I considered a day wasted if I didn’t spend 90% of it outside in a tree like some strange human/monkey hybrid. Unfortunately, as many of you know, in the millennia since our ancestors descended from that primordial foliage and started producing iPhones and Diet Coke cans, we’ve developed some truly unsavory habits, consuming resources at an unsustainable rate and causing climate change. Considering the sad fact that we can’t just grow the planet larger at will, dematerialization (using fewer resources) is the best way to avoid catastrophe. Cars are one of the most polluting assets we own, so building one for a fraction of the environmental damage makes a real, potentially life-saving difference.

While the prospect of saving our beloved ecosystem instantly captured my attention, as my dad and I continued talking, I also grew to appreciate the small-business aspect. Someone pointed out that the cost of opening a microfactory is roughly the same as that of opening a microbrewery. With this financially feasible plan, more people will be empowered to be entrepreneurs, leading to more job creation. Large corporations wouldn’t have to rule the roost. Innovation and creativity could bloom. Vehicles previously considered too niche to be produced would find a place on the open road. Greener technologies could be developed more easily, creating a feedback loop far more encouraging than the one involved in the melting of the polar ice caps.
I was sold.

In fact, I was sold enough to ask my father if there was a way for me to contribute. Since I studied theater in college, engineering or technical work was out of the question; however, we soon landed on the idea of starting a blog. Fabulous. Since I am very interested in learning more about our environment, our economy, and how the Divergent philosophy of dematerialization and democratization fits in with these two concepts, and since I love reading almost as much as love having a planet to live on, I thought the blog could consist primarily of book reviews. Every week, I plan to read a piece of relevant literature (often literature that inspired my father), and tell you what it’s about and how Divergent might fit into its framework or jive with its argument.

With any luck Divergent will be about more than just car manufacturing. It could be an environmental and ideological movement. But in order to be a movement, we need context and reasons to care—though of course there will always be those who will buy in just because the product is amazing (and that’s alright too).


Around 2 billion cars have been built over the last 115 years; twice that number will be built over the next 35-40 years.

The environmental and health impacts will be enormous. Some think the solution is at hand with electric cars or other low or zero emission vehicles. The truth is that if you look at the emissions of a car over its total life, you quickly discover that tailpipe emissions are just the tip of the iceberg. An 85 kWh electric SUV may not have a tailpipe, but it has an enormous impact on our environment and health. (more…)

A new, low impact model for manufacturing based on Divergent’s dematerialized approach

The current approach to manufacturing is expensive, wasteful, and energy-intensive; it hurts our environment as well as our economy. When it costs hundreds of millions of dollars to start a car factory, innovation becomes impossible. As we triple the number of cars on the road in the next thirty to forty years, the conventional approach is not sustainable. (more…)