Add it up: Doing the math on electric cars

Editor’s note: The opinions expressed by our contributing staff writers are their own and do not necessarily represent the opinions of the Houston Museum of Natural Science.

Electric cars are a popular idea. You see them in movies, hear about them in songs, and especially get to know them via inventive commercials. They claim that they produce no pollution, unlike their dinosaur automobiles with the internal combustion engines. But are they as green as they claim to be? (Note: For this blog I’ll be talking about pure electric cars, not hybrids.)

Doing the math on electric cars

A normal gasoline-using car produces pollutants as a result of converting fuel into movement. An electric car uses stored electricity to propel the vehicle. But how much pollution was created while creating the electricity? To compare the two, we’ll have to find some way to make gasoline and electricity equivalent. Fortunately, we can convert both to one unit: joules. While you might want to wear a jewel, a joule will help you get work done. A joule (abbreviated by “J” ) is a unit of energy. It’s the equivalent of applying 1 ampere through a resistance of 1 ohm for 1 second, or the force of 1 Newton over 1 meter.

A gallon of gasoline contains about 1,300,000,000 joules. One kilowatt of electricity contains 36,000,000 joules. So 1 gallon of gas produces about 36 kilowatt hours.

Burning a gallon of gasoline to move your car produces about 20 pounds of carbon dioxide. One kilowatt hour can produce different amounts of carbon dioxide, depending on what energy source was used to make it. In the United States, much of our electricity (about 42 percent) comes from coal-fired power plants. One kilogram of coal can produce 2 kilowatt hours and 2.93 kilograms of carbon dioxide. That’s about 3.3 pounds of carbon dioxide per kilowatt hour, which means that 1 gallon of gas’ equivalent in electricity produces 118 pounds of carbon dioxide if all the electricity is made from coal-fired power plants. From this information, it seems that the internal combustion engine outperforms the electric, but not all electricity comes from coal.

While the majority of our electrical generation comes from coal-fired power plants, there are other energy sources. Thirteen percent of our electricity comes from renewables such as wind and solar power, which produce no carbon dioxide. Nuclear power gives us 19 percent of our electricity and produces no carbon dioxide, either. Using this division of power sources, the amount of carbon dioxide produced making electricity for an electric car has been reduced from 118 pounds to just 8. But what about natural gas?

Natural Gas is measured by the MMBTu (one million British thermal units), which is about 1,000 cubic feet (1 mcf). One mcf of natural gas produces 122 pounds of carbon dioxide and can produce about 29 kilowatt hours. Are you still with me? This means that natural gas produces about 4 pounds of carbon dioxide per kilowatt hour. So when we add that back into the mix, our electric car is producing about 9 pounds of carbon dioxide per kilowatt hour. A gallon of gas is about 36 kilowatt hours and produces 20 lbs of carbon dioxide, or about half a pound of carbon dioxide per kilowatt hour.

Does that mean that electric cars produce more carbon dioxide than ones that run on gas? Maybe, maybe not. All those numbers are based on the national average of the energy mix. If renewables provide more electricity in your area, the amount of carbon will decrease. If you get your electricity from an all-renewable company, then you’re producing no carbon. Also, this blog has only addressed the amount of carbon dioxide produced directly by energy sources. It has not included all the other pollutants produced. It has not included the entire life cycle of the energy source. For example, a nuclear reactor produces no carbon dioxide, but mining uranium is a very energy intense project. Wind turbines produce no carbon dioxide while creating electricity, but carbon dioxide is produced when they are built.

The amount of carbon dioxide produced by electric cars can be brought down easily, where the amount produced by internal combustion engines can not. yo could switch the source of electricity. You could take stored electricity and use it for you car. Because our grid is a stupid grid and not a smart grid electricity is put on the grid as needed. If there is a moment with high wind generation and a high need for electricity, then the amount of carbon produced decreases. If the wind stops blowing and the need is still there, then the more traditional sources kick in and the amount of carbon produced goes right back up.

So while an electric car, on average, may currently produce more carbon dioxide than a gas-powered car, depending or your location and your electric provider, your electric car may be producing no carbon dioxide. Also, while there is little hope to improve the internal combustion engine to eliminate the production of carbon dioxide, researchers hope to eventually eliminate the carbon produced by an electric car. So “Let’s take a ride in an electric car/To the west side in an electric car/How can you deny an electric car/Won’t you take a ride with me/Come on and take a ride with me!”

All Along the Watch Tower: United States Military and Renewable Energy

“In the councils of government, we must guard against the acquisition of unwarranted influence, whether sought or unsought, by the military industrial complex. The potential for the disastrous rise of misplaced power exists and will persist.” – President Dwight D. Eisenhower, Farewell Address 1961

Over sixty years ago our president warned us of not letting a group, no matter how good their intentions, have undue influence on our government and people. In specific he was warning about the military industrial complex, or the different defense contractors as an industry (Michael Crichton has since warned about the politico-legal-media complex that he argues has replaced them). He was worried that a coordinated effort by any group would give them power to incant changes that would be harmful to the government and its people. But just as it has the potential for harm, it has the potential to help. And that’s what the military will do with their new energy policy.

This is the first time the United States military has created an energy policy that focuses on efficiency. Before now, it has been a policy of using as much energy as needed to get the job done regardless of its efficiency.

What has changed?

The military has come to a public realization that its’ current reliance on conventional energy and fuels are unsustainable and therefore they should take an active hand in solving the problem.

USS Midway aircraft carrier
Creative Commons License photo credit: cybaea

The military has always been conscious of their energy needs and the need for a more efficient and usable energy source. The Navy first used wind, but as technology advanced they went with propulsion systems that could provide more reliable and efficient energy. While wind is free, it does not always blow in a given area. This would lead to ships lost because they did not have wind. The Navy changed to coal and established a series of bases around the world to hold coal for them. Then they switched to oil and were able to have fewer bases to hold supplies. After that some ships converted to nuclear power. This allowed them to stay at sea for years at a time.

While the military has been moving towards a more efficient model, they have not had a well defined plan. And now they do. Currently the military uses about 1% of the fuel used in the Unites States, or about 5 billion gallons annually. As we all know the cost of fuel goes up. The military spent around $13.5 billion on fuel in 2010. The price has increased by 255% since 1997, and they expect it to continue to increase.

The Department of Defense’s new energy policy calls for 3 specific goals:

More fight, less fuel.

More option, less risk.

More capability, less cost.

These are good goals for good reasons. In 2010 there were over 1,100 attacks on military convoys carrying fuel to forward units. Less use of conventional fuel would mean fewer attacks, and would free up more units to go to the front. Today’s soldier on the ground carries over 10 pounds of batteries to operate his equipment. By 2013 it will be up to over 20 pounds. They will need more efficient equipment to keep the weight constant or even reduce it.

The Department of Defense is also shrinking its budget.

The Army is planning to use $1.4 million to implement a program to monitor their energy usage. It’s important to know what goes where and how much. It can be a little bit more challenging if it’s spread across 4 continents. They have another $5 million earmarked to help develop solar and wind generators to be used on the front lines. While solar powered battery rechargers have already been used in Afghanistan, there is need for more and better use of solar and wind power generation. $20 million is going to help reduce the weight of batteries and expand the capability of the dismounted soldier.

The Navy has plans as well. They have set aside $133 million for science and technology research. $16 million will be used toward making hybrid electric drives for ships. What is that, you may ask. It’s a drive that while still using fuel, can also run on a battery. If you have ever seen a Toyota Pruis, you have seen a hybrid electric drive. Currently, most ships use steam power to turn a turbine, which powers and moves the ship. With a hybrid drive, like a Prius, the Navy would save fuel. Ships would work even better with a smart meter and a smart electrical system. A smart meter would keep track of which systems are using electricity. If the entire system was smart it would optimize the electrical usage by giving just the systems that currently (that pun again) need electricity just the right amount. The Navy’s fleet is also moving to more bio fuels. Imagine fleets of ships and planes that run off of a bio fuel.

The Marine Corp (OORAH) has an ambitious plan as well. Their first step is to instill an energy efficient conscience. They also plan to reduce their use of fuel by 50% over the next 15 years (with a 25% decrease in 4 years). This is so the modern day Spartans will be more self-sufficient. Instead of having to shepherd supplies to the front, the Marines can focus on the front. They will be deploying more solar and wind arrays and even doing the small things such as using LED lights.

Air power on display at Red Flag 10-4 [Image 3 of 3]
Creative Commons License photo credit: DVIDSHUB

The Air Force plans on reducing their fuel needs by 10% in the next 4 years. They are also doing research into new and lighter materials to reduce the weight of planes. The Air Force Academy in Colorado Springs is ramping up its use of solar energy and trying to become 100% renewable.

So why does this matter to me?

While I enjoy a good military thriller, how can an energy efficient military help me? If the military uses less fuel, there is more on the market for me to buy. By reducing their costs, and therefore the amount of money my government spends, they have the potential (however small) of helping to lower the deficit.

But what will help the most is all the technology and procedures that they’ll develop. The military industrial complex is a large industry. Because of that they try to find multiple uses and markets for their products. They’ll repackage as much as they can for non-military use. Do I want a car that has a smart power system, so it can use less energy? Sure, I would even be OK if it did not have a combustion engine (as long as it still worked). Do I want smaller batteries that last longer? Of course, I would love for the charge in my iPod to last more than one chapter of a Patrick O’Brian novel.

Changing Energy Policies Across the Globe

Nuclear Power Plant
Creative Commons License photo credit: Intamin10

Japan will cut its electrical use by 15% this summer. After the earthquake, tsunami, and nuclear disaster, their electrical production capability has been decreased. Nuclear power plants made up for a quarter of their electrical production. After the disaster at Fukushima, public opinion in Japan has shifted against using nuclear power. Because of this, some plant managers in Japan are postponing turning their reactors back on after scheduled maintenance. Not only are they concerned about making sure their reactors are safe, they don’t want to take the reactor down again once new government regulations come into effect.

Time for some 101 facts about Japan.

Just to make sure we’re all on the same page, Japan is an island, or rather, a chain of islands. Japan is an energy power house. While it is only the 10th most populated country, it is 3rd  in electrical generation. (America has double the population and is the largest electrical producer, China has the largest population and is second in electrical production.)

Japan does not have a lot of crude oil or natural gas. Most of what they use is imported. That’s one of the reasons they turned to nuclear power for electrical production. It takes fewer imports to run nuclear facilities than the coal, oil, and natural gas equivalents. There have also been fewer uranium crises than oil crises during the last 50 years.

In order to reduce electricity usage, the Japanese government has called for office thermostats to be turned up to 82 degrees Fahrenheit throughout the entire summer. This is an easy way to save electricity, however it would be very uncomfortable in a 3 piece suit and tie. The government is promoting a new “Super Cool Biz” look. They are encouraging people to wear shorts and polo shirts. The government is getting some resistance. While I would love to have to wear only polos and shorts (guess what I’m wearing now) at work, a nice suit and tie does bring off a certain professional air.

Upolu Point Wind Farm
Creative Commons License photo credit: footloosiety

With all that has gone on, some countries are rethinking their strategy for nuclear power.

Germany has decided to shut down all of its nuclear reactors over the next decade. Nuclear power generation currently (ha, a pun) accounts for nearly a quarter of their entire electrical generation (coal counts for about half, and renewables counts for about 16%). They plan to convert all the nuclear power generation into renewable. There may not be as much hot air in Germany as there is in the States, but Germany is the second largest producer of wind produced electricity (with the United States being first). In fact it makes up nearly 7% of their total electricity generation.

If the German government wants to bump wind up to over 30% of their electrical production, not only will they need to install more wind turbines, but they’ll also need to replace the older models with new and more efficient models. They will also need to bump up their solar energy. While Germany is one of the top installers of photovoltaic cells, solar only accounts for a few percent of their energy production. With more efficient cells, it should not be too hard to move that number up.

The Italians also voted to abandon nuclear power again.

They abandoned it after Chernobyl and do not have any actual nuclear plants. The vote was more a comment on their current Prime Minister who favors the use of nuclear power.

France is still a proponent for nuclear generated electricity to remain in the EU’s energy mix. France is one of the largest producers of nuclear generated electricity. It accounts for over 80% of their electrical power generation.

As with most exciting things in the world, we’ll have to watch and see what unfolds.

America’s New Energy Policy

On Wednesday, March 30 President Obama revealed an update on his energy policy for the country.  He called for a 1/3 reduction in the importation of foreign oil from 2008 levels in a decade or so.  His plans to pull this off include more domestic drilling, more reliance on other fuels and alternatives, and greater efficiency.

Every president since Nixon has tried to limit or end our reliance on imported oil.
“Let us set as our national goal, in the spirit of Apollo, with the determination of the Manhattan Project, that by the end of this decade we will have developed the potential to meet our own energy needs without depending on any foreign energy source.”
- President Richard Nixon (November 7, 1973)

Despite the fact that every president, regardless of party, has proclaimed the need to reduce oil imports and develop alternative energies, the amount of oil we import has almost always gone up. (There was a period in the mid eighties where it went down).  So what has changed?  What makes now different from 1973?

Technology has advanced; progress goes forward (if you’re a modernist).  But what has really changed is how we see energy in our lives.  From the 1980’s onward, the price of gasoline has continued to rise.  Two very different things happen as the price of gasoline rises.  One is that the gasoline costs more, not online dollars but as a per cent of our lifestyle.  The other thing is that alternatives become more attractive, cost effective, and more people use them.  It may not be worth my time and effort to pay a $1.25 to ride the light rail one way if gasoline costs $2.50 a gallon, but it does become time and cost effective around $3.75 a gallon. 

Creative Commons License photo credit: barekim

The United States has 22 billion barrels (1 barrel = 42 gallons) of proved crude oil reserves.  Proven reserves are oil that we know where it is, have the technology to get to it, and it is economical to go after it.  Unproven oil reserves are what we think is probably there (based on the geology) or what we know is there but don’t have the technology to get to. Each year the amount of proved reserves changes.  This can be because new fields have been found; old fields are no longer producing, improvements in technology, and many other reasons.  To put that amount in perspective,  Saudi Arabia has 267 billion barrels in reserve and Mexico has 12.  We use 21 million barrels of oil a day, so if we had all our proven reserves producing 21 million barrels a day they would last almost 3 years.  So domestic drilling will help, but it can’t be the only way to go.

Other energy sources will have to be tapped.  One of the alternative fuels the presidents mentioned was natural gas.  Natural gas burns cleaner than coal or gasoline.  Right now natural gas is used mainly for electrical power generation and crude oil for transportation.  In order for natural gas to replace some or most of our crude oil use, there would have to be a major infrastructure shift.    Natural gas can not simply be put into gas tanks (it does not help that many different things are called by the same name).  A car would have to be retrofitted with a specially made natural gas tank.  That new tank would probably have some freezing element in it.  Natural gas in its gas state takes up a lot of space.  If you freeze the natural gas down to -258 degrees it is reduced in volume by 600%.  Also gasoline stations would have to be converted to be able to contain natural gas.

Full of Sparks
Creative Commons License photo credit: jurvetson

Electric powered cars could be added to the existing grid and infrastructure more easily. It would take a whole lot less work to convert gas stations into electric stations, although with the amount of time it takes to charge an electric car it might be easier to work with businesses to put electrical stations in parking spots.  That way you could charge your car while you shop for groceries (no matter the size of my shopping list it always takes at least an hour for me to grocery shop, partially because of all the free samples and partially to make sure I have all the spices for my Bouillabaisse).  The more electric cars on the road, the more electricity we need to produce.  This is where it makes sense to use the natural gas: burn it to create electricity instead of using coal.  However, not all the houses built in the past 30 years will have the ability to plug in cars

Conservation is where a lot of oil can be saved.  The president wants to increase the efficiency in the cars we drive.  Some of us drive nice little sedans that get 30 or more miles per gallon (some of us even drive hybrids), while others drive SUV’s that get 12 or so miles per gallon.  While the choice of vehicle is an individual one governed by affordability, space, and use (it makes more sense to haul around 7 kids and their sports gear in a SUV than in a 2 door sedan), all cars can be made more efficient.  Weight could be saved on the frame by using lighter materials, the software that runs the engine (yes, lots of cars have software now, but no apps yet) can be optimized, or any number of things that can even be done after you’ve bought the car. 

All in all, the president’s plan to reduce the amount of crude oil we import over the next decade or so is an achievable end.  In fact it has already started.  We reduced the oil we import by 1.7 million barrels a day from 2008 to 2009.  So now what happens?   Many people will sit on the sideline waiting to see what legislation and regulations the federal government hands down.  “Change will not come if we wait for some other person or some other time. We are the ones we’ve been waiting for. We are the change that we seek.” We should all start the change ourselves. There are many different things we can do to use less oil.  Regular maintenance on your car, not having a trunk full of stuff, and driving less are just a few things you can do (for more information check out the ECC).