Oil Energy Independence – Can You Spare a 31-Mile Square?


Imagine that every car in America was an Electric Vehicle (EV) powered by a electric battery like the Tesla’s (Nasdaq: TSLA) Roadster.  Imagine also that each and every car was powered with solar energy. Here’s a question: what amount of land would you need to generate the solar energy to power every electric vehicle in America?  And how would that solar acreage compare with the land surface that the oil industry uses to drill today?

I did the numbers and the answer will surprise you.

Part of the angst with the recent BP (NYSE: BP) oil spill in the Gulf is that many think we are addicted to oil and therefore can’t stop drilling. U.S. Presidents since Nixon have proclaimed our addiction to oil and after announcing their plans for energy independence  oil demand has gone up. I have a different view.

We’re not addicted to oil. We are addicted to driving.

It is highly unlikely that as a society we’ll stop driving anytime soon.  The good news is that we can drive as we have been while not polluting the Gulf, import oil or use oil at all. The way to do it is to shift the way we power our cars – from gasoline to electricity – and power those cars with the sun.  I have previously predicted that the last commercial Internal Combustion Engine Vehicle (gasoline car) will be built around 2030.

So assuming all cars in America are battery electric vehicles and we drove exactly the same number of miles we do today, let’s calculate how much electricity we would need to power all of them.

Electric Vehicle Battery Power

Americans drive around 3 trillion miles (4.8 million Km) per year, according to the U.S. Department of Transportation.  How much electricity would be consumed driving all those miles?

I assume that Lithium-Ion battery can power an electric vehicle for about 4 miles (6.4 Km) per kilowatt-hour (kWh).  This is slightly lower that the advertised mileage of three battery electric cars as shown on the following table.

Battery Size(kWh) Miles per charge km per charge Miles per Kwh km per kWh
BYD E6 48 205 330 4.3 6.8
Tesla Roadster 53 245 392 4.6 7.4
Nissan Leaf 24 100 160 4.2 6.7

So 3 trillion miles divided by a mileage of 4 miles per kWh means that Americans will need 750 billion kWh annually for driving.

Now let’s calculate the total land needed by solar power plants to generate this much electricity in a year.

Solar Land Needs

The total power generated for a given land area will be given by the following formula

Power Generation = Land Area * DNI * Sunlight-to-power efficiency

(see the definitions and my assumptions below):

I’m using 15% efficiency and a DNI of 2,000 kWh/ m2/yr (see notes below for more).

Resolving for Land Area we get:

Land Area = Power Generation / (DNI * Sunlight-to-power efficiency)

=  750 billion kWh/year / (2,000 kWh * 0.15)

= 2,500,000,000 m2

= 2,500 Km2

= 965 square miles

So here’s the number: 965 square miles (2,500 Km2). That’s less than 1,000 square miles!  What this means is that a solar square with  31.1-mile sides (50 Km) could generate all the power that would power every single  car in America (assuming they were all electric vehicles.)

Ted Turner’s ranch in New Mexico is about 244 square miles – so he alone could generate enough electricity to power 25% of all cars in America. A solar plant the size of King Ranch in Texas with its 1,289 square miles could generate all of America’s electric vehicle power with 30% extra electricity to spare – maybe export it to Mexico?

The solar number is 1,000 square miles. Let’s compare this number with what the oil and gas industry uses today to power our gasoline cars.

Oil & gas land use

According to the U.S. House of Representatives, oil and gas companies lease 74,219 square miles (47.5 million acres) of land in the United States to drill oil. They also lease a further 44 million acres (68,750 mi2) for offshore drilling (2). Adding these two numbers we get that the oil and gas industries lease 143,000 square miles from the U.S. government—to meet just about a third of America’s transportation needs.

So to power just about a third of our cars, oil companies need 143 times the land that solar would need to power every single car in America (assuming they were all electric vehicles.)

Needless to say, oil drilling leaks and spills damage more land and water than the above numbers reveal. The BP (NYSE: BP) Gulf Oil disaster has damaged tens of thousands of square miles beyond its drilling permits.  As of June 2010 the U.S. National Oceanic and Atmospheric Administration (NOAA) Fisheries Services had closed an area around 80,000 square miles of water from commercial fishing.

The BP Oil Spill alone is eighty (80) times larger than the desert land that solar CSP plants would need to power every car in the United States (assuming they were all electric).  And no one has ever heard of a solar spill.

The conclusion is simple: oil is not just dirty – oil is a land and water hog. Solar is more than 100 times more land efficient than oil – without the pollution.

What does this mean to entrepreneurs?

When the most abundant source of energy on earth (solar) is also is 100 times more resource efficient than the competitor (oil) the message is clear: the transition from oil to solar to is going to happen.  It’s just a matter of when not if.   As the car industry also transitions to electric vehicles keep in mind this solar number:  just 1,000 square miles of solar plants in the desert can power all the (3 trillion) vehicle-miles driven every year in America. That’s what I call ‘Solar Trillions’!

Definitions and Notes

Battery Electric Vehicle range and mileage like gasoline car mileage will depend on many factors, including the car itself (weight, quality), driving conditions (city, highway, traffic, weather), driver, and so on.  Furthermore, not all Lithium-Ion batteries are made equal.  The number I came up with was based on a decidedly unscientific sample of three battery electric vehicles (Tesla Roadster, BYD E6, and Nissan Leaf) from three different countries (US, China, and Japan).  I used 4 miles per kWh of battery.

DNI = Direct Normal Incidence radiation. DNI depends on the location. I’m assuming the solar plants are built in desert land in the U.S. Southwest, which generally have high DNI. A solar plant in Barstow, CA, may receive more than 2,700 kWh/m2/yr while Las Vegas, NV, or Tucson, AZ, receive about 2,560 kWh/m2/yr.  I used 2,000 kWh/m2/yr.

Sunlight-to-power efficiency = What percent of the solar radiation (DNI) is converted to power.  This number also depends on the technology used. Thin film photovoltaic might convert less than 10% while Dish Sterling CSP efficiency may be closer to 30%.  Solar CSP with Combined Heat and Power (CHP) can have an efficiency of 75%-80%.

However, you need extra land for things like roads, power block, offices, and so on.  I used 15% efficiency.  Expect this number to go up over the next few years as new innovations, learning curve, and scale advantages kick in.


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  1. You’ve overlooked one vital fact: most people want to drive during the day, precisely the moment at which your 1000 square miles of solar plant will generate electricity.

    Storing the electricity generated during the day by photovoltaic panels would require an additional set of batteries that would then have to be discharged overnight to recharge the electric cars’ batteries. The battery is the most expensive single component of an electric car, so you’re looking at a huge increase in the cost associated with each car if you do things this way.

    Then there are the inefficiencies inherent in using that additional layer of batteries: you would need even more land covered in photovoltaic panels to compensate for the energy lost as heat during the charging and discharging processes.

    There’s also the problem that people are more likely to want to drive than to walk or cycle when the weather is wet, or cold in winter (and your photovoltaic panels are getting less sun.)

    One thing you’ve got right, though: people are not addicted to oil, they’re addicted to driving. Surely that is the societal illness we need to treat, rather than getting them hooked on some other energy source to get their fix?

  2. This is really a fantastic article.Out of the first 10 “developed” nations, USA is not even on the list for making alternative energy a priority.We have abundance of land in the Southwest. Mainly the Indian reservations (Navajo and Hopi) in Northern Arizona is sparsely populated. This land could be leased, use the land to produce energy with public and private partnership. The leased amount could be used to build hospitals, assembly plants, parks, homes for the local population and training facilities.I had lived in Northern Arizona for 23 years. I know this area well. These people have been living in one of the most squalid conditions despite the efforts of federal government’s efforts.The true unemployment is almost 40%

    Given the ongoing saga of Gulf oil spill, it is time we stopped talking and do something constructive to stop the out flow of dollars to support our addiction to driving and ever increasing thirst for oil.

    The cost of batteries will come down with increasing demand. The technology is also improving the performance of these batteries compared to 10 years ago.We do not a 3 ton SUV to go back and forth to work, shopping or even short trips. Make the cars lighter and more efficient.(Case and point TATA NANO).

  3. Mr. Seba, you do make valid points. But I’ll have to remind you that we are also addicted to flying. It’s going to be impossible to get all the airlines converted to solar – ever. I also think you are being overly optimistic about 2030 as the time frame for all cars being electric. It’s going to still be a mixed bag by then. There’s just to many people stuck in the conventional fossil fuels bandwagon, competing with alternative energy. Remember Mr. Fusion in Back to the Future? We haven’t even tried that yet.

  4. Lew Perelman on

    Blorg is on the right track. While Tony makes an interesting point, the real costs of such a conversion would be quite substantial. First, solar power generation currently needs almost ideal desert conditions to be anywhere near to grid parity cost. But to that, as Blorg notes, must be added the even greater cost of storage to make up for the intermittence of solar radiation. Adding wind to the ‘renewable’ power supply may smooth out the supply curve somewhat. And traditional hydropower — often opposed by ‘green’ activists — offers the most cost-effective means of backup and load-leveling.

    However, all of these ‘natural’ energy sources are subject to substantial decline or interruption by variable meteorological conditions. Even parts of the US southwestern deserts are at times covered with clouds and rain or even snow. Areas can experience a ‘drought’ or wind or precipitation for prolonged periods. The only reliable source of backup power that does not entail fossil fuels and that can cover these contingencies is nuclear power. But aside from its substantial costs and hazards, nuclear power is suitable only for constant baseload power supply, not variable peaking power.

    Natural gas, however, is suitable for variable load generation. And the domestic supplies are increasingly abundant. Hence, the Pickens Plan: combine natural gas and wind (or other solar power) generation to replace the petroleum-based fuels now used to power most transportation.

    Changing power sources is still only part of the cost of converting the existing transportation system. Changing power sources requires a massive extension and renovation of the existing electric grid whose total cost is estimated in the hundreds of billions of dollars. Not only does the cost of grid expansion demand additional land area, but also the costs of acquiring rights-of-way, compounded by the costs of litigation and lobbying related to the inevitable local opposition to transmission lines. Indeed, similar litigation and political costs attend the development of central-station solar power plants, wind farms, geothermal plants, hydroelectric dams, etc.

    The cost assessment of the electric-transport vision is still incomplete. Replacing the entire rolling stock of over 250 million motor vehicles currently in use in the US with electric or other alternate-power vehicles would cost over 6 trillion dollars at the very (too) modest cost of $25,000 each. And that is not counting the immense cost of disposing/recycling all the obsolete vehicles.

    To that the social costs also must be added: the loss of hundreds of thousands if not millions of jobs involved in the production, supply, distribution, sales, and service of existing vehicles, components, parts, fuels, and related systems; along with the economic disruption of not only businesses and industries but whole communities, regions, and states.

    The hypothetical promise of new, ‘green’ jobs and businesses, as we have seen, offers little comfort to those who face certain disruption, and who realize too well that those potential new opportunities may not benefit them.

  5. Do you propose to condemn people’s land for use in solar generation? Even Ted Turner might have other plans for his ranch, such as his natural gas field. Would you clean clear 1000 square miles? What about erosion? Frome whence the required water in a desert? Solar in the desert in Arizona is not going to make sense without the ability to transport it across country in a nation committed to opposing transmision lines.

    Additional requirements for solar energy:

    1) Water: Solar thermal requires huge amounts of water, a commodity by definition a problem in a desert. Even if for washing solar mirrors and panels after dust storms, water requirements are substantial.

    2) Transmission: X miles of right of way for transmission cables will be necessary along with reconfiguration of Y miles of grid; include step up and step down transformers, switching stations and substations.

    3) Specialized sealed landfill or other facilities for disposal/recycling/conversion of PV panels as the rare earths and other materials are highly hazardous.

    4) Specialized facilities for manufacture and assembly of PV equipment with provision for storage, disposal and recycling of materials and by-products.

    5) Aquatic insects mistake the solar panel and mirror surfaces for their habitats, laying eggs on the surfaces. Bad for the surfaces, bad for the insects, potentially disastrous for ecosystems.

    All is not sunny in the lookout for solar.

  6. Mr. Seba, it is clear that you may have overlooked a “few” major challenges. But rest assured that I am a strong advocate of alternative energy. It is indeed the long-term path to true energy independence and a greener environment. This is imperative for the survival of the human race, and the only way our modern society will be able to maintain our energy-hungry culture. It is exactly the resistance to change that makes it so difficult to solve our alternative energy challenges, in order to transform our society into a greener one. So people, PLEASE let’s stop gunning down the alternative energy advocates. Let’s admit that fossil fuels SUCK VERY BAD and that one day soon they will be ALL GONE. We must move forward and finally embrace solar, wind, hydroelectric, geothermal, and yes even nuclear energy as the SUPERIOR sources of energy.

  7. I really like your logic and your thought process, but please put things in perspective. According to http://www.eia.doe.gov/ask/electricity_faqs.asp, the total annual residential electricity consumption in the US is 1379 Billion kWh, which is not quite double your calculation of 750 Billion kWh needed for our cars. Said another way, if (when) we power all our cars with electricity, our residential demand will increase 50%, which is unfortunately not trivial. But then again, with (only?) 3000 square miles of solar panels (and enough storage to get us through nights and clouds) we could power all our energy needs with the sun.

  8. Dear comrades,

    I believe the author’s intention was not to propose building a solar power plant for centralized power generation. The numbers are for reference only for us to bear in mind that we can generate the electricity distributed. The idea of job generation via photovoltaic solar energy requires that the old concept of centralization (Generator concentration of income and hence poverty) should be abandoned and replaced by a decentralized system. The distributed generation of solar photovoltaics in the urban environment of cities but could generate energy for the new electric cars and solar heaters all heat and cold that we will need in the future. The vision is simple: conventional oil, and electricity will be too expensive to be used for applications such as heat water, turn on air conditioning and fuel the insane mobility model created by the chain of the automotive industry.

  9. @Carlos, you are right that distributed solar/renewable generation should be considered in them mix of options. However, the macroeconomic implications still remain daunting.

    First, broadly distributed solar/renewable generation would be substantially less efficient than when concentrated in optimal locations. As an alternative to centralized generation, distributed generation could avoid some or even much of the cost of electric grid extension. And under some hypothetical scenarios, large scale use of hybrid and/or electric vehicles could even help stabilize the grid by providing backup storage in vehicle batteries.

    But the feasibility of any large scale deployment of electrified vehicles is heavily dependent on broad, even national upgrading to a “smart grid” architecture. The latter is an undertaking that still faces difficult technical and socioeconomic obstacles. Estimates of the total cost of the smart grid upgrade range widely, from $165 billion (EPRI) to over a trillion dollars. Who is to provide the necessary capital investment, and how, remains unclear. Moreover, even if technically and financially feasible, the smart grid poses potentially disastrous security threats. While proponents concede that the security hazards must be solved before substantial smart grid deployment can be undertaken, the solutions so far do not exist.

  10. Richard Chrenko on

    @ Lew Perleman:

    Relative to the current costs to secure energy supplies in the Middle East and beyond, $165 billion to build a smart grid is peanuts. The invasion and occupation of Iraq in addition to the economic and military support given to various oil-rich Middle Eastern dictatorships have cost the United States well over $1 trillion over the past decade – a sum which would have been much more wisely invested in the transition of America’s energy landscape to local renewable sources and storage capabilities.

    Regarding “potentially disastrous security threats” of the smart grid, distributed generation provides a much more difficult target than does a small number of massive coal or nuclear powerplants. And the fact that virtually anyone can black out an entire city or region by plowing a semi-trailer into a critical high-voltage transmission mast doesn’t fill me with confidence about the security of our current grid.

    So let’s not get all caught up in potential problems, but rather forge ahead with solutions, even if they are initially sub-optimal. Because when it comes to providing an adequate and secure energy supply for America’s future, there is simply no time left to lose.

  11. Well, Carlos, solar has not thus far performed in Spain,

    At some point, after all these years of investment and subsidy, the alternative energy technologies and business models have to grow up and carry their own weight and water. All of the government and clean energy mandates, subsidies and wishful thinking cannot force poorly engineered technologies and empty business models to work or overcome the impediment of unacceptable operational risk for companies charged with support of the hundreds of millions of people dependent on any large regional section of the grid. In the clean energy industry, we’ve been retracing all this ground for three decades with little progress in technological performance. We all wish for an end to oil and gas and coal just as we wish for an end to war, famine, pestilence and disease, but wishing does not make it so.

    “Financial Times June 24, 2010

    Spain pressed over solar tariff cuts

    Spain’s cash-strapped government is under…plans to retroactively reduce special tariffs to photovoltaic (PV) energy operators…emission electricity from PV plants.Spain is the world’s leading per-capita…In recent years, generous feed-in tariffs – guaranteed wholesale prices – have…regulated returns to sink their savings into solar energy projects. Under the government… By Mark Mulligan”

  12. @Richard, with all due respect, I suggest your understanding of security issues is not well informed. First, it is fair to consider the relative cost-effectiveness of military, and perhaps also “homeland security” expenditures in relation to other hazards and social needs. However it is naive to suggest that all or even most security threats are related to access to petroleum resources. The Afghanistan-Pakistan region is largely irrelevant to petroleum supplies but nevertheless poses some of the most dire security threats to the US, its allies, and other countries. North Korea similarly is bereft of oil or just about any significant resources, yet poses a grave security threat. The persistent US commitment to the security of Israel certainly does not enhance the security of US oil supplies. The bloody war raging around and south of the US-Mexican border is driven by the drug not oil trade.

    It has only been about a century since petroleum became an important resource. Yet humans have found reasons to go to war since the beginning of history. The end of the petroleum age, whenever it may come, will assuredly not mark the end of war. If anything, historical conflict over access to territorial resources — land, water, forests, fodder, and food — is likely to resume and even increase.

    Your understanding of the threats to electric grid stability and security is also misconceived. Centralized power systems have always had points of vulnerability. But the large-scale expansion of the size of the grid, and of the number and complexity of the nodes and modes of interaction among elements of supply, transmission, and consumption, combined with the necessary connection to the Internet and/or other cyber-networks — all needed to accommodate an integrated. “distributed” architecture — geometrically compounds the system’s vulnerability to failure and/or attack. To better understand the security issues, I recommend, in addition to Richard Clarke’s new book on “Cyber War” and Charles Perrow’s book “The Next Catastrophe,” the following essay by Massoud Amin:


  13. I enjoyed reading this article. It was informative and shows a mind with a vision.

    If the prediction of the last gasoline car being built in 2030 is accurate, we only have 20 more years of the devastating effects of oil drilling. I can only hope it happens within the next ten years.

    Shell Oil is patiently waiting for the Alaskan Wildlife Refuge leases to reopen, the Canadian Oil sands requires more fuel to make the fuel and all the oil in the Gulf is on the sea floor. Yet we give $500 billion to oil subsidies and 45 billion to clean, renewable energy? What are the people in charge thinking?

    The land for solar panels is not necessary, use that formula to calculate the rooftop real estate and you will be more likely to effect the economy in an even more positive way.

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