Crop that stores carbon

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Scientists split CO2 into CO and hydrogen

Researchers at Sandia National Laboratories in New Mexico have designed a a solar reactor to recycle carbon dioxide and produce fuels like methanol or gasoline.

The solar reactor contains 14 cobalt ferrite rings, each about one foot in diameter and turning at one revolution per minute. As an 88-square meter solar furnace blast sunlight into the unit, the rings heat up to about 2,600 degrees Fahrenheit. At that temperature, cobalt ferrite releases oxygen. The rings subsequently cool to about 2,000 degrees and are exposed to CO2. The cobalt ferrite, which is now missing oxygen, will take oxygen from the CO2. So, the reactor divides carbon dioxide into carbon monoxide and oxygen, leaving behind just carbon monoxide. With the cobalt ferrite restored to its original state, the reactor is ready for another cycle.

That carbon monoxide can then be used to make methanol or gasoline, which are essentially just combinations of hydrogen and carbon.

Scientists Use Sunlight to Make Fuel From CO2
http://www.wired.com/science/discoveries/news/2008/01/S2P

Cheers!
Sam Carana

Venus' runaway greenhouse effect a warning for Earth

Venus was transformed from a haven for water to a fiery hell by an runaway greenhouse effect, concludes the European Space Agency (ESA), after studying data from the Venus Express, which has been orbiting Venus since April 2006.

Venus today is a hellish place with surface temperatures of over 400°C (752°Fahrenheit), winds blowing at speeds of over 100 m/s (224 mph) and pressure a hundred times that on Earth, a pressure equivalent, on Earth, to being one km (0.62 miles) under the sea. 

Hakan Svedhem, ESA scientist and lead author of one of eight studies published on Wednesday in the British journal Nature, says that Earth and Venus have nearly the same mass, size and density, and have about the same amount of carbon dioxide (CO2). In the past, Venus was much more Earth-like and was partially covered with water, like oceans, the ESA scientists believe. 

How could a world so similar to Earth have turned into such a noxious and inhospitable place? The answer is planetary warming. At some point, atmospheric carbon triggered a runaway warming on Venus that boiled away the oceans. As water vapour is a greenhouse gas, this further trapped solar heat, causing the planet to heat up even more. So, more surface water evaporated, and eventually dissipated into space. It was a "positive feedback" -- a vicious circle of self-reinforcing warming which slowly dessicated the planet. 

"Eventually the oceans began to boil," said David Grinspoon, a Venus Express interdisciplinary scientist from the Denver Museum of Nature and Science, Colorado, USA. "You wound up with what we call a runaway greenhouse effect," Hakan Svedhem says. Venus Express found hydrogen and oxygen ions escaping in a two to one ratio, meaning that water vapour in the atmosphere — the little that is left of what they believe were once oceans — is still disappearing. 

While most of Earth's carbon store remained locked up in the soil, rocks and oceans, on Venus it went into the atmosphere, resulting in Venus' atmosphere now consisting of about 95% carbon dioxide. 

“Earth is moving along the curve that connects it to Venus,” warns Dmitry Titov, science coordinator of the Venus Express mission. 

References: 

Venus Express - European Space Agency (ESA) 

http://www.esa.int/SPECIALS/Venus_Express/SEMGK373R8F_0.html 

Venus inferno due to 'runaway greenhouse effect', say scientists 

http://www.physorg.com/news115477239.html 

Probe likens young Venus to Earth 

http://physicsworld.com/cws/article/news/32018 

European mission reports from Venus 

http://www.nature.com/nature/journal/v437/n7062/full/4371071a.html

Combat Global Warming with Evaporative Cooling

Combat Global Warming with Evaporative Cooling - by Sam Carana

To combat global warming, wind turbines along the coastline could be used for the dual purposes of generating electricity at times when there is wind and evaporating water at times when there is no wind. Just a small breeze over the water can give the top water molecules enough kinetic energy to overcome their mutual attraction, resulting in evaporation of water and associated cooling of both water and air.

Such dual use of wind turbines can be implemented at many places where turbines overlook water; evaporation will work most effectively in hot and dry areas, such as where deserts or dry areas meet the sea or lakes. Evaporative cooling will add humidity to the air, which can also cause some extra rain and thus increase fertility of such dry areas as a beneficial side effect.

The energy needed to run the turbines can be obtained and stored in a number of clean, safe and renewable ways. ]

At times when there is plenty of wind, surplus energy from the turbines could be used to convert Water into hydrogen by means of electrolysis. Alternatively, bio-waste could be burned by means of pyrolysis to create both hydrogen and agrichar, which could be used to enrich soils. The hydrogen could be kept stored either in either compressed or liquid form, ready to power fuel cells that can drive the turbines at any time, day or night.

Another alternative is to run the turbines on electricity from concentrated solar thermal power plants in the desert. A desert area of 254 km² would theoretically suffice to meet the entire 2004 global demand for electricity. Ausra offers a solar thermal technology that uses the sun's heat to generate steam, which can then be stored for up to 20 hours, thus providing electricity on demand, day and night. Ausra points out that just 92 square miles of solar thermal power facilities could provide enough electricity to satisfy all current US demand.

Finally, there are some environmental concerns about wind turbines. There are concerns about carbon dioxide being released into the atmosphere in the process of making the concrete for the turbines. To overcome this, turbines could be made using alternative manufacturing processes, which can be carbon-negative. Furthermore, a recently completed Danish study using infrared monitoring found that seabirds steer clear of offshore wind turbines and are remarkably adept at avoiding the rotors.

In conclusion, wind turbines have a tremendous potential. They can potentially generate 72 TW, or over fifteen times the world's current energy use and 40 times the world's current electricity use. Offshore and near-shore turbines can make seawater evaporate and thus cool the planet, at times when they are not used to generate electricity.

References:

Ausra
http://ausra.com/

Wind power - Wikipedia 

http://en.wikipedia.org/wiki/Wind_power

Evaluation of global wind power 

http://www.stanford.edu/group/efmh/winds/global_winds.html

Solar power and electric cars, a winning combination! 

http://www.gather.com/viewArticle.jsp?articleId=281474977115548

Agrichar 

http://www.gather.com/viewArticle.jsp?articleId=281474977139103

Alternative method of manufacturing concrete 

http://www.tececo.com/

Massive Offshore Wind Turbines Safe for Birds 

http://www.technologyreview.com/Energy/18167/


Footnote: This article was written by Sam Carana; it can be freely copied and published elsewhere, as long as the autor's name is retained in the article.

The FeeBate policy: a combination of a fee that funds a rebate

Below, I posted articles on areas ranging from urban planning, agriculture, waste treatment and transport to energy. These articles form part of a wider vision, a package of policies recommended for global adoption, all aiming to curb emissions of greenhouse gases; in each case, a FeeBate is proposed, which constitutes the most effective way to deal with global warming. Furthermore, the FeeBate policy is ideology- and budget-neutral and has the least risk of feeding a wasteful bureaucracy. 

In essence, the idea of the FeeBate policy is that a fee is imposed on products that cause emissions of greenhouse gases, while the proceeds of these fees in each case are used to help better alternatives. Items that should attract fees include fossil fuel, fertilizers, meat and polluting concrete. The proceeds of fees on these items should pay for rebates on clean alternatives in energy, such as solar and wind power, respectively supply of agrichar, alternative food (my personal favorite is vegan-organic food served in restaurants in communities without roads) and clean concrete. 

This approach constitutes the most effective way to reduce the three major greenhouse gases: carbon dioxide, methane and mitrous oxide. In many respects, markets are best suited to work out which products and technologies should get support - the main criteria should be that they are replacements for items that attracted fees, that they are safe and that they cause little or no emissions of greenhouse gases, or - even better - that they are greenhouse gas negative. Fees can be collected locally as long as each community is serious about reducing greenhouse gases; importantly, the proceeds should fund rebates on local supply of better alternatives. As an example, rebates on supply of clean and renewable energy can be funded by fees on coal that is burned to supply electricity in the area. Similarly, agrichar can be produced by means of pyrolysis from various forms of biowaste - rebates on sales of agrichar can be funded by fees on fertilizers. 

The concept should be adopted globally, but implemented locally; levels of fees and rebates can be adjusted on an annual basis, depending on how successfully the shift takes place. This FeeBate policy can be regarded as a form of geo-engineering; it will change the shape of urban planning, agriculture, waste treatment, transport and energy supply around the world; moreover, it will transform politics and the very socio-economic fabric of society on a global scale. 

In conclusion, the FeeBate policy that I proposed includes:

• a fee of 10% on sales of new cars with internal combustion engines, with proceeds used to fund rebates for electric cars
• a fee of 10% on sales of gasoline, with proceeds used to fund rebates on purchases and installation of facilities that produce renewable energy
• a fee of 10% on sales of coal, with rebates given when electricity suppliers install facilities that produce electricity from renewable sources
• a fee of 10% on building and construction work using concrete that contributes to global warming, with proceeds used to fund rebates on buildings that used clean concrete
• a fee of 10% on sales of fertilizers, with rebates on sales of agrichar
• a fee of 10% on sales of meat, with rebates and vouchers for vegan-organic foo

Agrichar

Most households only use one or at most two different rubbish bins, one for recyclables (paper & packaging) and one for general waste. It makes a lot of sense to add a third type of rubbish bin, for biowaste, i.e. kitchen waste, soil and garden waste.

Many people already compost such biowaste in the garden, but all too often such biowaste disappears along with the general waste in the rubbish bin. As displayed on the picture below, analysis in Waikato, New Zealand, shows that about half of household waste can consist of kitchen waste, soil and garden waste. Such waste ends up on rubbish tips, where the decomposing process leads to greenhouse gases, such as methane. And all too often, farmers burn crop residues on the land, resulting in huge emissions of greenhouse gases.

All such biowaste could deliver affordable energy by using the slow burning process of pyrolysis to produce agrichar or bio-char, a form of charcoal that is totally black. Organic material, when burnt with air, will normally turn into white ash, while the carbon contained in the biowaste goes up into the air as carbon dioxide (CO2). In case of pyrolysis, by contrast, biowaste is heated up while starved of oxygen, resulting in this black form of charcoal.

This agrichar was at first glance regarded as a useless byproduct when producing hydrogen from biowaste, but it is increasingly recognized for its qualities as a soil supplement. Agrichar makes the soil better retain water and nutrients for plants, thus reducing losses of nutrients and reducing the CO2 that goes out of the soil, while enhancing soil productivity and making it store more carbon.

When biowaste is normally added to soil, the carbon contained in crop residue, mulch and compost is likely to stay there for only two or three years. By contrast, the more stable carbon in agrichar can stay in the soil for hundreds of years. Adding agrichar just once could be equivalent to composting the same weight every year for decades.

Agrichar appears to be the best way to bury carbon in topsoil, resulting in soil restoration and improved agriculture. Agrichar has the potential to remove substantial amounts of CO2 from the atmosphere, as it both buries carbon in the soil and gets more CO2 out of the atmosphere through better growth of vegetation. Agrichar restores soils and increases fertility. It results in plants taking more CO2 out of the atmosphere, which ends up in the soil and in the vegetation. Agrichar feeds new life in the soil and increases respiration, leading to improvements in soil structure, specifically its capacity to retain water and nutrients. Agrichar makes the soil structure more porous, with lots of surface area for water and nutrients to hold onto, so that both water and nutrients are better retained in the soil.

In conclusion, recycling biowaste in the above way is an excellent method to produce hydrogen (e.g. for cars) and to bury carbon in the soil and improve production of food. Agrichar is now produced for soil enrichment at a growing number of places. The top photo shows agrichar in pellet form from Eprida. Australian-based BEST Energies has built a demonstration pyrolysis plant with a capacity to process 300 kilograms of biowaste per hour. It accepts biowaste such as dry green waste, wood waste, rice hulls, cow and poultry manure or paper mill waste. The plant cooks the biomass without oxygen, producing syngas, a flammable mixture of carbon monoxide and hydrogen. The agrichar thus produced retains about half the carbon of the original biowaste (the other half was burned in the process of producing the syngas).

Also important is to compare different farming practices. Carbon is important for holding the soil together. Farmers now typically plough the soil to plant the seeds and add fertilizers. This ploughing causes oxygen to mix with the carbon in the soil, resulting in oxidation, which releases CO2 into the atmosphere. Ploughing leads to a looser soil structure, prone to erosion under the destructive impact of heavy rains, flooding, thunderstorms, wind and animal traffic. Given the more extreme weather that can be expected due to global warming, we should reconsider practices such as ploughing.

Furthermore, the huge monocultures of modern farming have become dependent on fertilizers and pesticides. The separation of farming and urban areas has in part become necessary due to the practice of spraying chemicals and pesticides. Instead, we should consider growing more food on smaller-scale farms, in gardens and greenhouses within areas currently designated for urban usage. Vegan-organic farming can increase bio-diversity; by carefully selecting complementary vegetation to grow close together, diseases and pests can be minimized while the nutritional value, taste and other qualities of the food can be increased.

An issue of growing concern is nitrous oxide (N2O), which is 310 times more potent than CO2 as a greenhouse gas when released in the atmosphere. Much release of N2O is related to the practices of ploughing and adding fertilizers to the soil. Microbes subsequently convert the nitrogen in these fertilisers into N2O. A recent study led by Nobel prize-winning chemist Paul Crutzen indicates that the current ways of growing and burning biofuel actually raise rather than lower greenhouse gas emissions. The study concludes that growing some of the most commonly used biofuel crops (rapeseed biodiesel and corn bioethanol) releases twice the amount of N2O, compared to what the International Panel on Climate Change (IPCC) estimates for farming. The findings follow a recent OECD report that concluded that growing biofuel crops threatens to cause food shortages and damage biodiversity, with only limted benefits in terms of global warming.

All this is no trivial matter. Soils contain more carbon than all vegetation and the atmosphere combined. Therefore, soil is the obvious place to look at when trying to solve problems associated with global warming. By changing agricultural practices, we can add carbon to the soil and can minimize release of greenhouse gases.

References:

- Soils offer new hope as carbon sink
http://www.dpi.nsw.gov.au/research/updates/issues/may-2007/soils-offer-new-hope/

- Surprise: less oxygen could be just the trick
http://tinyurl.com/ywalt4

- What we throw away
http://www.waikato.govt.nz/enviroinfo/waste/whatwethrowaway.htm

- The Carbon Farmers
http://www.abc.net.au/science/features/soilcarbon/

- Living Soil
http://www.championtrees.org/topsoil/

- BEST Pyrolysis, Inc.
http://www.bestenergies.com/companies/bestpyrolysis.html

- Eprida, Inc.
http://eprida.com/hydro/

- Biofuels could boost global warming, finds studyhttp://www.rsc.org/chemistryworld/News/2007/September/21090701.asp

- Biofuels: is the cure worse than the disease?
http://tinyurl.com/yq9t8o

Companies producing agrichar:
- terra preta at bioenergylists.org
http://terrapreta.bioenergylists.org/company

Communities without Roads

Communities without roads is an exciting concept that allows people to live within walking distances of colleages, customers, friends, medical and educational facilities, shops, restaurants, etc. The sedentary lifestyle of many people is a result of the way cities are currently designed. Instead, we should facilitate the opposite, i.e. people coming out of their houses, offices, and especially their cars, in order to meet other people, getting better food and becoming more healthy in the process.

The car has come to dominate the urban landscape, resulting in a metropolitan conglomeration of suburbs, stringed together along highways. Our most fertile land is now used for roads and cars, and the industries needed to support them. About half the urban area is for buildings, mainly three-bedroom homes on small blocks of land. The other half is used for roads, parks and grassland between roads. A large part of roads, buildings and gardens is also used to park cars.

Ever less fertile land is available food. Global warming forces us to rethink all this. As prices of oil skyrocket, more land is being dedicated to grow bio-fuel, resulting in less land available for food. Also, more extreme weather conditions can be expected, resulting in increasing crop loss.

We need more land to grow fruit and vegetables, in ways as was once the case in traditional gardens and on smaller farms. One place to find such land is by converting roads and office blocks into gardens. This doesn't mean a return to those ‘good-old-days’ of small towns and villages. Instead, we should consider an entirely new type of urban design: communities without roads. Technological progress is not the enemy here. Better security and communication systems can help get such communities off the ground. Electric vehicles can be instrumental in getting such communities off the ground.

What I propose are communities with footpaths and bike-paths instead of roads. Houses would be built close together, around a local center of shops and restaurants. In communities without roads, houses could be smaller, since there's no need to park cars in front or in garages. Building houses close together itself reduces travel distances between them. Pathways to a nearby center could suffice for further daily travel, leading to shops, markets, restaurants, lecture and meeting rooms.

In such a center, people would conveniently eat in restaurants, without traffic and parking hassle and noise - just a short stroll by foot or ride on a bike or in an electric scooter. Eating out means less shopping, since food makes up most of our shopping. It also saves a lot of time - no more shopping, cooking, dishwashing and cleaning, no rubbish to get rid of. Walking more would be good for our health as well.

Living closer together means people could see each other more often, both at home or at such a nearby restaurant. Why travel to an office or University, when you can work or follow courses online? Homeschooling has long proven to be much more effective than school. Why should people be institutionalized, kids packed away into school, the elderly people into ‘homes’ and the sick in hospitals? Instead, we should encourage families to stay together as much as possible and as long as possible in communities without roads.

This would result in huge savings on the current cost of cars, roads, office buildings, car parks, garages, gasoline stations, etc. How much time and money could we save by reducing our daily travel between home and work? And how many lives would be saved if we had less car-accidents? Because of the shared walls between them, townhouses save on the cost of heating in winter and cooling in summer.

To start it off, a University campus could be transformed into a community without roads, where people live and come to learn and work. Anyone who would like to nominate one?

Tax the sale of meat!

There are many ethical objections one can have against slaughtering animals and eating them. Vegetarian lifestyles have been around for ages, just like animal rights activists have long and very publicly protested against animals being used in tests of new cosmetics in laboratoria.

Consumption of red meat from cattle, sheep, goats and other ruminants has long been linked to heart disease, colorectal cancer and further diseases.
http://www.ajcn.org/cgi/content/full/70/3/525S
http://aje.oxfordjournals.org/cgi/reprint/148/8/761.pdf

The link between meat and obesity has only recently received much media attention, with a focus on the fat and sugar content of fast food.

Similarly, environmentalists have long protested against the loss of biodiversity, as rainforests are cleared to make room for cattle or for soy plantations to feed cattle, all to satisfy global demand for meat.

Now meat has also been linked to global warming in various ways. As the impact of global warming starts to bite, many crops are at risk, due to more extreme weather conditions such as floods, drouhts, storms, heavy rain and moisture. It takes a lot of fertile land to put meat on the table, land that could otherwise be used to grow crops top feed the poor and hungry. At the same time, energy suppliers are increasingly looking at using bio-mass as a replacement for fossil fuel, so food is increasingly competing with energy in agriculture.

Finally, animals like cows and pigs release huge amounts of methane gas, which is twenty times more potent than greenhouse gas as carbon dioxide. A recent study led by Anthony McMichael, professor at the National Centre for Epidemiology and Population Health at the Australian National University, Canberra, provides some figures. It points out that 22 per cent of the world's total greenhouse gases emissions come from agriculture, as much as industry and more than what transport emits. Production and transport of livestock and their feed accounts for nearly 80 per cent of these agricultural emissions, through release of gases such as nitro-oxide and carbon dioxide, but mainly in the form of methane. A cow can belch up to 300 pounds of methane per day. The study was published by the Lancet, at:
http://www.thelancet.com/journals/lancet/article/PIIS0140673600025642/abstract

Before you try and find more details, note that the Lancet has an elaborate registration process demanding that you name your medical speciality and probably at some point your blood type, so if you prefer to bypass such things, you can try BugMeNot, at:
http://www.bugmenot.com/view/www.thelancet.com

In conclusion, a tax on the sale of meat therefore makes most sense. We could leave it up to politics to work out how high such a tax should be, but a flat 10% tax on all sales of meat looks like a good start. The tax could be higher the more methane was released, which would go hand in hand with compulsory disclosure on products of the amount of greenhouse gases that was needed to produce and ship them. Once we've got a good system in place that displays how many greenhouse gases were released in production, we could tax accordingly. There could be different tax rates, even a gliding scale proportional to the emissions. This would encourage research into different diets for cows or somehow replacing the methane-producing bacteria inside a cow's gut.

If the proceeds of such a tax merely used to help the poor pay rising prices for food, then little will be achieved for the environment. Instead, the proceeds of such a tax should be used to create communities without roads, where people can have vegetable gardens close to their homes. We should start building such communities without roads on university campuses, designing small houses for staff and students to live around shops and restaurants. Small houses need less heating and air-conditioning. If we leave out roads, garages and other car-parking spaces, they can be built closely together, so anyone can easily walk or bike their way around. That would be more healthy as well!

Anyway, it makes a lot of sense to turn vegetarian, or even better vegan. Even if you didn't have ethical problems with eating meat and if you lacked compassion for the poor and hungry, you still would help the environment by becoming a vegetarian and thus yourself!

The Hydrogen Economy

Hydrogen fuel cells constitute an efficient way to store energy and as such they form an important component in our struggle to contain global warming. Hydrogen fuel cells are a convenient and clean way to power cars and supply electricity on demand virtually everywhere. 

The importance of hydrogen as a technology is huge, as it constitutes the clean and renewable storage compliment to clean and renewable ways to capture energy, such as solar, wind, geothermal, wave and hydro-power.

The Hydrogen Economy is much more than that; it promises to change the fabric of our society. Hydrogen, holds the promise to break up the current cartel of energy suppliers that works hand-in-glove with a military-industrial complex that holds the entire world in a suffocating stranglehold. Hydrogen can clean things up and set the economy free. Hydrogen is the elixir that can remedy our polluting habits to create a better society, without the monopolies, the pollution, the taxes, regulations and the military controls that come with the current ways of supplying energy. Currently, energy is largely obtained from sources that centralize the economy around a single supplier, such as a huge nuclear plant or coal-powered plant. Similarly, oil is pumped up under monopoly conditions and transported in huge tankers, which has created these almighty oil companies that extend their grip over society through services stations and political lobbying to keep cars polluting the world.

We should look forward to a world in which anyone can capture energy for free in their backyards, from renewable power sources such as solar, wind, geothermal and hydro-power. This energy can be directly stored in fuel cells that are built into heating and cooling systems of buildings, lights, TV-sets, stereo equipment, computers, cars, mowers, scooters, power tools, etc. Wherever you now see rechargeable Lithium batteries used, such as in mobile phones, think hydrogen and you'll get a preview of the bright future that awaits us. Hydrogen fuel cells will enable us to cut the wires through which the puppetmaster controls us now. Hydrogen fuel cells hold the promise to set us free. Let's take a serious effort to give this technology a chance!

References:

- The Hydrogen Economy

http://www.gather.com/viewArticle.jsp?articleId=281474977120122

- Hydrogen Efficiency

http://www.gather.com/viewArticle.jsp?articleId=281474977121475

Solar power and electric cars, a winning combination!

Who killed the electric car? It's an excellent documentary video, a must see! It was released on DVD to the home video market on November 14, 2006. 

http://earthissues.multiply.com/video/item/16 http://wikipedia.org/wiki/Who_Killed_the_Electric_Car%3F

There's more great footage at the Earth Issues website, such as a race between an electric car called the X1 against a Ferrari and a Porsche, and underwater recharging of an GM EV1 battery.

http://earthissues.multiply.com/video/item/14

http://earthissues.multiply.com/video/item/15

The electric car dates back to the 1830s, when Robert Anderson of Scotland invented the first crude electric carriage. Around 1900, electric cars outsold all other types of cars in America. Why? Because they did not have the vibration, smell and noise of gasoline cars and required neither gear changes to drive nor much manual effort to start (as with the hand crank on gasoline cars). The only good roads then were downtown and most car travel was local, perfect for slow electric vehicles with a limited range.

Now it's time to reinvent the electric car, for its convenience and for the positive contribution it can make in terms of the environment and global warming. Solar power and electric cars is a winning combination. Let me explain. Wind and solar power is not continuous, and this is where car batteries can help out, by storing electricity at times of high supply, to feed electricity back into the grid when supply is low. I can well imagine car batteries both drawing and feeding power to/from the grid at night. Intelligent net metering will assist with this.

How much solar power is needed for all this electricity? How much surface does it take to supply solar energy? The red squares on the image below show how much surface needs to be covered in theory by solar power facilities to generate enough electricity to meet the entire demand of respectively the World, Europe (EU-25) and Germany.

http://en.wikipedia.org/wiki/Image:Fullneed.jpg

Using concentrated thermal solar power, a mere area of 254km x 254km of desert land would theoretically suffice to meet the entire global demand for electricity for 2004.

The electricity can be transported nationwide over high voltage direct current (HVDC) lines, with line losses of about 3% per 1000 km (620 miles), adding $0.01 - $0.02/kwh to the local price of electricity.

Of course, it's hard for solar power to cater for peak demand during cold winter evenings, so it makes sense to complement solar energy with stored energy, wind energy, hydro energy, geothermal energy, etc, depending on local conditions. Anyway, as Ausra calculates, if solar facilities would store energy in molten salt, they could cater for almost all US day-and-night electricity needs, and would theoretically fit inside a square with 153 km sides. To additionally accommodate an entirely electrified vehicle fleet, the land area would grow to a square with sides of not more than 211 km.

From this perspective, the "how much surface" in the above question was better rephrased into "how little surface". Solar power alone could well provide enough energy for both our current electricity needs and can supply the additional energy needs to run our cars as well. Indeed, cars need not be bad from an environmental perspective. In fact, the combination of cars and solar power can be a winner for both. Again, let me explain.

Electricity can be stored in car batteries during the day, when cars are parked under roofs that are covered with solar panels that recharge the batteries. That could easily recharge the car battery enough for the owners to drive home and still leave sufficient power in the battery for other use. Note that 70% of Americans drive less than 33 miles per day. Late afternoon, when most people return home, they can plug their cars in at home for their own power use in the evening. Many will even have sufficient energy left to feed power back into the grid, selling electricity at top rates due to peak demand for power in the evening. Even if the battery became fully discharged in the evening, this still makes economic sense, as one can recharge later from the grid (during the night or early in the morning) when rates should be cheaper. Imagine there's a lot of wind during one part of the night. The meter will indicate that this is a good time for empty batteries to recharge. Conversely, when there is no wind in the evening, one will be able to get top dollars for feeding electricity back into the grid, pre-setting the battery to keep enough charge to get to work in the morning. As discussed, the car can then fully recharge from the solar panels on the roof of the parking place at work.

Sounds far-fetched? I'm very impressed with the Tesla Roadster, which has specs that many don't expect from electric cars, specifically an acceleration from 0 to 60 in about 4 seconds and a top speed of over 130 mph. It also looks great! You can recharge the battery at night in your garage and it will cost you as little a $2.50 in electricity for a full recharge.

With the Tesla, you'll be able to drive up to 250 miles on one single charge. This radius is achieved partly with regenerative braking that stores energy produced when braking. Recharging an empty battery with an EVSE system (operating at 70 amps) takes as little as 3.5 hours, but it also comes with a mobile-charging kit that lets you charge from any standard electrical outlet, e.g. in case you get stranded with an empty battery. Anyway, this short recharge time allows one to feed power back into the grid in the evening (when demand is high and supply from solar power sources is low) and still recharge later at night or early in the morning. Indeed, later at night rates are low, so it makes sense to recharge then. If sufficient wind is blowing, supply from wind turbines may be abundant in your area.

Electric cars requires less maintenance, since there are very few moving parts; you don't need to change engine oil, filters, gaskets, hoses, plugs, belts, there's no catalytic converter or exhaust pipe to replace. The Tesla uses Lithium-ion (Li-ion) batteries, for a number of reasons. They charge rapidly, have higher voltage, weigh less and last longer than Nickel Cadmium (Ni-Cd) batteries. Li-ion batteries do not contain polluting substances such as cadmium, lead or mercury. Li-ion batteries do not have the memory effect that makes that other batteries decrease in capacity when they are recharged before they are empty. Li-ion batteries do not have to be fully discharged, before they can be recharged, so one can top them up several times a day, e.g. at home or at the office. Nevertheless, Li-ion batteries will deteriorate over time, Tesla estimates that the battery pack needs to be replaced after about 100,000 miles. Also, cost is an issue; the Tesla Roadster 2008 model has a price-tag of $92,000 and the battery pack warranty is limited (I think it's only warranted for 100,000 miles, while it does cost thousands of dollars to replace). But battery cost is expected to come down in future, while at the same time battery capacity and performance is expected to increase over time.

http://teslamotors.com/

Also have a look at Google's initiative on plug-in cars:

http://www.youtube.com/watch?v=oDjSbWTJbdo

Google still uses plug-in hybrids, but it sets a trend away from using fossil fuel. There are also ethanol-electric hybrid cars; more than a year ago, Saab (General Motors Swedish car unit) already showcased such a car, combining an electric motor with an E85 Ethanol engine.

http://www.forbes.com/finance/feeds/afx/2006/03/23/afx2616065.html

Google.org has issued a request for proposals to the tune of $10 million in order to advance sustainable transportation solutions.

http://blog.google.org/2007/09/drivers-start-your-batteries.html

Let me also pass on some links to the Rocky Mountain Institute in Colorado, at:

https://www.rmi.org/

They envisage a "Hypercar," made of ultralight, super-strong, carbon composite material, which is 12x as strong as steel on impact. Manufacturing cars and trucks using these materials would dramatically increast the range of electrical cars.

http://www.rmi.org/sitepages/pid191.phphttp://www.fiberforge.com/

Hydrogen is another way to store energy and is also promising in expanding the range of electric cars.

https://www.rmi.org/images/PDFs/Energy/U02-02_CleanerGreener.pdf (1.59 MB)

In conclusion: Just like we shouldn't rely on any single source of power (wind, hydro, solar power, geothermal, wave, tide and more), we shouldn't rely on a single way of storing power either. Apart from using car batteries for storage, we can think of capacitors, hydrogen, fly-wheels, compressed air, steam, sodium, molten salt, pumped-up water, etc. Clocks in the old days used weights to store energy. Similarly, bricks could be used as weights in larger contraptions. At even larger scale, we could use the Great Lakes as a reservoir not only of water, but also of energy. At times of peak supply of wind and solar power, surplus power could be used to pump water back from a lower to a higher lake, in order to use hydro-power at times when supply of other types of power is low. Free markets are good in sorting out which technology works best where and when. I have no doubts that the nuclear alternative will be prohibitively expensive once risk factors are better taken into account (accidents, waste management, terrorism, etc).