Posted by Max Dunn
Thu, 19 Mar 2009 19:48:45 GMT | no comments
I admit it – I am a numbers geek. I love to play around with numbers and think about them, and no more so than with electric vehicles. So imagine how happy I was too see some fantastic numbers about the Tesla Roadster!
The first of these graphs shows how much energy it uses at different speeds. The fact that energy goes down to a certain point is not surprising – all cars have a sweet spot where they operate most efficiently – but what is surprising that it is about 20 MPH versus about 55 MPH for gas cars. Another interesting point is that at 65 MPH the Tesla uses about 280 Wh per mile. This is measured from the battery to the wheels, so adding in the charging losses will decrease it to about 3 miles per kWh, which is the figure I normally use.
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Posted in Electric Vehicles
Posted by Max Dunn
Thu, 19 Mar 2009 04:38:23 GMT | no comments
What does it cost to build a new electric power plant? Here is a graph that shows this:
However, you do need to adjust this for utililization, since nuclear operates about 90% of the time, while solar operates only about 20% of the time:
(Source: What does Sustainability Mean for Energy?)
Posted in Sustainable Energy
Posted by Max Dunn
Mon, 09 Mar 2009 22:25:54 GMT | 1 comment
Sometimes people talk about "running out of oil", but the world will never completely run out of oil. There will always be some oil remaining somewhere that can be scavenged from old fields, reclaimed from tar sands or stripped from oil shale.
There is, however, a limit to how fast we can pull oil out of the ground. Peak Oil will occur when the world hits this peak in production – and this will likely happen soon!
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Posted in Peak Oil
Posted by Max Dunn
Sun, 08 Mar 2009 05:22:16 GMT | no comments
Previously, I posted a table showing how oil in the US is used. Here is a graph that shows the same information in a prettier form:
(Reference: Year 2000 data from Ending the Oil Age)
Posted in Peak Oil
Posted by Max Dunn
Thu, 05 Mar 2009 18:12:54 GMT | no comments
A lithium air (Li-air) battery with a novel structure is looking very promising for use in battery-powered vehicles.
One problem with battery-powered vehicles (and an argument for hydrogen fuel-cells) is that it takes a while to recharge the batteries. While this is fine for city driving (since the batteries can be recharged overnight) it makes it tough to drive a long distance, like driving from San Jose to ski at Lake Tahoe.
This Li-air battery could solve the problem of long charge times by allowing service stations to replace the liquid electrolytes and metallic lithium cassette, allowing battery-powered cars to be driven continuously.
Then the metallic lithium can be electrically regenerated from the used liquid electrolyte making the process sustainable.
This Li-air battery could prove very useful in making battery-powered vehicles more practical.
(Reference: AIST Develops New-type ‘Li-air Battery’)
Posted in Electric Vehicles, Peak Oil
Posted by Max Dunn
Fri, 27 Feb 2009 04:03:36 GMT | no comments
I just went to an interesting talk about distributed solar and found out that prices of solar PV panels are dropping dramatically. Soon, PV will be about $4 per watt installed (in large installations) which works out to about $0.17 per kWh.
By comparison, coal-fired electricity sells for about $0.05 per kWh. This includes about $0.02 for the coal itself ($2.15 per MMBtu and 1 MMBTU produces about 100 kWh) and $0.03 for all other expenses.
Adding in a $30 per ton CO2 tax would add about $0.03 per kWh to this price, (coal produces about 2 lbs of CO2 per kWh) for a total of $0.08 per kWh.
So even with a CO2 tax, coal electricity will still be half the cost of PV.
Therefore, for coal electricity to cost about the same as PV electricity, a tax of 400% would need to be added to coal!
Posted in Global Warming, Sustainable Energy
Posted by Max Dunn
Wed, 25 Feb 2009 00:54:16 GMT | no comments
While looking for the external costs of coal, I ran into a great table that shows how much it costs to build and run various types of electric power plants.
It is interesting to note that while a convention coal plant costs much less to build than a solar thermal plant, the coal plant costs more to maintain so over 30 years, the total costs would be equal.
Table 1: Specification of electric power technologies used in GMM model. All costs are
given in $(1998). The progress ratio (pr) is the rate at which the cost declines each time the cumulative production doubles. The data presented in the table comes from various sources: IIASA MESSAGE model database, literature reviews. Characteristics of technologies with CO2 removal are adopted from [8].
(Reference: Internalisation of external cost in the power generation
sector)
Posted in Global Warming, Sustainable Energy
Posted by Max Dunn
Wed, 25 Feb 2009 00:20:21 GMT | 4 comments
Natural Capitalism is a terrific book. But it got one thing wrong – its hope for hydrogen cars. Dan Neil at the LA Times put it well: "Any way you look at it, hydrogen is a lousy way to move cars." (Ref) Here are a few of the reasons why hydrogen won’t work:
- Hydrogen is only an energy carrier. It is not an energy source. (Ref)
- Hydrogen is made from fossil fuels. And this will likely be the case for the next several decades. (Ref)
- Hydrogen production produces CO2. (Ref) For instance, the Honda FCX Clarity hydrogen car indirectly produces 176g CO2/mile while the Toyota Prius hybrid produces less CO2 at 167g CO2/mile. (Ref)
- Hydrogen cars are very expensive. The FCX Clarity costs several hundred thousand dollars and it will take many years to even drop below $100,000. (Ref)
- Hydrogen leaks. A hydrogen car left in an airport parking lot for two week could lose 50% of its hydrogen. (Ref )
- Hydrogen isn’t very efficient. (Ref) Only 20% to 25% of the energy needed to make hydrogen can be recovered. (Ref) Even using renewable energy, battery powered vehicles can still go 3-times further on the same electricity than hydrogen vehicles. (Ref)
- Hydrogen cars fill up slowly. It currently it takes about 30 minutes to fill up a hydrogen tank. (Ref)
In the long-term, maybe the challenges with hydrogen cars will be solved. However, it is also likely that the few remaining problems with battery powered vehicles will be solved too. Physics will then remain firmly on the side of battery powered vehicles and it will be easier and more efficient to just transfer renewable electricity over power lines to charge battery vehicles than to convert the electricity to hydrogen, ship it, and convert it back into electricity again.
Posted in Electric Vehicles, Global Warming
Posted by Max Dunn
Sat, 21 Feb 2009 19:39:13 GMT | 1 comment
With the recent financial breakdown, it was refreshing to hear of a new type of bank at the VLAB event Upside of the Downturn on January 20th, 2008.
Renaud Laplanche, Founder & CEO of the Lending Club described how normal banks pay 2-3% but collect 16%. Lending Club lenders on the other hand, get 10.29% while borrowers pay 13% on average. The Lending Club narrows the spread rates by transacting over the Internet and having people lending to other people. As a lender, you can choose which borrower to lend to which creates a connection and social responsibility among users. Borrowers are also carefully screened and 85% are declined, so only prime borrowers are accepted. This leads to a low default rate of 2.7% and a late rate of 3.8%. The Lending Club is experiencing high growth rates of 50-100%, and in December of 2008, $2.5M was placed.
Maybe this is a new model for more sustainable banking!
Posted in Random Thoughts
Posted by Max Dunn
Mon, 09 Feb 2009 01:21:55 GMT | 4 comments
In the late thirteenth century, the church came up with the idea of indulgences, which was paying someone else to do the good works demanded of you. Church officials argued that clergy were doing more good works then they needed to, so why not sell them to raise money?
Are carbon offsets like these medieval indulgences? Just reducing our guilt without really helping the planet? Let’s look a little more closely at them.
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Posted in Global Warming