Posted by Max Dunn
Tue, 02 Dec 2008 16:56:34 GMT | no comments
It is well known that a large part of our military expenses goes to protecting the flow of oil from the Persian Gulf. What has not been as clear is the actual cost of this protection. However a recent study sheds some light on this hidden expense.
In this study, Mark Delucchi of the Institute of Transportation Studies at UC Davis estimates that American taxpayers spent between $27 billion and $73 billion in 2004 (which was the most recent year data was available) for military protection of US oil interests in the Persian Gulf region.
While this is a huge number by itself, it works out to only $0.03 to $0.15 cents per gallon of gas for motor vehicle use.
Posted by Max Dunn
Thu, 20 Nov 2008 15:42:20 GMT | no comments
I have always thought that LED bulbs should provide the best energy efficiency and lowest lifetime cost of any bulb. However, looking into this more, I am not so sure.
(Note: Lifetime is 50,000 hours, and I used an electricity cost of $0.11/kWh)
Even though LED bulbs are much more expensive than CFLs (compact fluorescent), they are also about 40% more efficient, so adding in lifetime electricity costs their total cost would be about the same.
However, there is a catch. If an LED bulb is used 4 hours per day, it would last almost 35 years – and what is the chance that over those 35 years the LED bulb gets broken or there is a power surge that damages it? Probably pretty good! So assuming that LED bulbs actually last on average only 10 years, this would make them twice as expensive as CFLs.
So until the cost of LED bulbs come down quite a bit, CFLs will still be the better buy.
Posted by Max Dunn
Mon, 17 Nov 2008 15:58:01 GMT | no comments
According to the EIA’s Monthly Electricity Review, net US generation of electricity from renewable energy sources surged by 32 percent in June 2008 compared to June 2007.
Renewable energy (biomass, geothermal, hydropower, solar, wind) accounted for 11.0 percent of net US electricity generation in June 2008 compared to 8.6 percent in June 2007.
Hydropower still accounts for a large part of this renewable energy, but over this period wind power leaped by 81.6 percent and solar surged by 42.6. Now non-hydroelectric renewables account for just under three percent of total net U.S. electricity generation.
Posted by Max Dunn
Thu, 30 Oct 2008 16:40:14 GMT | no comments
Much of the criticism of solar and wind energy is that they don’t produce power all the time and that we don’t have any good way of storing electricity. There is some pumped hydro storage, but it is only able to contribute less than 3% of the power, and it is not likely that we will be able to build more.
However, another way of storing energy is to compress air underground. There are a lot of areas that can be used for this underground air storage including underground aquifers, carved out salt caverns, depleted natural gas wells and old mines.
The air is compressed using an electric turbine which can be driven by solar, wind or even off-peak electricity. Then when it is needed, the compressed air is fed into a natural-gas fired electric plant which normally would need to use a lot of energy to compress the air. This makes CAES systems almost 3 times more efficient than single cycle gas-fired plants, and almost twice as efficient as combined cycle plants. In addition, CAES equipment is simpler and has lower operating costs.
Currently there are two CAES plants in operation around the world. A 290 MW plant in Germany operating since 1978, and a 110 MW plant in Alabama operating since 1991. Now, there is a third 200 MW CAES plant being built in Central Iowa (ISEP) that received a federal funding earmark in 2009 for $1.5 million.
CAES is a very promising technology that can make sustainable energy much more practical and we should be working harder and faster and devoting more money to develop this technology.
Posted by Max Dunn
Tue, 21 Oct 2008 18:18:51 GMT | no comments
Many people are dismissing wind power as irrelevant in solving our energy problem since wind power has been in production for a long time but the total output is still relatively small. However, it is useful to compare the ramp-up of wind power to nuclear power:
It is interesting how closely these two growth curves align! In the US today, nuclear provides about 20% of our electricity so it is not unreasonable to assume that wind power can be ramped up to eventually provide the same percentage of power.
GCEP is an interesting group based at Stanford University that seeks new solutions to one of the grand challenges of this century: supplying energy to meet the changing needs of a growing world population in a way that protects the environment. With funding of $225 million from Exxon, GE, Schlumberger and Toyota, GCEP supports a lot of diverse high-risk and high-reward projects in areas such as solar energy, batteries, cellulosic ethanol, hydrogen, CO2 capture and storage, advanced combustion and more
This was a fantastic symposium where researchers from Stanford and around the world discussed GCEP’s projects. Some of the highlights for me were:
Burning coal in super-critical water to capture all CO2 and other emissions
The benefits of using miscanthus for cellulosic ethanol (which is better than switchgrass)
Using nano structures to improve photovoltaics
Using biological organisms to split hydrogen
Various techniques to make fermenting cellulosic ethanol a reality
Posted by Max Dunn
Wed, 27 Aug 2008 03:35:06 GMT | 1 comment
It is so incredible it is a little hard to get my brain around. Several months ago, without any fanfare, Nanosolar showed off its new production tool that can produce 1GW (gigawatt) of solar cells per year.
To put this in perspective, most plants produce less than 100 MW (megawatts) per year, less than 1/10 of Nanosolar’s 1GW machine. For instance, here is a Masdar plant being built in Germany that will produce 70MW a year and cost $230 million. So it would take 14 of these plants to equal the output of one of the Nanosolar machines.
The cost of the Nanosolar machine? $1.65 million! This is 2,000 times less than the Masdar plant! (While this is a comparison of a production tool to an entire plant, it is still an astounding difference.)
Posted by Max Dunn
Fri, 30 May 2008 04:10:09 GMT | no comments
There was an interesting talk at the Woods Energy Seminar at Stanford yesterday by Dr. Gavin Conibeer about 3rd generation photovoltaic (PV) devices.
The 1st generation are the PV cells we have now that cost around $6/watt and are around 20% efficient. The 2nd generation are the thin film cells which cost around $1/watt but are only about 12% efficient. The 3rd generation cells will use quantum dot technology created using thin-film manufacturing methods, so they will be a lot less expensive than 1st generation devices but will also use a variety of techniques to boost efficiencies up to 65% which will drive the cost down to $0.20/watt.
This sounds pretty great! However, the catch is that when asked when these 3rd generation PV cells would start going into production, his answer was “It is still a long ways away.”
Posted by Max Dunn
Wed, 28 May 2008 19:47:27 GMT | no comments
All of the major electricity generating systems in use today have a fairly steady output. Whether they are powered by nuclear, coal, hydro or natural gas, the electricity output will be fairly constant unless there is a malfunction. However, solar and wind systems aren’t consistent – clouds can dramatically affect the output of solar systems, and lulls and gusts can affect wind systems.
In our electrical grid, it is important that the supply of electricity consistently matches its demand. This will become more challenging once solar and wind systems are producing a larger percentage of the total electrical power, and there are currently no good ways to smooth out these fast fluctuations. Spreading the solar and wind units far apart helps so that clouds and gusts won’t affect all the units at the same time. Also pumped hydro (where water can be pumped up into a dam using electricity as well as letting it out to produce electricity) can help smooth things out as well as using natural gas spinning reserves.
However, we will still need more regulation that is much faster than these, and this is where Vehicle-to-Grid can help. If we can reach a level where a significant amount of electric vehicles are hooked up to the grid with fast command communication, they will be able to quickly smooth out the electrical surges and lulls from solar and wind systems. Otherwise, we will likely run into severe regulations problems with these systems due to clouds and gusts.
Posted by Max Dunn
Mon, 12 May 2008 16:04:32 GMT | no comments
Here is another illustration of how expensive hydrogen is. Popular Mechanics looked at how much it would cost to drive across the country in vehicles using different types of fuel. As a baseline, a car getting 33 MPG would cost $213 (with fuel at $2.34/gallon). A hydrogen fuel-cell vehicle would cost $804, while a battery electric vehicle would cost only $60!
