2010 Solar power, Wind Power and the end of the oil age
by dtaylor2, Sun Jun 22, 2008 at 01:38:55 AM EDT
As we all wait to see who Obama will pick for VP I thought it would be good to talk about something different.
So here are my thoughts on solar power.
How solar can help balance the trade deficit
It is not my intention to use the following to back any particular company but rather to show how the US may escape imported oil via electric cars and solar power.
Currently Tesla Motors has a car that delivers ~4.7 miles per KiloWatt-Hr (1)
A good MPG for a typical car today is worse on average than 30 MPG.
In many areas such as california, arizona, nevada etc there is a yearly average of 5+ hours good solar. (2)
Domestic home solar panels currently cost roughly $8 dollars/Watt installed (3)
One barrel of oil nets 42 gallons of gas (4)
To replace 1 barrel of oil requires 42 gallons * 30 MPG / 4.7 miles per KiloWatt Hr = 268.1 kiloWatt - Hr
To reduce consumption of 1 barrel of oil per year would require 268.1 kiloWatt Hr divided by 365 days divided by 5 hours a day= 0.147 kWatts worth of solar panel at $8 a watt or $1176.
So one gallon per year reduction can be purchased for $1176/42=$28 this gives favorable return from a straight economic sense as gas is currently over $4.5 a gallon in crude cost alone.
However the kicker is that the positive effect of the US trade yearly deficit is roughly $0.09 for every dollar invested in reducing foreign oil. (5)
The initial cost of a plan to totally remove car gas usage could project as high as 8.5848 Trillion to completely remove 20 million barrels of foreign oil a day. However 10% of oil consumption could be reduced for 800 billion which is 200 billion a year. At the end of a 4 year term this would account for a $72 billion reduction in the trade deficit and would likely reduce oil prices which would further reduce the trade deficit.
(1)http://www.teslamotors.com/efficiency/we ll_to_wheel.php There are 3.6 MJ per KiloWatt-Hr and 0.6 Miles per km so 2.19 km MJ *0.6 mi/km *3.6 MJ/KiloWatt-Hr=~4.7 miles per kiloWatt Hr.
(3) http://www.smartmoney.com/greenscene/ind ex.cfm?story=20070925 This link quotes it needs to go down a factor of 2 to $3 installed I use $8 to be conservative.
(5) This is based on $120 a barrel oil and $1176 to replace 1 barrel a year
Solar Global Cooling
Did you know Solar photovoltaic cool the environment?
Did you know $109 Billion of solar cells would cool LA 5 degrees without using any of the solar powered electricity for cooling?
Too good to be true?
Every Watt of photovoltaic solar power converts radiationinto electricity, electricity that would have otherwise turned into heat. So a 1 m^2 solar panel $900 installed generates electricity (that can be used to run your electric car) but it ALSO cools the environment.
The city of Los Angeles is 1215.9 km^2. If solar panels were put over 10% of LA that were 10% efficient (they convert 10% of the solar power to electric power) then 1% of the suns radiation hitting LA would be converted from heat into electricity.
So how much cooler is that?
LA often gets above 86 degrees F which is about 30 degrees C or 303 degrees Kelivin. Radiant heat from the sun is what makes the earth warmer than the 2-3 Kelvin that outer space is (thermal heat from the center of the earth adds a very small amount of heat but the sun provides the VAST majority of heat to the earth surface). So the earth is 300 Kelvin hotter than outer space because of the 100% of the suns radiation, if only 99% of the suns radiation hit the earth then it would be 1% cooler or 3 degrees Kelvin which is 3 degrees C or 5.4 degrees F.
How much would that cost? A solar panel is roughly $450/m^2 retail and $900/m^2 installed if you buy it from home depot or other retail photovoltaic solar seller. To cover 10% of LA CITY would cost 109 Billion, but that electricity could be used to power electric cars and replace foreign oil and so would pay for itself. The cooling effect is FREE.
For the purpose of Air conditioning the difference between 70 degree F building and 86 degree F air is 16 degrees while the difference between 70 degree building and 81 degree air is 11 degrees this is a 31% reduction in the heat needing to be pumped out of buildings. Using 100 F this drops to a still impressive 16.6%. So the solar LA should expect to spend a full 16.6-31% less energy in cooling during summer if the air itself were cooled 5 degrees F.
In practice 15% solar cells are likely to be available and localized hot spots can have their temperature reduced without any surrounding heat entering (due to the hot spot still being as hot even after cooling 5 degrees F). Otherwise the surrounding area would just blow hot wind into LA and the cooling although real would be spread out over a larger area and thus smaller in degrees.
Also please note that nanosolar is claiming $1 per watt solar cells while all my numbers are based on $4 per watt and $4 per watt in installation. In practice a large buy would be cheaper and if 15% cells were used a 8.1 degree reduction in temp could be realized.
PS I simplified the equations and radiated heat isn't linear with temp its 3rd order but this only accounts for a ~2% deviation 99%-99%^3=2% which is made up by using 12% efficient panels and I didn't take the heat savings from the Air Conditioners that don't need to run which also heat the environment.
How Solar can exceed 100% efficient without violating the 3rd law of thermo dynamics
>100% power utilization is possible for solar thermal because it can displace inefficient energy 100%-x with efficient energy ~100% yielding a net savings of 100%(100%-x%)>100%.
One limit to solar power is that the extraction of useful work from solar tends to be below 50% of the available energy. Commercial photovoltaic cells are usually below 15%. Even solar thermal steam or equivalent is limited by the carnot cycle maximum efficiency making 40-80% efficiency practical depending on the lengths taken in engineering and the temperatures used, this complicates the design as the total power is then limited by the energy stored and transmitted in the steam or steam substitute and its ability to cool.
The exception to this is when solar thermal is used to produce heat in an application where a rival energy source would also be used to produce heat. In this case every kJ of solar heat can offset a kJ of captured HEAT from a rival source often that kJ was created at the expense of more than 1 kJ of rival fuel, in this way water heaters can capture much more energy than solar cells for the same area exposed to equivalent solar radiation.
This trend has the potential to be perhaps most practical in generating electricity in the production of aluminum. Aluminum production requires a lot of electrical power input that is basically used to rupture chemical bonds that could be ruptured with heat. It is estimated that 10% of commercial electricity is used to generate aluminum. It is possible that a method for using solar heat to replace this electrical heat could produce more than 100% utilization of solar and possibly therefore be much more economically viable.
So while 5 square meters of solar cells at 20% efficiency are required to produce ~1kW of electrical power or alternately 1.2-2 kW of coal power is required to create and distribute the same 1kW it may be possible to use a mere 1 square meter of solar thermal in the production of aluminum to replace either the 5 square meters of photovoltaic solar or the 1.2-2 kW of coal energy needed to create 1 kW of usable electrical energy thus yielding a useful replacement energy for that square meter of between 120% to 500% of the actual energy that hits the square meter.
Wind power on the cheap
Anyone living in a windy area should follow this link for instructions on how to build your own windmill CHEAP
Wind is the cheapest non nuke form of renewable power and is cheaper than using grid power for many people.
The system described would pay for itself in less than 2 years in a sufficiently windy area.
2010 is the year of the plug in hybrid and the hydrogen car
Plug in hybrid Chevy Volt will be sold in 2010
Plug in hybrid Mitsubishi Colt EV
Honda Hydrogen car
Ford Hydrogen car