[Peakoil] more on electric cars...

[Haudy Kazemi]

On 4/6/2011 7:05 PM, Keith Thomas wrote:
> Well, coal-fired power stations are also around 30% efficient:
>
> http://www.euractiv.com/en/energy/analysis-efficiency-coal-fired-power-stations-evolution-prospects/article-154672
>
> Take from this 30% the energy lost in transmission over the grid, and 
> electric cars are already less efficient and more polluting than 
> petrol cars are today.

When comparing transportation fueling systems, remember to account for 
energy losses at every stage.  Do a "wells to wheels" type comparison 
that includes all energy used in the 
extraction/mining/pumping/collection and refining of various energy sources.

Coal, for example, needs less processing before it is used in a coal 
power plant (which in some cases is located adjacent to the coal mine), 
while oil must be transported and refined into gasoline, diesel, and 
other fuels.

Nuclear power plants depend upon the mining and refining uranium both of 
which need significant amounts of energy.  The amount of energy used to 
mine nuclear fuels and amount of nuclear waste produced could both be 
significantly reduced if we reprocessed spent fuel (only about 1% of the 
uranium in a fuel rod is used before the fuel rod is considered to be 
used up), and used newer more advanced reactor designs (e.g. IFR).

When I last did a wells to wheels comparison on using oil/liquid fuels 
vs electric for transportation, I found that in the /worst /case the 
overall efficiency and overall pollution of coal generated electricity 
used for electric transportation was equal to that of oil.  In the 
average case (a mixed power grid), electric had an advantage.  In a 
hypothetical fully renewable power grid, electric wins.

A primary advantage of electricity is that it is a universal form of 
energy, meaning that you can readily generate electricity many different 
ways (e.g. hydro, nuclear, coal, liquid fuels, tidal, wind, solar, 
natural gas, etc.) whereas converting between those other forms (e.g. 
nuclear to liquid fuels) is difficult or highly inefficient or near 
impossible.  A grid originally powered only by coal can have other clean 
energy production systems added to it, gradually cleaning it up, with no 
need for the electrically powered equipment to be changed or converted.  
Cleaning up dozens or hundreds of power plants can be easier than 
cleaning up millions of road vehicles.


With a bit of creativity, these different means of electricity 
production can be made to complement each other:
1.) hydroelectric/pumped storage can fill in during periods of low wind 
or clouds
2.) solar production peaks during the work day when power consumption is 
near the highest
3.) rooftop solar (with microinverters) produced power on-site where it 
can be used locally
(Note: this neatly bypasses issues of long distance transmission losses 
and capacity problems.  Most of the transmission energy losses take 
place during the peak power demands...this is due to Joule's Law and 
Ohm's Law...P=V*I and V=I*R ==> P=I*I*R .  On average, about 2% of the 
electricity produced at UK and 6.5% at US power plants is lost in 
transmission by the power grids.
http://tonto.eia.doe.gov/tools/faqs/faq.cfm?id=105&t=3
http://www.nationalgrid.com/NR/rdonlyres/4D65944B-DE42-4FF4-88DF-BC6A81EFA09B/26920/ElectricityTransmissionLossesReport1.pdf
http://www.nationalgrid.com/uk/sys_08/default.asp?action=mnch7_15.htm&Node=SYS&Snode=7_15&Exp=Y#system_Power_Losses

4.) natural gas turbines can provide additional peak power production 
capacity
5.) distributed electrical energy storage (made possible by widespread 
battery-electric vehicles) allows off-peak energy to be used on-peak 
(and done correctly would have minimal impact on the users, similar to 
how modern utility-controlled air conditioner power switches are only 
used for 15 minute intervals)
6.) coal and nuclear can also be used for baseload; some of these plants 
also support power scaling/load following
7.) existing power plants could be converted into combined 
heat-and-power facilities that produce electricity and hot water for 
district heating.  Heat at rural power plants could be used to heat 
greenhouses.
8.) national/continental grids with appropriate interconnects allow 
local/regional energy surpluses and deficits to be balanced out


The full impacts of any energy source should be considered, whether that 
is strip mining coal, pit mining uranium, or citing wind turbines away 
from bird flyways.  The magnitude of the impacts also should be 
considered...if our pet cats are killing 500-1000x as many birds as 
turbines, should we be so concerned about the impacts wind turbines are 
having?  Is the particulate matter released from coal power plants worse 
than the risk of a nuclear accident and contamination?  Should we be 
just as concerned about the radiation released continuously while 
burning coal in coal power plants as radiation released in a rare 
nuclear accident?  Even when the levels released are near to the natural 
background radiation levels?  Should we be concerned about the mercury 
released while burning coal to run an incandescent bulb vs using a CFL 
bulb?  Keeping things in perspective matters.


> The trick is to need to do less travel, not to hope for ways to 
> continue travelling "business as usual".

Less travel can be part of the solution for some, even most people.  
Less travel can mean eliminating completely random, wasteful, or 
non-combined trips.  Direct costs borne by the travelers are one way to 
encourage appropriate conservation.  Temporary price shocks do hold 
value in this regard as they bring attention to the issues at hand, get 
people thinking, and can serve as a early warning for later longer 
lasting price shocks.



-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://act-peakoil.org/pipermail/peakoil/attachments/20110407/a680b95a/attachment-0001.htm