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  1. globi5

    One engineers perspective on global warming

    I agree EVs are currently rather expensive (and I actually have converted my car to run on Propane). However, in the long run the increase of the renewable share in the grid and the electrification of the heating, hot water and transportation sector is sensible (economically, employment-wise...
  2. globi5

    One engineers perspective on global warming

    Just noticed that hydro power is still growing considerably. Apparently 40 GW of new hydro capacity was added to the grid last year: http://www.ren21.net/REN21Activities/GlobalStatusReport.aspx (For comparison, 4 GW of new nuclear power was added to grid worldwide: http://www.iaea.org/pris/ )
  3. globi5

    One engineers perspective on global warming

    cranky105 In those 0.188 kWh/km Tesla states the efficiency of the drive train and battery is included. http://www.teslamotors.com/en_AU/models/facts 0.188 kWh/km corresponds to less than 2 l of gasoline per 100 km which is well over 100 mpg. (The energy content of 1 l of gasoline is 11.6 kWh)...
  4. globi5

    One engineers perspective on global warming

    At least living standard and fossil resource usage don't need to coincide. A person who lives in well insulated house which is getting its heating and hot water from an efficient heat pump which is primarily powered by hydro, wind and PV requires far less fossil resources than a person who...
  5. globi5

    One engineers perspective on global warming

    HenryOhm Germany has far less renewable resources than the US (Germany has less solar, less wind, less biomass, less geothermal and even less hydro) and even though Germany is still subsidizing coal, the renewable power production in Germany in 2014 was already 63% higher than the power...
  6. globi5

    One engineers perspective on global warming

    cranky108 150 years ago the whaling industry was even the biggest economic sector in the US-Northeast. Does this mean the whaling industry should have been saved, because it was under pressure due to the growing petroleum industry? And would the US be better off today if whaling was still a...
  7. globi5

    One engineers perspective on global warming

    Let's just assume that climate change is a hoax invented by the majority of scientists to conspire against oil sheiks, gas oligarchs and what not. What's wrong with reducing dependence on costly fuel imports and invest more money in the local economy? Also, if we don't need more efficient...
  8. globi5

    Standard Definition of Displacement. Is there one?

    1. The rotary engine still pumps only 1.3 l per revolution and not 3.9 l, because for the third time: The rotor only moves 120 degrees when the crankshaft which delivers the actual engine revolution moves 360 degrees. 2. For the reason above the rotary engine pumps 3 x 1.3 l = 3.9 l in 3...
  9. globi5

    Standard Definition of Displacement. Is there one?

    This sentence in the English written wikipedia page regarding the Wankel engine is actually false: "In auto racing, the displacement of a Wankel engine is usually doubled for classing purposes. This is of course a marketing ploy and wrong." Naturally, the 1.3 l displacement has to be doubled...
  10. globi5

    Standard Definition of Displacement. Is there one?

    The rotor of the Wankel does only spin at 1/3 of the speed of the crankshaft. Each rotor has 3 chambers with 0.65 l maximum volume each. Therefore each rotor displaces the volume of only one chamber (0.65 l) per crankshaft revolution . Thus, the Mazda RX-7, RX-8 Wankel engines with 2 rotors...
  11. globi5

    The bad news about windfarms....

    I also believe that increasing tax on energy and reduce tax on work would be better than any subsidies. (Where I live I pay about 3 times as much on gas and half on income tax compared to a person living in the US and I certainly prefer these tax-rates). However, feed-in tariffs are normally...
  12. globi5

    The bad news about windfarms....

    Why don't you just read the facts I provided instead of just randomly bad mouthing renewables and efficiency measures with false accusations? By the way, my household is at 300 kWh per year and person electric energy consumption and we are not missing out on any comfort (granted we don't get...
  13. globi5

    The bad news about windfarms....

    As I said before: The utilities already have to deal with a much larger variable demand anyway. Dealing with a variable and very predictable wind power fraction is not an issue, besides wind turbines can always reduce their power output if the grid could not handle it...
  14. globi5

    The bad news about windfarms....

    Actually, most people are not willing to simply read facts (which can easily be found). The point is: Asphalt doesn't add to global warming - greenhouse gas emissions do (besides PV as opposed to asphalt produces electric power and thus cannot heat as much as asphalt can - 1st law.) Two thirds...
  15. globi5

    The bad news about windfarms....

    Btw, China installed more wind power last year than North America and Europe combined: http://alturl.com/y8axu Not too long ago wind farms in Texas prevented a rolling black-out: http://news.sciencemag.org/scienceinsider/2011/02/when-wind-is-reliable-turbines.html Last March Spain wind power...
  16. globi5

    US truck fuel economy and Obama's new rules

    Also, aerodynamics alone can improve fuel efficiency of an OTR truck up to 12%: http://www.sciencedaily.com/releases/2008/06/080611154206.htm http://www.sciencedaily.com/releases/2008/04/080417105446.htm
  17. globi5

    US truck fuel economy and Obama's new rules

    Btw, this commercial 40 ton truck got 12 mpg with a 25 ton load and 50 mph average speed: http://www.daimler.com/dccom/0-5-1087728-1-1087768-1-0-0-0-0-0-8-7163-0-0-0-0-0-0-0.html
  18. globi5

    4-strokes obsolete?

    Well I certainly hope that everybody was aware that CO2 emission (which drwebb was referring to) means g_CO2 per km and is directly related to the fuel economy of the vehicle and the fuel used. Anyway the major difference between Euro 4 and Euro 5 is apparently a 25% reduction in NOx...
  19. globi5

    4-strokes obsolete?

    I'm not sure about the sulfur and the CO2 (and I don't think that the RX-8 has been getting a special treatment just because it has a Wankel engine), but the unburned hydrocarbons in the RX-8 exhaust are taken care of by a hydrocarbon-burner/converter fed by a secondary air pump (which is...
  20. globi5

    4-strokes obsolete?

    "Any engine that utilized oil in the fuel for lubrication would be flat out for automotive applications, and soon for almost any other application." --- That's not entirely true: The Mazda RX-8 with its rotary engine uses oil for lubrication to lubricate the rotor seals and combustion chamber...

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