2 posts • joined Friday 20th June 2008 19:53 GMT
Re:Thanks for the attempt
Yep, mixed up the L/km bit (clearly we need more fuel efficient cars in North America...). The point was, in using either figure, he's accounted for the engines efficiency, which you seem to think he didn't. Since I remain confused by what exactly he's done "fundementally wrong" in his calculation, can you do it for me. What is the energy consumption per day of a Petrol car, running on gas, going 50 km a day with a fuel economy of 12km/L. He says 40kWh, you say he's wrong. Fair enough, what is it? Remember, the point of that section was to calculate this value, not that of an electric car. I don't care what an electric car gets, it's not what he was calculating.
As an aside, if he "has the nerve of presenting his arguments as the final word in the renewables debate", what exactly are you, I or anyone else doing? We're all presenting arguments....the nerve! His is one of the most balanced I've seen. By admitting you've an axe to grind, you're admitting to a lack of objectivity. That's great for an amusing argument, but not so great for intelligent policy.
@Anne van der Bom again...Re: you're hot water calculation.
1. 15 to 35C. The average human is about 38C, A 35C bath, that's not hot it's tepid. The author was using 10C to 50C, that's a lot more typical, though if we want to skew the numbers I suppose we could be warming Saharan water from say a balmy 45C to 50C and save a whole lot of energy. Makes ther case better!
2. 70L. Based on a typical Canadian Bathtubs internal size (maybe Europe's different) of roughly 142cmx61cmx36cm, 70L gets me 8.1 cm of soaking glory. The author suggests larger dimensions and deeper water, again more realistic.
So the hot bath is now defined as 8cm of lukewarm water. I'd like everyone to go home and try this out tonight.
3. Now we heat it. You assume a 90% gas heater. Why? This gets around the irritating 35% generating efficiency you goose the 2W standy unit with. Nice.
Personally, When I bath I use a small bucket (10L) and limit the temperature to a balmy 25C. I like it brisk. Did I mention I have black solar coils on my thatch roof in my equatorial abode, so I'm pretty efficient.
Tongue in cheek aside, you can manipulate your numbers to make your case, and in your case I think perhaps you're being a bit generous to your case. Again, you're not being skeptical, you're agenda is obvious here. From what I've read of the paper, the author is making ballpark calculations, and it's obvious, he makes no effort to hide this. The values he chooses are general, typical, what the average person uses. Be average, it's what everyone else is, and if you base your case on anything else, your argument doesn't hold much water (hot, tepid or brisk), because it assumes the best of people, that they'll change out of the good of their heart. Perhaps you've noticed, that's not reality.