This story illustrates both the upsides and limitations of trash-to-energy programs. On the positive side: many sources will pay you to take their trash from them. There's nothing like free energy. On the negative side: - Sweden's exhaustion of its own sources of trash show that the concept is inherently limited, even in an abundant consumption economy. That is, one which is producing ample waste streams. As the arti…
If, as you say, 971 GWh is equivalent to 6% of total energy usage, then 980 TWh is 6000% total energy usage. Of course, you don't get 100% efficiency in incineration, but an oversupply of 60x leaves a lot of room for inefficiency.
Here's my calculation. I've used scientific notation to reduce the possibility of order-of-magnitude errors:
> 230 million tons Avoirdupois = 2.3e8 tons
> 2.3e8 tons * 2e3 pounds/ton = 4.6e11 pounds
> 4.6e11 pounds * 0.45 kg/pound = 2.07e11 kg
> 2.07e11 kg * 1000 g/kg = 2.07e14 g
> 2.07e14 g * 17 kJ/g for carbohydrates = 3.52e15 kJ
> 3.52e15 kJ * 2.78e-4 kWh/kJ = 9.8e11 kWh
That's 980 billion kWh, or 980 million MWh, or 980 thousand GWh, or 980 TWh.
I wonder if maybe you're getting nutrition Calories (uppercase) confused with gram calories (lowercase). Nutrition Calories are actually kilocalories!!! If you forgot to multiply by 1000 to account for this, then that would explain your result.
In Europe, nutrition labels are listed in kilojoules. This eliminates the confusion over calories.