The Energy Cost of Electric and Human-Powered Bicycles (2004) [pdf]

"Save the environment, take the elevator"?

Let's assume 15 floors since otherwise you'd probably save time walking.

The article suggests a grid efficiency of 50% and a motor efficiency of electric e-bike motors as 75%. It looks like elevator motors are actually more efficient (increasingly so as more people are loaded) [4]. It's only about 5 percentage points higher, so for simplicity let's keep 75%.

Ignoring the transportation and manufacture cost of the elevator assembly (not totally unreasonable since it has a long lifetime), elevators have an energy ratio of 2.5:6.7 or 1:2.7, which looks far better than the 1:28 that the article quotes for humans.

Gee, that kind of upends my worldview... I guess I'll just wait until bodies are deprecated in favor of high-efficiency cybernetics.

[0] https://captaincalculator.com/health/calorie/calories-burned...

[1] https://www.livestrong.com/article/301539-calories-burned-cl...

[2] https://www.quora.com/How-much-electricity-does-an-elevator-...

[3] https://fatknowledge.blogspot.com/2007/02/how-much-energy-do...

[4] https://www.me.ua.edu/me416/LECTURE%20MATERIALS/MotorEffic&P...

> The above figures were all produced by assuming average or typical cases. To be fair, it is entirely possible for a bicycle rider to deliberately eat only locally grown and unprocessed foods. In that case, the ratio of primary energy to food calories is closer to 1:1 (Günther 3). Combined with a metabolic efficiency of 25%, this increases the human energy efficiency to 1:4, slightly better than the lithium-ion electric bike.

> ...

> Conclusion: ... Despite the intuitive sense that electric bikes would require more resources than regular bikes, life-cycle analysis shows that they actually consume 2-4 times less primary energy than human riders eating a conventional diet. This conclusion is largely due to the considerable amount of transportation and processing energy that is associated with our western food system.