Depends on the type of greenhouse emissions you're talking about, as well as what type of EV. The Nissan Leaf powered by the US-average blend of electricity will indirectly - through the long tailpipe - cause CO2 emissions slightly higher (~130 g/km) than the Toyota Prius directly emits (~109 g/km), per the EPA. Same CO2 emissions as a 50 mpg bike, fwiw - though the bike will likely emit far more of the other greenhouse gases.
An Enertia is close in performance to a Honda CBR125R, 80-90 mpg bike. Not really 70 mph highway safe, like the Enertia. Enertia should be around 46 g/km @ 110-120 wh/mile, CBR125R should be around 64 g/km.
Oh boy... here we go.
Protomech, are you counting the 64 g/km on the CBR125R as the amount of CO2 emissions from the bike's tailpipe or the amount involved in the pumping of the oil, transporting the oil to the refinery, refining the oil, and transporting the oil to the end user?
Comparing emissions at the gas bike tailpipe vs emissions directly at the power plants. In both cases emissions due to harvesting and refining fuel are not considered. I've seen numbers quoted around 77% efficient for well-to-pump efficiencies, but have never seen anything similar for power plant fuel (coal / nuclear / natural gas being the big 3, hydro / solar / wind have all the fuel on-site).
From the
eGRID2010 Technical Support Document p9:
"Also, eGRID does not account for any pre-combustion emissions associated with the extraction, processing and transportation of fuels and other materials used at the plants or any emissions associated with the construction of the plants."
Coal is used for about half the power generated in the US, but produces a larger proportion of CO2 emissions. (75%? can't find numbers right atm). So if you're looking at an EV powered purely by coal, raise the CO2 emissions by about 50%. And likewise, if you power an EV with solar or hydro or wind, adjust accordingly.
Bottom line, I'm not sure car EVs produce less net CO2 than hybrid car ICE considering the national energy mix. Bike EVs likely DO produce less net CO2 (and many more harmful emissions), but only because bike ICE is tuned more for power and rarely if ever for efficiency. Thanks largely to the EPA, car engines are pretty efficient and a complicated set of emission traps scrub away the majority of the harmful emissions. The EPA does very little regulation of bike engine emissions, and (consequently?) bikes are pretty dirty.
