Remember to add the CO2 emissions from the grid to your EV. You'll need to know he power mix for the region and based on that estimate the CO2 generated to deliver the electric power to the EV.

Dear Gurudas ji, thank you for your response, power mix is not the problem in this case. All the electricity in my study comes from Hydropower which is zero emission energy source.

In order to calculate a future CO2 offset solely from fossil fuel use as compared to hydroelectric generation of electricity used in EVs, you need first to determine the time horizon for the CO2 offset (e.g., 2015 - 2030), then you need to establish what vehicle types (passenger cars and their size/utility, urban buses, delivery vehicles, etc.) and both how the number and usage of these vehicles will occur during your time horizon and how that will change (human population impacts, increased/decreased vehicle distances driven for each vehicle class, vehicle retirement from crash, breakdown or sale out of country, predictable improvements in vehicle technology and design). For each type of vehicle, you need to establish a CO2 inventory based on how each vehicle class is used. This can be established by acquiring vehicle road data or by modeling vehicle use in normal modes (e.g. inner-city urban, urban-expressway, extra-urban expressway, rural-secondary, etc.). With respect to hydroelectric power, there would likely still be some component of fossil fuel usage for a small percentage of the power due to the need for grid frequency regulation.

A more detailed analysis would also include upstream CO2 emissions from vehicle production, fuel production, building of increased hydroelectric capacity, etc. By far, the largest energy usage and CO2 contribution would be from vehicle propulsion.

http://www.epa.gov/otaq/

You might consider the MOVES model from EPA.

MOVES should have everything needed to form the basis for this sort of analysis from a North American perspective, including VMT, vehicle retirement, etc. It might prove fairly difficult to adapt MOVES to a developing country like Nepal because of the differences in fleet mix, road condtions, driving patterns, altitude, etc.

Thank you Joseph for your critical analysis. I would love to do all those things that you have mentioned but there is no funding for this study and I have to complete within this month. The vehicles for the study are three-wheelers that run about 110km (on average I interviewed with their owners) in a day commuting 14 persons at a time and there are 650 of them in my study area (Kathmandu). I am going to calculate the amount of CO2 reduced by these vehicles by calculating per person emission if they commute in 1. Bus 2. Microbus 3. Minibus instead of that vehicle.

First, you have to realize how the Electricity is Produced -- probably by burning Hydro-Carbons. This is almost as big a hoax as the god thing.

Bob H

Richardson Texas USA

And method of generating electricity without producing emissions especially

the CO2 emissions would be helpful. When we take anything from inside the

Earth ( hydro-carbons ), and part of it ends up in the atmosphere, then the volume of the Atmosphere increases. When the volume increases, the Pressure and the

temperature increases at every elevation on the planet.

We need to begin moving away from producing any form of power by

burning anything. Solar, wind, wave, geothermal, hydro-electric, and

nuclear can power our needs. We just need to change how we do

business......... it we want to survive in the long term.

Since the 1700's the in crease in the Volume of the Atmosphere has been

on the order of 10^16 kg increase in mass when the original mass was

near 5.1 x 10^18 kg.

The acceleration in the rate of consumption in the past 100 years of coal,

natural gas and oil is staggering, and it is still accelerating.

Eventually it will lead to a glacial melt down and a 220 foot rise in sea levels,

which in turn will accelerate the rise in temperatures. When the land is

closer to sea level, the temperature is higher.

That increase alone will be ( 220 / 1000 ) x 3.5 F = 0.77 F at all elevations.

Vijay - three wheelers are a particularly interesting class of vehicles to study in Asia. I saw thousands of these vehicles during trips to Bangkok 8-10 years ago. At that time, nearly all used small displacement (125-250 cc) 2-cycle engines and many had been converted to propane fueling. Regardless of fuel, you need to be careful when using CO2 inventories for three-wheelers if they are using 2-cycle engines. In my experience, CO emissions are nearly equivalent to CO2 for either gasoline or propane due to the amount of overfueling necessary for exhaust port cooling. Atmospheric CO has a short tropospheric lifetime (2-month mean lifetime) with most of it oxidized by OH to CO2. If the 3-wheelers in Nepal are two-cycle engines, then an inventory based solely on tailpipe CO2 measurement inventories would underestimate the CO2 contribution by up to 50%.

Thank you for your concern Joseph, all the 3-wheelers here run on battery operated engines with the power of 800cc. And they recharge their batteries by electricity from hydropower, so zero emission.

That's pretty interesting. Is there a link you could share or a journal article that describes these vehicles in more detail?

Sorry for the late reply Joseph, it's been a while since I visited this site. I don't have any article as such, I interviewed the mechanics working in their workshop.

There are some good "well-to-wheel" studies that have been published comparing the total CO2 emissions of various vehicle drivetrains. You need to look at the Energy and CO2 in the energy source, through the pertrol/diesel/electricity creation process, account for distribution losses and then the losses/emissions on the vehicle itself.

The answer varies per region, as the pertrol/diesel sources are different (e.g. bio-fuel mix, crude oil type, coal-to-fuel) and the electricity is sometimes has low/no emissions (PV, wind, nuclear) and could be very high (coal, oil, gas). In South Africa for example, electricity has 1015g of CO2 per kWh, whereas France is a mere 46g per kWh due to al the nuclear.

In a country like South Africa, EV's end up being a bit worse than the very best Petrol/Diesel vehicles, but way better than the average vehicle. In France, or if an EV is charged by night-time "surplus" electricity, EV's have a much lower C02 footprint than the best Petrol/Diesel/Hybrid vehicles.

There are no short-cuts - you have to do the research and the calcs - just make sure you start at the energy source, not assuming that making Petrol is CO2 free.

You would need to compare the CO2 from the electric power plant to the

CO2 from the tail pipe

@Michael. I think if one only considers the tailpipe CO2 you are missing a large amount of the CO2 related to conventional engines. Typically the oil extraction and refining to fuel adds about 15% of CO2, but this is higher when you have difficult oil sources such as Tar Sands or Coal-to-Liquid ( above 30%).

[doi:10.1016/j.apenergy.2014.10.082]

Further to the already provided answers on the importance of the specific grid electricity used in the electric vehicle (EV) as well as the vehicle's range:

The range itself not only affects which commuting routes an EV could be used for, but also the (life cylcle) CO2e emissions the EV causes per any one mile driven. Your application to specific commuting patterns is interesting because is raises the important issue that EVs cannot contribute to CO2e savings for those trips for which the EV's range is not large enough. In other words, even if a user (a "capita" if you will) or family does own an EV, there are plenty of situations where that user will have to use a gasoline vehicle instead. This must be taken into account when trying to assess how EVs affect the overall CO2e balance from e.g. commuting (as in your "per capita" example). This paper attempts to include all above effects: doi:10.1016/j.apenergy.2014.10.082