Prius PHEV conversion now $4,995

[Flying White Dutchman]

maybe some modern coal gassing plants need to be build? or are there already coal gassing stations in the us?
this burns more of the coal more efficiently

[clett]

Originally Posted by joewein

Coal causes more CO2 output per kWh than any other source of power.

Even when an electric vehicle is running off the worst possible source of electricity (coal), it emits less CO2 overall into the atmosphere than an equivalent gasoline / diesel or hybrid vehicle.

[joewein]

Yes, coal gasification would be somewhat cleaner, but not many existing coal-burning stations are going to be replaced with anything cleaner during the projected 2 year lifetime of this battery system.

Plug-in electric vehicles would be genuine "zero emission" vehicles only if you were to live in a country that uses neither coal, oil nor gas for generating power. If you happened to live in Iceland, where 80% of electricity is hydroelectric you would come close. Most other places would not.

Another point worth considering is that replacing the standard 68 kg NiMH (no lithium ion as claimed in the article) traction battery of your Prius with a 163 kg lead acid one adds an extra 95 kg (210 lb) to the weight of the car.

An old rule of thumb amongst engineers is that every 100 kg of extra vehicle weight increases fuel consumption by about 1 L per 100 km in urban driving. That means, if you were getting 5 l / 100 km (47 mpg) with the 68 kg battery you'll now only get 6 l / 100 km (39 mpg) with the 163 kg battery on board.

If you were doing 15,000 km (9000 miles) per year then over the two year lifetime of the battery that would add up to an extra 300 litres (80 gal US) of fuel or its equivalent in electricity = coal, simply because of vehicle weight.

I think it makes more sense to wait until at least lithium ion batteries become available with enough lifetime for a car. With their higher energy density (four times that of lead acid batteries by weight) you would at least not burn as much coal to carry around batteries.

[joewein]

Originally Posted by clett

Even when an electric vehicle is running off the worst possible source of electricity (coal), it emits less CO2 overall into the atmosphere than an equivalent gasoline / diesel or hybrid vehicle.

My sources indicate that it's not the case.

According to Hans-Dieter Schilling (Energie-Fakten), the average efficiency of all coal power stations in the world currently stand at around 31% (Analysis: Efficiency of coal-fired power stations – evolution and prospects )

By comparison, the 1NZ-FXE 1.5 litre engine of the Toyoto Prius manages 34% efficiency when producing 13.5 hp.

If you consider that charging a lead acid battery is no more than about 85% efficient and that there are transmission losses in the grid between the power station and your home, the coal fired power station would have a hard time delivering power more efficiently to your driving wheels than the Atkinson cycle engine of your Prius.

Another way to do the math is this: Coal fired power stations in the US produce on average about 2 lbs (0.9 kg) of CO2 per kWh generated. To recharge the 5 kWh pack would therefore generate 4.5 kg (4,500 g) of CO2. The Prius is officially rated at 104 g of CO2 per km. In other words, if you were to drive a Prius for 43 km (27 miles) it would produce as much CO2 as recharging the lead acid battery pack from coal power. The quoted all electric range of a Prius with that specific battery pack is only 10-15 miles (16-24 km). That's without even looking at charging losses, in reality it looks even more bleak for the coal fired battery scenario.

If you have data that backs your claim, I'd like to see it.

[clett]

Originally Posted by joewein

Coal fired power stations in the US produce on average about 2 lbs (0.9 kg) of CO2 per kWh generated.

This is correct, which means a car that manages 5 miles per kWh (which is about what a Prius sized EV or PHEV manages in real life) and uses a lithium-ion battery (which are 95-98% efficient) will release about 184 g CO2 per mile travelled, or about 115 g CO2 per km.

The reason most people assume that a Prius emits less than this (at 104 g/km) is because it is not widely advertised that the published CO2 emissions for gasoline vehicles account for ONLY the CO2 released directly from the vehicle's tailpipe.

No allowance is made at all for the amount of CO2 (and energy use of other forms) required to get the gasoline from the ground into the tank in the published figures. When you include the drilling, pumping, refining, and transportation of the fuel on a well-to-wheels basis, it adds about 20% extra on top of that, taking it to around 125 g/km.

However remember that, even in America, coal amounts for only 50% of the electricity grid mix, and the remainder is much less carbon intensive (nuclear, gas, hydro, wind).

[joewein]

Originally Posted by clett

This is correct, which means a car that manages 5 miles per kWh (which is about what a Prius sized EV or PHEV manages in real life) and uses a lithium-ion battery (which are 95-98% efficient) will release about 184 g CO2 per mile travelled, or about 115 g CO2 per km.

However Plug-In Supply Inc, the makers of that $4,995 conversion kit, only claim 2-3 miles per kWh (10-15 miles all electric for a 5 kWh battery pack) for their kit in a Prius and I wouldn't suspect them of being overly conservative if they're trying to find buyers.

[clett]

Plug-in supply, and several others that use lead-acid batteries, only use around 60% of the available capacity of the battery (ie from 20% charge to 80% charge), as full discharges would otherwise ruin the battery within around 200 cycles.

Their battery is rated at 5 kWh total capacity, but only around 3 kWh is actually used.

[ken1784]

Originally Posted by clett

This is correct, which means a car that manages 5 miles per kWh (which is about what a Prius sized EV or PHEV manages in real life) and uses a lithium-ion battery (which are 95-98% efficient) will release about 184 g CO2 per mile travelled, or about 115 g CO2 per km.

I think you forgot about transportation of the coal between coal mine to power plant, then it's apprx 10%. Also, there are some power loss between power plant to consumption point, then it's approx 5%.
Therefore, the number is 115 * 1.1 * 1.05 = 133 g CO2 per km.

No allowance is made at all for the amount of CO2 (and energy use of other forms) required to get the gasoline from the ground into the tank in the published figures. When you include the drilling, pumping, refining, and transportation of the fuel on a well-to-wheels basis, it adds about 20% extra on top of that, taking it to around 125 g/km.

Toyota uses the well-to-tank efficiency is 88%(12% loss).
TOYOTA: Company > Technology
Using that number, Prius number is 104 * 1.12 = 116 g CO2 per km.

Ken@Japan

[clett]

Coal power plants are usually close to the coal resources, so little energy is used to transport it to the plant. Neither is the coal refined before burning, so I very much doubt the LCA for coal to power plant would add up to anything like as much as 10%.

As for gasoline, I have seen a wide variety of figures for well to wheels efficiency. Toyota's figures are very much on the high (optimistic) side. Closer to the average is probably the US Department of Energy figure they typically use for petroleum refining and distribution efficiency (Tp) of 0.830 (83%).

That would put the Prius at 104/0.83 = 125 g CO2 per km.

The average amount of CO2 released by USA power stations is 610 g CO2 per kWh, putting an EV today at 90 g/km including your factors. In future it will be much less than this with the shift to renewables and nuclear.

[Brennos]

Originally Posted by TheForce

They simulate and "out of gas" experience for the car. The car thinks its out of gas and must be shut down to exit that mode. If you don't shut down the engine will not come back on even if you still have gas.

how are they pulling off that simulation??