Honda Car Forum

BMW Mini to Sell Electric Cars in U.S. From Summer 2009...
http://www.techespot.com/2009/06/bmw...ars-in-us.html

"jolly" <freedatingsites@gmail.com> wrote in message
news:4026449f-b8ec-49d0-a4cf-cf561ad13031@f33g2000vbm.googlegroups.com...
> BMW Mini to Sell Electric Cars in U.S. From Summer 2009...
> http://www.techespot.com/2009/06/bmw...ars-in-us.html

Hmm...try recharging that thing in CT, where the KW per hour charge is
$0.23. I wonder which would have larger carbon footprint, a gas
powered vehicle or the fossil fuel needed to recharge an all electric
vehicle.....

Isaiah wrote:
> "jolly" <freedatingsites@gmail.com> wrote in message
> news:4026449f-b8ec-49d0-a4cf-cf561ad13031@f33g2000vbm.googlegroups.com...
>> BMW Mini to Sell Electric Cars in U.S. From Summer 2009...
>> http://www.techespot.com/2009/06/bmw...ars-in-us.html
>
> Hmm...try recharging that thing in CT, where the KW per hour charge is
> $0.23. I wonder which would have larger carbon footprint, a gas
> powered vehicle or the fossil fuel needed to recharge an all electric
> vehicle.....
>
>

The gasoline powered vehicle. In fact, even where the electricity
comes from coal, it still pollutes less using an EV than an IC vehicle.
But don't let inconvenient reality intrude on your rant!

"Leftie" <No@Thanks.net> wrote in message
news:ioU4m.10421$Il.4190@newsfe16.iad...
> Isaiah wrote:
>> "jolly" <freedatingsites@gmail.com> wrote in message
>> news:4026449f-b8ec-49d0-a4cf-cf561ad13031@f33g2000vbm.googlegroups.com...
>>> BMW Mini to Sell Electric Cars in U.S. From Summer 2009...
>>> http://www.techespot.com/2009/06/bmw...ars-in-us.html
>>
>> Hmm...try recharging that thing in CT, where the KW per hour charge
>> is $0.23. I wonder which would have larger carbon footprint, a gas
>> powered vehicle or the fossil fuel needed to recharge an all
>> electric vehicle.....
>
> The gasoline powered vehicle. In fact, even where the electricity
> comes from coal, it still pollutes less using an EV than an IC
> vehicle. But don't let inconvenient reality intrude on your rant!

It's not a rant, it is quite the contrary. One was an observation,
the other is a viable question. Many proponents of electric cars talk
about no emissions, yet there are emissions from the power generation
that is required to charge the vehicle, but I never have looked into
it, and thought someone may have the information readily available, so
I guess I'll do a little digging for a few minutes to try and get some
facts to answer my own question.....

http://www.gm-volt.com/index.php?s=r...hp?s=recharged

At the bottom of this page from the above link, it it shows a rating
of 26-38 KWH per 100 miles, and an average of 32.5. At the electric
rates in CT, the cost would be about $7.47 to operate per 100 miles.
A gas vehicle that gets 35 MPG would take almost 3 gallons to to
operate, so even at the rate of electricity in CT, at the current cost
of fuel, this electric car would be an operational winner in that
respect.

http://www.eia.doe.gov/cneaf/electri...t/co2emiss.pdf
has some information on carbon footprint for for differing types of
power generation (for most recent year 2000).

Type Lbs/KWH Grams/KWH
Coal 2.117 961
Petroleum 1.915 869
Gas 1.314 596

According to http://www.terrapass.com/carbon-footprint-calculator/ a
Ford focus emits just about 318K grams per 1,000 miles driven (can't
validate the numbers, I just found it and used the Focus and reduced
what I got to a per 1k miles)

Using electricity, an all electric vehicle like the one shown above in
the first link would need about 325 KWH to drive 1000 miles, coal CO2
emissions would be about 312K grams, while petroleum generation would
be 282k grams and gas generation would be 194k, and improvement of 2%,
11,5%, and 39% respectively.

So in this comparison, if your power generation is mainly coal, there
is marginal benefit, while the others get progressively better.
Unfortunately in the DOE document, it shows that about 50% of our
power generation is based on coal, so that will minimize the gains on
the CO2 emissions. For us to really take advantage of electric cars,
it seems what we really need to do is revamp how we produce
electricity (though in general, an average CO2 savings of somewhere
around 16%-18% if all vehicles were electric is nothing to sneeze at).

I wonder how many KWH per 100 miles it would take for an all electric
Hummer?

(a more up to date document would be more helpful, but I don't have
anymore time to invest in it right now).

That seems to be a little more realistic.

"Isaiah" <isaiah@isaiah.org> wrote in
news:h31af5$qg1$1@news.albasani.net:

>
> "Leftie" <No@Thanks.net> wrote in message
> news:ioU4m.10421$Il.4190@newsfe16.iad...
>> Isaiah wrote:
>>> "jolly" <freedatingsites@gmail.com> wrote in message
>>> news:4026449f-b8ec-49d0-a4cf-cf561ad13031@f33g2000vbm.googlegroups.co
>>> m...
>>>> BMW Mini to Sell Electric Cars in U.S. From Summer 2009...
>>>> http://www.techespot.com/2009/06/bmw...tric-cars-in-u
>>>> s.html
>>>
>>> Hmm...try recharging that thing in CT, where the KW per hour charge
>>> is $0.23. I wonder which would have larger carbon footprint, a gas
>>> powered vehicle or the fossil fuel needed to recharge an all
>>> electric vehicle.....
>>
>> The gasoline powered vehicle. In fact, even where the electricity
>> comes from coal, it still pollutes less using an EV than an IC
>> vehicle. But don't let inconvenient reality intrude on your rant!

>
> It's not a rant, it is quite the contrary. One was an observation,
> the other is a viable question. Many proponents of electric cars talk
> about no emissions, yet there are emissions from the power generation
> that is required to charge the vehicle, but I never have looked into
> it, and thought someone may have the information readily available, so
> I guess I'll do a little digging for a few minutes to try and get some
> facts to answer my own question.....
>
> http://www.gm-volt.com/index.php?s=r...-volt.com/inde
> x.php?s=recharged
>
> At the bottom of this page from the above link, it it shows a rating
> of 26-38 KWH per 100 miles, and an average of 32.5. At the electric
> rates in CT, the cost would be about $7.47 to operate per 100 miles.
> A gas vehicle that gets 35 MPG would take almost 3 gallons to to
> operate, so even at the rate of electricity in CT, at the current cost
> of fuel, this electric car would be an operational winner in that
> respect.

Ah,but when the Obama carbon "cap n trade" goes into effect,coal-generated
electricity will SOAR in price(and US economy will take a nasty dive).
Obama has said he wants to put the coal electrics out of business.
That's >50% of US electric capacity.Obama will only allow nuclear plants
when we have "safe storage",but is killing Yucca Mtn repository by cutting
it's funding. Solar and wind cannot make up the difference.
Also,we are aleady near full capacity;no room for additional electric
loads.
>
> http://www.eia.doe.gov/cneaf/electri...t/co2emiss.pdf
> has some information on carbon footprint for for differing types of
> power generation (for most recent year 2000).
>
> Type Lbs/KWH Grams/KWH
> Coal 2.117 961
> Petroleum 1.915 869
> Gas 1.314 596
>
> According to http://www.terrapass.com/carbon-footprint-calculator/ a
> Ford focus emits just about 318K grams per 1,000 miles driven (can't
> validate the numbers, I just found it and used the Focus and reduced
> what I got to a per 1k miles)
>
> Using electricity, an all electric vehicle like the one shown above in
> the first link would need about 325 KWH to drive 1000 miles, coal CO2
> emissions would be about 312K grams, while petroleum generation would
> be 282k grams and gas generation would be 194k, and improvement of 2%,
> 11,5%, and 39% respectively.
>
> So in this comparison, if your power generation is mainly coal, there
> is marginal benefit, while the others get progressively better.
> Unfortunately in the DOE document, it shows that about 50% of our
> power generation is based on coal, so that will minimize the gains on
> the CO2 emissions. For us to really take advantage of electric cars,
> it seems what we really need to do is revamp how we produce
> electricity (though in general, an average CO2 savings of somewhere
> around 16%-18% if all vehicles were electric is nothing to sneeze at).
>
> I wonder how many KWH per 100 miles it would take for an all electric
> Hummer?
>
> (a more up to date document would be more helpful, but I don't have
> anymore time to invest in it right now).
>
> That seems to be a little more realistic.
>
>
>

People are not going to quickly replace their present gasoline autos with
electrics;many cannot afford it.
Also,electrics will not do everything gas-powered cars can.
Businesses will not be able to use them,they take too long to recharge.

--
Jim Yanik
jyanik
at
kua.net

"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns9C4253A6B5FD1jyanikkuanet@74.209.136.83...
> "Isaiah" <isaiah@isaiah.org> wrote in
> news:h31af5$qg1$1@news.albasani.net:
>
>>
>> "Leftie" <No@Thanks.net> wrote in message
>> news:ioU4m.10421$Il.4190@newsfe16.iad...
>>> Isaiah wrote:
>>>> "jolly" <freedatingsites@gmail.com> wrote in message
>>>> news:4026449f-b8ec-49d0-a4cf-cf561ad13031@f33g2000vbm.googlegroups.co
>>>> m...
>>>>> BMW Mini to Sell Electric Cars in U.S. From Summer 2009...
>>>>> http://www.techespot.com/2009/06/bmw...tric-cars-in-u
>>>>> s.html
>>>>
>>>> Hmm...try recharging that thing in CT, where the KW per hour
>>>> charge
>>>> is $0.23. I wonder which would have larger carbon footprint, a
>>>> gas
>>>> powered vehicle or the fossil fuel needed to recharge an all
>>>> electric vehicle.....
>>>
>>> The gasoline powered vehicle. In fact, even where the
>>> electricity
>>> comes from coal, it still pollutes less using an EV than an IC
>>> vehicle. But don't let inconvenient reality intrude on your rant!
>
>>
>> It's not a rant, it is quite the contrary. One was an observation,
>> the other is a viable question. Many proponents of electric cars
>> talk
>> about no emissions, yet there are emissions from the power
>> generation
>> that is required to charge the vehicle, but I never have looked
>> into
>> it, and thought someone may have the information readily available,
>> so
>> I guess I'll do a little digging for a few minutes to try and get
>> some
>> facts to answer my own question.....
>>
>> http://www.gm-volt.com/index.php?s=r...-volt.com/inde
>> x.php?s=recharged
>>
>> At the bottom of this page from the above link, it it shows a
>> rating
>> of 26-38 KWH per 100 miles, and an average of 32.5. At the
>> electric
>> rates in CT, the cost would be about $7.47 to operate per 100
>> miles.
>> A gas vehicle that gets 35 MPG would take almost 3 gallons to to
>> operate, so even at the rate of electricity in CT, at the current
>> cost
>> of fuel, this electric car would be an operational winner in that
>> respect.
>
> Ah,but when the Obama carbon "cap n trade" goes into
> effect,coal-generated
> electricity will SOAR in price(and US economy will take a nasty
> dive).
> Obama has said he wants to put the coal electrics out of business.
> That's >50% of US electric capacity.Obama will only allow nuclear
> plants
> when we have "safe storage",but is killing Yucca Mtn repository by
> cutting
> it's funding. Solar and wind cannot make up the difference.
> Also,we are aleady near full capacity;no room for additional
> electric
> loads.
>>

IOW, any financial gain will be negated, which will reduce the amount
of EV sold. Maybe if we let them place up to 3 spent fuel rods under
each new home built.....

>> http://www.eia.doe.gov/cneaf/electri...t/co2emiss.pdf
>> has some information on carbon footprint for for differing types of
>> power generation (for most recent year 2000).
>>
>> Type Lbs/KWH Grams/KWH
>> Coal 2.117 961
>> Petroleum 1.915 869
>> Gas 1.314 596
>>
>> According to http://www.terrapass.com/carbon-footprint-calculator/
>> a
>> Ford focus emits just about 318K grams per 1,000 miles driven
>> (can't
>> validate the numbers, I just found it and used the Focus and
>> reduced
>> what I got to a per 1k miles)
>>
>> Using electricity, an all electric vehicle like the one shown above
>> in
>> the first link would need about 325 KWH to drive 1000 miles, coal
>> CO2
>> emissions would be about 312K grams, while petroleum generation
>> would
>> be 282k grams and gas generation would be 194k, and improvement of
>> 2%,
>> 11,5%, and 39% respectively.
>>
>> So in this comparison, if your power generation is mainly coal,
>> there
>> is marginal benefit, while the others get progressively better.
>> Unfortunately in the DOE document, it shows that about 50% of our
>> power generation is based on coal, so that will minimize the gains
>> on
>> the CO2 emissions. For us to really take advantage of electric
>> cars,
>> it seems what we really need to do is revamp how we produce
>> electricity (though in general, an average CO2 savings of somewhere
>> around 16%-18% if all vehicles were electric is nothing to sneeze
>> at).
>>
>> I wonder how many KWH per 100 miles it would take for an all
>> electric
>> Hummer?
>>
>> (a more up to date document would be more helpful, but I don't have
>> anymore time to invest in it right now).
>>
>> That seems to be a little more realistic.
>>
>>
>>
>
> People are not going to quickly replace their present gasoline autos
> with
> electrics;many cannot afford it.

I realize this. I just wanted a clearer picture of what is meant by
reduced carbon footprint claims.....

> Also,electrics will not do everything gas-powered cars can.
> Businesses will not be able to use them,they take too long to
> recharge.

That may or may not be true, depending on how they are used. In
general, we are probably a good 20 years off from being able to change
ove en-masse IMO.

>
> --
> Jim Yanik
> jyanik
> at
> kua.net

Jim Yanik wrote:
> "Isaiah" <isaiah@isaiah.org> wrote in
> news:h31af5$qg1$1@news.albasani.net:
>
>> "Leftie" <No@Thanks.net> wrote in message
>> news:ioU4m.10421$Il.4190@newsfe16.iad...
>>> Isaiah wrote:
>>>> "jolly" <freedatingsites@gmail.com> wrote in message
>>>> news:4026449f-b8ec-49d0-a4cf-cf561ad13031@f33g2000vbm.googlegroups.co
>>>> m...
>>>>> BMW Mini to Sell Electric Cars in U.S. From Summer 2009...
>>>>> http://www.techespot.com/2009/06/bmw...tric-cars-in-u
>>>>> s.html
>>>> Hmm...try recharging that thing in CT, where the KW per hour charge
>>>> is $0.23. I wonder which would have larger carbon footprint, a gas
>>>> powered vehicle or the fossil fuel needed to recharge an all
>>>> electric vehicle.....
>>> The gasoline powered vehicle. In fact, even where the electricity
>>> comes from coal, it still pollutes less using an EV than an IC
>>> vehicle. But don't let inconvenient reality intrude on your rant!
>
>> It's not a rant, it is quite the contrary. One was an observation,
>> the other is a viable question. Many proponents of electric cars talk
>> about no emissions, yet there are emissions from the power generation
>> that is required to charge the vehicle, but I never have looked into
>> it, and thought someone may have the information readily available, so
>> I guess I'll do a little digging for a few minutes to try and get some
>> facts to answer my own question.....
>>
>> http://www.gm-volt.com/index.php?s=r...-volt.com/inde
>> x.php?s=recharged
>>
>> At the bottom of this page from the above link, it it shows a rating
>> of 26-38 KWH per 100 miles, and an average of 32.5. At the electric
>> rates in CT, the cost would be about $7.47 to operate per 100 miles.
>> A gas vehicle that gets 35 MPG would take almost 3 gallons to to
>> operate, so even at the rate of electricity in CT, at the current cost
>> of fuel, this electric car would be an operational winner in that
>> respect.
>
> Ah,but when the Obama carbon "cap n trade" goes into effect,coal-generated
> electricity will SOAR in price(and US economy will take a nasty dive).
> Obama has said he wants to put the coal electrics out of business.
> That's >50% of US electric capacity.Obama will only allow nuclear plants
> when we have "safe storage",but is killing Yucca Mtn repository by cutting
> it's funding. Solar and wind cannot make up the difference.
> Also,we are aleady near full capacity;no room for additional electric
> loads.
>> http://www.eia.doe.gov/cneaf/electri...t/co2emiss.pdf
>> has some information on carbon footprint for for differing types of
>> power generation (for most recent year 2000).
>>
>> Type Lbs/KWH Grams/KWH
>> Coal 2.117 961
>> Petroleum 1.915 869
>> Gas 1.314 596
>>
>> According to http://www.terrapass.com/carbon-footprint-calculator/ a
>> Ford focus emits just about 318K grams per 1,000 miles driven (can't
>> validate the numbers, I just found it and used the Focus and reduced
>> what I got to a per 1k miles)
>>
>> Using electricity, an all electric vehicle like the one shown above in
>> the first link would need about 325 KWH to drive 1000 miles, coal CO2
>> emissions would be about 312K grams, while petroleum generation would
>> be 282k grams and gas generation would be 194k, and improvement of 2%,
>> 11,5%, and 39% respectively.
>>
>> So in this comparison, if your power generation is mainly coal, there
>> is marginal benefit, while the others get progressively better.
>> Unfortunately in the DOE document, it shows that about 50% of our
>> power generation is based on coal, so that will minimize the gains on
>> the CO2 emissions. For us to really take advantage of electric cars,
>> it seems what we really need to do is revamp how we produce
>> electricity (though in general, an average CO2 savings of somewhere
>> around 16%-18% if all vehicles were electric is nothing to sneeze at).
>>
>> I wonder how many KWH per 100 miles it would take for an all electric
>> Hummer?
>>
>> (a more up to date document would be more helpful, but I don't have
>> anymore time to invest in it right now).
>>
>> That seems to be a little more realistic.
>>
>>
>>
>
> People are not going to quickly replace their present gasoline autos with
> electrics;many cannot afford it.
> Also,electrics will not do everything gas-powered cars can.
> Businesses will not be able to use them,they take too long to recharge.
>

Pickens has let off his wind farm pitch and now proposes re-powering
long-haul trucking and municipal transport with LNG, and investing in
storage and delivery/"gas station" facilities.

Thus spake "Isaiah" <isaiah@isaiah.org> :

>
>"jolly" <freedatingsites@gmail.com> wrote in message
>news:4026449f-b8ec-49d0-a4cf-cf561ad13031@f33g2000vbm.googlegroups.com...
>> BMW Mini to Sell Electric Cars in U.S. From Summer 2009...
>> http://www.techespot.com/2009/06/bmw...ars-in-us.html
>
>Hmm...try recharging that thing in CT, where the KW per hour charge is
>$0.23. I wonder which would have larger carbon footprint, a gas
>powered vehicle or the fossil fuel needed to recharge an all electric
>vehicle.....
>

The larger your powerplant, the more efficient it is. So that IC
engine is going to have less thermal efficiency that a 12,000 MW (or
however much) oil/gas/coal plant.

My f-i-l was a pwer EE and talked about some plants with turbines
exhausting at temperatures within 50 degrees of ambient. Now, today
the high was ony 105, so that might give "them" more leeway.
--

- dillon I am not invalid

"Jimmy, I'm sorry your girlfriend turned out
to be a cylon."
-Special Agent Tim McGee, "NCIS"

Jim Yanik wrote:
> "Isaiah" <isaiah@isaiah.org> wrote in
> news:h31af5$qg1$1@news.albasani.net:
>
>> "Leftie" <No@Thanks.net> wrote in message
>> news:ioU4m.10421$Il.4190@newsfe16.iad...
>>> Isaiah wrote:
>>>> "jolly" <freedatingsites@gmail.com> wrote in message
>>>> news:4026449f-b8ec-49d0-a4cf-cf561ad13031@f33g2000vbm.googlegroups.co
>>>> m...
>>>>> BMW Mini to Sell Electric Cars in U.S. From Summer 2009...
>>>>> http://www.techespot.com/2009/06/bmw...tric-cars-in-u
>>>>> s.html
>>>> Hmm...try recharging that thing in CT, where the KW per hour charge
>>>> is $0.23. I wonder which would have larger carbon footprint, a gas
>>>> powered vehicle or the fossil fuel needed to recharge an all
>>>> electric vehicle.....
>>> The gasoline powered vehicle. In fact, even where the electricity
>>> comes from coal, it still pollutes less using an EV than an IC
>>> vehicle. But don't let inconvenient reality intrude on your rant!
>
>> It's not a rant, it is quite the contrary. One was an observation,
>> the other is a viable question. Many proponents of electric cars talk
>> about no emissions, yet there are emissions from the power generation
>> that is required to charge the vehicle, but I never have looked into
>> it, and thought someone may have the information readily available, so
>> I guess I'll do a little digging for a few minutes to try and get some
>> facts to answer my own question.....
>>
>> http://www.gm-volt.com/index.php?s=r...-volt.com/inde
>> x.php?s=recharged
>>
>> At the bottom of this page from the above link, it it shows a rating
>> of 26-38 KWH per 100 miles, and an average of 32.5. At the electric
>> rates in CT, the cost would be about $7.47 to operate per 100 miles.
>> A gas vehicle that gets 35 MPG would take almost 3 gallons to to
>> operate, so even at the rate of electricity in CT, at the current cost
>> of fuel, this electric car would be an operational winner in that
>> respect.
>
> Ah,but when the Obama carbon "cap n trade" goes into effect,coal-generated
> electricity will SOAR in price(and US economy will take a nasty dive).
> Obama has said he wants to put the coal electrics out of business.
> That's >50% of US electric capacity.Obama will only allow nuclear plants
> when we have "safe storage",but is killing Yucca Mtn repository by cutting
> it's funding. Solar and wind cannot make up the difference.
> Also,we are aleady near full capacity;no room for additional electric
> loads.


I really wish that you were right in your worries. The fact is,
though, that Obama has already caved to the powerful coal industry in
his energy plans. So you can stop worrying about that and start worrying
about some other Right-wing Bogeyman. Obama isn't going to "kill" the
coal industry (more's the pity) or the economy.



>> http://www.eia.doe.gov/cneaf/electri...t/co2emiss.pdf
>> has some information on carbon footprint for for differing types of
>> power generation (for most recent year 2000).
>>
>> Type Lbs/KWH Grams/KWH
>> Coal 2.117 961
>> Petroleum 1.915 869
>> Gas 1.314 596
>>
>> According to http://www.terrapass.com/carbon-footprint-calculator/ a
>> Ford focus emits just about 318K grams per 1,000 miles driven (can't
>> validate the numbers, I just found it and used the Focus and reduced
>> what I got to a per 1k miles)
>>
>> Using electricity, an all electric vehicle like the one shown above in
>> the first link would need about 325 KWH to drive 1000 miles, coal CO2
>> emissions would be about 312K grams, while petroleum generation would
>> be 282k grams and gas generation would be 194k, and improvement of 2%,
>> 11,5%, and 39% respectively.
>>
>> So in this comparison, if your power generation is mainly coal, there
>> is marginal benefit, while the others get progressively better.
>> Unfortunately in the DOE document, it shows that about 50% of our
>> power generation is based on coal, so that will minimize the gains on
>> the CO2 emissions. For us to really take advantage of electric cars,
>> it seems what we really need to do is revamp how we produce
>> electricity (though in general, an average CO2 savings of somewhere
>> around 16%-18% if all vehicles were electric is nothing to sneeze at).
>>
>> I wonder how many KWH per 100 miles it would take for an all electric
>> Hummer?
>>
>> (a more up to date document would be more helpful, but I don't have
>> anymore time to invest in it right now).
>>
>> That seems to be a little more realistic.
>>
>>
>>
>
> People are not going to quickly replace their present gasoline autos with
> electrics;many cannot afford it.
> Also,electrics will not do everything gas-powered cars can.
> Businesses will not be able to use them,they take too long to recharge.


I appreciate your research, Isaih, but it only confirms what I
wrote (which wasn't a rant, just an assertion), and you are mistaken
about electrics 'taking too long to recharge.' Commercial vehicles will
have recharge times of about one hour to 80% and maybe four hours to
100%. Commercial plug-in hybrids will have no problem getting through
the day on a single charge.

>

On 2009-07-08, Jim Yanik <jyanik@abuse.gov> wrote:
>
> People are not going to quickly replace their present gasoline autos with
> electrics;many cannot afford it.
> Also,electrics will not do everything gas-powered cars can.
> Businesses will not be able to use them,they take too long to recharge.
>

I'd imagine that this could be rather easily overcome by getting the
car companies to standardize the batteries, and have them be quickly
and easily replaced. Then, filling stations could stock the batteries
fully charged, and swap them on-the-go, putting the used ones on the
chargers.

Of course, that's nothing like it is now...


--
Joe - Linux User #449481/Ubuntu User #19733
joe at hits - buffalo dot com
"Hate is baggage, life is too short to go around pissed off all the
time..." - Danny, American History X