Plug-in Prius here now?

<div class='quotetop'>QUOTE(ryogajyc\";p=\"84134)</div>

I only bashed nuclear power when you said it's the "way to go" and our country will have a slow realization. Nuclear power isn't clean or green, it just doesn't make air emissions. I am not for Coal power, I pay "energy credits' for wind power to offset my home residental use. Polluting technologies (like Nuclear) may look "cheaper" in our electric bill, but many "economic externalities" are paid for in our taxes or health care costs. We were once told nuclear power would be "too cheap to even meter." yet safety problems made the need for greater regulation and no one today calls it cheapest, they're hoping for "cost effective". CO2 emissions are paid for by the entire planet equally, there's no NIMBY factor there. The possiblity of someone purposely trying to cause a nuclear disaster was previously remote, now our nuclear plants are a vulnerability in our security network we have to pay extra to keep safe. If they succeed, what will nuclear power cost those affected and our economy as a whole? Solar & wind will look VERY cheap at that point, now doubt!

Renewable energy will be more cost effective as we start to pay the "true" cost of conventioal energy, rising natural gas & oil prices, and difficulty in locating sites to build coal & nuclear plants make our electric costs rise.

I don't know where other countries store their waste. Most of our waste is being stored at the facility that makes it, primarily because we don't have a long term storage developed (Yucca Mountain, anyone?) Yucca is way behind schedule and constantly delayed in court. The temporary storage at the plants is designed to be that, termporary, and not built for long term containment. It would be easier and safer to have a permenant facility, but no one wants it. I would have to say myself included. If the choice was to have it stored across the street from me, or pay 2X my electric bill, I'd happily pay. It would be chepaer than the loss of value to my home!

Everythig has a cost. If we all drive electric cars we have to get the power from somewhere, and we'd need a lot of it. Nuclear has the capacity but brings so many problems of its own, it also prevents the renewable energy market from developing. Just like rechargable batteries have developed from their widespread use, no doubt solar panels would get lots more tech dollars and work better if they were on every roof.

 

Ryogajyc-
Allow me to respond to some of the points that you raise. I will put your text in quotation marks.

"I'm not sure where you get 200 Wh per mile, but 10 cents per KWh definitely sounds reasonable."

response- the 200 Wh per mile comes from the calcars website. I think it is a little bit of a stretch as I think the average would be more like 250 but I used it.

"Of course the analysis makes somes suppositions, like a non-rising gasoline price (IMO unlikely), stable electricity pricing (IMO very likely)"

Response- My electric rates have risen 30% in the last 18 months due to fuel surcharges brought on by rising natural gas prices. I see this as a continuing and accelerating problem.

"I think saying the battery is going to last only 100k mi is like saying the any device will fall apart as soon as the warranty conditions on it expire. "

Response- I figured the battery to expire at 200,000 miles. The manufacturer says the battery will last for 2000 deep cycles. In your scenario that comes to 150,000 miles. I was throwing the other 50,000 miles in to help you stretch the envelope. Unfortunately, by then the efficiency of the pack will have dropped along with it's performance. That's OK, we're stretching your envelope for you. No way it makes it to payoff though. No mention of a warranty at all. Battery makers claims of cycle life rarely match real world experience by the way. That is why the Prius does not deep cycle.

"As for solar panels, the current cost per KWh is $0.23 compared to coal, wind, clean coal, biomass, and nuclear which range from $0.05 to $0.07. To be competitive, you are talking about a 4x drop in cost per KWh in the next 10 years, which I think is highly optimistic."

Response- Current cost of solar systems comes to around 28 cents per KWh if you ignore finance costs. The variables in arriving at this figure are so numerous as to make it almost silly for me to make the statement but the following is more black and white. The current average cost of a solar panel is $5.12 per watt. Here's the link. http://www.solarbuzz.com/Moduleprices.htm
I think we will see these prices fall to the range of 75 cents per watt in today's dollars(manufacturers claim 60 cents) Solar panels account for 45-50% of the total cost of a solar system. Inverters and controll systems will fall in price as well. According to the DOE, the average price of residential electricity in the US in January of 05 was 8.49 cents per KWh and rising. I'm not sure if that included the fuel surcharges. This is 3.1 percent higher than January of 2004.

"While I think we will see Toshiba batteries in products within 5 years, I don't think they will be cost-effective/mainstream until around 10."

Response- Toshiba is releasing them in 2006.

"As for the solar panels, I'll believe in their efficiency gains at a viable manufacturing cost when a I see someone willing to risk a business in manufacturing and selling them."

Response- Agreed

"I hope you have a great day as well."

Response- I did. Thank you and thanks for the discussion.

 

Re: Plug-in Prius & Solar

The "bottom line" figures are correct. We too often forget that the value is more than the bottom line. The Prius is designed primarily to minimize emissions, hence, the AT-PZEV rating, with good fuel economy as a benefit.

Hybrids need to be taken a step further with PV panels integrated into the vehicle - dashboard, rear deck, windows and sheet metal (or plastic). Yes, windows - glass that does double duty, you can see through it and integrated PV design generates electrons. For the skeptics, I have always kept a PV panel or two on my dashboard directly linked to the conventional battery. This keeps the battery topped off and is especially helpful in cold weather when cranking capacity drops.

Whether driving or parked, sunlight is passive and free. Better to capture sunlight and sustain batteries, rather than have to plug-in and pay for a full "tank" of grid electrons. Capturing sunlight has a positive effect on air quality by decreasing battery charging and reliance on the ICE.

People considering EV Prii need to read Factor Four: Doubling Wealth - Halving Resource Use: A Report to the Club of Rome
by Ernst von Weizacker, Amory B. Lovins, L. Hunter Lovins, Kogan Page (July 15, 1998) ISBN: 1853834068, $32.12.

 

Until solar panels become more efficient, I wouldn't want them on my car. The dash PV panels that exist today are top-off chargers, could they charge the battery from completely dead to full charge, in any length of time? Even if they could, the 12V battery holds such a tiny amount of charge compared to the main battery. What kind of solar cells would be needed to bring it from 40% to 80% charge? I would guess they'd need to be bigger cells than the car, though I don't know for certain.

Having the cells at your home for charging there seems more effective, since they can be located for maximum efficiency and usage. On your car you'd get no electroncs in a garage! They're too expensive to miss out on good sun. Your home could always sell excess back to the grid, wheras your car must stop when it's battery is full. A fender bender could really make for a sad day when the cost of expensive solar panels wsa added to the damage!

 

I'd like to make some points in regards to the fossil fuel v renewable arguments.

Literally hundreds of billions of dollars have been spent on R&D for the ICE since it's invention 100+ years ago. The R&D for solar and wind and for who knows what else is, added together, literally a decimal point of that figure.

So why do we continue to defer an investment on the scale of that applied to the ICE? One reason, the business model is flawed for solar and wind.

Nuclear power, Oil/Coal/or LNG based power plants centralizes the profits. Build the plant and then get energy users to pay you every month forever. Profits go to a few people, and if you count stockholders, they may go to a few hundred or even a thousand people.

Solar and wind have the wrong business model. If you build a great solar collector, you build it once, sell it, and that's it. You cannot collect a user fee every month forever. There would be manufacturers all over the planet. Profits would be spread out among thousands or even hundreds of thousands of people.

There are mega wind projects that maintain the centralized business model. But there is a flaw there too. Any breakthrough in a mega wind project could probably be applied to MUCH smaller projects. Thus, the research would work against those who want those profits maximized.

So IMHO, the reason we don't see the research in solar or wind is not because the technology isn't there yet, we don't see that investment because the business model is wrong.

It's never been about technology. It's about business. Hydrogen also does not have the right technology, not by a long shot. But it has the right business model. Hence that is where our tax dollars will go.

 

Wow -

I don't think you could be more right. Granted, I live in a capitolist Country - but I think it's a safe thing to say that "If it doesn't make a lot of money, it won't be mass produced".

In fact - I'd say that those who make profit from a competing source would likely pay real money to keep any research from developing.

Makes me wonder about all those urban legends of "water powered cars" where you hear it was invented but the oil companies paid the inventor to shut up. Maybe there's some truth to it.....

I recently saw an article about a prototype AIR powered car. It was a hybrid like out precious Prius, but the other power sourse was powered by compressed air that ran the pistons when the electric motor needed power assistance. I think it was a Korean invention. I'm sure that such a vehicle WOULD need to be charged (electric compressor assisting electric motor - power has to originate SOMEWHERE - and there's no ICE) - but what a concept.

I wonder if this AIR powered car will get hushed up by oil conglomerates....

Yoda

 

Oh and the even sadder thing is that the cost at this point to plug in the prius with the Lion battery is over 11,000. Ouch, can that be true?

 

"$11,000?" I've been reading these articles on the plug in battery system and this is the first time I've seen a dollar figure. Thanks for the info.

So with 2005 technology we've got 120 MPG for an $11,000 premium. And this is doable using 2005 infrastructure. Now how does hydrogen compare to that? From what I've heard, the cheapest hydrogen vehicle is in the 6 figures and that's with no infrastructure.

SO it sounds like the plug in hybrid is decades ahead of hydrogen. So why the rush to hydrogen? Could it be the business model?


It sounds to me we need better batteries and better ways to make electricity. And thanks to Toyota, we are making real progress with the former.

 

Even if solar collectors are a "durable good" item rather than a commodity, there's still a good incentive to sell them. Refridgerators last 20+ yrs for most people but they're for sale. But if there was a cheaper alternative, we'd buy that instead, even if it slowly made our lungs black. Solar Panels are expensive because we're not buying or researching them in a meaningful way, we're not buying them because they're too expensive! Conventional power is cheap because we "subsidize" the bad parts through taxes so the price looks low in comparison.

Solar farms aren't being built on a mass scale just because the economics aren't there. If they could make the power as cheap as a coal plant, or electricity prices go up 4X, they would be a LOT more attractive and easier to build, since the neighbors won't complain and sue you as much. All tech is doomed to obsoetence. A new coal or nuke plant (if they were built, I suppose) would definately be cleaner and more cost effective than one 40yrs old. We don't wait for tech to get better or we'd never build anything!

The "invisible hand" of the market will take care of us. The job of our government is to make sure we have something set up before the hand strangles our economy with it! ($4 gas and $0.25kwh electric coming fast would be devestating as things are today)

 

Wow, I didn't realize so many posts occurred since my last one this morning. I got a bit of catching up to do.

I agree with Tadashi, that there is also the early adopter appeal of it, though at $11,000 (where did this come from?), I think my wallet disagrees.

Hytec, the example was merely to recoup the cost to a hypothetical owner. I was listing the free charging spot as an example that I'm not making it up, since I've heard of quite a few tech type companies which do this sort of thing as well as seen parking spots at malls an universities with the like. If we wanted to get into true cost-of-operation, I haven't got a chance at figuring that one out. I mean, there's the cost of recycling all the materials after the product is no longer useful, emissions from using and manufacturing which will probably come back and bite us in the butt sometime in the future, but like all industry, we'll ignore for now. Etc.

gschoen, I have no problem with a differing opinion, but I did not like the fact that you, in your own words, bashed. But I think I gave (without the bashing of course, just some playful turnabout) as good as I received, so it's all good


First of all, let's list some people who think nuclear power is the logical answer: Hugh Montefiore, trustee of Friends of the Earth; Patrick Moore, cofounder of Greenpeace; and James Lovelock who developed the Gaia theory. These longtime "green" people have realized that their original stance of anti-nuclear power doesn't make sense and that nuclear power is the current best solution. I probably haven't convinced you, so there's more.

Let's say we were to replace all power generated, ~650 GW, with one particular type of power. We'd need about 650 nuclear reactors (actually only about 550 new ones, since there are about 100 currently operating in the US) increasing current capacity by ~5.5x. We could alternatively replace it with all renewable solar energy (I would love to, but here's there's a bit of a clincher). We'd have to consume 60 square miles per gigawatt. This would take 39,000 square miles, or an area about 2/3 the size of Illinois. Of course, before saying it's green, we may want to consider the massive ecological impact 39,000 square miles for the US power generating needs. Keep in mind a single gigawatt solar plant would already be the largest industrial structure ever built, so we may have some engineering difficulties. Alternatively, we could switch to wind power which would take 300 square miles per gigawatt with a grand total of 195,000 square miles of windmills. This would probably severely change some weather patterns as well as as kill at least 390,000 birds of prey. Annually. PETA might have a bit of a problem with that. Also, our hypotethical US wind generators are now consuming what is several states, so it may be a bit harder to get by since at least with solar power solution 49 states could gang up on one and put the entire solar plant there. The odds are a bit worse with wind.

Now the scary scenarios of nuclear meltdown were from nuclear power was in its infancy and we were messing around with generation I nuclear plants. We are now at generation III+ and I think we've learned a the hard way to be more careful with nuclear power. Europe and Japan have a bunch of generation II reactors and not a Three Mile Island among them.

There's also development in the field of pebble reactors, where unlike traditional reactors where there are a lot of conditions you have to keep right to prevent the reaction from going out of control and causing a meltdown to you have the opposite. You have to keep a lot of conditions right to keep the reaction going. You mess something up, it's probably a bit of hassle that you have to restart the nuclear reaction, but no real (read meltdown) harm done.

While nuclear sabatoge maybe a problem, that's why we have to maintain tight security. I mean any structure like a stadium or skyscraper is a potential terrorist target, but we can't live in fear of terrorism or they win. We have to defend ourselves.

Nuclear waste can be turned into weapons, but until we are willing to protect other nuclear waste stockpiles which are barely guarded if at all in other parts of the world, we aren't really focusing on the real high percentage threats.

Now, I would like power sources that don't leave behind radioactive waste and don't pollute our world in other ways. But these other solutions have much bigger problems compared to nuclear power today. We do have to deal with radioactive waste, but it's not something that's actually going to be a problem for 250k years. We'll develop a way to make it non-radioactive (there's work on this already actually), or we'll dispose of it by disposing of it in fusion reactors when we develop them or just jettison it into our nearby natural fusion reactor, the sun (I haven't done the cost analysis on this one yet, but I'm guessing we'll need some cost reductions per pound for space payload before this one is really feasible). The US is coming to the slow realization the nuclear power is a reasonable choice now, and it's not so bad that we took our time. We can build the latest and safest generation of reactors now.

 

Re the onboard solar charging idea.

As soon as a plug-in Prius appears with at least a moderately sized battery (ie >=4kWh), the whole concept of getting significant driving range from onboard solar charging becomes very much a reality.

There is enough surface area on the Prius using the latest 20.4% efficient solar cells to extract an AVERAGE of ~18 miles of EV mode range (or many more miles of assist) per day (~6500 miles per year) - for many people this would halve their fuel bills and emissions.

The cost of the solar panels (over and above the sticker price of the plug-in Prius) would be an extra ~$3,000 - some people might pay that just to avoid the hassle of having to plug in!

This whole idea was discussed over here a while ago, but be warned it aroused some strong opinions on both sides!

But for those who aren't convinved, remember that the solar racers can go more than 500 miles per day on sunlight alone - a solar Prius can easily manage one twenty-fifth of that!

 

Hytec, I forgot to reply to #2 in your post earlier since I haven't had a chance to review all the information myself. The 9kWh is the approximate amount of the entire battery pack. This makes sense with their photos which show 18 Valence Saphion U-Charge battery cells each with a capacity of 534 Wh nominal. To be more accurate, the total capacityis actually 9.612 kWh nominal.

Ray, now your putting words in my mouth and I have a feeling that you missed my point. I'm not trying to stretch the envelope in any sense. My point is that there is a range of situations based on many variables and that recouping the cost of the conversion lies somewhere within that range. I originally objected to your flat-out statement the cost of conversion was unrecoverable. I'm actually leaning to agreeing with you now that I know the battery packs in the prototype cost $15k, but if this gets mass-marketed that price will probably drop significantly ($11k may be an early adopter price?--I still haven't found out the source of this number). I simply provided a reasonable example where it may be viable to recoup the conversion cost. Your example proves that it is not viable for you, which is fine as well, but you concluded it was not viable for anyone.

The 200 Wh/mi you mentioned is also from 35-mi all electric @ <35mph, yet the 70-mi trip is set at 115-150 Wh/mi. This makes it cheaper than I previously thought. Also, I had not considered off-peak power rate, which also makes it cheaper than I previously thought. I did make a incorrect assumption that the battery SOC was controlled entirely by the Prius which prevents deep discharging (I thought the battery pack had this huge capacity and just used a small portion of it). This hurts my case, but I'm not sure it is a fatal blow. As for getting 60MPG at 55mph, that's great, but at the stated 120-180MPG with the conversion, we are still talking about 2-3x improvement and a grid power contribution of 1/2-2/3 of the entire power expendicture of a converted Prius. The rise in energy cost in your area seems like local electric price hike, but I'd have to investigate that further.

I said before, I have to verify these numbers a bit more rigorously to make sense. Hopefully, I'm getting a more accurate analysis the more I understand the specifics.

clett, you are comparing a solar racer which weighs a few hundred pounds with no amenities, seating for one, nor cargo space and a Cd much lower than a Prius with a Prius, a mid-size hatchback. Even with a relatively heavy solar racer that's about 1000 lbs, let's say, a 3000 lb Prius is 2k lbs heavier. At 1/2 HP per 10 lbs of weight, we are talking about needing an extra 100HP just for the two to accelerate at comparable rates which is the approximate horsepower rating of the Prius. You make it sound as if the Prius should be able to do much better with your 1/25 comparison, but it really seems like an apples-to-oranges comparison to me.

 

There exists a prototype for a solar/LNG/plug in hybrid already built in Australia.....

Solar Electric Hybrid Prototype on Display in Queensland

..."In sunny weather the UltraCommuter can travel up to 60 km (37.3 miles) a day on solar power alone. Drawing on power stored in its 360V Li-Ion battery pack extends this to 200 km. For longer journeys compressed natural gas (CNG) powers a 10 kW generator to feed electricity into the batteries, producing a total range of 500 km (310 miles)."....

http://www.greencarcongress.com/2005/04/so..._electric_.html


Remember, this is only a prototype. Just think if GM was this creative and forward thinking!

 

Joe, I just believe that 9KWH available solely from their batteries is too low a capacity to power a car the size and weight of a 2004 Prius for 60 miles at what I assume to be commuting speeds in nominal traffic conditions. However, if their test was performed on a closed track, at a constant speed for lowest drag, under ideal environmental conditions, and they drained the battery to exhaustion at exactly one hour, then they would have had an average of 12HP at their disposal. This scenario possibly would have given them the desired results for publication in a marketing brochure without liability.

 

The point I was trying to make without writing a book is... we all call nuclear power "clean" but we still don't have a long term waste storage solution. No one wants it, it's difficult to manage, it's dangerous, we don't know what the world will be like in 100 years let alone 1000, etc. Yucca Mountain is supposed to "fix" that for us, but in addition to legal problems from the state of Nevada, the latest report has shown instability that could threaten the planned structrual integrety. DOH! Problems like these aren't unusual, it happens in EVERYTHING! Stuff happens. Saying future tech will solve these problems doesn't mean we can build reactors today and pray the research comes through. We've been trying to neutralize waste and get sustainable fusion for decades, and we learn things, but no one's planning a prototype of a fusion plant anytime soon. Fusion is in it's infancy. One of the problems with science as we get to more basic levels of manipulation is many times our actions have consequences we don't know about at the time. Remember "breeder" reactors? They could use spent fuel, make more energy, and leave low level waste but OOPS create lots of weapons grade material at the same time! While the US might have felt they could guard their own reactors, research stopped and North Korea or Iran will have to finish research on their own if they want to build them. Can you guard science as well as you guard nuclear material? You want to put nuclear material into the sun?? What is the cost analysis??? Yikes - I think we have bigger problems here than economics. What are the consequences? This would be a big "oops" if we screw it up, even 99.9999% certainty is too low here. What will the rest of the world say as we start putting nuclear material into space? If the EU, Russia and China are tired of us making planet decisions now, I can only imagine what they say when we start messing with the sun. At least if we screwed up we wouldn't have to say sorry!

Can we build a nuclear plant today and say "there is no way it will ever meltdown - it's impossible!" Of course, we know the problem with that attitude, the brass at Chernobyl thought so and felt so safe were willing to do reckless things (like the "test" that day). Nothing is 100%, the problem with nukes is the consequences are huge and they last a LONG time, more caution is needed than a coal plant. Nuke tech is a complicated and relatively new science. We are constantly learning new things and realzing how much there is to learn in this exciting new field. I agree we can't live in fear of terrorism, but we can defend ourselves to the eye teeth, we could live in a police state, and terrorism still occurs. Greater security doesn't prevent terrorism, it just changes the shape. Attacks on skyscrapers and stadiums are horrible and painful, but they won't unleash a cloud of death that circles the world. We can rebuild on those sites and send a message of defiance, a nuclear site is a painful and deadly reminder whose effects keep returning. What would 9/11 be like had they targeted nuke reactors with airplanes? What are the effects of a full meltdown of a large reactor? We've never seen it - Chernobyl was partial and the effects mitigated by heroic "sacrificial" workers. How can we guard everything? How do you completely guard against an enemy who uses suicidal troops that believe they're on a mission for God? Who will pay for it? Suddenly the costs are more expensive. There is no free lunch, and nuclear power is no exception. If the research gets here someday, great, there's no guarantee what will get discovered. Using "vaporware" to justify the negatives is junk science.

The plan for renewable energy isn't an "all at once" - there isn't enough manufacturing capacity currently to build the solar panels you suggested, and there wouldn't be for a LONG time. As an urban society, we have lots of rooftops, just putting solar panels there would give a lot of supplemental juice with no open space taken. They also reduce the "urban heat" generated by heavy development. Other tech possibiliites are available (ocean gyros, wave energy) but are more expensive and only viable if we first took better advantage of what's available now.

To say nuclear is the answer and has no drawbacks leads us away from truely renewable, safe power. I don't care what "environmentalist" supports it-you could tell me the Pope and Dali Lama issued a joint press release supporting nuke power, I'd say great when is the Vatican taking the first shipment of waste? Nevada will be so HAPPY!

Yes ryogajyc, I could tell you didn't like my post, of course your "playful turnaround" implied I supported coal power, an argument I never made. I'm glad you're not bashing renewable, green power. I'd hate to see what you'd be saying if you were. Perhaps if I put a smiley it's all good?

(OOPS wasn't supposed to be a book. I'll go back to one liners)

 

Gotta agree with ryogajyc on a point here, the solar racer is a LONG way from a usable vehicle. Don't they only test them on really sunny days in really sunny areas? Hopefully the research will lead to future advances that could go to mass market.

 

The 11,000 number came from my reading yesterday on a site that had different stages and methods laid out by one of the griddable hybrid groups but I am unable to find it today to provide a link. Dammit. The Batteries however really aren't going to last much past 120,000 in a form that will continue to provide the length of commute in our example. The batteries are getting better though. I just think that as the batteries improve, we will just switch to full electric vehicles.

I also think we will have reserve batteries for getting us to a charging station when we misjudge our capacity.

Let's simplify the math. 120,000 miles divided by 50 MPG is 2,400 gallons times $2.25 per gallon equals $5,400. That's the total cost to drive the unmodified Prius the estimated life of the batteries.

Something is going to have to drastically change to make this work out. Price of gas could double and electricity prices not rise and financing could be really cheap and the price of the batteries could come way down and then we have a winner.

 

I didn't have the patience to read this entire thread, but in response to using 2/3 the state of illinois for solar power, who says it has to be in one place? I could use new roofing material, it would be great if instead of putting tar paper that only gets hot thus adding to my cooling bill, have it generate electricity?

Do you think we have 2/3 of illinois in roof space? I think so.

 

I have to extrapolate a bit, but from my calculations we do not have that much roof space. Chicago has 680 km2 of roof area, which is 263 mi2. With a population of about 3 million, and a US population of about 295 million, this gives an estimated US roof area of 25,817 mi2. This leaves us still short by about 12,000 mi2 or about 1/5 the state of Illinois.

My initial hunch was that it wasn't possible, b/c otherwise I probably would have heard of some house(s) that is/are powered entirely off solar power panels on its roof. Now I'm not saying it isn't possible to run a house entirely off roof solar panesl, but the house would have to have very efficient appliances and power-saving features.

Increases in solar panel efficiency may make it possible to power everything from rooftop solar panels, but it is still a huge undertaking to install solar panels in every roof in America, as well include costs of producers selling their electricity to the grid (b/c things like skyscapers probably aren't going to be able to supply all their own power).

 

Joe, apparently I was mistaken with my assumptions concerning battery capacity, and the amount of energy required to power a 2004 Prius.

Yamaha is marketing a golf cart, the 2005 G-Max, which has a battery that provides 56 Amps at 48 Volts (~2.7KW) for 121 minutes (~2 hours) while moving the cart at a maximum of 15 mph. If my calculations are correct, this should equate to a 5.4KWH battery capacity that can power a 549 pound golf cart (plus batteries) for 30 miles. So it appears possible that a 9KWH battery system can power a 2890 pound Prius (including batteries) for 60 miles.

Appears that battery energy density technology has come a long way since the mid-50's.