Plug-in Prius here now?

This looks promising but my question would be 1) how many extra batteries do you need? 2) how does the new system tie in with the existing system? 3) where/how do you store the extra batteries? and 4) how much extra weight do you add? I did not question the price yet because I think these questions are most relevant.

 

Them batteries look awfully small to seem any good. I wonder too how it would tie into the system and be easily removable.

One other question that hasn't been answered in any Prius+ program: prognosis on battery life. The current Prius battery will last the lifetime of the car due to the fact that it only uses 40% of its full capacity. So, if these batteries fully deplete, how long will they last?

 

The Valence Lithium-ion batteries use an unusual phosphate based chemistry. This means no fires, 10 year lifespan and 2,000 deep cycles.

The cells fit in the gap underneath the floor in the back, so no real loss of space (see below). The pack adds ~90kg in weight, but this is offset quite a lot by taking out the original OEM NiMH battery pack.



The 9 kWhr pack should be sufficient for 60 miles of assist - so with deep discharges you'd be looking at a battery life of ~120,000 miles. However, most journeys would be less than 60 miles, so with shallower cycles it's likely higher mileages could be achieved before needing a new pack.

By the way, not attached to any of the Plug-in Prius Projects at all - just a keen observer!

 

Do the batteries in the photo take up the space used by the spare tire?

 

Great idea, but the real key is cost. How much is it? Also how much to install or can it be done by anyone?

 

I contacted the Valence company. They only created one car to prove it could be done. They have since started a smaller company to handle sales, marketing, and production of further units (in California). I have since sent an email to that POC but have not gotten a response yet.

 

Not knowing this group (other than what I have read) I would think IMHO that they are a couple of years off from creating a cost effective "after market/conversion kit". I would think the start up cost would be a major factor in the production, then it would be finding manufacturing facilities for the components. My limited/basic ‘business 101†take on it.

 

The mixed charging characteristics and risk of overcharging one or the other or over draining one or the other caused the problems I think.

 

Their brochure hyping 125 mpg is nice as far as it goes, but it doesn't mention other costs of operation. Plugging a charger into the wall also burns fossil fuels, albeit at power plants. Also, electric power costs the home consumer anywhere from $0.05/KWHr to $0.20/KWHr, possibly more, depending on location. The cost of recharging every day could be a significant amount, possibly adding as much as $100 to the monthly electric bill, or about one fill-up a week for an unmodified Prius.

I would be interested in reading a report of a study performed by an independent company. A realistic study that addresses ALL actual costs of modifying and operating this vehicle, not only theoretical reduced fuel consumption. I would assume that the study would show that it would take many thousands of miles just to recover the cost of modification, possibly as much as 25K miles depending on how the vehicle is operated.

 

It would not ever pay off the additional cost. The electrically powered miles are cheaper than the gas powered miles in a plug-in hybrid due to cheap coal generated electric power. The rate of savings; however, is not sufficient to overcome the time horizon dictated by the discount rate.

The future lies in fully electric vehicles made possible by the huge developments that are happening now in battery technology. Nanotechnology is just now coming into play and will change forever the way power our homes and vehicles. The efficiency of most of our appliances will improve and many things that we could not manufacture before will become possible.

In less than ten years, fully electric vehicles will be commonplace and hybrids will be more efficient than ever. Solar energy will be much more viable, as nanotechnology slashes their cost of manufacture. The typical electric vehicle will travel 500 miles on a charge and will recharge in less than an hour. Performance will surpass that of today's V8 cars. It's about to get very exciting.

 

I don't agree that there a plug-in Prius will definitely not pay off the additional cost. Your analysis relies on developments in solar panels and assumptions on battery/electric vehicle development which I would consider highly optimistic. Perhaps you know more about the subject than I do, but renewable energy (including solar) as a percentage of total electrical energy produced has fallen over the last 15 years.

Currently, the cost per mile to operate a Prius is approximately $0.05. With a converted Prius, this should drop down to about $0.025. With a $0.025 savings, a $5000 conversion could be recouped across 200k miles, is easily within the lifespan of the car. This may be an oversimplified analysis, but there is also the possibility of further rising gasoline prices, federal/state incentives to push for higher mileage/cleaner vehicles (in the forms of rising gasoline/carbon emission taxes or tax incentives).

Now the above analysis is also moot, b/c I don't know even some of the basic numbers to make the analysis, such as the cost of the conversion. In a nutshell, I think it's way too early to come to a conclusion.

 

At the calcar website the numbers they use are a little skewed to prove their viability. For instance the quote a 70 mile trip with 80% of the miles on the freeway at 55 mph and 20% in the city. If I had that kind of trip I would get over 60 MPG in my 2004 Prius. They also use a figure of 5 cents per KWh. I think these numbers that they use are going to make the accuracy of the EPA estimates for the Prius look conservative. I ran my numbers like this.

If you can run half of your miles on electric power and half on gas the numbers would come out like this.

55 MPG at $2.20 per gallon equals 4 cents per mile.

200 WH per mile at 10 cents per KWh equals 2 cents per mile.

Average cost per trip is 3 cents per mile for modified car as opposed to 4 cents per mile for unmodified car. I won't haggle about their 200 WH per mile if you won't haggle about my 55 MPG. I get that in my car and I trust that when they are careful that they get that in theirs. Anyway, it makes the math simple. If the modification costs $5,000.00, then the un-amortized payoff horizon is 500,000 miles.

Here's where it gets depressing. If you figure in the cost of the money, in other words, the discount rate, the numbers are even worse. Say you borrow the $5000.00 at 5% interest. Let's say you drive twice as much as the average. At 25,000 miles per year it takes 20 years to recoup the 5k. Now figure the interest on the 5k at 5% over 20 years and the total payoff comes to $7,920. That payoff is racing away from you and the battery, conservatively figured, failed you in year 8.

You can change the numbers any way you want but to twist them enough to see a pay-off in dollars you would have to get your electricity for free, your financing for free, and not take many long trips. Also your battery would have to last longer than the manufacturer forecasts.

On the subject of solar power and battery development, you can search on google using nanotechnology, battery, photovoltaic, and improvement in your search and find out what's happening right now to change tomorrow. Also look into the new Lion battery from Toshiba that is going to turn the battery industry on it's ear starting next year.

Have a great day.

 

Of course if you drive 25,000 miles per year it will be practically impossible to get half your miles from electric power.

 

I may have to verify these numbers a bit more rigorously a bit later, but let me try a quick scenario to see if I can convince you of its potential viability. Now these numbers don't exactly work for me, but I think you'll be willing to let me go to the envelope of what's reasonably possible.

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

Let's say your one-way commute is 70 miles. At work, you have free electricity hookup (there is actually a spot like this at my work which I am unable to take advantage of). Gas is $2.51 (the cheapest around where I live, and this has actually dropped from it's highest).

$/mi (normal) = $0.04566
$/mi (home => work) = $0.03282
$/mi (work => home) = $0.02282
$/mi (home => work => home) = $0.02782
$/mi (difference) = $0.01752

The $5000 conversion is borrowed at 5%. Inflation is say 2.5%, so the effective interest rate is 2.5%. This gives an amortized cost over 10 years of $5656. It takes 322,831 mi to recoup this cost. At 70 mi x 2 way trip x (52 weeks - 3 weeks vacation) x 5 days a week = 34,300 mi/yr, it takes 9.41 years to recoup the cost of the conversion.

Of course the analysis makes somes suppositions, like a non-rising gasoline price (IMO unlikely), stable electricity pricing (IMO very likely), inflation rate (this has varies a lot from decade to decade, but 2.5% seems like a reasonable average between the inflation rate of the last 10 years), conversion cost (maybe I can ask a friend who works in the battery field to give me a better (smaller?) ballpark figure), and that the battery lasts that long (I give it at least a 50% chance). 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. Pretty likely on a crappy product, but I think Toyota is a bit (read a lot) more conservative than that.

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. Keep in mind that these articles that you are referring me to in Google have the same optimistic viability calculations that Valence would have. While they may not be trying to sell you a product, they are trying to sell their research (in terms of getting grants). I am actually aware of the Toshiba LiOn battery developments as well as possible uses of nanotechnology for both batteries and solar panels. 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. 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.

Nuclear power is the way to go, IMO (of course with all the hard issues addressed first). This is a slow revelation that is being reached by our government which has already been reached by others around the world.

I hope you have a great day as well.

 

Can we store the spent nuclear fuel at your house? No one seems to want it - not even Nevada!

 

Like I said, the hard issues have to be addressed. As of the moment, since my house has not been proven capable of holding radioactive refuse for the 250k years required for it to decay, I'm gonna have to say no. On the other hand, it may be cool to have the extra security around my house to safeguard against terrorists/rogue states from stealing nuclear refuse from my house in their evil plots of nuclear proliferation. I wouldn't have to worry about normal criminals either; I mean what burglar is going into the house with the radioactive sign hanging out the front?

Since we don't have the extra nuclear waste at the moment due to the coal plants, how about we store 150 million tons of carbon we are spewing into the atmosphere at your house, gschoen? Per month. It may be a bit hard to collect and actually store, so you may be off the hook. We'll just let it float around in the air and cause problems in air quality/global warming around our neighbors and the world in general.

I'm actually curious where other countries currently store their radioactive waste. I don't recall such outcries regarding nuclear refuse storage from other countries which heavily use nuclear power. Actually, where is the US storing it's nuclear refuse now?

 

Somethign else to think about is that this technology is in its infantcy. Just like those pioneers who bought the first Prius. It was not as good as it it now but if they did not support it we would not be driving around in our Prius IIs.

I feel it is the same way with the plug in mod. We will be lucky to break even over the life of the car but it will help push development of better and better systems. Then again I am probably one of those who will spend $5000 to save 5 MPG.

If my daily commute is only 35 miles a day (17 miles one way) then I wonder if I will ever use any gas. I would love to be able to say "Yep I filled my gas tank 6 months ago."

 

Joe, you provide a well stated financial analysis. However I would like to offer two comments.

1 - Even though the plug-in at your office is provided as a no cost employee perk, the power is not "free". Your Company is paying for it, so it should be included in the car's cost-of-operation calculations.

2 - I think the stated battery capacity of 9KWH in the brochure (and upon which we are basing much of this topic) is misleading. Based on the following rationale, I think that 9KWH may be the capacity of one cell or cell package, not the entire battery system as is implied.

The brochure states that the car can travel up to 60 miles on electric power alone. Let's assume this means the car will operate for about 3 hours at an average speed of 20 mph, which is reasonable for combined commuting driving. Therefore the car will consume 3KW per hour supplied by a 9KW battery. Since 0.746KW equals 1 HP, the car will have no more than an average of 4HP available for power over the three hour period (at 100% electrical efficiency), which I believe is far less than the power required to overcome drag, rolling resistance, and all other negative factors at the assumed average speed. Therefore, I feel that the brochure's battery capacity is understated, allowing one to infer that the figure refers to total battery system capacity. After all, the document is a marketing brochure, not a technical design specification.