Can Residential Wind Power the Electric Cars of the Future?
December 16, 2009 by admin
Filed under Featured Small Wind and Community Wind Articles, Understanding Wind Power
I have been somewhat intrigued by the topic of wind power charging the electric cars of the future as of late. After reading through a number of blogs and different Q & A areas on the internet, I decided to take the question of feasibility into my own hands, so that I can calculate the outcome and offer you the facts.
The first production scale electric vehicle will be the Nissan Leaf, which will hold a charge of up to 24 kilowatt hours. According to Nissan, this 24 kilowatt hour battery can be changed fully in approximately 4-8 hours, and during a quick charge can be 80% charged in only 26 minutes. Wouldn’t that be great, or I guess I should say “won’t that be great” because it is already set for production. It seems that if I were to install a 1.5 kilowatt turbine on my house it should theoretically charge my car over night so it will be ready for me when I head off to work the next day. That’s what I thought too, but the calculations just don’t support it.
The Nissan Leaf will carry 24 kWh of electricity and travel up to 100 miles per charge.
Let me first start out by explaining a kilowatt hour and how it differs from the 1.5 kilowatt output of our turbine. So, we have this 1.5 kilowatt turbine on our house, how much power is that really producing? Well, when wind speeds are ideal (usually around 12 mph) your wind turbine will be producing 1.5 kilowatt hours each and every hour, or at least until the wind dies down. As the wind dies down, the power output exponentially decreases until the wind reaches a low speed (generally around 4-6 mph). At this low wind speed no power production will occur, the wind just does not have enough energy to spin the blades on the home wind turbine. Since, the wind doesn’t always blow at 12 mph or higher, scientists have calculated averages for actual wind power production from a turbine. Now I won’t get into all the details, but 40% peak production is very good and we will use that for the calculations to follow.
So now that we know that we have a 1.5 kilowatt small wind turbine and we know that 40% annual power production is near the best we could ever hope for, we can calculate a best case scenario for power output. Simply multiply your turbine’s rated output by the number of hours in a year as well as the 40% annual production statistic.
This gives us a theoretical annual output of 5,256 kilowatt hours. Now from here, we go back to the car. The Nissan Leaf can store up to 24 kilowatt hours of energy and can travel approximately 100 miles per charge. Since we know that the average American travels 12,000 miles per year, we can accurately deduce that in order to drive the Nissan Leaf as we would like to, we will need to charge it a minimum of 120 times. So, since we are considering best case scenarios, let assume that every time your car is plugged in you will be producing energy at the constant 40%. If that were the case, the Nissan leaf would require 2,880 kilowatt hours (or 120 x 24 kilowatt hours) of energy per year, and that is very do-able.
Now this is where I see a lot of analysis stop. People simply assume that that should work and life should be peachy, however that isn’t the case. As mentioned above and further explained in Understanding the Basics of Windpower, a wind turbine can only produce it’s capacity (in this case 1.5 kilowatts) once each hour. So in the 4-8 hours of charging time for your Nissan Leaf, your 1.5 kilowatt turbine will only produce a maximum of 6-12 kilowatt hours, while the car requires 24 kilowatt hours. And just to emphasize the 6-12 kilowatt hours is a maximum, when output is full and the winds are howling.
I just want to close by saying that in no way am I saying small wind and residential wind systems are not the future of America’s energy policy, nor am I saying that they will not have a large part in powering the cars of tomorrow. I simply wanted to dispell any misconceptions concerning the feasibility of residential wind equipment charging the electric cars of tomorrow.
Have always wondered why no one puts the turbine on the car. The car would create its own wind which could spin the turbine and constantly be recharging the battery. If this were ever to come to fruition I could see the car powering the house since the car’s wind would always be blowing every time you drove it.
based on testing at the Nation Wind Technology Center our 10 kW wind generator could do the job. It costs $80 to 95,000 installed on a 120 foot tower and will produce up to 20,000 kWh in a 12 mph site. In the US there are many areas that have good wind resource. We could see a few million cars powered this way. Not the majority but a piece of the problem.
I’ve always believed that an electric vehicle utilizing wind power from regeneration was extremely feasible. It would be necessary to utilize both active as well as passive winds. What is necessary for such a unit to be created would be to begin micro-sizing wind turbines, generators and energy storage units. I can forsee that if thought through properly that such a vehicle could also produce excess energy to be used in home and industrial power needs. One argument against Renewable Wind Energy in certain areas of the US is that there is insufficient winds. When a vehicle is driven it creates its own wind resistance which is what is necessary to obtain power. Think about how many vehicles are on the road in the world at any one given moment in time and you can begin to see the potential for energy that is there.
A short review of basic physics will quickly dispell your idea. Anything that you do to harness what you call passive winds which I assume means apparent wind caused by the movement of the car, will require more energy to drive the car than it returns. You cannot win and you cannot break even.
Interesting concept but not likely to have much market share as both the volume of the Leaf sales will be quite small then the number of buyers who also have a suitable site for wind power AND the homeowner regulations that will permit it ais bound to be a very small number of people most likely not more than 10.
The first few years of sales of the Leaf will primarily be to very affluent individuals and companies who feel a compelling need to make a “green” statement without looking at the total environmental impact of their decision. They will be able to pay for all the electricity the Lead could ever consume even at Tier 5 rates in California.
As a patented inventor in the USA, I love inventions and I love wind power. But if you check out this link http://green.autoblog.com/tag/michelin+electric+wheel/ you will find an amazing invention by Michelin that will power the car electrically ONBOARD without external needs. And I thought I was a genius with my Proton One electric car that recharges itself as it drives… this Michelin idea may be much better… except in semi-flooded streets after heavy rain.
An electric car powered by its own small wind turbine is a beautiful, but pretty hopeless romantic dream. You will always have to live with no or insufficient energy on the battery for long periods. You can minimise that by over-dimensioning the wind turbine – but not very much – and that would be at the cost of having too much energy in other periods.
The only thing that make sense technically is using the electric cars in a large utility grid, where you choose the time to charge to fit the capacity of the production units in the grid. By doing that in a grid with lots of wind power you will automatically get a much larger share of wind power than delivered as an average to the grid. They can then help balancing the grid and save spinning reserves.
Wind power is a fantastic technology, but it has its limitations. And we should not spoil the good reputation of wind turbines by installing inefficient small wind turbines in residential areas where there is too little wind, and try to make them do something they are not very good at.
Is there turbulence behind a large-scale three blade tubine? If not, why can’t they put them closer together and get more generating power on smaller plots of land? And why not multi-blade turbines of say 10-16 curved-tip blades? Too close together to really chop up birds?
As for electric cars as a mainstay? How will the US Government get billions each day in tax revenue (to give away to countries who hate the USA) if there is no need for gasoline anymore?
Why can’t the electric cars have a band of small multi-blade (6″ diameter) shrouded turbines across the roof or rear deck lid, painted to match the car, not too prolific standing out, and as the car moves forward, the blade spin and recharge the battery. Standing traffic is not the best, but, the bank of batteries will sustain the electric drive motor temporarily.
If you’ve ever held a small PANCAKE fan out the window of your car at 25 mph, that fan hums at about 5K rpms or more… easily.
Your 12 mph (6 m/s) average wind speed assumption for a residential area seems highly optimistic. 5256 kWh annually with a 1.5 kW turbine based upon a 40% capacity factor is therefore in my view highly unrealistic.
In residential areas the wind resource is relatively poor. Wind is slowed down a lot due to natural and man-made obstacels compared to rural locations with relative undisturbed wind flow. Simultaneously the turbulence level can be very high, which by itself is an infamous contributing force to accelerated material fatigue and premature installation failure. Based upon experiences in the Netherlands and the UK 1.5 – 3.5 m/s would be more realistic average wind speed figure for your yield calculations. Furthermore, the wind turbine swept area together with the average wind speed are the two leading variables for a proper yield indication. The wind speed at hub height can be raised substantially by putting the wind turbine on a high tower, like what is done with large state-of-the-art turbines. The power rating is by comparison only of limited value considering the relative low wind speeds. And unless your proposed residential turbine is located at an excellent spot like facing the sea or put in a correct manner on a high rise building, 50 – 200 kWh/m2 rotor swept area are in practice obtainable annual yield figures. Now assume the 1.5 kW turbine in your example is fitted with a a 2.8-metre size rotor (swept area 6.15 m2) , a realistic estimate of the expected annual yield is depending on location variables and relevant wind turbine efficiencies roughly between 300 – 1200 kWh.
I agree with your analysis. I have discussed before that recharging an electric vehicle, whether you plug in at home or at a recharging station is not sustainable in the urban setting where most vehicles are. Because I live in NYC, there is no possible way for me to recharge my future EV by plugging in at home. I would have to run a cord over the sidewalk in front of my townhouse. Further, what about emergency situations? What if I had to rush to the hospital (God forbid) in an emergency and my EV is not charged at all? I can call for an ambulance at a cost of $1400.00. Here are some scenarios that EV manufacturers are not discussing. Which is why ICUs will unfortunately dominate the transportation market.
My company has developed a fuel cell (not hydrogen) and battery for the EV market. We can take a vehicle 350 miles on one charge. BTW we have two (2) Guinness Book of World Records for taking a retrofitted Honda Insight 328 miles in one charge. That was achieved 5 years ago with the first generation of our technology.
I say this to argue that we have invented a better approach to plug-in vehicles. We can refuel an EV in under 10 seconds and travel over 350 miles with our current technology. We have proven that not only can EVs have way more than 24kWhs, they can travel further as well without having to be plugged in. We have also addressed the cost. We can do this for less than $0.10 per mile. Our technology has more power density than lithium-based technologies at 1/4th the cost and does not require air or water cooling (which adds to the cost).
Thomas Edison and Henry Ford had the same idea around 80+ years ago. I wish it were possible but how many people can put a 10kw wind turbine in their backyard? Not many and those who could probably live pretty far from town. Even if you spent $15,000.00 for the skystream installed it would take a long time to reach the breakeven point (if you are paying around 10 cents per kwh). Unless you live in a state where the state gov will pay around 50% of the cost (NY, NJ, CA) plus the 30% federal gov incentive.
On another note, what is the deal with people suggesting that people with plug in hybrids can charge them up overnight at their house and drive them to work to help run their bosses business? I have heard many people say that they like the idea. They must be business owners and hope that their employees think the same. After running the business all day on the charge in the batteries you would have to drive home on fuel. It makes NO sense in my opinion.
The past 30 years of modern wind power development has clearly shown that the cost per kWh comes down with an increase in turbine size. In this respect I like to quote Siemens Wind Power Henrik Stiesdal who said in the February-March issue of WindDirections: ‘When we developed our Bonus 55 kW turbine in the 1980s, it was difficult to see how we could ever make a turbine work better,” he says. “It was a beautiful and efficient product. But when we made the 1.3 MW machine fifteen years later, we found that its cost of energy was exactly half that of the 55 kW. That process is still going on.’
I fully agree with Henrik and fact is that small turbines are by definition less efficient compared to large state-of-the-art commercial windturbines. See for some background an article I have recently written on small wind turbines and that has just been published in the Autumn 2009 issue of WindStats Newsletter. The title is: ‘Small wind turbines position in a sustainable energy supply.’
My conclusion was that the performance of small wind turbines may not be ideal, but can be improved substantially by putting them at windy rural sites on a high tower, and by choosing a mature well-proven product with a relatively large rotor.
This, as in all energy aspects in our country, must be a combined technology effort. Small wind has it’s place in many american homes, along with solar. You must have a combination of small wind, large wind, solar, and grid energy. One aspect will not solve any answer.
Technology is getting to the point of making things cost effective. Paybacks on small wind can be as little as 5 years in many cases. But it is this method of thinking that has to change. If we install solar and small wind on all new construction then the costs WILL come down. Balance the wind and solar where it is most effective. Some places might have more turbines, others solar panels.
Sure, it would cost a fortune to put in a system large enough to charge a car. That’s not the point. Put in a system that brings balance. Eventually gas prices will be so high that the price alone will make turbines effective. It will be cheaper to install the turbine than pay for gas over five years.
If the numbers in the article are correct, then it means 24kwh can run for 100 miles, given for example 0.20 $/kwh elec rate that is $4.8 cost of electricity for 100 miles and for a car with fuel efficiency 20 miles/gallon and $2.5 /gallon gas price, the fuel cost for 100 miles is $12.5. And the amazing part is that it only needs 4-8 hours to recharge the car fully. I am going to buy one of these electric cars if the math is correct.
I would check out the following link – it might shed some light on how well smaller wind turbines are developing. http://www.windtamerturbines.com/
Ed, are you talking about this company?
http://www.wind-works.org/SmallTurbines/WindtamerHypeNeedsTrimmed.html
If you like this, I have a really great anti-gravity perpetual motion airplane to sell you.
There are many examples of highly unrealistic small wind turbine yield claims.
In the Netherlands a new market entrant Everkinetiq offers a diffuser augmented system named Piqo. Featuring a 1.12 metre rotor diameter 3000 – 3500 kWh annually is claimed at 6 m/s average wind speed according to company product specifications. This implies a factor 2 higher energy yield per m2 rotor swept area compared to the calculated annual yield per m2 of an offshore wind turbine operating 100 km from the North Sea shore but with 10.5 m/s average wind speed. It should be noticed that at 10.5 m/s average wind speed the wind contains a factor 5.4 more energy compared to wind blowing at 6 m/s.
Power generated from wind farm (or bigger turbine) are more cost effective, especially when one factors in the intitial investment cost (system, maintenance and permits) and the potential shadow and noise generated. Thus it won’t work in the city dwellings. It is far better to use the power delivered thru the grid from wind generators.
This stream has certainly generated extremes of opinion. Our experience in researching and developing a small wind turbine ( http://www.powerhousewind.co.nz ) is between the two poles. To make a reasonable contribution to running a house and an electric car, a turbine of about 7.5 kW in a situation with a 5m/s average wind speed would be needed. 330 W/m^2 average would be achievable assuming a tower of a height sufficient to get reasonable wind, which is normally between 10 and 20m on a useful wind site. The turbine swept area would be about 38m^2 and diameter 7m. Clearly this is not for urban or suburban sections, but can make sense on a rural or semi-rural site. People who write small turbines off entirely compared to megawatt turbines forget that small turbines are competing with the retail cost of power, which includes the cost of the transmission and distribution infrastructure. Small wind also give some people the option of renewable electric power in situations where a grid connection is just too expensive. So don’t write them off, small wind is a technology with a contribution to make, but in the right circumstances of adequate wind resource and land suitability.
There are cheap to make , large turbines that you can build for a couple thousand including the tower and plans for the ten foot blade model are free. http://www.otherpower.com
Most turbines nameplate ratings are a lie concealed in a wind speed that your turbine will almost never see. Rating a turbine at 28 mph should be against the law unless that is the average wind speed for the area it’s sold in. It’s deceptive and dishonest, and does more to limit wind turbine sales than anything else. Build your own, make it as high , and then as big as you can afford to. When you double the blade swept area, you quadruple the power output. Make sure it’s designed for your realistic wind speeds. If your wind rarely exceeds 6mph, it makes sense not to install a turbine that needs 7 mph to start rotating.