Little wind turbines along highways?

PDN777
PDN777 Registered Users Posts: 2
Hi,

Driving along yesterday, I thought, "why not place a long series
of little wind turbines next to major highways?" They would pick
up the wind eddies created by cars and trucks whizzing by, no?

--PDN

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Little wind turbines along highways?

    Welcome to the forum.

    Well yes you could spin some blades from the roadside turbulence but ...
    It would not be very much power nor would it be very consistent output. As such it would not be worth the investment to put up all those micro-turbines to try and harvest a few Watts.

    If you look at the commercial installations that have been done you'll see they are large and in the path of steady, consistent wind.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Little wind turbines along highways?

    Another interesting point to think of--If you had an express way with a prevailing wind caused by traffic, a series of wind turbines would slow down that "breeze"--And now the vehicles would get worse gas mileage because there is less of a "group tail wind".

    Nothing is for free, any energy collected from the system will likely cause other parts of the system to be less energy efficient.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • solarix
    solarix Solar Expert Posts: 713 ✭✭
    Re: Little wind turbines along highways?

    "Our world is full of energy" - its just that most of isn't worth the effort of collecting it.
    Its all free - you just have to work like hell to collect it.
    That fossil fuel stuff is so nice - all packaged up in nice (not neat) convenient packages....
  • PDN777
    PDN777 Registered Users Posts: 2
    Re: Little wind turbines along highways?

    All interesting points. Thanks. Regarding where to place them: you'd want stretches of highway with the highest % of a given 24-hour period with lots of traffic going at least 30 mph. Roadways with the most traffic don't necessarily win (think bumper to bumper stand-stills). A company that could inform this discussion is www.tomtom.com. They do extensive traffic data collection. I wrote to them -- let's see if they answer.

    Re: comment about losing "group tail wind." It might depend on where you place the turbines -- how far from the roadway. I'd want to model this in a wind tunnel to see what actually happens... see what the loss in fuel efficiency is as compared to watts gained from the turbines.

    Anyway, thanks for the conversation!
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Little wind turbines along highways?

    Remember that there are always conversion losses... And for wind turbines, the end to end efficiency (wind in, electricity out) is on the order of 10-30% overall efficiency--And smaller turbines are going to be (on average) less efficient than large (i.e., 40 meter tall turbines).

    So, typical worst case, you are looking at a 10% conversion efficiency, with means that 1/0.10 = 10x input power from vehicles moving the air to generate your output... For the most part, it is going to be very turbulent wind--Which has almost no "recoverable" energy in it.

    Long ago, for remote devices, solar panels + batteries have been the choice for power. I don't see that wind turbines are going to be of much use.

    When driving in the deserts of the southwest US, there are a few places where off grid power is commonly used... Advertising signs and rail road signaling equipment. I have seen a few with smaller wind turbines and solar panels on them--And the turbines were never spinning (when I was driving by), and quite a few seemed to be in poor repair (mounting poles were at 45 degree angles from vertical--they were not going to generate very much in the way of useful power like that).

    It looks like people have tried small wind, but it just never really pans out.

    Not to beat a dead horse--But even when mounted in clean air in a moderately windy location, small wind rarely works reliably or well with commercial turbines.

    Small windpower a scam ? Survey says SO
    Truth About Skystream & SWWP

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset