Announcement

Collapse
No announcement yet.

Electric Flying

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Ok, here goes:
    If we assume 6 electric microlights will be flown once per week and each uses 30kwh per flight, we have an energy requirement of 180kwh per week or 26kwh per day, or just over 1kw.
    An onshore wind turbine might operates at an average of a quarter of its maximum output (e.g. approx 6 hours/day), so we would need a 4kw turbine. This is a realistic sized unit with a rotor diameter around 6' and costing under 2k.
    Solar panels might operate at an average of a tenth of their maximum output, so we would need a 10kw array. This would cover over 50m of hangar roof and cost between 5k and 10k.
    Of course, one could mix and match between the two.
    This is all good provided we are happy to charge the aircraft batteries slowly and leave them charging unattended. Most airfields don't like even a small trickle charger to be left unattended.
    Pete T.

    "A closed mouth gathers no feet".

    Comment


    • #17
      Interesting, so rapid charge would require separate storage batteries capable of delivering about 30kw to an individual aircraft for an hour or so (= 10 electric kettles). Alternatively the aircraft battery installations could be designed to be interchangeable and belong jointly to the club. Individual users could book them out, so to speak, so if one didn't want to fly that day then somebody else could have two flights. They'd be local flights, obviously, unless they persuaded someone to drive to the destination carrying a spare battery for the return journey.

      So it's plausible. Independent slow charging facilities could be available within the price range of an aircraft power battery, though rapid charging for occasional use could be a different issue.

      Our hypothetical electric fleet, were it to be realised, would doubtless best be stored separately from any petrol powered fleet, just in case
      The pilot formerly posting as MadamBreakneck
      R examiner and TST pilot.
      and now a Tai Chi instructor

      Comment


      • #18
        30 KW of batteries for an hour. That is forty Horsepower. An hour's use of a 447, Not a 912. How big and heavy would 30 KW hours worth of batteries be?
        The one from my old Mercedes weighs about the same as an installed 447 and has a capacity of 95 Amp Hours at 13.2 Volts. 1254 Watt hours so twenty four of those will propel my SSDR for an hour.
        Yes, that is going to work.
        For my next trick, an orderly Brexit!

        Comment


        • #19
          An easily removable, interchangeable and standardised battery would be an ideal way to manage a number of issues surrounding electric vehicles of all kinds. However, it is not the simple 'unplug and lift' operation one might imagine. The high power batteries required for electric vehicles have complex liquid cooling systems, which would need to be disconnected (without risk of leaking the special coolant - you don't want it on your skin!). Alternatively, the cooling arrangement could be part of the removable battery pack, but as the assembly becomes larger and heavier it also becomes more difficult to manage and to package for multiple applications.
          Tom, the battery from your old Mercedes (from your figures) is a lead-acid type. The batteries used in electric aircraft are Lithium-ion and much lighter.
          Re. 30kw, the discussion has been about what is possible. Of course, more powerful electric aircraft can be built, and they will require proportionally longer charge periods or higher charge current.
          Pete T.

          "A closed mouth gathers no feet".

          Comment


          • #20
            Let us assume an that the lighter battery weighs twenty per cent of my old lead acid, in line with the bomb that nearly destroyed my aircraft versus it's now replaced and reliable SLA equivalent. Can you now get the power pack to a practical size and weight to fit the proposed 600 kg microlight?

            Comment


            • #21
              Yes. And No.
              Yes, it is certainly possible to assemble a battery and motor to fit into the proposed 600kg microlight.
              If you want the power of a 912, you can have it. What you won't get is the endurance to make it a practical proposition for most owners.
              Pete T.

              "A closed mouth gathers no feet".

              Comment


              • #22
                Nor, at present a cost that makes it viable although one or two outfits are making trainers with an hour's duration. Another fifteen minutes and four power packs and it could be possible but there is a long way to go.

                Comment


                • #23
                  Originally posted by Ginge Sunley View Post
                  It will be interesting to watch developements, both of Adrian Jones's electic Shadow project and the possiblities of the Pipistel. I hope for an undate on the Shadow project at the SSDR rally (please) and it is a sure bet that Deepak at London Airsports, already training with a Pipistrel, will have his eye on that ball.

                  It'll be interesting, but I don't expect results for quite sometime, meantime back to the trusty 503
                  The Pipistrel isn't doing that well under electric power, Registration: HB-SAA
                  Category: Accident
                  Location: 2,5 km from Ecuvillens Airport (LSGE) - Switzerland
                  Phase: Initial climb
                  Nature: Private
                  Departure airport: Ecuvillens Airport (LSGE)
                  Destination airport: Ecuvillens Airport (LSGE)
                  Investigating agency: STSB Switzerland
                  Narrative:
                  Shortly after take-off, the aircraft's electric propulsion system experienced a power loss followed by an emergency landing in a field. The aircraft was severely damaged during the landing.

                  Sources:

                  https://www.sust.admin.ch/inhalte/AV...hte/HB-SAA.pdf

                  Date: 13-OCT-2018
                  Time: 12:50 LT
                  Pipistrel Alpha Electro
                  Registration: I-D057
                  Aircraft damage: Written off (damaged beyond repair)
                  Category: Accident
                  Location: Vosseberg, near Stadskanaal Airfield (EHST) - Netherlands
                  Phase: Approach
                  Nature: Private
                  Departure airport: Drachten Airfield (EHDR)
                  Destination airport: Stadskanaal Airfield (EHST)
                  Narrative:
                  The Pipistrel Alpha Electro, an electric plane, crashed under unknown circumstances in a field along the road N975, about 2 km from Stadskanaal Airfield in the Netherlands. There was a post-impact fire. The pilot was fatally injured.

                  Date: 16-NOV-2017
                  Time:
                  Type: Pipistrel Taurus Electro ( not the Alpha, samepowerplant though )
                  Registration: ZK-GEL
                  Aircraft damage: Substantial
                  Location: 3.2 km west of Kaikohe Aerodrome NZKO - New Zealand
                  Phase: En route
                  Nature: Private
                  Departure airport: Kaikohe NZKO
                  Destination airport: Kaikohe NZKO
                  Narrative:
                  The glider took off in the afternoon to fly in the local area.
                  At 5:30 pm it was declared overdue, and the wreckage was found by a searching helicopter 3.2 kilometres
                  west of the airfield. The 72-years-old pilot was found dead.

                  Not entirely sure the Pipistrel electro engine is a safe option yet.
                  Barry C.

                  Comment


                  • #24
                    additional thought on this topic:

                    an electric engine is not the only electrical drain for an aircraft.
                    I have a radio - ok so it is small and requires little power, but others run transponders, or GSP units either fitted or tablets plugged into the 12v socket all of which will be powered by the same source as is running the engine....!

                    Comment


                    • #25
                      Not necessarily Peter, all those are a matter of choice, aside from the transponder all the others are available self powered. Indeed, my own favoirite aircraft is not fitted with any kind of battery at all, ok we have no transponder but all the others are no problem at all.

                      As far as the transponder is concerned for conspicuity there are now multiple other types of kit available and many of these can be self powered. With modern batteries in small devices the weight gain is minimal.

                      Comment


                      • #26
                        It may be difficult for those unfamiliar with electric propulsion to appreciate the scale of relative power consumption.
                        The electric motor for a single seat microlight, equivalent to a modest 40hp engine output, consumes 30kW. This is 30,000 Watts
                        If your 12V socket has a maximum 15A output (it will probably be much less than this) then you could consume 180W from it.
                        180W is 0.6% of 30,000W.
                        Using the maximum output of a 12V socket would reduce your 1 hour endurance by 22 seconds.
                        Pete T.

                        "A closed mouth gathers no feet".

                        Comment


                        • #27
                          Originally posted by Pete Twissell View Post
                          Using the maximum output of a 12V socket would reduce your 1 hour endurance by 22 seconds.
                          Excellent point Peter!

                          And that 22s could probably be reclaimed by flying accurately with the ball in the middle (I'm speaking for myself here
                          Martin Watson
                          Microlights in Norfolk
                          Fixed Wing Instruction - Exams and GSTs - Revalidations
                          07805 716407

                          Comment


                          • #28
                            There are difficulties with Lithium batteries at low temperatures. Drawing current helps to keep them warm but I'd think twice before using them in a motorglider!

                            Comment


                            • #29
                              all good points

                              Ginge - absolutely agree, all i have in a radio, which could be battery powered but for ease isn't. But i know others run plenty of other items, as mentioned a transponder and tablets/phones for SatNav/GPS positioning

                              Pete - with those maths it shows the gapping hole of my understanding - 22 seconds seems reasonable to manage.

                              Comment


                              • #30
                                I would suggest that we are too accustomed to a very high power- weight ratio, thinking back to older machines that were very capable on much lower power than is now commonplace.
                                The aircraft that most springs to mind is the first microlight that I flew, the Chevvron. A two seater equipped with a 32hp engine, ok it didn't spring into the air and climb rate was not sparkling but it was, in many ways, a delightful little aircraft and as stated a two seat machine.

                                https://www.pilotmix.com/chevvron-2-32c

                                It just shows what can be done with low power

                                Comment

                                Working...
                                X