1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Dyson has scrapped its electric car project

Discussion in 'Motoring Related Discussion' started by Tony Dyson, Oct 11, 2019.

  1. ajlsl600

    ajlsl600 Senior Member

    Messages:
    3,450
    Likes Received:
    1,291
    Joined:
    Nov 18, 2013
    Location:
    france
    Your Mercedes:
    clk3202001,sl6002003 with everything,A class 170cdi auto


    could try this. if u have plenty of sun !
     
  2. ajlsl600

    ajlsl600 Senior Member

    Messages:
    3,450
    Likes Received:
    1,291
    Joined:
    Nov 18, 2013
    Location:
    france
    Your Mercedes:
    clk3202001,sl6002003 with everything,A class 170cdi auto
    in my experience making the most of solar energy seemed to involve a few drums or avgas and a generally southerly heading !!!!
     
    Blobcat and LostKiwi like this.
  3. LostKiwi

    LostKiwi Senior Member

    Messages:
    20,374
    Likes Received:
    9,929
    Joined:
    Aug 25, 2006
    Location:
    Midlands / Charente-Maritime
    Your Mercedes:
    '93 500SL-32, '01 W210 Estate E240, 02 R230 SL500 (Malcolm Spec), 04 Smart Roadster Coupe
    Generally it's best to use a direct thermal solar heater (as opposed to PV panels with controllers, inverters, batteries and heat pumps).

    Something like these:
    https://www.bimblesolar.com/more/thermal

    You can build your own with black painted copper pipe and chromed half pipes (set the black pipes at the focus for the half pipes) but ideally the whole assembly needs to be in a vacuum to maintain efficiency.
     
  4. OP
    Tony Dyson

    Tony Dyson Senior Member

    Messages:
    1,274
    Likes Received:
    520
    Joined:
    Aug 26, 2018
    Location:
    God's Country
    Your Mercedes:
    2014 C 220 CDI W204 OM 651
    If by "more consistent output under variable real world conditions." you mean it works better in the shade then yes I've already conceded that point and your example of a low demand requirement in persistent shade is a good example.
     
  5. OP
    Tony Dyson

    Tony Dyson Senior Member

    Messages:
    1,274
    Likes Received:
    520
    Joined:
    Aug 26, 2018
    Location:
    God's Country
    Your Mercedes:
    2014 C 220 CDI W204 OM 651
    Where is the pool, Reykjavik or Rhodes?
    What is the volume of water in the pool?
    How many degrees C would you want to raise the temperature of the water?
     
  6. Frontstep

    Frontstep Senior Member

    Messages:
    6,943
    Likes Received:
    842
    Joined:
    Apr 22, 2007
    Your Mercedes:
    T210 320cdi
    England 60,000 litres 10 degrees centigrade.
     
  7. Frontstep

    Frontstep Senior Member

    Messages:
    6,943
    Likes Received:
    842
    Joined:
    Apr 22, 2007
    Your Mercedes:
    T210 320cdi

    Looking to purchase something a little less homespun.
     
  8. OP
    Tony Dyson

    Tony Dyson Senior Member

    Messages:
    1,274
    Likes Received:
    520
    Joined:
    Aug 26, 2018
    Location:
    God's Country
    Your Mercedes:
    2014 C 220 CDI W204 OM 651
    Cigarette packet calculations indicate you will need around 30m² of Evacuated Tube Solar Thermal panels south facing at optimum angles, to raise and maintain a 10° C increase in the UK, there are many variables but I need to go out today so can explain further later.
     
    Frontstep likes this.
  9. Frontstep

    Frontstep Senior Member

    Messages:
    6,943
    Likes Received:
    842
    Joined:
    Apr 22, 2007
    Your Mercedes:
    T210 320cdi
    That is certainly feasible as to the size, direction and angle, thank you.
     
  10. OP
    Tony Dyson

    Tony Dyson Senior Member

    Messages:
    1,274
    Likes Received:
    520
    Joined:
    Aug 26, 2018
    Location:
    God's Country
    Your Mercedes:
    2014 C 220 CDI W204 OM 651
    So by way of explanation of the above:
    It takes 4,200 J to raise the temperature of 1 kg of water by 1°C.
    ∴ (Joules x Total volume of water in kG x Target temp rise in °C) = Total Energy required in J.
    4,200 x 60,000 x 10 = 2,520,000,000 J Divide by 3.6e+6 for conversion to kWH, = 700
    Looking at my calcs of yesterday morning, I omitted to include the target 10°C temp rise which realistically has just blown this method of heating right out of the water! So to speak :) My apologies for raising your hopes.
    The Annual Energy output of this type of water heating in Northern Europe is around 2.5kWH/m²/Day, if you’re on the South Coast of England you could use 3kWH but you can halve these figures for the winter Months!
    Due to winter temperatures and the threat of freezing, this would also need to be an indirect system with antifreeze used in the primary circuit and a Calorifier utilised with further losses, to heat the pool water.
    The construction of the swimming pool is going to have a huge influence on the energy required to initially heat and maintain design temperatures as the heat losses from such a large body of water can be significant if adequate insulation isn’t provided which will need to maintain a core temperature of say 15°C for comfortable swimming at 25°C. I would be interested to know how you get on with your project, I believe Ground/Air Source Heat Pumps will be a more practical alternative.
     
    Frontstep likes this.
  11. LostKiwi

    LostKiwi Senior Member

    Messages:
    20,374
    Likes Received:
    9,929
    Joined:
    Aug 25, 2006
    Location:
    Midlands / Charente-Maritime
    Your Mercedes:
    '93 500SL-32, '01 W210 Estate E240, 02 R230 SL500 (Malcolm Spec), 04 Smart Roadster Coupe
    Not necessarily. The tubes themselves are evacuated so should be ok as there is minimal head transfer from the heated water to/from the outside across the vacuum.
    The vulnerable point is where the tubes join the remainder of the pipework, however if water flow is sufficient and the pipework is fully lagged the heat from the water in the system should prevent issues.
    You could even use a PV panel to run the pump (with associated batteries to support overnight).
     
  12. ajlsl600

    ajlsl600 Senior Member

    Messages:
    3,450
    Likes Received:
    1,291
    Joined:
    Nov 18, 2013
    Location:
    france
    Your Mercedes:
    clk3202001,sl6002003 with everything,A class 170cdi auto
    most places here use air source
     
  13. OP
    Tony Dyson

    Tony Dyson Senior Member

    Messages:
    1,274
    Likes Received:
    520
    Joined:
    Aug 26, 2018
    Location:
    God's Country
    Your Mercedes:
    2014 C 220 CDI W204 OM 651
    While I understand what you're saying, I think you would find it at best difficult to find a Manufacturer/Installer to guarantee a water based system wouldn't freeze in winter in the UK? I think the estimated losses and additional cost would be worth peace of mind as well?
    ETA And one hell of a pump to circulate 60 Tonnes of water?
     
  14. OP
    Tony Dyson

    Tony Dyson Senior Member

    Messages:
    1,274
    Likes Received:
    520
    Joined:
    Aug 26, 2018
    Location:
    God's Country
    Your Mercedes:
    2014 C 220 CDI W204 OM 651
    Yes I think Air or Ground source will be a better option.
     
  15. LostKiwi

    LostKiwi Senior Member

    Messages:
    20,374
    Likes Received:
    9,929
    Joined:
    Aug 25, 2006
    Location:
    Midlands / Charente-Maritime
    Your Mercedes:
    '93 500SL-32, '01 W210 Estate E240, 02 R230 SL500 (Malcolm Spec), 04 Smart Roadster Coupe
    It's an indoor pool so heat loss should be fairly controllable for the pool itself.
    That just leaves circulation of the water. The standard filter pump the pool already has should suffice as long as it can pump a sufficient head of water. Typically tat would require 4 to 6 PV panels depending on pump.
     
  16. OP
    Tony Dyson

    Tony Dyson Senior Member

    Messages:
    1,274
    Likes Received:
    520
    Joined:
    Aug 26, 2018
    Location:
    God's Country
    Your Mercedes:
    2014 C 220 CDI W204 OM 651

    It will be interesting to see what proposals the pool designers come up with for a solution?
     
  17. LostKiwi

    LostKiwi Senior Member

    Messages:
    20,374
    Likes Received:
    9,929
    Joined:
    Aug 25, 2006
    Location:
    Midlands / Charente-Maritime
    Your Mercedes:
    '93 500SL-32, '01 W210 Estate E240, 02 R230 SL500 (Malcolm Spec), 04 Smart Roadster Coupe
    One other consideration is that direct solar efficiency is typically around 4 times higher than PV. The best DS is around 90% efficient compared to the very best of PV at sub 50%.
    To run the entire setup from PV will need a large PV array.
     
  18. OP
    Tony Dyson

    Tony Dyson Senior Member

    Messages:
    1,274
    Likes Received:
    520
    Joined:
    Aug 26, 2018
    Location:
    God's Country
    Your Mercedes:
    2014 C 220 CDI W204 OM 651
    Another cigarette packet calc would indicate a PV array of 72 kWH to heat the 60 T body of water over 10 Days would consist of 288 Panels making up 500m² surface area installed and costing between £100-£120K, Solar PV in the UK is also a non-starter.
     
  19. Frontstep

    Frontstep Senior Member

    Messages:
    6,943
    Likes Received:
    842
    Joined:
    Apr 22, 2007
    Your Mercedes:
    T210 320cdi
    At the moment we have a fairly new 40 KW system boiler going through a pahlen heat exchanger.

    It raises the water around 1 degree every two hours this is an average with winter & summer variances.
     
    Last edited: Oct 18, 2019
  20. LostKiwi

    LostKiwi Senior Member

    Messages:
    20,374
    Likes Received:
    9,929
    Joined:
    Aug 25, 2006
    Location:
    Midlands / Charente-Maritime
    Your Mercedes:
    '93 500SL-32, '01 W210 Estate E240, 02 R230 SL500 (Malcolm Spec), 04 Smart Roadster Coupe
    Something must be off in your calculations I think.
    Going to a pool heating ASHP supplier they say a 23kW Air Source heat pump is suitable for up to 110 cubic metres (110k litres). That would mean you could probably get away with 15kW. Assuming an efficiency of 2:1 that's 7.5kW of PV.
    At 7.5kW using 300W panels makes for 13 panels. Add in all the support gubbins and it's about £15k.
     

Share This Page