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Thermodynamic solar panels

  • 16-10-2019 1:46pm
    #1
    Registered Users Posts: 677 ✭✭✭ Mitchomagic


    Hi

    Thinking of getting them and using them for heating hot water and might try heating the house.

    looking for some honest feedback where they worth the cost, any issues with set up etc did the do what the said they would do?.

    any feedback much appreciated

    thanks


Comments

  • Registered Users Posts: 2,820 ✭✭✭ air


    Hi

    Thinking of getting them and using them for heating hot water and might try heating the house.

    looking for some honest feedback where they worth the cost, any issues with set up etc did the do what the said they would do?.

    any feedback much appreciated

    thanks

    Just do a search on here and then run a mile.


  • Registered Users Posts: 6,376 ✭✭✭ Alkers


    What is your current heating system? Do you have separate zones for heating and hot water?
    How much do you spend a year on heating?
    How much do you spend a year on electricity?

    Personally, I would go with Solar PV in place of solar hot water as electricity costs 3-4 times per kWh as gas heating.


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 58,818 CMod ✭✭✭✭ unkel


    Alkers wrote: »
    Personally, I would go with Solar PV in place of solar hot water as electricity costs 3-4 times per kWh as gas heating.

    A lot of flawd logic in your argument.

    Let's go with an example of a 4+ family that use a lot of hot water (if you don't, then do not go solar thermal). Almost 100% of your solar thermal production is self-consumed. It is also very efficient. You get many times the equivalent kWh from a solar tube as from the same square meter of solar PV. And with solar PV, you only typically self consume 10-20%, the rest goes back to the grid for free. Unless you have a battery, but these are extremely expensive

    In practice, it depends very much on what subsidy system is in place. Currently with the extremely generous subsidy for solar PV with battery, such a system looks favourable

    The OP is mistaken though if they think they can use solar thermal for heating their house. That won't work. When you need heating your house most, solar thermal production is typically near zero

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



  • Moderators, Home & Garden Moderators Posts: 10,101 Mod ✭✭✭✭ BryanF


    Nanotechnology..


  • Registered Users Posts: 97 ✭✭ Coltrane


    unkel wrote: »
    And with solar PV, you only typically self consume 10-20%, the rest goes back to the grid for free. Unless you have a battery, but these are extremely expensive


    Unkel, agreed in the main but self-consumption rate will also be much higher if you have an electrical heating system; an EV will also help. I've both (an A2W and an EV) and was at 67% self-consumption (and 24% self-sufficiency) last year.


    Not that I'm against export, by no means.


    Aligning PV with an electrical heating system and EV seems to me the way to reduce the footprint. Although heat pumps are really expensive and the energy-mix in grid power is for now still a massive issue for both A2W and EV.


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  • Registered Users Posts: 97 ✭✭ Coltrane


    Coltrane wrote: »
    Unkel, agreed in the main but self-consumption rate will also be much higher if you have an electrical heating system; an EV will also help. I've both (an A2W and an EV) and was at 67% self-consumption (and 24% self-sufficiency) last year.


    Not that I'm against export, by no means.


    Aligning PV with an electrical heating system and EV seems to me the way to reduce the footprint. Although heat pumps are really expensive and the energy-mix in grid power is for now still a massive issue for both A2W and EV.


    PV is 5kWp east west.


  • Registered Users Posts: 2,820 ✭✭✭ air


    Disagree regarding the energy mix comment, the Irish grid is pretty good already and C02 intensity is reducing every year.
    EVs and heat pumps offer great benefits to human health from improved air quality where people live.


  • Registered Users Posts: 97 ✭✭ Coltrane


    air wrote: »
    Disagree regarding the energy mix comment, the Irish grid is pretty good already and C02 intensity is reducing every year.
    EVs and heat pumps offer great benefits to human health from improved air quality where people live.


    Agreed that things are improving (N.B. Moneypoint) but last time I checked in on it renewables accounted for only 20% of primary-fuel inputs in Ireland. A greater % of outputs with their better efficiency but that doesn't help what goes into the mix.


    I can help this locally with my PV.


    And I agree with your point about location, especially when it comes to diesel cars in our cities.


  • Registered Users Posts: 6,376 ✭✭✭ Alkers


    unkel wrote: »
    A lot of flawd logic in your argument.

    Well it wasn't really an argument, my recommendation would depend on the OP's responses to the few questions I posted before I stated my own personal preference.


  • Registered Users Posts: 677 ✭✭✭ Mitchomagic


    What is your current heating system? oil, stove back boiler
    Do you have separate zones for heating and hot water? no
    How much do you spend a year on heating? oil e1500
    How much do you spend a year on electricity? about e1500-1700


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