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Kerosene usage after installing an Eddi

  • 25-02-2022 3:53pm
    Registered Users Posts: 271 ✭✭

    Hi all.

    I am thinking of getting a 5kw 10 panel system with battery 6kw inverter and Eddi installed.

    Can I ask what is your Kerosene usage is like after installing an Eddi?

    Last year I upgraded to a Grant Vortex VORTMOD1526 External Oil Boiler, new kingspan oil tank and a 36 x 15 indirect insulated hot water tank.


  • Registered Users Posts: 6,720 ✭✭✭zg3409

    Solar and eddi heats hot water in summer when kerosene boiler is off. Solar PV will not heat home in summer nor winter, it's just a way if reducing esb bill for heating water and other electric consumers.

    Most people don't heat their hot water with oil in the summer. On some systems that are zoned you can heat hot water only with oil, and some people might do that for 15 minutes a day in summer.

    Solar batteries are generally expensive, they don't generate anything, they just store already generated power so you can make better use of power in evenings. It's totally unrelated to heating your home in winter. Typically solar systems break even after 7 years but it depends, mostly on how much you overpay for the solar system as prices vary a lot. I believe the grant for a battery is gone.

  • Registered Users Posts: 299 ✭✭spose

    I’d say I use the boiler less than a half dozen times to heat the water between April and October

  • Registered Users Posts: 1,732 ✭✭✭tnegun

    I have a 4.2kWp system installed since November with an Eddi. I use gas 365 days to heat water for 3-4 showers a day and during summer it costs 30-40 per month. For the first time since installation over the last two days, there was enough excess from solar to heat until the immersion cut out and it exported a few kwh. It was only enough water for about 2 showers though what I didn't realize until was that the boiler heats the full hot tank but the Eddi can only do about half as the immersion is short.

  • Registered Users Posts: 1,469 ✭✭✭MAULBROOK

    My boiler normally is switched off from mid March till late September/mid October, so about 6 months of the year I have no oil use. Because the solar PV and the water diverter covers the better months. My system is in since mid 2019 so i know it works.

    This should be factored into your solar PV pay back because your saving on not using oil.

    A full tank of oil (1000lt) for us us normally lasts for 18 months.

  • Registered Users Posts: 1,469 ✭✭✭MAULBROOK

    How is the Grant Vortex working out as I'm thinking of replacing our 20 plus year Firebird next year.

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  • Registered Users Posts: 271 ✭✭daarmcd

    The grant vortex is excellent and it is outside now. I used 500 litres of oil from November 1st and that was heating on the whole time at 23 degrees.

    The indoor firebird just started to smell after 20 years. Tank was 20 as well so I changed it.

    I paid 1450 for the grant vortex, with new circulating pump and fire valve and magna clean, plumber fitted it in 6 hours for 500 and took the old firebird away. Kingspan Tank was 550 incl replacing old one and taking it away

    I am hoping that with the Eddi the oil boiler will not have to heat up as much water to circulate

  • Registered Users Posts: 271 ✭✭daarmcd

    During the summer I would have the heating come on in the morning for 20 minutes to heat the water.

    I have backup batteries already here and ideally I would like 2 powerwalls. Next car will be EV hopefully with bi directional charging

  • Moderators, Home & Garden Moderators Posts: 6,077 Mod ✭✭✭✭graememk

    Ive often thought about putting a meter on the oil. If you cant measure it, you dont know where you stand.

    1 Litre of kerosene has about 10kwh of energy, So roughly for every 9 kwh of electric the eddi puts in, its a litre of kerosene, (Need to account for losses as you dont get all the heat from the kerosene)

    As for reducing the oil use in the summer, I am assuming its thermostatically controlled too? So you could either A) turn down the thermostat so it doesnt heat the tank as hot, and have the eddi "top it up"

    Or when do you need the hot water? could the oil be timed to come on in the evening and if its already hot from the eddi, it doesnt come on.

  • Registered Users Posts: 1,926 ✭✭✭Andrea B.

    Hi. Is the SEAI grant available for the boiler change and if so did you avail/was it worth it?

  • Moderators, Education Moderators, Home & Garden Moderators Posts: 8,166 Mod ✭✭✭✭Jonathan

    Condensing boiler grant is gone a good number of years now. The heating controls grant (€700) is still available.

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  • Registered Users Posts: 45,453 ✭✭✭✭Bobeagleburger

    Electric heaters and smart plugs are becoming more and more of a simple and clever option every day.

    A decent array couid make a good dent in oil consumption during spring and autumn months.

  • Registered Users Posts: 3,965 ✭✭✭mp3guy

    I have a year of Eddi data, I estimate savings of about 120L of kerosene per year. Based on the fact in a year my Eddi diverted ~1000kWh of energy, and the equivalent kerosene energy accounting for efficiency loss in the boiler and indirect heat transfer.

  • Registered Users Posts: 120 ✭✭shoehorn

    Still researching, pre-purchase.

    From the Solar FAQ:

    "The general thinking is that EDDI’s while they are a useful and convenient device, for €500 or so, it’s unlikely that you will get that money back in the lifetime of the device. If you think about it, €500 will probably pay to heat your immersion tank once a day everyday for 3 years. "

    I'm confused about the above. By that logic, aren't you getting your money back in 3 years? Is the lifetime of the EDDI shorter than that, or do I misunderstand the statement?

  • Moderators, Motoring & Transport Moderators Posts: 6,522 Mod ✭✭✭✭Irish Steve

    Cheaper and quicker option will be an electic elapsed time meter on the power supply to the burner, so you get the number of hours it was "alive", and then that's multiplied by the litres (or US gallons, careful there) per hour from the burner nozzle size to get the usage.

    Shore, if it was easy, everybody would be doin it.😁

  • Registered Users Posts: 120 ✭✭shoehorn

    Interested in how this might work - can you elaborate? e.g. how can you combine electric heaters with ones heated by oil boiler central heating? just plug in portable heaters into the main living areas, and rely on the room stats to keep the central heating off (saving oil). Then once you've used up all the power from the panels, you somehow have the electric rads turn off (is that what a 'smart plug' does?) .

    But if you use up all your juice on heating electric rads in Spring/Autumn, aren't you depriving the other appliances (dishwasher, kettle) of using the free solar juice, thus defeating the purpose?

    New to all this, so happy to be schooled on it.

  • Registered Users Posts: 3,965 ✭✭✭mp3guy

    It all depends on how much you might be able to divert to the Eddi. If your system is too small, you might never have 1MWh of energy exported to the grid at a time it is possible for the Eddi to pick it up.

  • Registered Users Posts: 189 ✭✭connesha

    With kerosene, its a very indirect way of heating, and the loses due to in-efficiency will build up quite quickly:

    A fire, to heat water, to be pumped through pipes outside the system (outside the boiler/cylinder), that heat exchange with different water...

    The immersion is very direct, practically 100% efficient.

    Take 1l of kerosene, it gives 10.35kwh

    A condenser boiler has a stated efficiency of say 90%. BUT, that rating is often under ideal conditions: certain water temperatures, pressure, and host of other factors. So the real-world efficiency will be less. Will it be 80%? Let's be optimistic and say 85% for this example.

    The water that the boiler heats is then circulated to the cylinder, via pipes that will have their own losses, and a heat exchange in the cylinder. This could lead to another up to 30% loss, but thats probably a more extreme example with bad lagging/long distances. Lets take it as 15%.

    And then you still are using electricity to power the boiler and the circulating pump.

    Add all this up, can see that 1L of kerosene (costing approx 1.80e) being the equivalent of the 6 or 7 kwh of solar excess that the EDDI put into the cylinder yesterday.

    (I accept that people will have different takes on the efficiencies I gave as example above. IMO they are generous for kerosene, but open for debate)

    Of course this is just a comparison of kerosene to "free" excess solar. Comparing an immersion on a timer running from 2am to 5am at 5 or 6 cents a kwh (bord gais EV plan) is a different comparison completely...

  • Registered Users Posts: 4,945 ✭✭✭paulbok

    1.80 a litre? Faints.....

    Was 85c a litre last time I filled up at the start of October, a quick Google has it around 1.75 around here today.

    Looks like I'll be cutting extra turf this year

  • Moderators, Home & Garden Moderators Posts: 6,077 Mod ✭✭✭✭graememk

    I dare say your not the only one.

    EI have one of the cheapest rates now at 18.9c day 9.35 night.

    If you bought oil at 1.80 (cheapest is showing it now at 1.50ish)

    It's cheaper to heat your water with an immersion than it is with oil.

  • Registered Users Posts: 65,331 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!

    Time to say goodbye to using fossil fuels. Never a better time to do so. And let's push our politicians to seriously make hay promoting installing wind and solar PV.

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  • Registered Users Posts: 1,279 ✭✭✭homingbird

    The Gov/Green Party want to push us all to solar think of all the tax they are going to lose out on how will they make up the difference.

  • Registered Users Posts: 6,207 ✭✭✭Ubbquittious

    They'll make you buy virtual petrol for your EV costing between €1-2 per litre. There will be a GPS in your car to track how much & where you drive.

  • Registered Users Posts: 6,207 ✭✭✭Ubbquittious

    While there is a lot of truth in what you say you have definitely massaged the figures in favour of the immersion. Most people will hopefully never pay 1.80 for oil and this is probably a temporary glitch while more oil production comes online and most people don't pay 5-6c/kw & there are other costs associated with going on that EV tariff. 2-5AM is not an ideal time to heat it, unless you get up at 5. A lot of the losses from the boiler contribute to heating the house

  • Moderators, Home & Garden Moderators Posts: 6,077 Mod ✭✭✭✭graememk

    if you ignore the smart meter tariffs currently, and call night rate at 10c and day at 20c,(SSE and EI are currently about this) Heating water with electric is about on par.

    On night rate, oil needs to be less than €1 for it to be even close to parity with an immersion. A simple timer could put the immersion on for 2 hrs before day rate kicks in at 8am (9 in the summer)

    Oil is still kicking in around the 150-160c mark (which is brutal, dont get me wrong) And if your buying it now, id be saying to think about heating your water with an immersion, and try and not buy too much at this high price.

    By extension of this, heating a house via resistive (be it oil, fan heaters, or even them infrared panels) heating, could be more cost effective than oil, Depending on your boiler, and your electricity price.

    If oil passes 8 or 9 times your electric unit rate, thats about the tipping point for sure.

  • Registered Users Posts: 189 ✭✭connesha

    While I agree that for some people it be at different rates, I don't thinks it's a fair response to say the figures are massaged.

    Everyones setup may be different. That's what I meant in acknowledging that everyones take may be different.

    What kind of boiler do they have?

    Where is the boiler situated? Inside/outside/shed/garage/etc

    How long are the pipes?

    Are they well insulated, and is it practical to upgrade the lagging on them? (buried? under that nice floor that you don't want to lift?)

    Are the pipes mostly inside or outside the insulation envelope of the house?

    Maybe some are still gunbarrel? (and again is it practical to replace them)

    Is the cylinder even inside the insulation envelope of the house?

    So, yea, while good answers on the above will give a good ratio, it may not be the case for everyone.

    One persons 8 to 1 may be another's 7 to 1. One persons losses will go back into the house, another's will be gone outside/underground.

    And on top of all that, this is a forum after all, full of great opinions and interpretations, and its great to see a conversation on it.

    I've no idea, or take really, on whether prices will go up or down, short or long term. I do know that if needed oil today, the local supplier is charging 899 euro for 500L (1.80), and the best on for the region is 1.71 for 500L right now. I do hope you're right that its a temporary glitch and that most people won't be paying that, but can only go on what its going for today... Sure, you could a get cheaper if you get a 1000L order, but if you're hoping it comes down, maybe would stick to 500.

    I wasnt really going there on the smart meter rate, but will respond to the not ideal comment : while its true that it won't suit some people, and there are costs associated with that plan (higher standing charge for one), there are also some people that it will suit. And while heating an unlagged, or red-jacket-lagged, cylinder at night is unlikely to be ideal, heating a factory lagged cylinder at 3am is great (for a fraction of the price of other times). I had that EV rate for a few weeks before getting solar, set the old rotary time-clock to heat the bath element from 3am to 5am, and this plenty-covered morning (8am) showers, and if no showers that morning it kept a decent temperature through much of the day. Will be doing it again come Nov/Dev.

    Anyway, going leave it there.

  • Registered Users Posts: 1,710 ✭✭✭Deagol

    OP, I have a 300L pumped system that heats either from the boiler or tank. Since I've fitted the Eddi, I don't use the boiler at all between late March and Late September to heat hot water. Last summer we had hot water every day without needing additional oil. Not sure what it save in litres though!

  • Registered Users Posts: 271 ✭✭daarmcd

    No grant was available at the time.

    The system was 1,500 euro cheaper buying the parts myself and sourcing a plumber for the job rather than getting a plumber to quote for the whole job.

    I am finding that I can do 10kw system with all extras cheaper than most companies are quoting with the grant. It is like most companies are using the grant as profit.

    This x 1000%

  • Registered Users Posts: 271 ✭✭daarmcd

    This is so true.


    Motor tax revenues generated €6.2 billion for the Irish Exchequer

    In 2020 The Irish State got €1.7 billion from Vehicle Registration Tax on new and imported cars, and VAT on servicing parts and repairs.

    It also got €3.5 billion from fuel taxes and €900 million from annual motor taxes.

  • Registered Users Posts: 65,331 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!

    The state got a lot more from VRT in 2007 than they got in 2020. The lost billions by switching to the CO2 system. They never looked into recouping that from the motorist. Even when the times were dire and this country lost its economic sovereignty

    Not saying they will not try to recoup it this time, they probably will. But it will take a very, very long time to introduce km based taxes. I'd say 2030s at the earliest.

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  • Moderators, Sports Moderators Posts: 19,010 Mod ✭✭✭✭slave1

    And whomever has km based taxes on their manifesto will not get elected, water rates anyone?

    My stuff for sale on Adverts inc. EDDI, hot water cylinder, roof rails...

    Public Profile active ads for slave1 (