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Replacing Oil and installing Solar

  • 04-02-2019 11:04am
    Registered Users Posts: 3,911 ✭✭✭ mp3guy

    I've got a one off rural build with traditional oil-fired central heating and electricity. I'm interested in 1) Adding PV Solar on to supplement energy supply and; 2) Replacing the oil completely with a different resource such as an air-to-water heat pump. The house is already BER B3 but I want to remove reliance on oil and reduce costs over the long term.

    Is this all just grand to go ahead or is there more I should know? I'm based in Cork so was just going to Google a vendor and get them in for a quote. However, there are two caveats / open questions I have for each.

    Regarding Solar, how much roof space is required? The main house itself has annoying dormer windows that stick out so roof space is limited. There is a sizeable outbuilding with electric nearby however, would it be conceivable to put the panels there? Can provide photos of each if it would help.

    On the heat pump, we do have space for geothermal but aren't really interested in that big a project and are not interested in renovating in underfloor heating, if that's even possible. Can we literally just replace our oil-based system with the air-to-water system and be done with it?


  • Registered Users Posts: 1,097 ✭✭✭ freddyuk

    I would do sums very carefully.
    I personally would work with what I have and improve that first.
    Solar PV can go anywhere within reason. Irish roofs are not very good as dormers are so "popular". Any shading is a no no. Run cables in DC over longer distances. Inverter should be close to your CU.
    The advantage of UF is you dig it out once. Your floors are then insulated and you will have around a 10c advantage in ambient temperature.
    Plug up all the holes and insulate as much as possible.
    Get your oil system checked so it is working at peak performance. You only need to use it during winter not all year. Zoning the house will mean heating only rooms you need to the temperature you want.
    PV can help heat water in summer.
    Heat pumps are prone to issues and will not work well in a draughty house so be warned. You may also need to oversize radiators if you don't have UF
    Plenty of info in previous posts so research everything so you know what you are looking for and don't rely on first installer through the door to have the magic bullet - there isn't one unless you build from scratch.

  • Registered Users Posts: 1,627 ✭✭✭ quentingargan

    I think if you have electricity in the shed already with 6mm cable running to the house, the losses will be negligible -vs- cost of running dc cables. It is VERY cheap and easy to install pv on a shed with a steel roof if you have one - much easier than slates, so I would go down that route if you can.

    PV will heat your water, but it won't make a meaningful contribution to a heat pump. But the grants for PV make this a no-brainer if you have a suitable roof.

  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 58,862 CMod ✭✭✭✭ unkel

    But the grants for PV make this a no-brainer if you have a suitable roof.

    The grants only apply for installs from SEAI registered approved PV installers though. And they know how to charge.

    It would be far cheaper to forget about the subsidy and do the install DIY. On a not so high shed, with a steel roof, this really is very simple like you say :D

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

  • Registered Users Posts: 3,911 ✭✭✭ mp3guy

    Hmm so it sounds like I should hold off on replacing the oil for the moment and go ahead with the PV? For the record I'm not interested in PV to run a heatpump, I'm interested in it for general electric demands.

    I was mainly keen in removing reliance on oil altogether. My previous homes had either gas or no fuel reliance for heating and I was interested in mirroring that in this house (obviously, gas isn't an option). But sounds like zoning my radiators and keeping the boiler in good service is the way to go for now.

    There are two outbuildings available, one is just a ground floor building with a slate roof and then there's a large steel shed with a roof about 5m high. Both have electricity but are 20m and 40m away from the main house, respectively.