Shaun McD Posted February 22, 2023 Share Posted February 22, 2023 Hi all, New build in Donegal, Ireland with a large almost directly south roof section. I am hoping to get some input and advice on how to weigh up the economics of a PV array, battery etc. The house will be heated with an ASHP, occupied by two working adults every day, assume for a slightly over normal electrical demand (home server, relaxed with lighting etc.) and plan to have a 300l+ DHW cylinder, no electric car at present but possibly in future. We get no grants or incentives so everything is out of our pocket to install. I watched some YouTube content on smart systems like myenergi but would like to know more about how i would design number of panels, battery size etc. to get a good balance of bang for buck. My uneducated side is concerned about life span of batteries and i do not think we are incentivised in ROI to think that selling back to the grid is economical but I could be very wrong on all these fronts. Let me know what details i can provide to help with any recommendations etc. TIA Link to comment Share on other sites More sharing options...
SteamyTea Posted February 22, 2023 Share Posted February 22, 2023 Forget batteries for a few years. As for system sizing, there are two trains of thought. Make it small, then you can use all you generate. Make it large, and reduce winter imports. It comes down to a game of averages. Much easier to be grid connected, but you need to see what limits you have on your local grid. Link to comment Share on other sites More sharing options...
Shaun McD Posted February 22, 2023 Author Share Posted February 22, 2023 3 minutes ago, SteamyTea said: Forget batteries for a few years. As for system sizing, there are two trains of thought. Make it small, then you can use all you generate. Make it large, and reduce winter imports. It comes down to a game of averages. Much easier to be grid connected, but you need to see what limits you have on your local grid. What size is large? 9kw? What about roof V ground mounting for price and performance? Is it possible that any/all of it could be a diy job? I will have an electrician for the house overall but maybe cover labor to install panels etc? Link to comment Share on other sites More sharing options...
SteamyTea Posted February 22, 2023 Share Posted February 22, 2023 9 kWpis a relatively large installation. Roof mounted, especially roof integrated, used less area for the same output than ground mounted. In England, there is a limit of 9m2 for ground mount, bigger needs planning permission. You will have to look up the connection/installation rules in the ROI, they will be different. Theoretical there is no reason a competent person cannot fit then, they are basic panels, held in place with captive bolts on rails, that are bracketed to the roof joists. Your structural engineer can work out the extra loads imposed i.e. wind and snow. The main thing to remember with PV is to make sure there is no shading. Even a small amount of shading on part of single module can seriously reduce the performance. 1 Link to comment Share on other sites More sharing options...
Conor Posted February 22, 2023 Share Posted February 22, 2023 Did my PV myself with just a spark to connect up the sparky bits and test / signit off. If you're doing a new build then an in-roof system is a no brainer as you save a fortune on slates and no issues with planning compared to ground mount. You get pretty good payments in the south these days for self generation so I'd fill your roof, as much as your ESB connection will allow you to. Start the convo now with them, will take months. 1 Link to comment Share on other sites More sharing options...
Shaun McD Posted February 23, 2023 Author Share Posted February 23, 2023 3 hours ago, Conor said: Did my PV myself with just a spark to connect up the sparky bits and test / signit off. If you're doing a new build then an in-roof system is a no brainer as you save a fortune on slates and no issues with planning compared to ground mount. You get pretty good payments in the south these days for self generation so I'd fill your roof, as much as your ESB connection will allow you to. Start the convo now with them, will take months. Who did you use for supply of kit and what size did you go with? Link to comment Share on other sites More sharing options...
Conor Posted February 23, 2023 Share Posted February 23, 2023 6 hours ago, Shaun McD said: Who did you use for supply of kit and what size did you go with? ITS group, 4.5pkW. couldn't go higher due to the size of the roof and single phase connection. No batteries yet. Just gone a full year so might do the calcs on that. 1 Link to comment Share on other sites More sharing options...
JackofAll Posted February 23, 2023 Share Posted February 23, 2023 10 hours ago, Shaun McD said: What size is large? 9kw? What about roof V ground mounting for price and performance? Is it possible that any/all of it could be a diy job? I will have an electrician for the house overall but maybe cover labor to install panels etc? Hi Shaun, Midlands man here, we will also be going the pv route and as Conor mentioned the integrated panels are a great way of saving money on slates/tiles. I have asked a couple of sparks re. connecting up solar and both said they weren't certified for solar, didn't know it was a thing to be honest as they are after all electrical components. We are looking at 9kw array also, https://midsummer.ie/https://midsummer.ie/ this crowd see reasonable if getting the gear in yourself. Having spoke to a couple of solar installers they both tried to persuade me away from integrated panels with, " that's the old way of doing it and rail mounted are better". If you can get a spark who is happy to do it you'll be flying and saving a pretty sum. Link to comment Share on other sites More sharing options...
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