Roger440 Posted February 26 Share Posted February 26 Me? Because connecting to the grid adds cost and complexity. I can consume everything i could generate in winter for heating, reducing the use of oil. Keeping this part off grid means i can do what i like, and myself. If only i understood it. Link to comment Share on other sites More sharing options...
Roger440 Posted February 26 Share Posted February 26 3 hours ago, SteamyTea said: Had a quick look, most of it is generic stuff like cables, switches and connectors. There are the modules and batteries, then the charge controller/inverter, the MPPT and the communication device (which is probably not needed, but is used to set up the system, so will be needed, think of it as a specialised spanner). As it is all Victron kits, I suspect it is well sized for the system and won't be unreliable, why you pay a lot extra for it, they have done the leg work. I am sure of you ask Bimble, they will have an installation guide. If you say its good gear, im sure it is. Its somewhat acedemic, however, as there absolutely no chance of me spending that kind of money. It would be irrational. If what i do isnt at least close to making financial sense, im not doing it. Link to comment Share on other sites More sharing options...
Dillsue Posted February 26 Share Posted February 26 1 hour ago, Roger440 said: Because connecting to the grid adds cost and complexity. I can consume everything i could generate in winter for heating, reducing the use of oil. Keeping this part off grid means i can do what i like, and myself. If only i understood it. Unless you've got a massive array its almost certain you'll use everything you generate in the winter and a fair chance you'll need more on occasion. The 4.5 kw you've got on a pallet will just scratch the surface in the winter. Even with a big array how are you going to power things if you have a run of bad weather. What if you have a breakdown without the back up of a grid connected system? Assuming your house already has a mains supply, connecting up PV costs can be minimal. Export less than 3.68kw and DNO costs are £0. Getting a spark to make the final connection to your consumer unit can be a couple of hundred £, less if youre well acquainted. The rest you can do yourself with research. Link to comment Share on other sites More sharing options...
Roger440 Posted February 26 Share Posted February 26 (edited) 40 minutes ago, Dillsue said: Unless you've got a massive array its almost certain you'll use everything you generate in the winter and a fair chance you'll need more on occasion. The 4.5 kw you've got on a pallet will just scratch the surface in the winter. Even with a big array how are you going to power things if you have a run of bad weather. What if you have a breakdown without the back up of a grid connected system? Assuming your house already has a mains supply, connecting up PV costs can be minimal. Export less than 3.68kw and DNO costs are £0. Getting a spark to make the final connection to your consumer unit can be a couple of hundred £, less if youre well acquainted. The rest you can do yourself with research. Its up there somewhere ^^^. Im connected to the grid. Heating is oil, and thats going nowhere. This would supplement it. Ideally to drive an ASHP to heat water in a massive tank. Ie, storing the energy as hot water instead of batteries. The principle being simple enough. Whilst the current array is 4.5kw, the panels are circa £100 each off ebay and i have unlimited space so would be able to expand. JohnMo seems to be getting some worthwhile output from his vertical panels, circa 17Kwh per day out of a sub 8kw array. If we assume a COP of 3, thats becomes a worthwhile contribution to the daily heating requirements. But at the risk of repeating myself and boring everyone to death, this doesnt fly if i start paying people thousands to do work. No doubt ill have to have a smart meter to export, which wont work as there is zero signal. Really, just not interested in export. Or the hassle of buggering about fretting about tarrifs i dont understand, getting my export rate reduced arbitairly etc etc. I just want simple. If i cant install it and maintain it myself, then its not happening. I cannot be beholden to other people in the event of issues. Its borderline impossible get anyone to do anything out here. Sadly, i dont think i have enough understanding to design what i need. As per the previous few posts, what im trying to do seems simple in principle, but not so easy in practice. My initial enthusiasm is waning fast as reality strikes! Theres a whole bunch of cost to deal with to do this aside from the solar side. I need to build a shed to put said water tank in, which would house the boiler, ASHP, stanby genny, as well, relocation of plumbing, power supply etc etc etc.. I can do all that myself, but its still not free. As i also said earlier, this has to make economic sense. I appreciate many on here have applied "man maths" to there own justification or other reasons, or super long payback periods, but im not doing that. It has to make sense. The context is 2000 litres of oil a year. So £2k a year. With no capital investment required. Its all there, working and relatively new. So you see, it needs be pretty cheap to make it fly. I thought having a "free" array would tip things the right way. Edited February 26 by Roger440 Link to comment Share on other sites More sharing options...
joe90 Posted February 26 Share Posted February 26 22 minutes ago, Roger440 said: But at the risk of repeating myself and boring everyone to death, this doesnt fly if i start paying people thousands to do work. No doubt ill have to have a smart meter to export, which wont work as there is zero signal. Really, just not interested in export. Or the hassle of buggering about fretting about tarrifs i dont understand, getting my export rate reduced arbitairly etc etc. I just want simple. If i cant install it and maintain it myself, then its not happening. I cannot be beholden to other people in the event of issues. Its borderline impossible get anyone to do anything out here. Sadly, i dont think i have enough understanding to design what i need. As per the previous few posts, what im trying to do seems simple in principle, but not so easy in practice. My initial enthusiasm is waning fast as reality strikes! I get that completely so i guess it’s all down to payback timing, how much you want to invest and the time it will take to pay it off which will be linked to your consumption. I am sure there are people here that will help you design it. Link to comment Share on other sites More sharing options...
JohnMo Posted February 26 Author Share Posted February 26 1 hour ago, Roger440 said: Its up there somewhere ^^^. Im connected to the grid. Heating is oil, and thats going nowhere. This would supplement it. Ideally to drive an ASHP to heat water in a massive tank. Ie, storing the energy as hot water instead of batteries. The principle being simple enough. Whilst the current array is 4.5kw, the panels are circa £100 each off ebay and i have unlimited space so would be able to expand. JohnMo seems to be getting some worthwhile output from his vertical panels, circa 17Kwh per day out of a sub 8kw array. If we assume a COP of 3, thats becomes a worthwhile contribution to the daily heating requirements. But at the risk of repeating myself and boring everyone to death, this doesnt fly if i start paying people thousands to do work. No doubt ill have to have a smart meter to export, which wont work as there is zero signal. Really, just not interested in export. Or the hassle of buggering about fretting about tarrifs i dont understand, getting my export rate reduced arbitairly etc etc. I just want simple. If i cant install it and maintain it myself, then its not happening. I cannot be beholden to other people in the event of issues. Its borderline impossible get anyone to do anything out here. Sadly, i dont think i have enough understanding to design what i need. As per the previous few posts, what im trying to do seems simple in principle, but not so easy in practice. My initial enthusiasm is waning fast as reality strikes! Theres a whole bunch of cost to deal with to do this aside from the solar side. I need to build a shed to put said water tank in, which would house the boiler, ASHP, stanby genny, as well, relocation of plumbing, power supply etc etc etc.. I can do all that myself, but its still not free. As i also said earlier, this has to make economic sense. I appreciate many on here have applied "man maths" to there own justification or other reasons, or super long payback periods, but im not doing that. It has to make sense. The context is 2000 litres of oil a year. So £2k a year. With no capital investment required. Its all there, working and relatively new. So you see, it needs be pretty cheap to make it fly. I thought having a "free" array would tip things the right way. There are two ways to heat water with electricity, heat pump or direct to immersion. Neither are as straightforward forward as they first seem. But breaking down practicality Heat pumps when you need them most they have the biggest power need (lowest CoP) and you are likely to have least PV available. So likely no heat pump running most of Dec-Jan. Looking at my PV today, which was quite overcast I did 17kWh, but the useful window for driving a heat pump off-grid was about 3 to 4 hrs. The other alternative would be direct DC to immersion heaters. You need to match the output of the panels very closely to the the power rating of the immersion to get them to perform as they should. You get a CoP of one, but you get useful energy whenever the sun's out. Panels from city plumbing are cheaper than ebay. Watch this and the spreadsheet mentioned is attached https://www.google.co.uk/url?sa=t&source=web&rct=j&opi=89978449&url=https://m.youtube.com/watch%3Fv%3DkVaxAfXQPDU&ved=2ahUKEwjZ2vnXhcqEAxXkZEEAHfX8DHkQo7QBegQIDhAG&usg=AOvVaw2ys-gKyKBdBX1Ku7fZDZ-M Solar PV Calculator.xlsx Link to comment Share on other sites More sharing options...
Hastings Posted February 26 Share Posted February 26 7 hours ago, SteamyTea said: As it is all Victron kits, I suspect it is well sized for the system and won't be unreliable, why you pay a lot extra for it, they have done the leg work. Be aware there is no real tech support with Victron stuff. You post your problem on a forum and wait/hope for a response from the community. Link to comment Share on other sites More sharing options...
Roger440 Posted February 27 Share Posted February 27 18 hours ago, JohnMo said: There are two ways to heat water with electricity, heat pump or direct to immersion. Neither are as straightforward forward as they first seem. But breaking down practicality Heat pumps when you need them most they have the biggest power need (lowest CoP) and you are likely to have least PV available. So likely no heat pump running most of Dec-Jan. Looking at my PV today, which was quite overcast I did 17kWh, but the useful window for driving a heat pump off-grid was about 3 to 4 hrs. The other alternative would be direct DC to immersion heaters. You need to match the output of the panels very closely to the the power rating of the immersion to get them to perform as they should. You get a CoP of one, but you get useful energy whenever the sun's out. Panels from city plumbing are cheaper than ebay. Watch this and the spreadsheet mentioned is attached https://www.google.co.uk/url?sa=t&source=web&rct=j&opi=89978449&url=https://m.youtube.com/watch%3Fv%3DkVaxAfXQPDU&ved=2ahUKEwjZ2vnXhcqEAxXkZEEAHfX8DHkQo7QBegQIDhAG&usg=AOvVaw2ys-gKyKBdBX1Ku7fZDZ-M Solar PV Calculator.xlsx 14.01 kB · 5 downloads Thanks for that. Hmmm, essentially you have pointed out my idea wont work, ie, use an ASHP. Essentially because, despite the overall collection, there will only be enough to run it for a short amount of time. Which, as you say, leaves the only option as direct immersion units. Clearly, it has simplicity on its side, as looking at that video there are no additional things other than panels and heating elements. (though with that level of simplicity how do you prevent overheating?) I need to do some more accurate calculations, but im not sure i see this making good financial sense. If i could just put the immersion into an exsisting tank, it might be OK, but given all the extra work to get to that point im not so sure. One thing i didnt understand in that video, is he showed how having them in series didnt work. But at the end on his calculator, he turned the sewries/parrall numbers round and still had the same output. Which directly contradicted himself. Dont understand that bit? Link to comment Share on other sites More sharing options...
JohnMo Posted February 27 Author Share Posted February 27 1 hour ago, Roger440 said: how do you prevent overheating Immersion thermostat. 1 hour ago, Roger440 said: Dont understand that bit? I found I had to lots of different configurations on the spreadsheet to get anything usable. 1 Link to comment Share on other sites More sharing options...
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