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Benguela's Achievements


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  1. Quick search and I could only find one of these from a European supplier for 12,000 euros. But, in the UK, there is a company called Powervault that use Nissan Leaf batteries to make home storage batteries. Can't see a price, though.... 'Contact us for a quote'.
  2. Hi Joth, Did you get further with this? Last month, I installed a 6kW solar array and a Solaredge HD wave 5kW inverter. I'm in the market for a battery, and my installer are trying to sell me: - LG Chem Resu Prime (this is the newest generation LG Chem battery) as a first choice... they mentioned physical size as the main advantage - StorEdge as a second place choice. Being DC coupled, my understanding is that neither of these two batteries will charge from the grid so that I can make use of Octopus Go. And that's why I haven't bitten yet. In summer, I have lots of spare solar to charge up my battery, so I can probably be totally self-sufficient. But in winter, I won't have any spare solar and then I would like to be able to charge up from Octopus Go and use that to run my GSHP for a few hours in the day. Otherwise, all the battery does is help cut my summer bill from £1 to zero... when my real problem is that I've got winter usage of £££'s per day. I'm now toying with a much cheaper AC coupled solution like Victron+Pylontech or Solax or Givenergy. Any thoughts from someone? About adding in an AC coupled solution after having gone for a SolarEdge inverter? Ben h
  3. Hi @dpmiller, can you tell us a bit more about your heatpump and Thermal Store combination? I've got a bunch of questions: What is your heatpump? How big is the thermal store? Do you use the TS to give DHW or space heating or both? What temperature do you heat the TS to? How much usable heat do you then get out? Any economic remarks... is it a money saver? I have a GSHP with a 100litre buffer and I'm also on an Octopus Go tariff. I have this crazy idea that if I run my GSHP during Octopus Go hours, I can heat up a large thermal store and then draw down that warm water into my UFH for the rest of the day. Do you or anyone else have a setup like that?
  4. Great answers, thanks guys. I totally understand: the excess solar isn't constant and if I tried to divert the excess solar to my heat pump, I would in effect be forcing it to short cycle. Severnside and Wil suggest some good ideas to smooth out the short cycles. But I'm going to take away that this solution needs a bit of thought!
  5. Hello all, I have a GSHP and am getting some solar panels installed soon. To use my excess solar, I'm getting a solar diverter. Now, most solar diverters divert your excess power to an immersion heater and immersion heaters have a CoP of 1. So I thinks to myself: 'why don't I divert my excess solar to switch on my GSHP whenever I have excess solar and with my CoP of 4, I turn 1kWh of excess solar into 4kWh of heat.' Granted, when it comes to producing DHW, my CoP is probably between 2 and 3... but that's still more efficient than my immersion heater. And on the odd sunny winter's day, I might run my GSHP on free solar for an hour or two mid-day. Problem is I can't find a diverter that is designed to switch a heat pump on and off... they can control immersion heaters, car chargers, even individual sockets, but nothing seems to be optimised to control your heat pump. Any ideas why that is? Or could such a thing be made?
  6. Dear All, I bought a converted barn in Norfolk and am working on improving my insulation. But to know how I can improve, I've first got to find out for sure what I've got and it's not totally apparent by just looking from the inside and knocking on walls. The house was converted in 2003. The walls are brick and flint and the roof is pan tiles. The rafters are exposed, but they're mostly infilled with ceiling board and through a small gap here and there I can see shiny celotex... so I'm pretty sure that the rafters have celotex in between. The majority of the internal walls are plasterboard... so my guess is that I've got a solid external wall that has been insulated on the inside with celotex and plasterboard. But I don't know this for sure... and I don't want to break the plasterboard open to have a look. Someone told me that I can request my original plans and building control documents because it would have all been specced there. How do I find these? I looked up all the past planning applications in my area... but, funnily, the application for turning this barn into a house isn't on there. Do I need to contact building control? They're separate from planning. And what, exactly, do I ask for? They charge a fee. Thanks!
  7. Thanks for comments, guys. Scottishjohn, the UFH is in 65 mm of screed. And under that screed, we've got insulation board.
  8. Hi Everyone, I've got a big (50 sqm) groundfloor space in my house that is floored with pine boards over wet underfloor heating. The rest of the house is ceramic tile over the same wet UFH. I didn't do the floor myself... bought the house like that... and I now want to replace the pine boards because not much heat is getting through from the UFH. I've got the original UFH installer's plans. They date back to 2004 when the UFH was laid and they call for (from bottom to top) hardcore, then a damp proof membrane, then the structural floor slab, then insulation board, then UFH pipes in 65mm of screed. I've lifted up one of the pine boards to see how the floor is laid and we've got battens that are chased into the screed... not quite an inch thick, maybe 15 or 20mm... and the pine boards screwed to the battens. So what we've got is the heated screed, then an air gap, then pine boards. To my mind, that is wrong because the air gap means the heat doesn't transfer from the screed upwards and the pine doesn't conduct heat very well anyway. Am I right that this is pretty poor? I would love to have a limestone floor, and got a quote, but the guy wants to break out the battens (price per hour of labour), get a specialist in to level the floor with latex for £1400, then charge me £50 psqm for labour to lay the stone tiles that I supply (they cost me about £40 sqm). So the whole job quickly comes to >£6,000. I'm now considering engineered wood that I lay myself. Questions: 1. I'll get engineered wood that is specced to work with UFH... any suggestions for what to go for or avoid? My heating adjusts with how cold it is outside and my buffer temp varies on a heat curve between 30C and 40C. 2. To lay it, I can see three options 2.1 Keep the existing battens (after all, we know they are level). Fill in the gaps between the battens with low tog underlay like Duralay Heatflow. That will fill up the air gap and make sure the heat transfers through from the screed. Then secure my new engineered wood floor onto the battens with glue. 2.2. Break out the existing battens. Use self levelling compound (brand suitable for wet UFH) to even out the floor. Glue the engineered boards down onto that. 2.3 Break out the existing battens. Roll out an underlay (brand suitable for wet UFH) and trust that it's going to even out the floor enough. Then float the engineered boards over it. What do people think? 2.1, 2.2 or 2.3? Thanks for any advice as never attempted a floor before.
  9. Thanks ProDave, What's making me wonder is this. The performance tool for the hit pump is online at https://www.stiebel-eltron.co.uk/toolbox/waermepumpe/... and it shows a reading for Inverter Speed % (look on the right hand side in the picture below). Maybe it's just a standard display thing in how Stiebel makes these graphs... or maybe it is an inverter model after all.
  10. Hello Everyone, I'm new here and love trawling through the questions and answers in the GSHP part of the forum. A little about me: I live in Norfolk and have a GSHP (Stiebel Eltron WPF 13 S). I've got about 700 m of brine loops in my garden and the WPF is paired with a 100 l buffer tank. I know that one of the most important efficiency considerations is to prevent short cycling - run the machine continuously rather than stop/start. Most heat pumps are either on or off... the compressor runs at 100% or nothing. But some heat pumps are variable speed... How can I work out if my heat pump is an inverter model or a fixed output model? I googled the model number and 'variable speed' and 'inverter' but nothing obvious comes up. More important, I'm beginning to wonder if that 100l buffer is too small. If I had a bigger buffer, that would also smooth out the short cycling, not so? Any ideas what difference a larger buffer would make? Thanks for any advice. ~Benguela
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