Caroline Posted March 13 Posted March 13 Hello We are building a bungalow 200sqm traditional brick/block. Our guy has suggested a 7KW Stiebel-Eltron WPL-A Premium ASHP, 13kw PV array and Solaredge battery. Heat loss calcs coming out at 4741 w power and 16365 kw energy. I queried the size of ASHP wondering if it is powerful enough. Also I believe the PVs are made in China, does anyone have any they could recommend made in UK or europe? Battery, Solaredge, any advice, are they any good. All of this with the UFH is coming out at £44.5k excluding the BUS grant. Any advice would be appreciated. Thank you.
SteamyTea Posted March 13 Posted March 13 20 minutes ago, Caroline said: Heat loss calcs coming out at 4741 w power and 16365 kw energy. Really, even ignoring the incorrect units. Those seem very high for 200 m2 in the South East of England. W [watts] is power, kWh [100 watts multiplied by time] is energy.
nod Posted March 13 Posted March 13 Everything seems to be made in China PV is a tricky one Unless you buy cheap and self install It May take a couple of decades to recoup the cost and your batteries will have probably been replaced a couple of times by then The people that purchased our previous build have just spent 17k on PV With the salesman promising an unlikely saving of £500 per year Still 34 years
Iceverge Posted March 13 Posted March 13 Do you have more details for your house please to send check your energy usage? Specifically: 1. Ventilation strategy 2. Airtightness target 3. Window type 4. Wall insulation and area 5. Roof insulation and area 6. Floor insulation and area.
JohnMo Posted March 13 Posted March 13 (edited) £44k - why would you bother. UFH £1k or less materials Panasonic heat pump £2.5k Hot water cylinder £1.5k That's it materials wise. Plumber and his mate two days to UFH. Just need pipe and manifold - no pump or mixer or actuators. 210L unvented heat pump cylinder. Bring supply pipe from ASHP through wall to 28mm diverter valve (not a mid point valve). One did to cylinder other to manifold. Return pipes just tee tee together and go back to heat pump via a strainer and a couple of isolation ball valves. Run everything from ASHP Controller. So £5k materials for full heating system is and £39k labour and PV installation. Even with a min buildings regs house 7kW is big enough. Airtight with MVHR you should be looking nearer 3kW. 13kW of PV is huge, and may be capped for export. So you really need to size correctly. We are NE Scotland and yesterday was no sun directly, hot water and 3hrs of heating done just on excess PV after charging battery, we only have 6kW and lots of shading at start and end of day. Battery, the inverter size is important, you need one that can do 6kW continuous output, connected to grid or in power outage. Then you don't need stupid emergency only power. Edited March 13 by JohnMo
Nickfromwales Posted March 13 Posted March 13 45 minutes ago, Caroline said: Hello We are building a bungalow 200sqm traditional brick/block. Hi. Why brick and block and not something far better? Especially if it’s a simple build like a bungalow. I really like the Stiebel kit, very good controls etc, excellent build quality etc. Solar Edge had one of the longest inverter warranties on the market so are considered very good for quality and reliability. Solarwatt are who I use for all my clients builds, German manufacture originally but now outsourced under tight supervision. Warranties are underwritten by BMW, as it’s the owners of BMW who started Solarwatt. The paints just dried on their new range of batteries / inverters / EV chargers / controllers etc, but most importantly for you they now have knocked boots with Stiebel and the kit all communicates with one another. Their Vision panels have a performance guarantee, 30 years at 90% or above, and the new batteries are 12 years at 80% DOD. Batteries are 2.6kWh packs which you just click together multiples of to increase your storage incrementally. It’s just very good stuff tbh, and I do favour them. 13kWp of solar would be a very decent chunk, and would contribute towards heating during the winter I suppose, but you may be better off with a bit less solar and a bit bigger battery; if you’re watching where each of the pennies go.
SteamyTea Posted March 13 Posted March 13 2 hours ago, Caroline said: 13kw PV arra What are the azimuth and altitude angles, these can make a big difference. You can get a good projection of what they will produce thought the year at PVGIS.
sharpener Posted March 13 Posted March 13 10 hours ago, Caroline said: Our guy has suggested a 7KW Stiebel-Eltron WPL-A Premium ASHP, 13kw PV array and Solaredge battery. Heat loss calcs coming out at 4741 w power and 16365 kw energy. I queried the size of ASHP wondering if it is powerful enough. Also I believe the PVs are made in China, does anyone have any they could recommend made in UK or europe? Stiebel Eltron are top end and correspondingly expensive, not sure you need that. Assuming good insulation, MVHR etc it is too big and will cycle a lot, you would do better with something like 5kW Vaillant which are also v good and the spec is generous too. You won't find PV made in Europe any more. 13kW is a massive array esp in comparison with HP size, are they trying to run the HP entirely from the solar power!? So get half that and 10 - 12 kWh of battery for a better balanced system, that will probably be enough to cook evening meal and run the HP from battery through the evening peak, more than that probably not economic.
SteamyTea Posted March 14 Posted March 14 5 hours ago, sharpener said: You won't find PV made in Europe any more https://www.solarfeeds.com/mag/top-solar-panel-manufacturers-in-europe/
MikeSharp01 Posted March 14 Posted March 14 17 hours ago, Caroline said: could recommend made in UK or europe? We have 7kW of Eurena panels all made in Spain, price is slightly higher but not much.
sharpener Posted March 14 Posted March 14 3 hours ago, MikeSharp01 said: We have 7kW of Eurena panels all made in Spain, price is slightly higher but not much. I stand corrected. Every day a school day! Stocked by Midsummer.
JohnMo Posted March 14 Posted March 14 Or Sharp half the price (430W at £65) made in Thailand and Vietnam. At least it's not China.
ReedRichards Posted March 17 Posted March 17 (edited) On 13/03/2025 at 13:20, SteamyTea said: kWh [100 watts multiplied by time] is energy. I remember the days when you got 1000 W multiplied my time (In hours) for your kWh. At only 100 W no wonder the energy companies are raking it in! Edited March 17 by ReedRichards
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