Solar Panel Quote 3.5kw

pinnks

Few thoughts:

First, I would not describe the immerSUN history as pathetic. While the instantaneous data is updated every 15 seconds or so the history is by the hour. I appreciate this may be too lumpy for some (including me) but does one really need an instantaneous chart? Nice but not really necessary. Let's lobby immerSUN for an improvement in the chart but don't rubbish the tool itself as it's a web page which displays the chart and the tool as a whole is really useful to help monitor usage and change habits.

Second, I just looked a the immerSUN site. Their retail price for immerSUN and monitoring as a bundle is now £399. Trade folk no doubt get it cheaper than that - just worth looking closely at the cost in any quotes you get. Fitting should take more than 30 minutes for any of these devices if done while the power is off and main panel being tinkered with anyway... All they have to do is clamp the sensors onto the relevant cables and either route those cables to the immerSUN or run mains to the wireless sensor. Then they have to interpose the immerSUN between distribution unit an immersion heater and screw it to the wall - not rocket science for a qualified electrician.

Third, I went small at 3.5kW as I could not get DNO approval for >3.6kW or more in time to meet a FIT drop at the end of a quarter and was keen to get in before a 3% drop in FIT. I then added 1.75kW 9 months later having got DNO approval. The second system cost 67% as much as the first for half of the capacity. (2 lots of travel, scaffolding, second inverter, TGM etch). Some of this may have been needed for a single "go large" as I am using a second roof but overall I would have thought less than 50% extra, not 67% extra as labour and travel cost are also reduced etc. Also, had I gone large from the outset (which was my plan) I would have gone 330W panels, not 250W and would have had an extra 2 panels on the big roof. So, 23 x 330Wp panels giving 7.5kWp, not 21 x 250W panels giving 5.25kWp. One can be so wise with hindsight...

Have you thought about a short-term bank or whatever loan to squeeze in the extra capacity, for all of the reasons mentioned in here? That is of course a personal decision based on personal circumstances which I would not expect anyone to air or share on here but just a thought if it suits your personal circumstances.

EricMears

pinnks wrote: »

First, I would not describe the immerSUN history as pathetic. While the instantaneous data is updated every 15 seconds or so the history is by the hour. I appreciate this may be too lumpy for some (including me) but does one really need an instantaneous chart? Nice but not really necessary. Let's lobby immerSUN for an improvement in the chart but don't rubbish the tool itself as it's a web page which displays the chart and the tool as a whole is really useful to help monitor usage and change habits

I agree the instantaneous view can be useful but repeat that the 'history' is pathetic.

By averaging up a whole hour's worth of data before you're allowed to see it you can have no idea what it really means. A zero reading for any hour might mean that Immersun had exactly balanced diversion to excess generation. OTOH, it could just as easily mean that you'd diverted nothing but spent 30mins exporting a couple of kWh then bought it all back in the next 30mins. And in the shorter term, you might decide that you wouldn't want to (say) run the dishwasher until you'd had a steady ten mins of export - but the only way you'd find that out from MyImmersun is to sit there watching screen for ten mins; similarly, it would be nice to watch the trace during that dishwasher run to find out exactly how much energy was used during the water heating cycle and if that pushed you into import mode (hence for future runs you'd know how much excess you needed to make sure it didn't happen again).

I quite like the trace that Wattson/Holmes produces - except that I've never been very happy with it (just how many supernovae do you expect to get at 3am ?) and can now see from MyImmersun that it's instantaneous indication is often wrong. No idea whether my (secondhand) Wattson is unusually inaccurate or if it might be a typical unit.

tunnel

Oneday77 wrote: »

Is there not an extra cost to SSE to get permission to go higher too?
Though you have cleared up that the FiT will suck.

Any installer worth their salt will apply to your DNO on your behalf, it didn't cost me anything for my approval, whether it does now and for you in your area I don't know.
I'm with pinks though on the financing, maybe a 0% credit card or low interest bank loan for the extra costs to "go large".

Oneday77

Thanks again everyone. Hindsight is always better than foresight. Of course that's why I thought to try and second guess it by getting a bigger inverter now.
Half my thought is, some suppliers might end up sitting on unshiftable stock next year, potentially reducing cost. Labour admittedly won't change but it would be a gamble.

I've ruled the Immersun out now. The iBoost will give me the immersion power I need and the Solaredge is more a necessity. So the £200 saved in an immersun will go towards the £500 for the optimisers.

As for an Application to SSE for a higher capacity, as with all 'syndicates' I expect a nonsense charge. We were £600 2 years ago to move our gas meter 4m from internal to external, right in line of the gas piping. So you can see why I expect more.

Yes going for a bigger system now probably would be more cost effective. The installer wants 2.75% card fee for anything on a CC. So say on £7k that's about £200. I could see if they'd do anything but I need to get a quote on a 6k system. Though we'd probably fit 6.27kW on. I'd rather avoid going 3 phase if possible, that will hurt.

pinnks

Wrong thread for this really but I am not sure this is how immerSUN records data. As I understand it, it just counts what goes where and deduces from generation and import/export how much the house has used. Diversion seems to be a simple count over time but I may be wrong. By that I mean that I don't think it averages over time.

Also, past performance is not a guide to future in terms of generation, so is not an equally good way to decide when to turn on the washer etc to know that it uses about x kW max and to look at the sky? That said, a more real-time graph like what I have seen on Wattson would not go amiss...

Martyn1981

Oneday77 wrote: »

Yes going for a bigger system now probably would be more cost effective. The installer wants 2.75% card fee for anything on a CC. So say on £7k that's about £200. I could see if they'd do anything but I need to get a quote on a 6k system. Though we'd probably fit 6.27kW on. I'd rather avoid going 3 phase if possible, that will hurt.

As others have said, if you are thinking about going bigger, then think about it now. My gut says that even with a 10% lower FiT rate, and some capping (even at 3.68kW), you'd still end up with a similar return as the cost of the bigger system will be cheaper proportionately (as T explained).

My application to the DNO was free, under G83/2, however I think it now has to be done under G59 which carries a fee, but it's not much, possibly £40?

I asked and got permission for 5.9kW, the sum of my inverters. If you are thinking about 6kWp to 6.27kWp, then first of all forget 10% as you'll hardly ever get that due to hot panel drop off, so 5.4kW to 5.6kW is a more realistic max, and even that won't happen too much, so a SE5000 will be fine.

I asked informally first, just rang em and asked, and they popped round and had a look at the street and the current cabling. I then got an informal ok, subject to a formal application from my installer.

Edit: Section 10 of the FAQs may be of some use.

Best of luck.

Mart.

EricMears

pinnks wrote: »

Wrong thread for this really but I am not sure this is how immerSUN records data. As I understand it, it just counts what goes where and deduces from generation and import/export how much the house has used. Diversion seems to be a simple count over time but I may be wrong. By that I mean that I don't think it averages over time.

Also, past performance is not a guide to future in terms of generation, so is not an equally good way to decide when to turn on the washer etc to know that it uses about x kW max and to look at the sky? That said, a more real-time graph like what I have seen on Wattson would not go amiss...

Whatever MyImmersun's method of calculation, if it changes the display every 15s it must be sending data every 15s - and very likely storing all such inputs in a database.

If I had access to their database, I could do whatever I liked with it or if I could see what was being transmitted I'd also be able to manipulate it (and I would probably do that with my own dBase).

Looking at the instantaneous MyImmersun display is rather more reliable than looking at sky (although forecasting the next hour's weather can only usefully be done by guessing which cloud is coming your way)

pinnks

Agreed on all counts :beer:

Oneday77

I'm starting to get a little disillusioned by this now. My preferred supplied has come back with my quotes.
4kW 14 x 285W, Solaredge and iBoost, no EPC as have one, £6100. iBosst and Edge add about £800 so I think that's there or there abouts.

6kW system, turns out only 21 panels will fit. So 21 x 290W, Solaredge and iboost. £9,200. With an additional proposed £660 to SSE I certainly didn't expect 50% extra cost for the additional panels. Although he's chosen higher output panels.

I've approached another local company that is offering to fit 8.33 285W panels so I'll see what they say.