Solar panels - is SolarEdge worth it?

Ingsy

Hello,

I have had various quotes from a few companies for my solar panels and have narrowed it down to E-On Solar as being my potential supplier.

They have given me two quotes, one for a standard set up of panels, and one optimised with SolarEdge. I understand the benefits of SolarEdge, but on my unshaded roof - apart from a chimney, I am not sure if it is worth the extra £1400 that I have been quoted £4498 for a 3.92 Kw standard array and £5830 for the same array, but with SolarEdge).

It seems as though SolarEdge gives you much better monitoring of usage and savings etc, and the standard array offers none of this.

Does this sound a fair uplift in cost for the SolarEdge system, and would it be worthwhile?

Thanks in advance for any replies.

Merlin139

You say the only shading you have on your roof is your chimney. How long each day will it be an issue and over what % will it cover. Unless you have looked at this at various times of the day maybe difficult to answer. It would take a long time to recover £1400 from your FIT payment.

Which direction does your roof face? What side of the roof is the chimney on? Just looked at your original thread and seen it is SSE -2.5 degrees.

For me I know it was the right option to take as I suffer from about 10% shading caused by the direction and height of the house on the east of my roof. I am also effected by my TV aerial which is to the west of my roof and it casts a shadow on a couple of my panels, but as I have SE it does not knock out a string of panels.

Martyn1981

Ingsy wrote: »

Hello,

but on my unshaded roof - apart from a chimney,

Hiya. As Merlin asks, can you explain a bit more. For unshaded roof don't bother, but for a roof where one panel (even at a time) is shaded by the chimney for many hours, particularly around mid day, then that's a potentially big problem.

Is the chimney behind the panels (to the north), or level with the top panels, or in the middle of the roof? It all makes a difference.

If the shading is minimal (time wise) then using a normal inverter but having two strings and isolating the shading to one string will be enough.

Or two strings each with its own MPPT if the shading is a bit more (timewise). Also necessary if each string doesn't have the same amount of panels, as with a single MPPT strings need to match for maximum performance.

But if there is a small amount of shading most of the time, then that will drag down the whole string all the time, and an SE system might be justified.

Great prices BTW.

pinnks

This might help your thinking https://www.dropbox.com/s/2k06xp8bjehyx32/More%20on%20the%20impact%20of%20shading.pdf?dl=0

https://www.dropbox.com/s/crk44rwesv9c8tb/IMG_5341.JPG?dl=0

The roof faces just east of south so the chimney shadow comes round by about 2pm to 3pm. SE would benefit here - shame I didn't know that way back when.

My other array is on a WSW roof and gets a morning shadow from that same chimney. https://www.dropbox.com/s/rdtwf442w3vnf40/IMG_3095.JPG?dl=0

However, as the pitch of the roof means that the panels only really get borrowed light until midday when the sun moves round to the west of south, the shading is irrelevant. I only generate a couple of hundred watts from a 3.5kWp system in the morning, so the reduction of 200W by a shadow is minimal and not worth spending money on SE.

Ingsy

Hello, thanks for the replies.

The house faces approx. 20degrees east of south with a pitch of 35 degrees (figures supplied from E-On survey).

The chimney will be in the top left corner of the roof. I noticed the other evening (approx. 6pm) a long shadow from the chimney going diagonally down and to the right, so it would affect quite a few panels.

However, this also shows that the sun is effectively behind my house (albeit above the roof line so there will be direct sun on the panels at this time, but at a very very shallow angle).

The further we move away from the longest day, the less the chimney is going to affect things as the sun will be going down before it moves round far enough?

Martyn1981

That's a tough call. If it only casts a shadow in late afternoon in the summer months when the sun is to the north, then it might not be worth it for £1,400.

Solaredge would be better, but probably not better enough IYSWIM.

pinnks

I agree. My roof in the linked PDF is about 20 degrees east of south, and 45 degree pitch, so I would think you may well get significant benefit from SE. Whether that warrants the £1400 is still a good question.

My estimate for my 7 panels is about £100 per year lost production/self-use but that is at my FiT of about 18p, so divide that by about 3, so £30?

If I had a larger roof the chimney shadow could cause more loss. On the other hand, if I had no valley, then the shadow would hit the panels later because it would be at ridge level, not at the front edge of the panels, hmm, difficult.

Overall I think the maths probably won't pan out and you would be looking at 15 to 20 years to repay the original investment. Trouble is, you will also look at that shadow and the low production on sunny days and wonder what could have been...:huh:

Zarch

The power optimisers are £50 each aren't they and you need one per panel? You don't say how many panels, but assuming 13 or 14 300w for a 4kWh system. 14 * £50 = £700

The SolarEdge inverter shouldn't be much more expensive than any other inverter should it? Call it £100 or £200 tops.

So where is the £1400 charge coming from? Doesn't seem to add up to me?

NineDeuce

£1,400 for a monitoring system is terrible. You can do this much cheaper by getting a smart generation meter (c.£150) and monitoring system (c. £50/annum).

Or you could find a solar calculator online to find your expected generation through out the year, take reads and do it manually.