Expanding a 4kW PV Only System

Waywardmike

EricMears said:

Can you actually see your panels from your own property ?  I can only see ours from a point well outside our boundaries (or by standing on a stepladder).

Do you really care if other people lie awake all night worrying about their view of your roof ?

It's a bungalow, and they're right on the front...  I can see them the moment I walk out the front door...

Every time I look at them it would annoy me that they don't match.

here's a google maps photo that shows how obvious they are....

[Deleted User]

Screwdriva said:

Given the advent of Flux, I've decided to take advantage of the Barclays Green Home Reward and expand upon our 4kW LG Bifacial PV system (roof pictured below). Leaving 100cm for Velux windows at the very North of the roof, it would appear that we may have space for 4-6 additional panels on East & West aspects, making this a theoretical 5.6-6.4 kW system. I expect to retain the SolarEdge 3.68 inverter and remain on G98 for now. I face the following questions:

1) Given LG no longer supply panels, I need to match a similar looking panel for one aspect and move the 2 panels over to the opposite aspect. 
2) I need to research if the MCS Certificate needs to be updated/ or reissued and/ or DNO notified to highlight that increased generation capability

Any thoughts from the experienced are most welcome! 

I am looking into this as well but I am slightly wary given that Flux is a beta tariff that could be withdrawn at any time. I was on Go Faster and Octopus withdrew this tariff earlier this year. I think that it is also a given that Flux rates will reduce on the 1st July. 

Screwdriva

[Deleted User] said:

I am looking into this as well but I am slightly wary given that Flux is a beta tariff that could be withdrawn at any time. I was on Go Faster and Octopus withdrew this tariff earlier this year. I think that it is also a given that Flux rates will reduce on the 1st July. 

You're right about the risk to the Octopus tariff. That said, maximizing panel coverage when the PV market has experienced a slowdown (for now) is probably prudent. From a renumeration standpoint, as long as the chasm between Solar generation and grid demand exists during the warmer months, I don't see the SEG tariff getting any less lucrative. 

Financially speaking, we had put aside £2K to invest into Ripple Energy but realized that we may get half of that amount back via Barclays if we invested in our own roof instead. 

Screwdriva

It's been roughly a year since installation of the additional 550W bifacial panels (left in diagram below) and the expanded system has performed admirably. Despite below average generation this year and utilizing the same 3.68kW inverter (loads of summer clipping), I expect a greater than 50% increase in annual generation for 2024.

greenbee

Thanks for the update! I'm just working with my installer on a proposal to add another 6.6kW on the remaining bit of south facing roof and the west (the initial installation was on the single storey garage). Getting a bit of extra generation in the morning (the house roof gets light on the south slightly earlier than the garage) and quite a lot of extra in the evening for most of the year (particularly since neighbours to the west have taken trees down) will reduce import (both in terms of direct use and topping up the battery), and maximise export. 

Screwdriva

greenbee said:

Thanks for the update! I'm just working with my installer on a proposal to add another 6.6kW on the remaining bit of south facing roof and the west (the initial installation was on the single storey garage). Getting a bit of extra generation in the morning (the house roof gets light on the south slightly earlier than the garage) and quite a lot of extra in the evening for most of the year (particularly since neighbours to the west have taken trees down) will reduce import (both in terms of direct use and topping up the battery), and maximise export. 

Wise move - I expect that will perform really well. That said, it's probably worth considering a larger inverter and G99 application, given the aspect and substantial increase in system size. 

greenbee

Screwdriva said:

greenbee said:

Thanks for the update! I'm just working with my installer on a proposal to add another 6.6kW on the remaining bit of south facing roof and the west (the initial installation was on the single storey garage). Getting a bit of extra generation in the morning (the house roof gets light on the south slightly earlier than the garage) and quite a lot of extra in the evening for most of the year (particularly since neighbours to the west have taken trees down) will reduce import (both in terms of direct use and topping up the battery), and maximise export. 

Wise move - I expect that will perform really well. That said, it's probably worth considering a larger inverter and G99 application, given the aspect and substantial increase in system size. 

Yep - that's all in the plan - it more than doubles the current capacity. 

Screwdriva

A few of end of year updates:

- Generated 5.8mWh (vs. ~3.9mWh in previous years)

- Swapped in a new 5kW SolarEdge inverter for the existing 3.68kW unit (a friend's installation was previously planned to have 12 panels but was downsized to 10 due to a lack of roof space). Total cost was £125 including 20 year extended warranty. The installer was keen to commission the new system and covered installation of my inverter as part of this swap, which I was quite happy with! 

- Located a couple of New old stock LG 415W bifacial panels which (with some repositioning) will fit onto the ENE aspect roof, bringing total system size up to 8.1kW, effectively doubling the original system size installed 5 years ago. This effectively maxes out all available roof space so will likely be the final upgrade to the system.

Expected annual generation will increase from 5800 kWh in 2024 to in excess of 6500 kWh per annum at a total cost under £1K all inclusive. 

Screwdriva

Couldn't procure the LG 415W bifacial panels in the end but did manage to pick up 2 barely used 570W Sharp Bifacial panels. £650 installed with optimizers. 

Final system size is 8.4kW + bifacial gain (more than double the original) paired with a 5kW SolarEdge inverter. 

The system has already clipped for a few minutes in March and will undoubtedly clip much more in the summer (existing wiring will not allow a larger inverter)

ENE aspect (bottom) to mirror the WNW aspect (top). 

Screwdriva

Final system expansion complete. 2 X 570W bifacial panels added for a total of 18 bifacial panels generating 8.45kWP, across 3 aspects, paired to a single 5kW SolarEdge inverter. 

This marks the (foreseeable) end to a journey spanning several years, filled with invaluable learnings from these forums. Thanks for your contributions along the way!