7.3 kW Bi Facial Rooftop Panels: ~7 year ROI: Fact OR fiction?

Coastalwatch

Solarchaser said:

When you say okish price....

I have to measure it up against my 300w split panels for £80 each a year ago

  Erm, whats a split panel? And, Is that price available to anyone?

Solarchaser

Rec twin peak, their connections are centre of the panel, so its like two smaller panels, so better for shading issues:-
https://www.recgroup.com/en/products/rec-twinpeak-2-mono-en

Erm yeah id think available to anyone, they come up on ebay quite often.

I tracked them for best price for a couple of months to get them at £80 each

Screwdriva

The bificial system hit a new peak generation of 3.07 kWh yesterday. Averaging well above 8kWh per day for March so far. 
https://imgur.com/a/GBrP10L

Petriix

Screwdriva said:

The bificial system hit a new peak generation of 3.07 kWh yesterday. Averaging well above 8kWh per day for March so far.

I think you meant 3.07kW.

For comparison, my 3.42kWp array (cost £4150 in 2017) has been averaging 9.5kWh (or 2.77 Os as the locals say) per day in March.

Including the FIT payments at 2017 rates I'm looking at breaking even after around 10 years. 
I calculate my savings based upon the average reduction in my grid imports from before installation to after which is around 4kWh per day, meaning we self-consume about 45% of what we generate to cover the same usage as before. That way the figures aren't skewed by any changes in our behaviour such as unnecessarily running the tumble dryer on sunny days just because it's free. That's not really a saving, after all.

Screwdriva

I'd be very keen to compare the bi-facial system to a conventional system in the same area as me to know if there is outperformance due to the bifacial technology.
On that note, hit a new system high of 15.02 kWh and a peak of 3.072 kW today.  As you can see from the curve, it will easily exceed a quad O on a clear day. 
Graph here

EricMears

It's not obvious from your post (or indeed the first few I viewed at start of thread) just where your area is or what the installed kWp is.

If it's any help,  my 4kWp system (installed at a rather unfavourable angle for this month) managed 16.65 kWh today with a peak at 3.3kW

joefizz

Solarchaser said:

Rec twin peak, their connections are centre of the panel, so its like two smaller panels, so better for shading issues:-
https://www.recgroup.com/en/products/rec-twinpeak-2-mono-en

Erm yeah id think available to anyone, they come up on ebay quite often.

I tracked them for best price for a couple of months to get them at £80 each

Thats a great price! Think I paid 240 each for 295 Ja solar plus p300 optimisers a year and a half ago.

EricMears

Screwdriva said:

EricMears said:

It's not obvious from your post (or indeed the first few I viewed at start of thread) just where your area is or what the installed kWp is.

If it's any help,  my 4kWp system (installed at a rather unfavourable angle for this month) managed 16.65 kWh today with a peak at 3.3kW

Located in Zone 2 SE London (Rotherhithe)

In which case you might expect to do rather better than me.  However at 200 miles away there are far too many variables in weather for a valid comparison.

If you were to add a few details to your profile signature,  it would be more obvious who should respond next time you seek a comparison.

Screwdriva

16.77 kWh generated today, a new high for the bifacial system by quite a margin! I expect that an additional 1-2kWh could have been generated earlier in the day in ideal conditions. That said, this week is looking very promising!
(If anyone is in the SE1/ SE16/ E1W area, I believe a comparison of performance would be very useful).

Graph here

Screwdriva

It would appear I predicted today's performance. 18.3 kWh today, smashing the previous record. Note that the graph will show that peak power was nowhere near prior performance, which tells me that a penta O (20kWh) should be possible. Tomorrow perhaps?