Nordintown Blog

Rubbish musings, projects and hackerings from Nordin

Solar PV, Aberdeen and me - Update 3

May 062018

I am currenly holidaying in sunny Gran Canaria and whilst dozing by the pool, I caught sight of a bank of solar panels. "Ah" I thought, I have those.

Its also been a while that I last blogged, so I thought I would kill two birds with one diamond laser and post an update. See graph.


It has been up and down with the generation rate but it has surpassed the conservative expectation that the installer gave me. Quite pleasing. The generation estimate was made against the avg Aberdeen sunlight hours, direction of panels, angles etc and the performance tracks  the avergate sunlight hours/day nicely - below, yellow line.


The sunlight hours highs are May followed by August, which appears odd at first (July being the hottest month) until you realise heat and sunlight are not the same thing. It does make me want to investigate all this talk on micro heat-powered Sterling engines I hear so much about. These are dinky blacker-than-black heat traps that expand and contract gasses to drive turbines that generate UnLiMeD POWER!!@%@45£!

At a 60% to 70% efficancy rating, Sterling engines kick solarpanels and their 20% max efficancy off the ballpark. They are more complicated I am given to understand, however the clever dicks are working on the problem and hope to have something investors can overspeculate on soon [1]. When done, we can call China and ask actual ballparks of them - hurrah.



Solar PV, Aberdeen and me - Update 1

Sep 082016

The install consisted of 12 BenQ PM096B00 panels, each equipped with a optimiser unit, all tied to s Solaredge SE3680 4Kw Inverter.  The total installed capacity is rated at 3.96KWp or 8.54 KWac. 

Plugging these stats together with the southern angle, plane elevation and shading factors, the Annual Solar PV Yield was predicted via the MCS method and PVsol simulation to be around 3277Kwh per year. Factoring in panel degradation, energy price inflation and the guaranteed FIT tariff (12.03p/kWhr) and export tariff rates (4.85p/kWhr), I am predicted a return of just under 12k over the next 20 year period. The system cost about £6.5k to install with the 20yr kit warranty. O/c this payback is realised over the long term with both the FIT payments as income and cheaper electric bills.

The predicted and actuals over the past month are below: 

Est. Generation Est FIT, Export income & Savings Actual   
Month kWh % of total Month Quarterly
(Running total)
kWh % of Est
Jan 166 2.83% £20.35   10   -
February   166 5.08% £36.52   187  111%
March 304 9.27% £66.67 £123.54 310  102%
April    367 11.21% £80.68   393  107%
May 440 13.43% £96.65   502  112%
June 432 13.19% £94.87 £395.45 482  110%
July 417 12.71% £91.45 £262 Paid from SSE, est. £133 saved on bill 430  103%
August 381 11.63% £83.66   460   -
September 292 8.90% £64.04 £634    
October* 211 6.43% £46.30 est. £230 due from SSE (tbc)    
November 122 3.71% £26.72      
December 53 1.61% £11.56 £719.47    
YEAR 3277 100.00% £719.47 £719.47    


Happily, so far I have generated more per month than the estimated - an average of 108% infact. This can only be a good thing but I have yet to compete the estimated bill savings against reality, which may eat up the extra 8% gain. Only time will tell. (updated Oct 5, 2016)