6.48 mm diameter nozzle delivering 0.91 l/s to the runner which is rotating at 1084 rpm and generating 225 watts into the grid at an overall efficiency of 47%.

Thursday 1 October 2020

End of year results 2019-2020

30th September marks the end of the 12 month period I use as my 'accounting year'; it is when I bring together data for how my Powerspout has done.  

The graphs below show how it has performed:

  • in each graph the bold black line represents the data for the year just ended; 
  • data is available because it is automatically captured by the installation's inverter (SMA WindyBoy) and transmitted by Bluetooth to a desk top display (SMA SunnyBeam), from which it is downloaded at the end of each month to a desktop pc.

Graph 1 shows power each day measured in Watts (left hand axis) and energy measured in kWh (right hand axis). 

  • the power data is derived from the energy data by dividing the kWh figure by 24; 
  • the value given for power is therefore the mean power generated in each 24 hours; 
  • the figure will be reduced by any event during the 24 hours which interrupted generation, and such interruptions are seen as a downward spike in the trace;
  • interruptions include events such as grid outages and turbine stoppages for maintenance; 
  • it can be seen there is not a single day in the year when the turbine failed to generate anything at all; 
  • sustained upward or downward steps in the trace are caused by a change of nozzle, either to a bigger or a smaller one, to suit seasonal changes in flow; 
  • I had to change nozzles 22 times during the year; 

Graph 2 shows the cumulative energy, measured in kWh, generated over the 12 month period. 

  • the output this year has been unprecedented, 5133 kWh, far exceeding the totals in the previous 6 years; 
  • the cause of this bounty was a wet winter which started unusually early in October and continued through to March, with exceptionally heavy rainfall in February; 
  • such wetness gave the turbine a stretch of generation at maximum output (920 W) lasting just under 160 days (26th Oct to 30th March).

Graph 3 shows how many days in the year a given level of power was achieved. 

  • this way of displaying the turbine's output gives an idea of how much time the turbine spends generating at different power levels; 
  • for example 200W was generated for the number of days between 260 and 315, i.e. 55 days; 
  • but these 55 days would not have been in one stretch; this type of graph aggregates all the days in the year which saw generation at this level;
  • Graph 1 shows most of the 55 days were in June / July with a few being added at the end of September; 

Graph 1

Graph 2

Graph 3



3 comments:

LJ said...

2020 seems to be an exceptional year all round! On course to be the same for solar too:

https://pvoutput.org/aggregate.jsp?id=41191&sid=37661&v=0&t=y

April and May definitely benefited from less pollution:

https://pvoutput.org/summary.jsp?id=41191&sid=37661

Bill said...

Hi LJ, - many thanks for posting your comment and especially for the link to your solar outputs over the years; before you drew it to my attention I didn't know of the pvoutput.org site. So thanks for that. I'll be checking back to see what your full year kWh total comes to. BW. Bill

LJ said...

Hi Bill, very welcome! PVOutput has some useful stats and graphs and the site owner is quite responsive to issues and suggestions, especially compared to Wattson/Energyhive which I find is quite restrictive and slow and their tech support is quite slow!