Production review between May, 1st 2015 and September, 1st 2015 (4 months)

The "MyPV" database collects detailed energetic informations since end of April 2015. Thanks to the new STATISTICS page of MyPV website, it takes now 3 clicks and 2 seconds to get the numbers. Try yourself :-)

I performed the calculations on the May to August period (4 months), and that's the result:

A few comments:

• The solar resource utilization ratio of 73 % is a very good figure. In fact the solar resource measurement is a bit pessimistic (indicates less than the reality by more than 10 %). I think that the real resource utilization ratio is rather near 60 %. So still 40% of the available solar energy is not used by the system. The solar power measurement precision will be improved soon.

• The 4 panels strings should provide approximately 25 % each. One can see that the part provided by String 2 is very low - only 13 % of the total amount of energy. One could think that String 2 has a failure. On the other hand the total strings output (964 KWh) is much less than field output (1157 Kwh). This indicates that the problem is probably due a faulty current sensor on String 2. This has to be fixed ASAP .

• The battery yield of 66 % is a rather low figure. This can be explained by the fact that the battery stays many hours each day in "absorbtion" and "floating" status. The energy put in the battery during these phases is almost completely lost.

• The solar hot water consumption figure is not currently computed. This field is a provision for when my Photovoltaic Hot Water Production project is finished. Thanks to this device, the solar resource utilization ratio should raise a lot in the future.

• The energetic autonomy ratio of 87 % is very good. The summer was really great this year and the system was on-line all the time. Note: the energetic autonomy ratio is computed with the inverter input figure and not computed with the field output figure. In this case the energetic autonomy ratio would be even larger, but not realistic.

• The average daily consumption (8.8 KWh) is in line with the assumptions I made when I designed the system (10 KWh). In winter the average daily consumption will be closer to 10 KWh.

• The autonomy versus time ratio of 87 % is completely in line with the energetic autonomy ratio. That means that our consumption is nearly the same every day.