25 April '11 : In my regular Sunday round up, the house is yet again achieving an all time low annual consumption for the whole house of 5,423 kWh and the GSHP of 3,442 kWh.
The ground temperature is up to 12.4ºC (whereby it was 9 point something a year ago). During the day, the deep ground temp is up to over 14ºC, but my system of measurement is to leave the ground to settle out in the evening, and measure it at midnight. The ground is consistently rising in temperature, and I don't expect it to get to a high temperature, but if that heat has moved out and settled in, then it represents good storage. If it gets to 14º then that is not high enough for it to get lost outwards.
The Sunboxes are maintaining an annual figure of over 3,000 kWh despite that they do not pull in as much when the GSHP is asleep as it seems to be most of the time now. The flow rate without the GSHP is only about 5 litres/min, but running at a good trickle for sometimes 13 hours a day, this is a good harvest.
The PV seems to be stable at an annual total of about 3,250 kWh but I suspect that the panels are dirty despite my recent attempt to hose them down. The long hot drought has baked a fine coating of atmospheric dust on the roof of the car despite it having a power wash and wax a short while ago, so I guess that the PV panels might have a similar problem. There is possibly a weather explanation as in the same weeks last year, the weather was very sunny, but also cold with the GSHP required to continue heating - so a good PV harvest!
Wow! On the 25th April, the PV roof broke through the 20 kWh barrier for a single day! Highest day of the year.
Meanwhile I need some very heavy night rain followed by a sunny morning, to get more figures like that!
Doh! A bad note is that the Volume read out on the energy meter seems to have gone wrong, but I have a spare volume meter that I will have to read instead. If the energy reading in kWh goes wrong, I shall just have to shell out for a replacement meter without any delay!