|Standing under this, the light from the|
mirror is blinding, but the camera light
meter flattens out the glare.
Today was sunny in the morning although with cold temperatures. Air temperature was 11-12º rose to a maximum of 18º during the day. Surface temperature rose briefly to 28º maximum when the sun shone brightest at about 11 am.
The Sunboxes were working well, and maintaining an air temperature internally of 38º, a full 20 degs higher than the ambient air, and note that the air temperature is being chilled by glycol all the time. If I turned the pump off the temperature would rise above 40º
The heat pump was sleeping (house warm and no hot water required) so the glycol was circulating.... it was coming UP from the deep borehole at 13.2ºC, rising to the Sunboxes and returning DOWN at 18.2ºC. - gaining 5 deg C on its 5 litres/min trickle around, and losing that 5 degs in the soil 48 metres down.
Due to the air temperature continuing chilly, the heating was on, and during the 24 hours, the 6 kW heatpump burnt a total of 4.04 kWh.
The Sunbox pump ran for 8.6 hours and collected 15.03 kWh (on a day when 30 sqm of PV roof panels collected only 7.50 kWh).
For the doubters, that is an Average of 1.75 kW per hour!
(only a datalogger could tell me what the Peak performance was....)
I am so convinced by the mirrors that I will add foot mirrors next March (to celebrate the Equinox). I am providing mirrors to the new Sunbox in East Leake. I bought the aluminium for that on Monday, and yesterday, I found an equivalent amount of the same thickness of shiny aluminium in a skip right outside my building at the University. It is amazing what people will throw away!