Digital sensors

We’re using external temperature sensors, always insulated from the outside. The Analog Devices / Maxim / Dallas Semiconductor DS18B20 is perfect for this, but the problem is that most ‘DS18B20’ sensors on the market are fakes; clones marked as the real thing. These work well for the most part, but Read more…

Insulated tank

We finally insulated the 1000-litre tank this morning with 100mm mineral wool plus a tarpaulin cover. Before this, the tank was un-insulated, which benefited us as it cooled overnight and allowed us to perform repetitive tests. It will be interesting to see how well the tank performs, and heat accumulates. Read more…

Stagnation testing

We ran the rest rig today, 18/08/2022, without the pump. The panel was dry. The panel temperature reached 92.88C. The ambient temperature at that time was 28.81C. So it’s possible to have the panel innards 64C hotter than the surrounding air, even in central Europe.

Inclination

Today, 03 August 2022, we finally adjusted the panels of the test array to 35° inclination. The morning was clear and fairly bright; a hot day with air temperatures in the region of 30°C. And we easily reached our target of over 700 watts per square metre output. In fact, Read more…

Test array

Up until today (02 August 2022), our test array was inclined at nearly 80° from horizontal. That gave degraded performance. We set it this morning to 55° and saw a large difference. You can see this in the graphs. We’ll set it to about 35° in the next few days. Read more…