New modules

The system we developed is modular, with modules connected together on a 2-wire data bus, with an additional 2 wires for power. Up until now, we have generally used premade pcbs connected to our own boards for this. But really this needs to change into a more professional solution. And Read more…

New test system

After running a test rig with two collectors for several months (on a scaffold tower next to the office!), we’re building a ten-collector system in a more permanent location. This one will have a more appropriate inclination for winter of about 60 degrees. We’re very pleased with the performance so Read more…

Differential controller

Our three channel differential controller prioritises heating of domestic hot water from the lowest cost source and conserves heat in the domestic hot water tank when the input medium temperature is too low. Inputs: – Solar accumulation tank. – Solid fuel boiler (such as wood gasification). – Electric resistive heater Read more…

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…