Carter’s solar system
In June 1979, President Jimmy Carter made a bold statement about renewable energy by installing 32 solar thermal panels on the roof of the White House. This event was not just a practical move to heat water for the White…
New modules – testing
The initial board tests yielded promising results, with only a minor issue identified relating to tracing to an ESD protection diode array. Despite this hiccup, I’m quite satisfied with the progress so far… yet, as always, there’s room for enhancement.…
New modules
The system we developed is modular, with modules connected 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 this needed…
New installation
The testing that we did earlier paid off. We had a nicely working prototype with a couple of collectors. That wasn’t enough, so we built a 10-collector array on some welded scaffolding. Our problem is that we have a historic,…
First truly global energy crisis
Tightening markets for liquefied natural gas (LNG) worldwide and major oil producers cutting supply have put the world in the middle of “the first truly global energy crisis” Dr Fatih Birol, Executive Director of the International Energy Agency (IEA) said…
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…
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…
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…
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…
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…