Recent content by MyK3y

You guys are still confused. Panels in series wired directly to nichrome wire coil in a circuit. That's it. No other elements involved. I found a bunch of SSRs, so I will wire in a breaker just for safety. So, further developments: Just picked up aluminium tubing - 10M @ 50mm x 2mm - and...

Have you looked at optical isolators? It’s what I use on things like CNC plasma cutters where stray amps can easily fry delicate electronics They can also step-down, should you need it to.

The music wasn’t the only terrible thing about that video

There seems to be a disconnect, somewhere. While the panels aren’t operating at peak power, they are still generating electricity and that electricity is still at 64V and still heating the element and that heat is still being stored in the sand. MPPT? It’s a panel directly wired to a...

I’m confused as to where melting sand, 240V, and conductivity came into play - it’s a fixed 64V and the sand has infinite resistance at 64V. The object of the exercise is to convert every watt of electricity to heat and store that heat for use in warning air. The panels vary in output as the...

I'm leaving so much power on the table. Without a controller, I want to use the maximum my panels can deliver - so as close to 80% of 10.8A (I think - without referring to the brochure). The element I have is drawing about an amp and a half. The answer to the question of what wattage I want...

What's a BTU?

Yesterday was reasonably productive. I wired up the panels in series and to the element and in free air it hit over 100C in short order. Buried it in around 15kg of sand and left it for the rest of the day and it got to over 200C And, I worked out that if I want efficiency at 60V, 240V...

That was my original idea. Hence the 'I will make one today' comment. I'm becoming impatient with the men from Aliexpress... where are my thermocouples???

The TCR for nichrome, for example, is 0.000112 ohm at 300C compared to 20C which seems to be the baseline temperature they use for measurements. Negligible.

I found something the other day where a guy used a rocket-type stove to heat sand for energy and I forgot to bookmark it for you. I'll see if I can find it in my history. And, I had a think - projects like the Finnish one use heat circulating through pipes in the sand to add energy and...

Yeah, It was the end of a long day and I was working out with a basic calculator - will spreadsheet it today and come back with something more sensible. I was off on the panel voltage by a bunchanumbers, too. 34Vx2 is a long way from 96V... dunno where I got that from - I was planning 3x panel...

No, they're not. 600C is easily achievable with basic domestic stove elements. 1600C is achievable with more advanced elements, such as industrial kiln elements. Thus, an additional 1000C of storage as a hypothetical to show the potential. But, 600C is perfectly adequate for my needs and...

To further expand on the above - while plagiarising the Finns: On a domestic scale, in a sunny, temperate country, with high winter solar kWh/m2, using high-efficiency (>20%) panels, feeding a well-insulated sand battery, price/performance is superior to water. In my case I have completed my...

You are ignoring that sand-based heat storages can store many times the amount of energy that can be stored in a water tank of a similar size or, put another way, you need 2000x the mass of water to store the same amount of energy as you can at moderate (1/3 the maximum...