Because I haven't got enough half finished projects to apply to my minimal motivation, I have started another one. A hydrogen Generator.
Was touched on in a discussion earlier but I have put it into practice. I made a small scale one and tested the gas a bit and as pure Hydrogen, it's not much different to LPG. The browns/ HOHOHO gas is completely different and in my mind dangerous but I am only using the Hydrogen with this and the Oxy is going off to enhance the atmosphere.
ATM I have an over supply of Solar power on my main array and have to apply a Dump load to avoid over voltage.Tthought it was mainly due to trying to pump too much power down the wiring but that didn't quite add up as it went voltage high well under what the cable is rated at and what I pulled through it with no unusul voltage drop.
In reading up on this I'm finding it's quite a widespread problem due to the lazy arse power Co's not maintaining their equipment right and having a very wide variation on power standards. Although the standard is 230, up to 253 at the point of use is acceptable yet the standards now limit inverters to 255.
Good way to stop people being too self sufficient and not paying enough to the power co's.
Instead of sinking this power into boiling water just for the hell of it, I want to turn it into Hydrogen and store it potentially to use on a stove at night.
Efficiency is not that important because anything I get is better than the 100% loss I have right now.
My gas generator seems a bit unique. Not seen anything like it on the net. I got a 240L plastic blue drum and cut the top off. Got a 110L dum and cut the bottom off. Fitted a Ball valve in the top and sealed it absolutely air/ gastight. Seems way bigger than anything else I have seen on the net.
On the outside of the small floating Drum I put a steel plate about 20x30Cm. This is the Anode that generates the oxygen that is released.
On the inside of the drum I put a same size plate as the cathode to generate the Hydrogen.
Put about 100L of water in the big drum and mixed in maybe 300G of KOH. Opened the valve in the top, sank the drum about 60% Depth. Didn't add more water because I can't find my bag of KOH again so I didn't want to dilute the water too much.
Connected the contraption to the 2 broken panels on the roof which still work fine and it made gas. And that's where the questions start.
It's not making near the gas I -expected- but I don't know if my expectations are realistic. Don't know how much gas, not sure, rough guess, 10 L day. Maybe less, no real way to measure.
Observations:
The 2 panels were feeding in around 19V -22V @ 4 XX amps. General measurement was 130W
I hooked up the 3 Kw array which was open circuit 340V. That fell all the way to about 30V and gave about 200W over all. The voltage/ power drop really surprised me because in the inverter it was producing about 900W at the time. Yeah I know about the lower voltage and all that but 300 odd to 30?
Maybe the electrolyte does need thinning to let the Voltage come up and the panels get more on their curve.
Today I got a 30A 3 Phase rectifier and hooked that up to a pwm. Then things really got confusing.
AC going in was 250V. DC coming out open circuit was around 300.... which didn't seem to add up. Thought meter was on the Fritz but 2 More meters read the same. Put that down to no cap and the pulsing in the output.
Connected to the electroliser and again Voltage plummeted to around 15V DC. My Meter was reading 16A @ 247V on the AC side ( which it sure as hell wasn't pulling) but only 336W dc which again didn't make sense. Pretty sure the amps were right, the wire on the DC side was smoking hot after a few min and the unsunk rectifier was getting well up on temp too. The AC voltage on the Rectifier after the PWM was down to 19-20V which again didn't make sense. When I took the load off, was back to 250.
Now some questions that I would think were basic but I can't find answers too.....
In production, what matters, the surface area of the plates or the amps you pump through the thing? My surface are isn't huge but I am getting the amps in there so would more plates do anything but make the " Resistance" larger?
Adding KOH will also increase the amount of amps that can be pumped in but do I need surface area for the gas to form on or is it reliant on the energy input?
Do I need equal plate area? If I put one plate on the oxy side and 10 on the hydrogen side, is it the same as If I had one on both sides or will more plates make more hydrogen gas?
I measured the output of the 2 Panels and got a bit over 6A. I measured the amps when connected to the plates and got 4.7 so I concluded the electrolyte and plate area is reasonable. I could increase the plate area x 3 with no problem if it's going to make a difference.
I wasn't very impressed by rectifying the AC, thought I'd have a boiling cauldron but the bubbles I'm seeing on the oxy side are pretty Piddling. I did wind the power up to a KW but still nothing to write home about and nothing like the boiling I'm seeing on some YT vids but then I see they are pumping 5Kw into their generators to get that. Ideally, I want to be able to dump about 750W. Not sure if putting a cap across the DC will help With the output.
Do I need Polarized caps for that or will normal motor Run caps suffice?
Tomorrow I was thinking to get a DPDT and wire it so normally the power is going straight to the inverter. When the Voltage monitor is engaged, One array will send the DC to the gas generator so the power drops but is put to use.
I -could- be doing better than I thought. Before I have bubbled the gas into water to get a visual indication of production. This time I'm just catching it in a floating drum in a bigger drum. Maybe I need to weight the floating drum down and connect a tube and bubble the hydrogen in water and get an idea that way?
I left the gas machine on a battery charger tonight and it was measuring 36W on the AC side so I'll see how much gas I have tomorrow.
Atm, I can't see this generating enough gas to cook a meal at night even if it is fed 5-700W for a number of hours. Maybe I need a lot more plates or electrolyte but I'm thinking what matters is the amps more than anything. Is this right or am I missing something?
Perhaps my excess power would be better heating an element to keep a Bio/ Gobar gas drum up to temp and I'd get more usable Fuel that way?