Yeah now I’ve done it




And now, some fairly dank memes:


And now, back to cats and electronics as usual.



Yeah now I’ve done it
And now, some fairly dank memes:
And now, back to cats and electronics as usual.
This is definitely a handyman’s truck….
So, uh, the way you usually do this is run the strings between adjacent panels side to side so you can dress the leads to the racking.
Someone thought they were being so clever here, but those wires are just gonna blow around and fatigue. Beehhhh.
“Sungrow” grid tie inverter. Hardly impressive like an SMA Sunny Boy. Feh.
A common mistake I see some people make when designing a solar energy system is that they will parallel the outputs of the solar panels without using a combiner box that has fuses or breakers.
This works fine in the “yeah, the lights come on” sense, but if you should ever have a fault in one of the modules, you may very well experience a fire at the module that will spread to any other flammable materials nearby….. yes, that means your ROOF.
Note that while the solar panel’s encapsulant and backsheet self-extinguish and only exhibit a couple millimeters of flame spread, the sheet of paper I taped to it to simulate the flammable debris that *will* gather around your panels does not! 🙂
Flammable crap you will typically find around and on your panels includes oily soot from smoke/automobile exhaust, dried leaves, paper, bird nests… anything the wind or animals can bring in!
This is the Morningstar Sunsaver MPPT charge controller, capable of pumping 15 amps into a 12 or 24 volt battery system from an up to 75V input. It’s fairly simple, though the 6P6C jack can be used for Morningstar’s Modbus system or Remote Meter to add more control, programming, and monitoring capabilities. The unit is driven by a Microchip PIC18???* microcontroller.
A typical MPPT controller consists of a switching buck or buck-boost converter with the input connected to the solar panel array, and the output connected to the battery system. A microcontroller monitors the solar array voltage and current (and multiplies them to calculate the power) periodically, and adjusts the switching of the converter appropriately to keep the input side voltage at the solar array’s maximum power point, Vmp.
Inside the Morningstar Sunsaver MPPT, there is… a switching buck converter with a micro… etc. Here you go:
* The conformal coating stuck to the top of the chip made it difficult to read. Like the flavor of PIC matters? XD
No fans or other active cooling are needed. The inductor is thermally coupled to the back of the housing, which is a tall metal fin attached to the heatsink/base. The switching transistors are, undoubtedly, potted somewhere in there. The potted construction is also used on the SunSaver PWM controllers.
Simple, elegant, but here’s the big question: WHY does it cost $250?! Rest assured, I’m scouring the market for some *good* low cost MPPT controllers. This is just a very good and not quite as low cost controller!
Warning: Engineering porn ahead. All images are clickable to view in full resolution.
The Outback Power FM80 solar charge controller is a high performance MPPT controller which converts a solar array’s output (up to 150VDC, 64 amps) down to charge a 12, 24, 36, 48, or 60 volt DC battery string using a high efficiency switching buck converter and an extremely flexible microprocessor control system. It is field programmable from the front panel and can be linked to other system components using Outback’s communication buss and the MATE controllers for system logging and remote control.
It is extremely well built, and solid as a rock.
More photos below…
The designer of the IndoorGenerator power units just dropped by here at Sun a few minutes ago. Their products are really interesting, especially for those of us down here in the Hurricane Belt.
Their product is, in a sense, like a giant UPS. Sealed maintenance-free lead-acid batteries are paired to a power inverter/charger unit in a nice cabinet. It’s also possible to get a unit from them which features a solar charge controller, and an outdoor rack to pair a couple of nice big solar panels to the system for off-grid operation!
Now, you see where I said “nice cabinet”? I mean it. Go look at their page for the PowerCubes – they look like a piece of fine furniture. You could use one as a nice end table or coffee table.
They also make some less aesthetically fancy but very functional UPS systems for commercial and office use. He was talking about using Outback Power inverter/charger units inside some of his systems, and those would be awesome for such use – they produce very clean power and transfer back and forth perfectly.
For those of you urban cliff dwellers, they also have a very nice looking balcony unit that unintrusively sits out there and can be wired to solar panels.
He’s going to bring over one of their standard series units in a couple of weeks for us to play with. I look forward to putting it through its paces and brewing a pot of coffee or two…
Modified Sine Wave HORROR! This is what I got off an inverter with a bad output filter. I believe this is proof of why you should invest in a true sine wave inverter if you’re running anything other than lighting and a refrigerator (note: a refrigerator with electromechanical controls — not an electronic control system.)
No, the scope isn’t lying here… see the last pic…
I almost missed this because I had a resistive load on the inverter. Apply a resistive load and it looks like this. Apply an inductive load and it still has those ugly spikes.
They really are that bad.
Set to trigger on the very start of one of those negative pulses. What you’re looking at is essentially a DC offset of -170vdc… with THAT on top of it. YES, THAT IS 200 VOLTS/DIV. HOLY ASS, BATMAN.
How to interpret solar panel specifications and use them to choose the proper panels for your application.
On a solar panel, module, cell, or laminate, there are a number of different specifications given. Here’s what you will find, and how to interpret it.
Here are some sample specs I, uh… stole for purposes of illustration. These are for a Canadian Solar CS6P-190-PE.
Power (W): 190 Watts
Open Circuit Voltage (V): 36.00 Voc
Short Circuit Current (A): 7.42 Isc
Maximum Power Voltage (V): 28.60 Vmp
Maximum Power Current (A): 6.64 Imp