Puts too much power in the hands of the customer to control and manage their fate. Utility company can’t have that!
Everyone would love to bust the 25% limit on PV panels. The cost-per-watt curve bends up steeply there. NASA can live on the other side of that curve, but I can’t afford to.
Perovskite panels (currently) require Fresnel lenses to work properly, and then they collect more than 30% of the energy for a given area. That’s a big improvement but it doubles the cost of the panel (or more, I think).
ok, but even the subcontractors were unaware of these additional requirements. I believe it is just an evolving process and the utilities are minimizing expenses and making “system” improvements to streamline operations.
aok, i did not know. makes sense too.
I finally have a date: Next Thursday!
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It happened!
I contracted Skyfire Energy to do the project. They have a long successful track record in Alberta (and beyond). Watching them grow over the years and meeting the founder a long time ago gave me confidence in them. Pictured below is Caleb the technician who led the installation team. Three people were on the team on Day 1, two on Day 2 of the installation. They worked methodically both days and got it almost done. There wasn’t enough sunlight at the end of Day 2 to complete the system testing. Here at 51 degrees latitude North, the sun sets at 4 pm.
They’ll be back to finish the system next week, and supposedly the county inspector will come soon after, thus completing the permit and official Power ON will be mid-November, thereabouts.
The battery isn’t connected yet. That’s my own project. Thus the wind turbine is still independent of the grid-tied system.
Very cool!
Congratulations SparWeb.
The time elapsed photos/video is so cool. sunrise, shadows moving, sunset, watching wind generator, and watching the clouds slide on by . . . very good! wish i had one.
straightforward installation!
congratulations on completing the installation. please let us know the results of the PV operation.
Thank you!
Thanks, everyone.
Tentative switch ON date is 22 November.
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I wish I could be there.
I’m to retired to have the money or the energy for a project like that, but I enjoy watching your project develop.
Thanks for sharing.
Well, it’s not switched ON yet.
The inspector’s been and gone, left a sticker on the panel so that’s done OK.
The problem now is that the “remote shut-down” can’t get good data from the Sol-Ark. Some finger pointing going on between the installation company and the manufacturers of the equipment.
I haven’t been impressed by the implementation of remote shut-down equipment I’ve seen, though I don’t deny the safety aspects of the system. Having to make various components from different manufacturers talk to each other and use sensors to detect the fault just begs for integration problems. There doesn’t seem to be a standard to implement this, so different inverters need different RSD’s to work. That would be fine if the inverter manufacturers made RSD’s suitable for their equipment, but it seems they don’t.
A VERY common problem. It’s got me a time or three in the past. Good luck with it, but most importantly, hold payment until they fix their problem!
Do you NEED remote shutdown capability? Or is it really just “nice to have”?
edit: does the system work ok otherwise?
Legal necessity, and for safety.
Without RSD, the only system shut-down point is the inverter. This leaves the DC wires from the panels to the inverter live. These wires can carry over 500V in extreme cases, and 400V+ is common. Mine will be 300VDC. So, how do you work on the system if those wires are live all the time (daytime)? Only work at night? Sure you can shut the inverter off, which makes the AC side inert, but the DC wires only shut off if the panels are not illuminated. Got a 30-foot square blanket? How does an electrician work on the system?
It’s a practical issue and a safety issue for both electricians and firemen.
Why does the shut-down have to be “remote”?
Can you not use a simple disconnect switch?
I realize that interrupting any current at 500 Volts may be a challenge.
That said, I once encountered an issue where an inductive arc started an arc across relay contacts.
The arc was only an Amp or so, but that was enough to sustain the arcs and the arcs eventually melted the silver alloy relay contacts which then flowed together and completed the circuit, and cooled off leaving small silver alloy hour-glasses where the contacts had been.
As I remember, the relay was double break and rated at 600 VAC.
Two poles were in series for an expected AC breaking capability of 1200 Volts.
Once the inductive kick lit up four little arcs, there was no zero crossing to extinguish the arcs.
I haven’t up-dated my copy of the Canadian Code for 9 years
While the 2015 code requires a disconnect in the DC circuit, I see no mention of “Remote”.
Is this a change in the CEC or is this required by a code other than the CEC?
Here is a manual disconnect from Amazon:
Solar Disconnect Switch, DC Isolator Solar Switch PV Solar Disconnect Switch Overvoltage IP65 Waterproof Miniature Circuit Breaker 63A 1000V. $28.74
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Yes, I believe it’s just a remote-controlled switch. Don’t know why they do it the way they do it, though. Yes that’s the danger with high voltage DC and I believe exactly that kind of problem confronting workers who encounter these systems.
I honestly don’t know the whole logic “tree” of AND and OR conditions to be satisfied for the RSD to allow/disallow current to flow in the drop wires. What is pretty obvious is that any interruption to the service AC causes the inverter to stop energizing its feed to/from the grid, and that also sets a condition that signals the RSD to disconnect, too. However, it’s not just as simple as that - there also seems to be a current sensor or something that signals 5mA, the part they’re waiting for.
Here’s a single-line diagram to help show the overall system (but omits the current sensors):
The red-label beside the service main disconnect might give the impression something special is going on there, but it’s the same old meter, breaker and busbars. That seems to be enough for it to be acceptable as an “initiating” device to the RSD and the code
Yes I believe this is fairly new in the code.
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I am wondering, first, can your solar panels be shorted without being damaged?
Second, could the system be safed by shorting the leads at the panels?
Thinking back many yeas ago when I worked in the City of Vancouver Street Light Department.
In the older parts of town series strings of street lights were common.
The current was controlled by a constant current transformer.
These were moving coil transformers, not saturable transformers.
On long circuit the transformer terminal voltage reached several thousands of Volts.
An open circuit would drive the voltage even higher.
THe circuits were safed by shorting.
No fuses whatsoever.
The lamps were bridged by small buttons that would short out at around 90 Volts in the event that a lamp failed.
The transformers were protected by shorting buttons that would hold the working voltage but would short out on open circuit voltage.
The advantage of shorting is that the current does not have to be interrupted, just diverted through the shorting switch.
Just a thought for discussion.
Yes, I’m sure an individual panel can be shorted.
However, shorting a string of PV panels is not so simple. A single panel might have 60 volts and some rare designs can be over 100 VDC. Several panels in series multiplies the DC voltage. Shorting them requires some care. The arc can be sustained if the short is not opened quickly and/or blocked.
