EEVblog #632 - Solar Roadways Are BULLSHIT!

[jippie]

Based on the datasheets for the microinverters, I am surmising that the panels operate at 24VDC, since the lowest input voltage is 16VDC. 

Haven't been following this thread really, so bear with me if someone already noticed this.

There are 16 square cells in the top half, 16 square cells in the lower half and 16 half size solar cells in the middle. I'm no solar cell expert, but I'd expect three parallel strings (square || square || half-sized) as I wouldn't expect strings of mixed sizes. That would mean 16 × 0.6V = 9.6V per panel. Which in turn is a bit odd unless several panels are connected in series, but it would explain the lower current rating.

Afterthought: 5 inverters, 30 panels => 6 panels per string => 6 × 9.6V = 57.6V which is close to the maximum input rating of the converters if I recall correctly from the other post.

[StillTrying]

I wonder when they will finally give up.

When the money finally runs out, by which time, if they are smart enough to have created a highly favourable business plan, they will personally be rich enough just to retire to Florida and lie on the beach in the sun (a solar fricking breach!!)   

And be well known as very clever entrepreneurs and inventors, with patents to their name and everything!
I don't know why people in the real world bother.

[LabSpokane]

Based on the datasheets for the microinverters, I am surmising that the panels operate at 24VDC, since the lowest input voltage is 16VDC. 

Haven't been following this thread really, so bear with me if someone already noticed this.

There are 16 square cells in the top half, 16 square cells in the lower half and 16 half size solar cells in the middle. I'm no solar cell expert, but I'd expect three parallel strings (square || square || half-sized) as I wouldn't expect strings of mixed sizes. That would mean 16 × 0.6V = 9.6V per panel. Which in turn is a bit odd unless several panels are connected in series, but it would explain the lower current rating.

Afterthought: 5 inverters, 30 panels => 6 panels per string => 6 × 9.6V = 57.6V which is close to the maximum input rating of the converters if I recall correctly from the other post.

Good eye and good post! For the current ratings I've been posting about recently, I've been referring to the power output to the heaters. As for the operating voltage and current rating of the solar side, I just don't know what SR is doing there. Scott Brusaw was not present during my visits and he was the only knowledgeable person as to the design. At this point, I doubt SR is willing to share any information - at least not voluntarily.

[ludzinc]

And finally, the media have turned:

http://dailycaller.com/2017/03/07/americas-first-solar-roadway-is-a-total-disaster/

[Brumby]

And finally, the media have turned:

http://dailycaller.com/2017/03/07/americas-first-solar-roadway-is-a-total-disaster/

It will be interesting to see if this propagates through the media - or fades into obscurity.

[AndyC_772]

Tough call, IMHO.

Ordinarily, the press wouldn't have any hesitation in latching on to a negative story, taking every possible opportunity to tear apart the people involved with it, and bemoaning any taxpayers' cash that was wasted on it.

On the other hand, they also can't resist the temptation to report positively on anything that's marketed as "green".

Can't help but think of this...

[wikktor]

And finally, the media have turned:

http://dailycaller.com/2017/03/07/americas-first-solar-roadway-is-a-total-disaster/

And if you check comments - It is amazing that there are still people who are believing in this project: "It was a first prototype which naturally had a number of design flaws and engineering problems".

[mtdoc]

And finally, the media have turned:

http://dailycaller.com/2017/03/07/americas-first-solar-roadway-is-a-total-disaster/

It will be interesting to see if this propagates through the media - or fades into obscurity.

The unfortunate thing is that the message many will take away from this boondoggle is that solar PV itself is not viable - providing abundant confirmation bias for those of that mindset.  The media was complicit in hyping this scam and because of political nonsense, I fear it will now be used by sites like The Daily Caller to rally their faithful against solar PV - ignoring the engineering failures here.

[Brumby]

The unfortunate thing is that the message many will take away from this boondoggle is that solar PV itself is not viable - providing abundant confirmation bias for those of that mindset.

I don't think that is even possible - unless you have tunnel visioned bigots in mind.  **

Solar PV is out there and working extremely well in tens of thousands of installations across the world.  The only real issue is storage of energy - but that is an issue for wind and wave as well.


** But, wait.... we are talking about the media, aren't we?  Hmmm...

[rollatorwieltje]

This actually works, there is video evidence on the internet:



 

[SpaceCow]

It will be interesting to see how this is portrayed in the media. In the US, there tends to be a "black and white" approach environmentally friendly stuff. You are either for it or against it. I suspect that the Republican side will gobble this up once they find it, as they are entirely anti-solar. It will be interesting how those anti-environmentalists will probably use this story to argue against solar power as a whole, completely different to what Dave is saying here.  On the other hand, the liberal  environmentalists in the US will likely miss the real message: "PUT THEM ON THE ROOF" and take it as an all out assault on "being green."

What Dave is doing will be misinterpreted in the US, because we prefer to start from a belief and search for evidence to back it up while Dave tries to figure out what is objectively true.

[ataradov]

It has been 12 days since the panels went dark. It is safe to say, they will miss their 7-10 days deadline

[Domagoj T]

And 11 days since I wrote to Sandpoint City Administrator regarding fire, power generation and power consumption.
Still no answer.

[bitwelder]

And 11 days since I wrote to Sandpoint City Administrator regarding fire, power generation and power consumption.
Still no answer.

Their mail system was clearly running on Solar Roadways produced energy! 

[LabSpokane]

It has been 12 days since the panels went dark. It is safe to say, they will miss their 7-10 days deadline

Where Spokane Roadways is going, there are no freaking deadlines.

[ludzinc]

Took a look - panels are showing animations again.

Any one get pics of the repair efforts?

[jahonen]

It looks like they reduced the number of leds on simultaneously presumably to reduce the power consumption and heating.

Regards,
Janne

[LabSpokane]

Ampacity matters.  So does the size of your conduit.   

If anyone from the City of Sandpoint is still reading this thread:  how on earth can you allow this to go on?  The fire was a clear, unambiguous sign that the electrical engineering behind all this is beyond questionable.  Any decent, licensed electrician would have spotted this back in October. 

[RGB255_0_0]

Broken again

[FrankBuss]

  this must be embarrassing for them.

[djos]

Oh Dear! 


 

[ludzinc]

Interesting that they are covering the panels with a board (what the guy is kneeling on).

Is that to make it easier on his knees, or to protect the glass surface, you know, the one they want to drive cars on?

[Brumby]

Spot the difference...

[moz]

Is that to make it easier on his knees, or to protect the glass surface, you know, the one they want to drive cars on?

There's someone standing next to him on a different panel, so I'm guessing that kneeling on icy glass is no fun.

[LabSpokane]

Is that to make it easier on his knees, or to protect the glass surface, you know, the one they want to drive cars on?

There's someone standing next to him on a different panel, so I'm guessing that kneeling on icy glass is no fun.

No ice in Sandpoint.  It may drop to freezing at night, but the spring melt is in full swing. 

The system is back on tonight.