I was looking at code books and have come to the conclusion that Architects think that they are God. To think that they actually think they can write code for "Solar Systems"? (International Residential Code article 313 title)

Shane (P.E.)

I don't want to get into a debate over which is worse

I think you've stumbled on some of the current trends that bother me, though.

First, I expect that we're going to face some major code / power quality issues regarding any form of local electrical generation. It's only a matter of time before these various 'pop up' suppliers start making mistakes.

I also distrust the political/religious element involved with alternative energy. There seems a deliberate effort is being made to rush into things, and take the 'market' out of the equation. Energy credits, rebates, LEED certification, etc .... and much of the 'push' seems to originate in the architectural community.

Since these are the same folks who 'eliminated poverty' by giving us the 'housing project,' then went on to invent the 'planned community" where having the right mailbox is more important that having toilets that flush ... I worry.

I think these alternate energy and reverse metering ideas are fine but the utility still needs the same amount of capacity as they always did if they want reliability.
Do we really want to depend on harry homeowner to maintain his "plant" and be as reliable as the PoCo? When you have a cloud going across the city the PoCo will need to come up with a bunch of megawatts immediately, then be ready to drop it offline as soon as the cloud passes. How can that capacity ever pay for itself? The fuel itself is just a fraction of the total electric bill.

I will agree with John { Reno } and Greg {Gfretwell} with their comment on the situation but also one thing I did noticed that most architects did not bother to check the new code section related to the solar system and among other issue as well.

However I know there will be a running change to meet the solar setup.

Greg.,

I am not surpised if there is large number of solar panels and with good one they can work with cloudy day but with cloudy days the capaitcy will be reduced somehow., but to keep the system avabilty you will have to light up the peaking plants to keep the load catch up. but nite time that is complety diffrent story there.

Merci.

In Florida you will still need engineering for the panel mounting. That keeps the amateurs out of the business. They are still evolving how they are going to license solar installers and what kinds of listings you will need. I am not sure how they will handle wind, if that gets going, without immediately making several million agricultural well pumps illegal. The issue is not as much that the equipment survives but that it doesn't become a missile itself when it breaks.

Yeah that true to do the safe manner and to install solar panel is tricky if not done right.



I will treat them just like any fixed wing aircraft ya have to know the lift or reverse lift it will affect the structure.

Unforeteally to my suprise when I deal with few solar panels many Engineers and Architects don't relized about the wind speed it can actally lift or push the panel(s).,

while we are on the same subject here I do not know how they will handle with very high windloads it will really affect it and if something break it can become missle to hit something in the way.

That something the Engineers and Architects have to think about it when they design the panels.

Merci, Marc

And my thoughts were simply how ludicrous it might be to think that code might effect the way our "solar system" operates or that because there is a code section on it, even God may have to go back and do retrofits because of the trash left causing the astroid belt.

I thought after I had posted that I should have put in a smiley face. I just tend to find humor in the oddest places. It feels great to go around with a big smile on my face.

Ahhhh. You got me!

Let's just hope Planet Earth doesn't get 'red tagged' anytime soon

Doesn't "solar systems" imply that there would be more than one?

Certainly there are other systems of stars with planets orbiting around them, but AFAIK there is only one star designated as "Sol", and that's the one closest to us....

Architects and structural engineers *should* all know how to do wind load calculations; they're not terribly difficult calculations, but have tremendous impact on how the structure is designed. (And they apply to virtually every zone in the US.) For commercial, I hope we can assume a competant engineer will design it. If we're just talking strictly residential, then there's really no excuse- even if the trades are unaware, the GC knows. IBC has tables and calculations and dumbs it right down to the lowest common denominator as to what the wind loading forces are. Windows, doors, etc, all have to meet it- solar panels are similar. It's "only" 15-25psf in my area, but in Florida, it can be much much higher.

A little extra flying debris during a hurricane is a small concern, though, compared to all these solar panels back-feeding the utility lines during an outage. It's very easy to buy an inverter and wire it to a breaker and BAM, you're on the grid, shaving electrons on sunny days. But then the power fails... and that solar system is still dumping 120-240V onto those secondaries, and is inherently current limited, so it's not going to stall like a generator would, and it's not going to trip the breaker, so unless the inverter is smart enough to know better, it's just going to keep on pumping electrons until the sun stops shining.

I don't know about solars but my windows had to be 55 PSF plus large object impact protection.

Most of the inverters require input power to function, for safety reasons, I suppose. However, I install a two pole contactor with the coil powered by the normal source. If utility power drops off line, the contactor de-energizes and disconnects the invertor from the grid. I don't like to rely on electronics to keep people safe. There is also the issue of a disconnect at the point where the power enters the structure and labeling indicating multiple sources of power at the panelboard.

I agree with you 100%. I doubt if any electronic switch could be called a "disconnect". I sure wouldn't trust it.

i thought we had art 690 for this...?

~S~

Isn't the inverter in parallel with the utility, though? It seems as though the contactor would be self-sustanining, with the inverter powering its own coils even if utility power is lost. You couldn't even use directional CTs, as loss of utility power would be indistinguishible from selling power back to the grid.

Does this method rely on the impedance of backfeeding the grid to be so low that internal resistance depowers the coils below the sustainment threshold?

There are different causes for loss of utility power. At one extreme your service drop is knocked down by a tree. Your inverter or generator could keep those wires hot without any significant current drawn. Someone picking it up could die.

If there is no damage in your area/town but the upstream transmission grid is what is out, you should see about the impedance of your nearest utility transformer. Unless we are talking about a solar/wind farm, it is likely all the other customers are going to overload the system. Current going too high and/or voltage going too low should ideally trip the disconnect.

Now you can monitor the utility for power restoration. But there is a new risk: someone else's power system could make it look like the utility is back.

NJwirenut, There's also Sol Rosenberg. He thinks the world revolves around him too....

I'm sure I've been an electrician for my entire working life; but when I read 'solar system' I thought - 'who can get out there to check outside of Earth?' and 'well, at least the rest of the Galaxy, and the Universe, have been left alone for now.' - photovoltaic arrays didn't even enter my mind.

Frenchy I'm figuring the 'fly apart' concerns regarding Florida wind generation would pertain to hurricane safety.

I think designing a wind generator for 150 MPH winds is within the technology but wind borne debris is another problem. I would have the same concerns anywhere that has tornadoes, even the little "dust devils" some east coast folks call tornadoes. (compared to the mid west monsters)