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Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
6/20/23 2:07 p.m.

In reply to GIRTHQUAKE :

In order to connect my array to the grid, I had to give the capacity. The utility needs this information to ensure my local grid isn't going to get overloaded - apparently the number of solar installs in my neighborhood is getting high enough that some of the transformers are going to need updating. Even a DIY builder is going to have to do this, so the utility definitely knows the capacity of any grid-tied array. They just don't have any control over what will be installed, although there is a "110% of annual useage" limit that kicks in and affects...something. I don't know because ours is at that 110% number :)

The utilities can predict solar output reasonably well by using the weather. If they know there's X kW of solar out there and it's sunny, they'll get X kW of generation. If it's going to be cloudy today, it'll be more like 0.5X. If it snowed yesterday and it's cold out, 0.01X. Partly cloudy days are probably a hassle as the solar comes and goes. There's been a bunch of machine learning thrown at this if I understand.

The duck curve, though, that's a real thing. That refers to the dip in demand for utility power during the day and then the tapering of solar just as the evening peak hits That's where utility-scale batteries come in handy, to time-shift the afternoon production to evening delivery. There are also ways to encourage behavioral shifts with time-of-day metering - encourage people to shut off air conditioners for a few hours when it's expensive, for example, or set their EVs to start charging at midnight instead of when they get home from work.

Sucked 124 kWh off the roof yesterday. Dunno what the FM shop pulled down, but it's a smaller array so probably about 90. Put me in the "I like what you're doing here, Israel" camp.

thatsnowinnebago
thatsnowinnebago GRM+ Memberand UberDork
6/20/23 4:47 p.m.

I do GIS work for a utility and have seen/used data showing solar generation potential for different buildings. I went looking for something I can share and found this tool from Google: Project Sunroof that appears to use the same data I was looking for. Kinda neat to play with. 

Kreb (Forum Supporter)
Kreb (Forum Supporter) GRM+ Memberand PowerDork
6/20/23 6:15 p.m.

Seems like a no-brainer to put up solar panels in places like Israel and Phoenix. Some asshat power companies find ways to push back and disincentivize, but I suspect Israel's government is smarter than that.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
6/20/23 7:42 p.m.
thatsnowinnebago said:

I do GIS work for a utility and have seen/used data showing solar generation potential for different buildings. I went looking for something I can share and found this tool from Google: Project Sunroof that appears to use the same data I was looking for. Kinda neat to play with. 

That's cool. Hasn't reached my address yet, but I'll keep an eye on it. I have found it very interesting to see how the various houses around me have chosen to mount panels. 

Folgers
Folgers Reader
6/20/23 8:56 p.m.

One thing people forget about, when comparing the USA to other countries, is scale. 
 

Israel has somewhere around three million fewer people than the state of Illinois. California has a million more people than the entirety of Canada. 
 

What works well for 9ish million people, may not work for 332ish million people. I'm always cautious when people start saying we should just do it like so and so. 

DrMikeCSI
DrMikeCSI Reader
6/21/23 5:24 a.m.

I went to a presentation on solar a few years ago, it was at Honda of Cleveland Heights. They had installed a solar roof over the car lots. They said on of the benefits was they didn't need to spend as much time cleaning snow from the cars in winter. The presenter also said that Walmart is one of the largest owners of rooftop solar in the USA.

SV reX
SV reX MegaDork
6/21/23 6:09 a.m.

In reply to DrMikeCSI :

That's confuses me. The snow has to go SOMEWHERE.  The snow load on top of the panels makes the structure very significant (and therefore expensive).  When the snow is sitting on the panels they generate zero power, and when the show slides off the panels it lands in piles at the base (which impede the parking) which turn into ice piles as the water continues to drip off the panels.  Those ice piles would be hard to remove, and plows would have to work around the structure's support columns. 
 

What am I missing?

alfadriver
alfadriver MegaDork
6/21/23 8:34 a.m.

In reply to SV reX :

Not on the cars, at least.  Off the side and piles someplace else.  Much like a carport.

alfadriver
alfadriver MegaDork
6/21/23 8:35 a.m.
Folgers said:

One thing people forget about, when comparing the USA to other countries, is scale. 
 

Israel has somewhere around three million fewer people than the state of Illinois. California has a million more people than the entirety of Canada. 
 

What works well for 9ish million people, may not work for 332ish million people. I'm always cautious when people start saying we should just do it like so and so. 

That's why going the opposite direction may be helpful- microgrids.  Not everyplace can deal with solar, and some places are really good with it.  Even better, they already have a poor power system that needs rebuilt.

Ian F (Forum Supporter)
Ian F (Forum Supporter) MegaDork
6/21/23 8:52 a.m.

Israel could be doing this for economic reasons. 

While they have meager oil reserves (95th ranking of producers) they are more than self-sufficient in natural gas production and export the excess.  Reducing domestic usage could allow them to export more, which should be quite profitable on the current European market. 

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