California Now Has More Than 150,000 Solar Roofs

[jpak]

http://www.kcet.org/news/rewire/solar/photovoltaic-pv/california-now-has-more-than-150000-solar-roofs.html

And that number keeps climbing. According to the California Solar Statistics website, the number of California roofs generating power from the sun reached 150,428 as of Wednesday, with a total generating capacity of 1,560 megawatts -- about equivalent to three typical coal-fired power plants.

Los Angeles County now leads the state in the amount of rooftop generating capacity, with 171.4 megawatts of rooftop solar installed. San Diego and Santa Clara counties come in second and third, at 141 and 110 megawatts respectively.

San Jose leads California cities in total rooftop solar capacity, at 59.4 megawatts, a 21-megawatt jump since summer 2012.

The stats are compiled from data on rooftop solar arrays hooked up to the electrical grid through Pacific Gas & Electric (PG&E), Southern California Edison (SCE), and arrays outside those utilities' service areas financed by the California Center for Sustainable Energy and GRID Alternatives. That means that rooftop solar in areas served by other utilities such as the Los Angeles Department of Water and Power or the Imperial Irrigation District may not even be included in these totals.

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[FBaggins]

1. Picking a more attractive target doesn't make the claim more honest.

1.6 GW of solar capacity is not "equivalent" to three typical coal plants. Even in SoCal, it will produce only a small fraction of the total power that they will create.

There are plenty of advantages to tout for this success without stretching the truth.

[railsback]

2. According to the US EPA E-Grid

the average coal-fired power plant produces 600 MWs, so the statement is relatively true.

[FBaggins]

5. That wasn't where the error was.

Label capacity simply isn't comparable across generation sources that are so different.

Let me use a different example. In a future world where solar/wind make up half of our electricity generation, there will be a need for quite a bit more gas peaker plant capacity... but those plants won't need to run very often. Their value to the grid is neither their label capacity nor the actual amount of electricity that they generate per year - it's in their availability on short notice (their ability to stabilize the grid). They'll literally get paid to just sit there - hoping that they don't get used very often. How much of that capacity would be "equivalent" to 100 MWs of solar? How much annual producing would be? Neither comparison is really appropriate because they aren't comparable by either metric.

In this case, you could compare the total amount of electricity that the solar panels could be expected to generate in an average year - to the annual generation expected from those coal plants. But the only reason that would be fair is because we're talking about SoCal (Where there's a pretty good change that almost all of the solar PV generation could directly offset the need for "baseload" generation). In most parts of the country, even that comparison would suffer from the relative value of power supplied when you want it vs. the value of power supplied when it happens to be available.

[railsback]

6. That would be under the assumption

that electric use would remain constant, rather than factoring in new technologies that make usage more efficient. Also to consider is the eventual mass production of high capacity batteries, or fuel cells, which homes would use to store their own power, or the excess being fed back into the grid.

[FBaggins]

7. Not exactly... but let's assume that to be the case.

We'll imagine that all of those technologies are in place... and have zero cost... and have zero loss from one cycle to the next... and no shortage of capacity. Then the proper comparison would be the total amount of electricity produced by each source over the course of a year. You don't care when or how reliably it's produced... just how much.

By that standard, the solar still isn't close to "equivalent". The coal plants run capacity factors in the 60-75% range (and could go higher)... while solar PV in California is in the 17-20% range. So those three average-sized coal plants produce somewhere between 3.5 and 5 times as much as the 1.56 GW of nameplate capacity in solar. In that imaginary world, the solar would still be easily worth building... because it would be much cheaper.

Taking it out of the range of the imagination... the ratio is much higher.

[tinrobot]

8. ...and most coal plants waste power.

This is why they sell power cheaply at non-peak times, because the plants don't shut down at night. They simply produce power that goes unused. So, going with your point, 1.6MW of coal does not mean all of that power is used.

But whatever. More solar is good. Nitpicking on the details doesn't make it less good.

[oldhippie]

9. Let me guess ......

You're not an engineer.

They simply produce power that goes unused.

[railsback]

3. They just completed a rather large 'field' of panels here in SF

In our Sunset district, there is one entire block used for water. Perfect use for wasted space. One block of panels on top of of a reservoir.

[RobertEarl]

4. Big Power Executive is Depressed

He sits in his office reviewing the latest numbers. Coal deliveries are down 10% and next year deliveries will be down another 10%. Each year less and less.

Eventually, he ponders, the coal burners will only be needed at night, and there is very little electricity used at night, so his business is not growing, it is dieing.

His friends at other corps look at him sadly for they know the fellow and his business is a dinosaur, soon enough to be buried in time.

Those damn hippies, he mutters, they have ruined me. First they cut back on their consumption and then pushed for solar power. He thinks of the millions he wasted trying to fight solar but vows he'd do it again. The money was easy come, easy go, so spending on lies and lobbying was worth it, he still thinks.

93 million miles away sits his biggest competition. And yet, even now it reaches into the corners of his office lighting it up so he can see, but all he sees is his company going down the tubes. Damn the sun, he wails. As it burns on and on, really, too cheap to meter.