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Comment Re:Help me out here a little... (Score 1) 533

> Since we are paying retail rates for energy generated by NEM customers, it is shifting the burden of grid maintenance to the customers without PV.

Then fix THAT problem.

The problem isn't solar, the problem is that no one, no one, pays the actual cost of grid maintenance. If grid maintenance wasn't being partially(or completely) hidden in the $/kWh, the problem would disappear completely.

Comment Re:Help me out here a little... (Score 1) 533

> I can state with great confidence that it was not in fact considered.

I can state with *perfect* confidence that it was. The 7% cap was written right into the language of the original REC system in Ontario, for instance, which was introduced in the early 2000s.

> This is because there are countries ... (Germany, Denmark, Australia)

Do you live in, installed PV in, or otherwise have anything to do with any of these three countries? Where does your great confidence come from exactly?

Here's the actual facts. Germany had a 5% cap on PV in any single branch, Italy set it at 7%, and most others have also selected 7, including most of Canada and the US. The exceptions have been ones that *raised* the cap to allow more PV, like Germany, California and Hawaii.

Comment Re:Obvious (Score 1) 350

> Laws of physics

Ahhh, this is always a good start...

> That's why your phone can talk to base station a kilometer away, your WiFi will
> not carry over about 100m and bluetooth peripherals barely have 10m range.

With only very minor corrections, like the last 10 metres or so, all of these are due entirely to radiated power. The two corrections are near field effects, and building materials.

> 2. Meters long? AM receivers? What?

The limit for practical efficient antennas is about 1/4 wave. A 100 kHz AM signal is 3 km long. An efficient antenna for AM is about 750 meters long. The typical car antenna, at about a metre long, has a gain around -20 dB, around 1% efficiency. That is one of those "laws of physics" you claim to understand. The only reason you can hear anything on AM is because they broadcast tens of thousands of watts. Here, read something:

http://www.antenna-theory.com/basics/gain.php

> Because GPS sends on wave length that is relatively clear from other signals and
> that is able to carry the weak signal over the necessary distance

No, it's because the quarter wave antenna at 1575 MHz is about 5 cm, which fits quite nicely in a cell phone. While a car AM antenna has a gain around -20 dB (and a Walkman is probably down around -25 or less due to the antenna being the earphone which isn't exactly straight), the typical cell phone GPS antenna has a gain around -9 to -2 dB.

http://www.antenna-theory.com/design/gps.php

Recall that dB is logarithmic; this represents and improvement of two orders of magnitude, meaning that the ~250W of radiated power from the GPS is received at about the same power density as 25kW from AM. Actually more because of the physics of AM:

http://fas.org/man/dod-101/navy/docs/es310/AM.htm

There are minor adjustments throughout, but this is good to an order of mag, or better.

Really, you should make sure you know what you are actually talking about before you try to quote physics to the /. crowd.

Comment Re:Power beaming [Re:Revising a previous concept] (Score 1) 167

> We looked at lasers for space-to-Earth power beaming, but it's less practical than you might think

Actually that's precisely why I asked. I recall this was offered up as a solution to the inefficiencies of microwave beaming, only to find that it was even worse.

Space power is a bad idea, but it refuses to die.

Comment Re:Obvious (Score 1) 350

> Have a much greater range. In most cases you will be able to hear a station transmitting from tens of kilometers away

Well yeah, because they're broadcasting tens of thousands of watts. What, did you think this was due to some magical properties of the waves?

> Are typically designed to have backup power in case of an emergency

So do lots of cell towers. And since cell towers are in the hundreds of watts they are much easier to power and the total power needed to cover a particular geographical area is much smaller (see inverse square law). To the point where there was an article here only a day or two ago about solar powered towers. Know any FM stations that cover 20+ mile range that are solar powered?

> most FM receivers also have AM receiver function

Which require an antenna several meters long. https://en.wikipedia.org/wiki/Chu–Harrington_limit

> That means they don't rely on phone's weak transmitter's ability to reach the tower

Keep thinking inside that box. Meanwhile the same cell phone is receiving GPS signals FROM SPACE.

Comment Re:Obvious (Score 1) 350

> Let us know how that data service is working when a serious disaster strikes.

Exactly as well as the FM stations.

But we're arguing about which of two solutions is best. That's called the fallacy of the excluded middle. We don't want to debate whether FM or cell is better for emergency broadcasts, we simply want to know what's the best way to send emergency broadcasts.

So what is the actual problem? We want to

* provide rapid emergency information to people over a city-to-country sized area
* have that information appear on their cell phones even in the event of a natural or man-made disaster that takes out the infrastructure
* we want that to happen using the technology we already have in the cells phones

Ok, so now lets look at what technology we have in the cell phones:

* various cell receivers
* maybe an FM receiver, but it only works with an external antenna
* GPS and GLONASS receivers

And suddenly anyone who suggests that this should work using FM receivers looks like an idiot. The obvious solution to this problem is to define a few standard messages and stamp them with time, time-to-live, and geographical area-of-effect and send them into the GPS bitstream. John Deere's been doing this for years with Starfire.

Comment Re:Help me out here a little... (Score 1) 533

> Yes, but you still need to have variable, reactive supply to deal with that 50% variance

Lolz. You always needed that. Here's a graph:

http://www.ieso.ca

Note that demand varies between 12 and 16.5 over 3 hours.

> Reactive supply is less efficient than constant supply

Sure, if your supply has something that's large and spinning. Totally false otherwise, like in the case of an inverter.

Comment Re:Help me out here a little... (Score 1) 533

> It becomes a problem when some business that normally draws power through some massive feeder
> lines from a cogen plant starts drawing power from all of those houses through wires that weren't designed to allow that much current draw.

There's no difference in grid terms. The power ultimately ends up in the big cable that runs into the business. Where those electrons initially came from is hidden in the grid.

There is one concern though. Most older transformers are designed to be efficient in sending power in one direction only. They will send it the other way, but they're not designed to. When a lot of energy is flowing the "wrong way" that inefficiency comes out as heat, which can cause the transformer to start heating up and shut down. It's non-linear, small amounts of power flowing back are essentially frictionless because that wasted energy is tiny compared to the heat capacity of the transformer. It's only when you start getting into the 50% range that it gets interesting (depends on the model of course).

The solution to this problem is to limit the total amount of generation on the other side of the circuit to some fixed percentage. Here in Ontario, with a completely outdated grid (thanks Darlington) we're capped at 7%. That means even if the grid is down and all the PV is blasting, the total amount of power flowing back is 7% of what it's designed to handle downstream. This keeps it far, far, from the point where backfeeding is a problem. Of course 7% is a problem. In California it's 15 to 30%, depending.

Comment Re:Help me out here a little... (Score 3, Informative) 533

> By whom?

By all levels of government.

> Where's the budget item in the state/local/federal budget?

Right here:

http://www.eia.gov/analysis/requests/subsidy/

It's about $30 billion a year in direct subsidies. This does not include outside R&D, like the share of nuke development that happens as a side-effect of weapons programs (which has very recently dropped to just about zero now that MOX is largely run out). It excludes more wishy-washy issues like nuke liability insurance issues, or the more nebulous concepts like funding the Navy to keep the sea lanes open. This is pure, direct subsidies.

> Stop repeating paranoid memes.

Stop repeating BS that ten seconds of google will prove to be blatantly false.

Comment Re:Help me out here a little... (Score 1) 533

> I'm not sure how it does it

The MPPT puts the panels way off their I-V curve, so their efficiency goes to zero. They are not dumping energy, the panels actually stop producing.

https://en.wikipedia.org/wiki/Maximum_power_point_tracking

> or based on local factors such as overvoltage in the grid?

That is exactly how they work, well, one of the techniques anyway.

https://en.wikipedia.org/wiki/Islanding

> This tolerance is quite wide, because otherwise inverters wouldn't work a lot of the time.

The tolerance is exactly the same for all grid-connected generators, whether they be nuke plants of a couple of panels on your roof.

http://www.cleanenergyministerial.org/Portals/2/pdfs/A_Guidebook_for_Minigrids-SERC_LBNL_March_2013.pdf

Comment Re:Help me out here a little... (Score 1) 533

> Theoretically, you can design a control system that'll handle the problem. But, so far, noone has bothered

IBM has, and it's widely implemented around the world.

http://www.ibm.com/smarterplanet/us/en/smart_grid/nextsteps/

This is one among hundreds of similar solutions from companies large and small.

The utilities are perfectly aware of these systems, and have used them for decades to model load changes due to transient events like cloud cover spiking the demand for lighting and aircon, and similar issues.

> Right now, that cost if covered by your electric bills

That depends on where you live.

> because they sit behind a customer's meter and we don't have a means to directly measure them

The systems they already have in place are perfectly capable of estimating the collective output to numbers behind the decimal point. They may have to deploy a few more weather stations to improve the gridding, but the claim that this is some sort of impossible mission is utterly bogus.

Comment Two months eh? (Score 2) 186

When I was in grade school I was taught that the speed of sound increased with density. The examples were air, water and steel.

Actually, the speed of sound goes *down* with density, for the obvious reason that there's more atoms to get through. It goes up with springiness, which transmits the motion more rapidly. The science textbook from school simply selected three examples where the later was true - steel is much springier than air.

This utterly wrong "fact" is still being taught today.

The wiki took two weeks to correct carefully hidden wrong information? I'm supposed to be worried about this?

Comment Re:Who cares about fusion (Score 1) 57

> Cost effective fusion reactors

Oxymoron.

We *might* build a working fusion reactor someday.

However, we already know it will not be cost effective. Everyone knows this. The head of the French nuclear research group and the director of the Max Planck Institute co-wrote a paper explaining why. So did the former director of the US fusion program. So have lots of other people.

The problem is very simple. A wind turbine consists of a generator, a turbine, and a metal pole. A coal plant consists of a generator, steam turbine, cooling, piping, coal boiler, scrubbers and a very large building. Thus, after initial development during the 1990s and 2000s, wind turbines have become much cheaper than coal plants. As a result, coal plant construction has fallen. You may point to China, but China is installing more wind than coal, as is everyone else on the planet.

And this will be true forever. The inherent comparative complexity of the two systems means that wind will always be cheaper. In fact, even if you skip the boiler, the rest of the plant is still more expensive. Make sure you understand that; a complete wind turbine is less expensive than half of a coal plant.

A fusion plant consists of all of the same parts as a coal plant, except we replace the boiler with a FANTASTICALLY EXPENSIVE fusion reactor, lithium cooling system, tritium extractor, superconducting magnets, etc etc. This part will always, always, be fantastically more expensive than a coal fired boiler. So it will never, ever, be cheaper than wind turbines. Ever. Not even remotely close.

At this point you'll want to say something like "you can't predict the future" or similar twaddle, in spite of science having been invented to do just that. But there's a more powerful counterargument: as it stands, wind is cheaper than a coal plant without a burner. So even if you can build the fusion reactor for zero dollars, no one will build one. So now you start thinking of ways to lower the cost of the rest of the system, inserting unobtanium or some science fiction energy extraction system. The problem is you've just made coal and fission cheaper too.

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