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Comment Re:Density is nice, but what about longevity? (Score 2) 185

SSD lives in an actual experiment are in this article:

The drive that did the worst failed at the 728TB written mark. These were 250 GB drives, so I would expect 1 TB drives to be able to sustain approximately four times the write volume. The means we should expect failure at about the 3.5 Petabyte mark. Two video streams should pretty much never exceed 10GB/hour. 3.5 PB/10GB =350,000 hours. That's about 40 years.

  Yeah, I think SSDs are OK for DVRs.

Comment Re:So paying more in the long run is better? (Score 3, Insightful) 53

Was this some sort of lease to own scheme?

It would be pretty stupid if it was not. About 20 years ago, most office buildings changed up the ballasts on their fluorescent lights from magnetic to active which gave huge electricity savings. It was pretty common to see deals like this back then. The company that I was consulting at did this. They had a company come in and replace the ballasts. The deal was ten years of half of the savings on the electricity and then the leasing company walked away. So from the POV of the customer, they had no up front cost, for 10 years the customer got half the electricity savings, and for the remainder of the life of the product the customer got 100% of the savings. If purchased outright, the ballasts would have paid for themselves in just a couple of years so it was a really sweet deal for the leasing company.

Comment Re:20-40% overblown (Score 5, Informative) 597

> If you're using somewhere near the inverter's peak output, then you can get as much as 90% efficiency

  These days inverters are much better than that. To use a random product that is currently shipping, an SMA Sunny Boy 5000 runs at 95.5-97% efficiency. Bigger inverters are even better with some commercial scale monsters at 98% efficiency.

  The original article is pure nonsense. There are already three port inverters on the market. Those ports are: your 120V AC, your solar array, your battery bank. If the energy is going from the solar array to the battery there is simply no intermediate conversion to AC. With a three port inverter, there is only ever a single conversion from DC to AC. And, as I previously mentioned, will only get hit with a 3-4.5% loss. There is simply no way the world is going to change how electricity is delivered to avoid that.

  Since the Tesla Power Wall is pretty much for sure going to be a high volume product, there are inverter manufacturers falling all over themselves to design and build three port inverters specifically optimized for the Tesla product.

Comment Re:Wind and Solar Converge (Score 1) 262

The latest EIA 2014 projections for growth. Hardly exponential, and they've been pretty close to reality in those projections.

EIA has been massively off on renewables for as long as I've been following them.

According to this paper:

renewables are one of the EIA's biggest trouble spots in predicting.

Note the paper is from a few years ago. EIA was screwing up forecasts of renewables way back then, and (IMHO) they still are.

Comment Re:How could they? (Score 1) 179

At some point, someone said "ummm, guys, we can't legally do that" and was told to STFU.

I've been in meetings like that before. I suspect it was more along the lines of this.

Suit 1: So, we can block all the wifi hot-spots and make everyone pay us $10-$100 a day for access. Any downsides?

Suit 2: Yeah, it is illegal.

Suit 1: So, what happens if we are caught?

Suit 2: A fine, something like a million bucks tops.

Suit 1: LOL, and this thing could bring in five grand a day in revenue per hotel. No brainer, Approved!

IMHO, this is why the fine should have been much much bigger. I'd wager serious money that Marriott came out ahead on this. It has a taste to me of fining a bank robber 10% of what he stole and calling it a day.

Comment Re:Are they really that scared? (Score 1) 461

Personal experience. My wife runs a solar energy web site and she routinely interviews people in the solar industry. That includes executives at electric utilities. I am the camera man. Since I am an electrical engineer, I always chat with the people before and after the on-camera interview.

The difference in attitudes towards solar PV before and after that report were nothing short of jaw-dropping. It was kind of amazing how patronizing many (most?) people in the utilities were towards solar. That report was like everyone in the industry had just watched a horror movie involving their own personal destruction. No one is dismissive or patronizing towards solar PV anymore.

BTW, possibly my favorite interview is this one:

Karl Rabago is a great pro-solar guy who is also been utility guy who has also been a regulator. That gives him an amazingly well rounded perspective since he is one of a very small number of people in the industry who has been on both sides of the table.

Comment Re:Are they really that scared? (Score 5, Informative) 461

The Edison Electric institute is a trade group for electric utilities. They published this report in January of 2013.

That report changed the attitudes of a huge number of electric utility executives. Before this report, I would describe most electric utility executives as indifferent to solar PV. They viewed it as a marginal technology and that it would probably always be a bit-player. After that report, pretty much none of them feel this way. Many executives at electric utilities are terrified of solar and are spending significant amounts of money lobbying against it.

Comment Re:No, no feasible storage, not even close (Score 1) 237

I agree it is cheaper to buy it from the power company today. That said, we might be a bit closer than most people think. LCOE (Levelized Cost of Energy) of new solar PV is around 10 cents per KwH. Right now, energy storage is in the ballpark of 30 cents per KwH. Get one third of your power without storage and the rest has to cycle through storage, and you are looking at an average cost of around 30 cents per KwH. About the only place that would save money right now is Hawaii.

  Going forward, Solar PV's price has been falling by around 8% a year for decades and I don't see that trend stopping any time soon. Battery costs have been falling even faster, but let's use 8% for those as well. By 2020, we will be looking at 20 cents a kwh. By 2025, it should be down to 13 cents, and by 2030 about 8.5 cents. Remember, that's for a system with solar PV and storage to take you through the night.

  That's assuming no big tech breakthroughs, just the incremental 8% a year we have been doing.


Comment Possible sequence (Score 3, Insightful) 171

I don't know that this is what happened, but it seems likely.

1) Apple wants to use sapphire for main glass in Iphone.

2) Apple signs contract with GTAT to supply the sapphire, including a pile of money to build sapphire production facilities.

3) Apple pushes all risk onto GTAT. IOW, if Apple decides not to use the sapphire for the displays, GTAT has to repay the pile of money from step 2.

4) Apple does not use sapphire. GTAT can't repay money because they already spent it building sapphire production lines which no have no demand.

5) GTAT declares bankruptcy.

Comment Re:Yes, we know that. (Score 1) 245

The reason it is difficult to handle the load swings is that coal and nuclear plants can not be quickly turned off and on. For example, it can take a full day or two for a coal power plant to go from cold start to full power output. We do have some power plants that can react quickly, natural gas can react in a few minutes with the newest plants to an hour with the older ones. Hydro is very fast and can be switched off and on in seconds.

  So take a typical grid that is getting half it's power from coal, maybe 10% from nuclear, and the rest from natural gas and hydro. Now do what Germany did and put in enough solar PV that 5% of the total energy of the year is coming from solar PV. As the previous article showed, the instantaneous peak that results from this is as high as 50% of the total demand. In Germany's case, when that happens, all the gas and hydro plants are off and all their power is coming from coal, nuclear, and solar. And there is the breaking point. If solar increases any more in Germany, when solar is peaking, they either have to start rejecting some of the solar power, the coal power, or the nuclear. The solar can not be rejected under current German law, which leaves only coal or nuclear. And those boys really can't turn off their plants very well. The result is that they push the spot price down to encourage anyone who can respond to the spot market to take power.

  Germany has already experienced negative electricity prices in the spot market because of this problem.

  Now imagine Germany doubles the amount of solar PV they have. This would result in them getting around 10% of their total electrical energy from solar PV. The instantaneous peaks would be as high as 100% of total demand. What is supposed to happen then? The obvious thing to do is to simply cap solar PV to an instantaneous peak of around 50% of total demand. That happens infrequently enough that Germany could still probably get 9.5% of their total energy from solar PV. That only would reject about 5% of the power the solar panels could have collected. That's reasonable technically, but illegal under current German law.

  If you look at this paper,

  The authors introduce the concept of system-LCOE. LCOE is levelized Cost Of Energy. It is a common utility term. The idea is to sum up every single cost to produce electricity and reduce it to a single number. Historically, LCOE ignores any issues with integrating with the grid. System LCOE is meant to try to incorporate both LCOE and grid integration issues. If you look at their graph on page 19, you can see how the cost of integrating solar PV increases quite dramatically as the share of energy coming from solar increases. If their graph is correct, Germany is paying in the ballpark of 15% extra to integrate into the grid.

Comment Re:Yes, we know that. (Score 1) 245

Once Solar PV penetration gets to the point where about 5% of all electricity is coming from solar PV..

Uhm. You realize you're talking almost a (not even taking into account rising consumption) 20-fold increase right?

Germany is already past that.

In 2013, Germany got 5.3% of their total electrical energy from Solar PV.

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