Elon on Solarcity and Tesla (national clean energy summit)

[Lloyd]

Crystal powered Star Wars light sabers...

Crystal powered Star Trek starships...

And they were DiLithium Crystals! (Li)2

 

[TEG]

And Scotty was the first human to ride in a SpaceX rocket!
(Well, posthumously...)

 

[vfx]

 

[cinergi]

Made me think of this ...

edit: damn you vfx :smile:

 

[vfx]

You been TEG'd!

 

[Norbert]

Obviously, as battery tech improves, we'll have battery power backup in lots of places. Even gourmet restaurants. Maybe.

 

[raymond]

Why would a wallmart need batteries?? Perhaps something to do with Tesla charging?

I would say batteries make no economic sense except for high peak load applications.

• 25kW 4 hour backup batteries = 100kWh = $40,000 (plus electronics, not factoring in cell degradation)
• 25kW generator = $4,000 (plus a few bucks in fuel)

But the 100kWh batteries can output 200-500kW of power, very useful for high speed charging.

Second-hand batteries are cheaper, but for backup power - which by its nature is used very infrequently - I don't think they make sense.

 

[FalconNinetyD]

The permitting process can be very long and difficult to get a generator installed, at least here in California. However, I agree, the generator is still probably a cheaper alternative.

 

[VolkerP]

I agree that batteries cannot compete with genset as emergency power. But batteries are an energy storage that can be cycled. Every storage cycle yields a yearly return on investment with the dollar amount that each cycle generates times the number of cycles per year.

If storage batteries cycle once a day, every work day, to save $1,000 demand charges, your ROI is $250,000 per year. Now if batteries cost $1m and last 10 years, they pay for them selves after 4 years plus some capital interest.

 

[raymond]

I agree that batteries cannot compete with genset as emergency power. But batteries are an energy storage that can be cycled.

Agreed. And what reasons other than dumping 100+ kW into a Model S are there to cycle these batteries?

 

[JRP3]

I agree that batteries cannot compete with genset as emergency power.

Solar panels + batteries = long term emergency power. In a widespread power outage you might not be able to get fuel for your generator.

 

[Robert.Boston]

The bulk power grid has long relied on large-scale storage to balance supply and demand. The biggest of these are pumped-storage hydroelectric facilities: two lakes (one high, one low) connected by large pipes with reversible pumps/generators. Move the water up at night, flow it down during the day. It's only about 75% efficient, and these plants often have substantial ecological impacts. Taking used EV batteries (with a cost a small fraction of new-battery costs), combining them into grid-scale storage, and using them to balance intermittent renewable generation with load is a very sensible application.

 

[raymond]

Taking used EV batteries ... is a very sensible application.

Yup, but that's not what's going on at Walmart as the supply of used EV batteries is pretty much zero right now.

BTW: Stuffing your basement with used EV batteries is great for lowering your center of gravity! (Oh, wait...)

 

[jcstp]

Yup, but that's not what's going on at Walmart as the supply of used EV batteries is pretty much zero right now.

I think they said it nicely in the video
The cost of food wasted in fridges, clients lost by 1 grid failure, are much greater than the investment in the battery-system

 

[gjunky]

There are some other projects underway, although still in the research state, for very large grid connected battery systems. I don't know if these will scale down to Walmart size.

An Interesting talk on Ted:
http://www.ted.com/talks/donald_sadoway_the_missing_link_to_renewable_energy.html

 

[jerry33]

In addition, there is a lot more maintenance involved in a generator system then there is in additional batteries. A generator system needs to be tested at least once per month, usually in conjunction with the vendor, because of the complicated diesel engine used to power the generator. And large scale generator systems also have a battery backup because the generator can't instantly provide power, so you're basically paying for both a battery system and an engine system. A battery system should need far less maintenance.

 

[ggr]

A generator system needs to be tested at least once per month, usually in conjunction with the vendor, because of the complicated diesel engine used to power the generator.

Sometimes testing isn't enough. Back in 1982 or so I was assisting in a lawsuit in Australia involving Qantas' data center. The backup generators all worked fine when tested, but somehow they overlooked the fact that they used grid power to start them...

 

[jerry33]

Sometimes testing isn't enough. Back in 1982 or so I was assisting in a lawsuit in Australia involving Qantas' data center. The backup generators all worked fine when tested, but somehow they overlooked the fact that they used grid power to start them...

That just means they didn't do a proper test. A proper test means that you shut off the grid power to the building. At least that's how the tests are conducted where I work (and given that vendor personnel are on-site it's not a cheap test).

 

[VolkerP]

Normally the person in charge (IT manager) shies away from the risk of performing such a test. If it runs OK, CEO says "well that's what was to be expected, we shelled out some $m for this toy!". If disaster sets in, everybody points at the culprit.
I encountered such a disaster when the "uninterruptible power supply" was taken offline for maintenance. The service personnel triggered the switches to take it offline, but in the wrong order. As a consequence, the data center lost power :scared: but not the office cubicles

 

[jerry33]

That doesn't happen if the system is designed properly:

1. UPS directly powers the productions systems

2. PDUs distribute the main power to the UPS

3. Standby power with battery backup or power from the utility

What's tested is #3. The individual UPS are still providing power to the production systems.

If you can't safely test the backup, then you only have a check list backup power system, not a real backup power system.

In Volker's case, it's my opinion that it's far better to have the outage during the maintenance window when there are people standing by to fix things than it is to find out during a real emergency (usually Friday at 17:30) when no one is available.