Yeah, if I was either younger or healthy again I'd be very keen on trying to install solar myself. As it is the installations costs are pretty crazy for the couple of quotes we had. 

I used to have a single 25 kVA pole mounted transformer feeding a 320A meter base at the house, which in turn had 2x 200A panels behind it, and a 400A meter base at my shop with a single 200A panel behind it.  The 320A meter base was feed via 350 MCM Al and the shop meter base was feed via 500 MCM Al.  350 MCM Al is rated for 280A and 500 MCM Al is rated for 350A.  This is at 90C btw, which the power company is allowed to use.

A 25 kVA transformer can only do about 105A (and peak loads up to about 140A or so @ 240V).  Around my parts most homes with 200A service have a 15 kVA transformer, and large homes have a 25 kVA transformer.  Really large residential homes have a 50 kVA transformer.  A large 50 kVA is still only able to deliver 210A or so on a 24/7 basis.  And once you get much past that, the 350 MCM Al wire running between the transformer and your meter base begins to become the limiting factor.

When I started consuming above 20,000 watts 24/7, I had the power company come out and swap my 25 kVA for a 50 kVA one.  There was no cost to me.  Where I live in rural Virginia, nothing needs to be filed or justified with the county, it is all just between me and the POCO.  I just called them up one day, and 20 minutes later an engineer was at my door step and I showed my power usage and he said yep, let's swap in a 50 kVA for you.

For residential service, POCO always size based on peak loads, so having dual 400A services from a single 25 kVA is ok, as based on their experience, they never see a residential customer coming even close to pushing the continuous rating of a 25 kVA transformer.

Technically correct, but transformer power ratings are more of a moving target rather than a fixed number because as long as the core is sized properly for the voltage swing and frequency the power throughput is entirely dependent on the temperature rise of the windings. Taken to the extreme, that means a nearly infinite amount of power can flow through a transformer if the windings are superconductors. I know it sounds crazy, and using superconductors for windings isn't exactly practical, but it's true.

Even with humble copper windings most utility distribution transformers are immersed in oil for cooling so they can take a high degree of overload for surprisingly long periods of time, particularly if the ambient temperature is well below 25-35C. Hell, one cheap way that utility companies can instantly increase a transformer's power rating is to slap some fans on it; good for at least a 25% bump in continuous load rating, as long as the higher voltage drop is permissible.


The willingness of the utility company to upgrade your distribution transformer very much depends on the particular company and municipality (and, of course, how much average power you have drawn or are projected to draw). In my neck of the woods you practically have to set the pig on fire before the utility will replace it for free, and while they will gladly upgrade it if you pay them to do so, that can take weeks for the paperwork or whatever to work its way through the various bureaucracies.

Can confirm. In Malaysia it takes 2 months just to pull 250A 3 phase power in. Meanwhile you gotta make do with the default 63A 3 phase.

Those are good numbers but serms to me btc mining has never been more unprofitable now than its ever bern
im sitting on six s9s I bought last year, 14th units , I couldn’t even sell them with bitmain dumping thier T1s and 9is

I don’t think ill ever buy another asic, unless baikal comes out with like an x16 or lyra miner

the m3 was real

https://bt.irlbtc.com/view/2390138.0


Original post by philipma1957, posted in November 14, 2017:

Some people have reported making a killing on it, especially in our current market Huh

If they're using one of the more recent upgrade process versions, it's possible.
They DO have a legit 28nm miner with efficiency that could argue with the Spondoolies SP20.

Also, NOBODY has 7nm or 10nm in production for a miner yet - eBang will probably be the first given announced plans, unless Bitmain or Inno switch to using Samsung for a fab.

Zcash difficulty took a pretty big drop today. No clue why but I’m going to enjoy it while it’s here.