Hi all. I live in Australia and pay $0.24.2AUD per KWh (US 18c) of electricity. I have always wanted to install solar, even prior to mining crypto. So when the feed-in tariff was recently increased to 13c (US 10c), I pulled the trigger and had a large system installed.
Here is an aerial shot of my 72 * 300W panels -
The 20KW inverter -
All-time generation data showing daily average production of 93.4 KWh -
A typical sunny day parabola showing >5KW of production from 7am - 5pm (10 hours) -
Due to the parabolic nature of generation, I calculated the 'green % time' in 200W increments of constant draw (mining), all the way up to 3000W, on average throughout the year. As you can see, the first 200W is a massive 49% green while the 2800W-3000W are 38% green -
--- 200W 400W 600W 800W 1000W 1200W 1400W 1600W 1800W 2000W 2200W 2400W 2600W 2800W 3000W
January 56% 54% 53% 53% 52% 52% 51% 50% 49% 48% 47% 47% 46% 45% 45%
February 54% 53% 53% 52% 50% 49% 47% 47% 46% 45% 45% 45% 45% 44% 43%
March 49% 47% 45% 45% 44% 43% 43% 42% 41% 40% 39% 39% 38% 37% 37%
April 46% 45% 44% 43% 42% 40% 40% 39% 38% 38% 37% 37% 36% 36% 36%
May 42% 39% 38% 37% 37% 37% 37% 36% 36% 35% 34% 33% 32% 31% 31%
June 38% 38% 37% 37% 36% 35% 34% 33% 32% 31% 30% 30% 29% 29% 28%
July 39% 38% 38% 37% 37% 37% 37% 36% 36% 36% 34% 33% 32% 32% 32%
August 46% 44% 42% 40% 39% 38% 38% 38% 37% 37% 37% 36% 36% 35% 34%
September 49% 46% 45% 45% 45% 45% 44% 44% 43% 42% 41% 40% 40% 40% 39%
October 52% 51% 49% 49% 48% 48% 48% 48% 47% 46% 45% 44% 43% 43% 42%
November 58% 56% 54% 52% 50% 50% 50% 49% 48% 48% 47% 47% 46% 44% 44%
December 60% 55% 53% 53% 53% 52% 51% 51% 50% 48% 47% 46% 46% 46% 45%
---
Total 49% 47% 46% 45% 44% 44% 43% 43% 42% 41% 40% 40% 39% 39% 38%
Finally, and what was originally the point of this exercise, I will calculate the amount (in terms of W drawn at the wall) of mining equipment I can have running 24/7 while maintaining a zero sum electricity bill.
---THESE NUMBERS ARE ALL IN AUD---
My historical usage is roughly 5,300 kWh per year, of which, 2,000 kWh is expected to be during generation hours. Lets say 800 kWh of generation hours is baseload (200W), which does effect the constant draw and 1200 kWh is on-demand during peak generation (dishwasher / washing etc) which doesn't effect constant draw due to excessively high peak generation.
Combined total generation: 31,844 kWh
Non-Mining self-consumption: 2,000kWh ($0)
Ordinary Export: 29,844 kWh @ 12.87c ($3,841)
Non-Mining Grid consumption: 3,300 kWh ($799)
Service Charge: 365days @ 90.2c ($329)
Typically, I would see a yearly credit of $2,713 on my bill. So lets attempt to use that by way of mining;
Our household baseload is at 200W, so a mining baseload starts there. We have $2713 to 'spend'. We have to factor in that for every 200W of mining equipment, we must also reduce our FIT;
Draw Cost Norm_Cost
200W $327 $424
400W $331 $424
600W $333 $424
800W $334 $424
1000W $336 $424
1200W $337 $424
1400W $338 $424
1600W $339 $424
1800W $341 $424
2000W $342 $424
2200W $344 $424
2400W $345 $424
2600W $346 $424
2800W $348 $424
3000W $349 $424
So we begin to reduce our $2,713 by each increment (starting with $331) and we get to;
1800W constant draw with $24 left over.
So we can have mining equipment with a constant draw of 1600W at the wall and maintain a $0 bill.Over the last 3 months I have acquired gear and built rigs around the 1.6KW figure.
Here is the frame I use which is made out of $10 worth of aluminium angle and two pieces of 4*2. You just need some tin snips and screws -
You can use angle off cuts for PSU/HDD guide channels. Just put felt buttons under the motherboard -
I have a 5 * 1080ti mining rig -
And a 4 * Vega56 mining rig -
Which together draw 1730W (who's counting
)-
Time will tell just how my rigs balance out. Regardless, I am keen to expand anyway - the summer months will be better for mining due to extended daylight. Janurary is 45% green right up at 3000W. And in winter I can move rigs into bedrooms for some heating capacity.
I am keen to get another rig going for the 3 months of summer. Here is my garage set up so far showing two rigs, the inverter and my IT cabinet. Yes I will add some decent cable management or even run new outlets
As you can see, I have room for another shelf and perhaps 2 more rigs -
Current ventillation
. I will be adding exhaust fans above rigs soon -
Version 1 next to Version 2 (I'm improving). Oh boy how sexy are Vegas?
-
Here is a screen management of the miners. The 1080ti rig is mining equihash on nvOC. The Vega rig is managed through Chrome Desktop, running windows 10 and GPU0 hashes slightly slower due to no HDMI dummy. It still it manages 7000 H/s Cryptonight. The other window is the gaming PC that I manage them from, which also has 3 nvidia cards mining equihash.
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UPDATE 19/01/18OK, I finally got around to installing;
- Another shelf
- 4 * exhaust fans (combined; 152W, 1,440m² (15,500 ft²) / min)
- 2 * 20A breakers
- 8 * outlets
- extra rig
The two 20A breakers, with 20A wiring, are wired directly to 2 * double outlets and allow for a maximum of 8A on a socket, up to 16A total (per breaker)
So that's 3,840W * 2 = 7,680W total.
My 4 smart plugs are rated to 2,400W so no troubles there in putting 1920W on each.
Thanks to my smart meter, I know exactly what I use currently. Right now I'm pulling a constant draw of 5,230W
You can see in this graph, grid-consumption is zero from about 6:30am to 4:30pm. This is when I'm self-consuming. Production is so high that I still manage to feed back to the grid around 75kWh. Seeing as I get credited for feeding in at a rate of 50% the grid rate, this effectively offsets another 37.5kWh of usage. So my 67kWh of grid-use is offset down to 29.5kWh, which is roughly $7 per day. Not bad for 5,230W constant draw! I wish they were all sunny days like this example.
I have 5 more cards at the post office, ready for pick-up. They will go straight into spare slots on these motheboards, bringing me to 5800W constant draw. Remembering that my new breakers are good for 7,680W, there is still room to expand! The limiting factor now is shelf space. But I think clearly there is room for 1 more rig on the left shelf.
More soon!
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