I still haven't moved everything out of the Inner Drive Technology Worldwide Data Center to Microsoft Windows Azure, because the architecture of Weather Now simply won't support the move without extensive refactoring. But this week I saw the first concrete, irrefutable evidence of cost savings from the completed migrations.
First, I got a full bill for a month of Azure service. It was $94. That's actually a little less than I expected, though in fairness it doesn't include the 5–10 GB database that Weather Now will use. Keep in mind, finishing the Azure migration means I get to shut off my DSL and landline phone, for which AT&T charges me $55 for the DSL and $100 for the phone.
I also found out how much less energy I'm using with 3 of 5 servers shut down. Here is my basic electricity use for the past two years:
The spikes are, obviously, air conditioning—driven very much by having the server rack. Servers produce heat, and they require cooling. I have kept the rack under 25°C, and even at that temperature, the servers spin up their cooling fans and draw even more power. The lowest usage periods, March to May and October to December, are cool and moist, so I don't use either air conditioning or humidifiers.
Until this month, my mean electricity use was 1100 kWh per month overall, 1386 kWh in the summer, and 908 kWh in the shoulder seasons. In the last two years, my lowest usage was 845 kWh.
Last month it was 750 kWh. Also notice how, during the much hotter summer in 2012 (compared with 2011), my electricity use was slightly lower. It was just harder to see the savings until now.
Including taxes, that means the bill was only $20 less than the usual shoulder-season bill. But I'm not General Motors; that $20 savings is 20% of the bill. Cutting my electricity bills 20% seems like a pretty good deal. And next summer, with no servers in the house, I'll be able to run less air conditioning, and the A/C won't have to compete with the heat coming off the server rack.
Now I've just got to figure out how to migrate Weather Now...