Insulate your espresso boiler!
Spoiler: If you insulate your espresso machine's boiler, you will save between 7 and 30 bucks a month on your power bill.
Cafe Power Bills
In 2007, I moved with my brother to Pueblo, Colorado in order to open a coffee shop together. One of my main jobs was to reducing operating costs of doing business, and the electricity bill was a big one! Between the lights, ovens, coffee brewers, walk-in refrigerators, and espresso machine, the bill was over $1500 per month. Often times way over.
Measuring Espresso Power Baseline
One item that I identified as a major power-suck was the all-important espresso machine. I took the top off and clamped an amp meter around one leg of the heating element. The Astra Mega III volumetric espresso machine draws a solid 4200W of power when the element is on. I installed a little power-timer so that its number wheels count up when ever the coil is on, this way I could get a time-averaged value for how much power it actually uses. I let it sit for several weeks.
I actually got two different baselines: One for a period of time when we were switching the machine off every night for 12 hours at a time, and one when we just left it on night and day. Both practices are common with commercial espresso machines, depending on hours and staffing.
Insulating the Boiler
Once I had collected enough baseline data, it was time to insulate the boiler. You may be shocked to know that virtually no espresso machines are insulated in any way! When I asked a manufacturer, he just said, "It's so the cup warmer stays warm." The cup warmer being the flat spot on the top of the espresso machine, right above the boiler. (By this logic, you might call a missing front door your 'porch warmer.')
I found a supplier of 3/4 inch thick industrial high temperature felt in Illinois and ordered a yard. After hours one night, my wife and I popped the lid of the Astra and measured where all of the pipes, hoses, and wires protruded from the boiler. We went home and cut the felt to match, with some degree of difficulty. We then wrapped it and secured the felt with big zip ties. It now looked like this:
Over the following several weeks, I ran a new pair of tests: Power off at night, and power on all the time. I averaged the power usage over time for each of the test scenareos, and this is the graph of the data:
Interpreting the results of insulating your espresso machine's boiler:
- If you plan on leaving your espresso machine on all the time, you'll reduce it's power consumption by 30%. That is a difference of 247 kwh, or around $30 a month at a rate of 12 cents per kwh.
- If you plan on switching your machine off for 12 hours a day, you'll still reduce its total power consumption by around 12%. That is a difference of 59 kwh, or around $7 per month at a rate of 12 cents per kwh.
Applied to the the coffee industry at large
If we were to apply this data to the conservative estimate of 24,000 coffee shops in the USA, we could expect to see a reduction in power consumption between 5.9 and 1.4 GIGAWATT-HOURS, for a total savings of between $6 million and $160 thousand per month for the industry at large.
I recommend getting a water heater timer that turns off your espresso machine at night but turns it on in time to warm up before employees arrive in the morning. And also to insulate your boiler. :-)