One Cup, Many Energy Sources.

The Christian Science Monitor recently took on an age-old question: What's the most energy efficient way to heat up a cup of water? Some people swear by electric kettles, others by gas stoves, and still others - now including the Christian Science Monitor - by the microwave, because it heats the liquid that needs heating, rather than the vessel holding it. Here's the problem: sometimes the vessel gets mighty hot in the microwave. Another problem:  microwaves aren't all that efficient. That doesn't mean the CSM is wrong. It does point out a frailty in our system. Despite our increasing prowess in measuring energy consumption, we can't really answer this question yet.

The good news is that people are thinking about efficiency these days. Motives vary, but the bottom line is: we all win when we use less. We pay less to utility companies, and we give the earth a break. Maybe, as Michael Bluejay told the Christian Science Monitor, our time would be better spent changing a few light bulbs.

But at the heart of the tea cup challenge is a puzzling question: how do we compare energy sources? We are closing in on great data from Smart Meters, helped by Google PowerMeter, about our electricity use. We continue to be excited about that development. But we currently suffer from a dearth of ways to evaluate our household energy use as a whole. Forgive me, but our houses are a bit like tea bags - they work with help from multiple energy flavors.

Amidst recent (albeit largely debunked) arguments that increased reliance on electric cars simply shifts our dependence from one dirty energy source (oil) to another (coal), it's clearly time for the full picture to emerge. The morning ritual of heating water for tea is a pretty good starting point. It is possible, for example, that one cup benefits from tap water heated by oil before coming to a boil on a gas stove top, an electric range or microwave. If the only energy we measure in that calculation is electricity, we're missing the sugar cube.

We love our whole-house monitors, and our electricity use has changed dramatically since we started to have reliable data about how we use it. Imagine what we could do if we had the full picture. When Google decided to open its APIs, it opened the door for input from many quarters on measuring and reporting electricity data. We will continue to monitor those developments. We will also work closely with the great minds turning their attention to the full range of energy uses in the home. Let's answer this question, shall we?

Enjoy your tea.