Is Smarter Greener?

As microprocessors, sensors, and communication links grow ever-smaller and ever-cheaper, a new set of industries and functions that still run largely on analog and human control are becoming digitized, or "smarter" in marketing lingo. Can't find a parking space? Your iPhone PrimoSpot app will find one for you. Gigantic, coal-fired power plants are being retrofitted with sensors tied to an artificial intelligence neural network that "learns" how the plant runs and adjusts it to maximize output more precisely than any mortal operator. IBM has mounted a massive campaign to create Smarter Cities, with excellent examples (visit their website and check out the great graphics) of how all sorts of municipal functions that aren't yet digitized can be made more efficient. Innovation expert Rob Atkinson recently described a similar vision in the Atlantic, with smart bridges and roads talking to cars. A recent Forrester research report urges CIOs and CTOs to begin positioning themselves as critical enablers of the "smart city."

The question is: does all of this infotech hardware and software really reduce the energy and carbon footprint of a particular activity or purchase? The answer isn't as easy as it sounds.

To start, it's important to distinguish between the various ways of making systems smarter. One way is to retrofit smart systems onto existing process hardware and infrastructure, such as retrofitting your current house with a smart power meter and controls on your appliances. Even when taking into account the energy required to make and operate the smart hardware you've added, this can still reduce your carbon footprint. Net energy analysts like Professor Cutler Cleveland of Boston University have been calculating results like this for many years. In one of his studies, Professor Cleveland found that photovoltaic (solar electric) cells produce about six times as much energy as they take to manufacture.

The savings achieved purely by adding smart hardware to our current energy-using infrastructure tend to vary and can sometimes distract folks from the more extensive changes and policies that could have much larger impacts, but also require greater investment and effort. For example, home automation linked to dynamic price signals can reduce household energy use by as much as 20 percent, though in practice the number is often closer to 4 to 5 percent. (For more information on the impacts of dynamic pricing, see the work of Ahmad Faruqui, principal of The Brattle Group.) However, building a home that is efficient to begin with can reduce energy use by 60 percent or more -- plus the additional savings from smart-grid-enabled controls and dynamic prices. Similarly, while plug-in hybrid vehicles have about half the carbon emissions of typical internal combustion engine (ICE) autos, designing a city to be transit, bike, and pedestrian friendly from the start can't be beat.

Smart systems may help make the case for a full scale rebuild of a structure or process when they make the entire system inherently more efficient and smarter. In cases such as these the life cycle savings tend to be much larger. For example, the VKR zero-carbon house saves most of its energy by a smart passive solar design, aided by smart windows that figure out when to close their shades or open them up to allow ventilation. In addition, a recent smart grid paper by Ryan Hledik, my colleague at The Brattle Group, showed that national deployment of smart grid infrastructure could serve as a catalyst for several cleaner, more efficient technologies, which would generate significant reductions in CO2 emissions.

But effective environmental policies to reduce carbon emissions don't focus solely on how structures operate, which is the main part of what smart sensing and control systems do. Effective carbon reduction policies include the appropriate use of price signals and markets and/or regulations, codes, and a variety of other policies to encourage greater efficiencies. Such policies often mean designing and building an infrastructure that has an inherently smaller environmental footprint rather than simply retrofitting existing systems. To see this, contrast the comprehensive environmental redesign of cities backed by the Clinton Global Initiative with the more limited "Smart City" retrofit vision. Would anyone make the mistake of equating sound national policy on climate change with a neural network upgrade to power plants?

By the same token, we should deploy energy-reducing smart hardware everywhere it's cost-effective, but we should not let this distract us from the larger task of rebuilding our energy-producing and consuming infrastructure for a cleaner, sustainable future.