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Dissecting ISO 37120: What the new smart city standard says about energy

Submitted by scc staff on August 8, 2014

George Karayannis, LEED AP

Image removed.We continue our series on the new ISO 37120 Smart City standard with a look at the third of 17 themes defined in the standard – energy indicators.  As previously described, ISO 37120 includes 46 ‘Core’ (must report) and 54 ‘Supporting’ (should report) indicators. 

Energy, of course, powers modern society and impacts most aspects of our daily lives -- allowing us to heat and cool our homes, charge our ever-expanding array of electronic devices and create economic value in our offices and factories.  While there are many aspects of energy to consider, ISO 37120 focuses on a city’s energy efficiency, energy availability and energy mix.  The impact of human energy consumption on the world’s climate is disputed by some, mostly in the U.S., where fully 32% of respondents in an Ipsos MORI 2014 Global Trends study disagreed with this statement: "The climate change we are currently seeing is largely the result of human activity."  On the other end of the spectrum, only 5% of respondents from China disagreed with the statement. 

"Supplying energy to a modern and dynamic city like New York is a complex task that requires the development, deployment and management of advanced technology,” notes Col Smart, Section Manager - Energy Efficiency and Demand Response at Con Edison.  “We believe that a consistent set of strong, executable and repeatable standards is important for the advancement of smart cities. The International Standards Organization is a credible and important administrator of such a set of standards and we applaud their initiative."

Let's examine those indicators ISO 37120 calls out in the smart city energy theme.

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Core Indicators

1.     Total residential electrical use per capita (kWh / year).

The residential sector is the largest user of energy globally, responsible for 36% of consumption according to the International Energy Agency’s World Energy Outlook 2010.   Like several indicators, this data has historically been reported at the country level, which we can use as a proxy for now.  According to the CIA World Factbook, Iceland has the highest electricity use per capita at 52,620 kWh per year – more than double the second highest per capita user, Norway, which consumes 24,557 kWh per capita per year.  The U.S. is ninth in per capita electrical consumption at nearly 12,000 kWh per year.

2.     Percentage of city population with authorized electrical service.

Electricity theft causes over $200 billion globally in losses each year.  Losses reach 50% in some areas of South Asia, Sub-Saharan Africa and the former Soviet Union, placing a technical strain on electric grids and an economic strain on the balance of customers who end up paying for unauthorized usage.  This problem exists in developed countries as well -- U.S. electricity losses totaling $6 billion annually -- making it the third most stolen commodity after credit card information and vehicles. 

3.     Energy consumption of public buildings per year (kWh / m2).

This indicator reflects the importance of cities leading by example and is focused on the energy intensity in municipal buildings.  Commercial buildings consume about 18% of all U.S. energy use, and many cities already track and report public building energy efficiency.  Some U.S. cities including AustinBostonChicago and New York have also passed commercial building efficiency disclosure ordinances requiring buildings above a certain size to audit and report their energy efficiency. 

Image removed.4.     Percentage of total energy derived from renewable sources, as a share of the city’s total energy consumption.

This indicator measures the carbon intensity of a city’s energy supply.   Some cities are taking bold actions to provide greener power to their citizens.  The city of Boulder, Colorado, for example, has one of the most carbon-intensive energy supplies in the nation and is seeking to invest hundreds of millions of dollars to separate from its investor-owned utility and create its own municipal utility to better serve its citizens.  

The wording on this indicator is currently unclear as to how nuclear power should be treated, as it recommends cities break out energy consumption by source, including “fossil fuels, nuclear and renewables.”

Supporting Indicators

Total electrical energy use per capita (kWh / year).

This indicator spans commercial, industrial and residential sectors and is intended to provide an inclusive, city-wide energy intensity metric. 

Image removed.2.     Average number of electrical interruptions per customer per year.

Both this indicator and the next measure electrical service quality. The practices for recording service interruptions have evolved over time leading to inconsistencies among utilities although this has improved lately.  This indicator is known as ‘SAIFI’ in the utility industry, and the U.S. average is 1.5 service interruptions per year per customer (generally defined as an outage of five minutes or more).  The Netherlands enjoys the fewest outages per year at 0.3, and Italy and Spain are tied for the most at 2.2.

3.     Average length of electrical interruptions (in hours).

This indicator measures the duration of the average service outage, or ‘SAIDI’ in industry terms.  SAIDI varies widely across the world, with Singapore at 2.2 minutes per year, Japan at 6 minutes per year, the U.S. at 214 minutes per year, and Columbia at 9,480 minutes per year.  ISO 37120 excludes major storms and weather events but, unlike IEEE Standard 1366-2003, does not define how long an outage must last before it is counted.  


George Karayannis has over 25 years of emerging technology and complex solutions sales, business development and marketing experience and has held leadership positions at Schneider Electric, Lockheed Martin Energy Solution, AT&T and wireless sensor startups.  He has also served as a city councilman and is restoring a 100-year old opera house to LEED Gold status. @gkarayannis

So far in our series: