Giving Thanks for Grid Reliability?

Smart Grid technologies make the grid more reliable.  Distribution automation, such as remote sensing and management technologies give utilities real-time knowledge of grid conditions.  Utilities can become proactive in resolving any problems that occur within the domains of generation, transmission, and distribution of electricity.   Technologies that make it easier for utilities to proactively manage their equipment have additional benefits to end users – as grid reliability is increased, the frequency and severity of outages is reduced.  Some reports indicate that as many as 90% of all US power outages occur in the distribution system.  The US grid operates at an average of three nines (99.9%) reliability.  Compare that to Japan’s grid, which performs at five nines (99.999%) reliability.  The difference is several hours of outage in the USA (8 hours, 46 minutes) versus a few minutes of outage in Japan (5 minutes, 15 seconds).   The economic impacts of outages are estimated by the Galvin Electricity Initiative to cost the American economy $150 billion annually.   In good economic times or bad, we cannot afford and should not be expected to tolerate these losses.

Of course, perhaps it’s not fair to compare the USA to Japan.  We have a larger land mass to cover with a more widely distributed population.  But when you look at overall distribution losses, the USA has an eye-popping 245.881 billion kilowatthours of lost electricity.  Canada has 56.416 billion kWh in comparison.  The UK has 28.195 billion kWh in losses, while Denmark is a real virtuoso in electrical grid performance at 2.358 billion kWh in losses.   What are they doing that we’re not doing?

Public Utility Commissions (PUCs) use metrics to quantify the reliability of investor owned utilities’ (IOUs) electricity delivery – usually measuring customer outage minutes using SAIDI (System Average Interruption Duration Index), SAIFI (the System Average Interruption Frequency Index), and MAIFI (Momentary Average Interruption Frequency Index).  IOUs receive fines from their regulatory agency when they exceed the targets defined by these metrics.  SAIFI is calculated by taking the number of customers impacted by an outage and dividing that by the total number of customers.  SAIDI is calculated by taking the duration or time of service interruptions and dividing that by the total number of customers.  MAIFI is a calculation of the average frequency of momentary interruptions.  Its formula is the total number of customer momentary interruptions divided by the total number of customers served.  These measurements do not include planned maintenance when power may be interrupted, which makes sense.  However, these measurements exclude storm outages because these are considered beyond the control of utilities to have managed or mitigated.  Anyone who has traveled outside of the USA has probably experienced a severe storm in another part of the world.   How do other countries, including our neighbor to the north, manage to have much better grid reliability numbers?

So while I am thankful to have my 3 nines reliability, next time I experience an unplanned power outage, I’ll be asking why the US grid doesn’t perform as well as its peers, and when I’ll see the application of Smart Grid technologies and services that improve the delivery of electricity to consumers.