Between the Poles

Distributech 2013: Smart grid becomes mainstream

If there was one consistent message at Distributech this year, it was that smart grid has become mainstream - every utilty is doing something related to smart grid.

A very good example of some the things that utilities are abe to do because of their investment in smart grid technology is the keynote given by Michael Niggli, COO and President of San Diego Gas and Electric Company (SDGE).  SDG&E is a regulated public utility with 3.4 million customers and 1.4 million electric meters and more than 840,000 natural gas meters in San Diego and southern Orange counties.

Smart grid

According to Mr. Niggli smart grid is accelerating like never before.  SDG&E has deployed 2.3 million smart meters to electric and gas consumers. And there are other smart-grid related initiatives that SDG&E has undertaken including distributed generation, primarily solar photvoltaic (PV), plug-in electric vehicles (PEVs), and a new outage management system that leverages real-time data from smart meters..

Social networking and customer engagement

Having smart meters has helped in a way that SDG&E probably didn't originally project.  When SDG&E had to take the San Onofre nuclear plant, which represents 20% of their generation capacity, off-line in January 2012, they had to look for ways to dramatically reduce load.  SDG&E leveraged their smart meter network to help reduce power demand.  I have blogged before about utilities using social networking to communicate with the public.  In this case one of the ways that SDG&E took advantage of their AMI network was to use social networking to help reduce load.  The smart meter network (AMI) allowed them to  compare different schools' power usage so they used social gaming to create a competition among schools to see who could reduce their energy usage the most.

Green button

Another area where SDGE and a number of other utilities are helping consumers become more energy consciousus is the Green Button program, originally modeled on Veteran Affairs' Blue Button program.  SDGE's Green Button program not only allows users to access their own usage data, but also to make it available to 3rd parties, typically companies who analyze consumers' historical usage to help them reduce their power usage.  Across the country about 16 million consumers have access to their electric usage data via a Green Button program and another 30 mllion are exptected to get access soon.

Distributed generation

California is leading the country in clean energy.  California has mandated 33% renewable energy by 2020, and has also mandated reducing emissions to 1990 levels, by about 30% from current levels, in the same timeframe.  In addition new federal regulations targeting 54.5 miles per gallon in all new vehicles by 2025 is dramatically changing the energy landscape in California.  And as Mr. Niggli and other speakers emphasized, what is happening to utilities in Califiornia will happen to utilities in the rest of the country.

Distributed generation is an important source of renewable energy for SDGE.  According to Mr. Niggli In SDG&E's service territory there are 21'000 rooftop PV installations with a capacity of 160 MW.  New rooftop PV installations  are increasing at a rate of 3% per month.

Plug-in electric vehicles

Presently there are 2'500 plug-in electric vehicles in San Diego currently and SDGE is projecting that this could rise to 200'000 by 2020.  SDGE has used time of use pricing to motivate PEV owners to charge at super off peak when electricity is at a very low rate.  As a result 84% of vehicle charging is occuring between 12 midnight and 5am.

Wind and solar intermittent energy sources changes the daily demand profile

When intermiitent sources like wind and solar generation contribute more than about 20%, they begin to significantly impact the daily generation profile.  On the demand side, plug-in electric vehicles and increasing customer awareness of electric usage are changing daily load profiles.  The difference between the two is critically important to SDGE because they need to provide generation capacity to fill the gap.   Mr. Niggli gave two examples from the Californi ISO where generation dropped by 4'500 MW in 2 hrs, and then ramped up by 12'500 MW in 2.5 hrs, as a result of wind and solar generation.

SDG&E expects to start seeing the impact of the new daily power profile in 2015 and is working now to find dispatchable energy sources that can ramp up and down rapidly.  To put this in context, it takes months to ramp up nuclear, weeks for coal-fired plants, minutes for hyroelectric and natural-gas turbines, and microseconds for batteries.

Wild fires

Wild fires are a big problem for SDG&E because that makes SDGE liable for damage caused by fires started by SDGE equipment, for example, by poles being blown over. 

SDGE has implemented 144 weather stations to monitor local weather conditions in their service territory.  If winds get too high in an area increasign the risk of dmage to poles and other equipment, SDG&E will proactively shut down part of the network.  They have also put cameras on transmission lines and nstalled software that can automatically detect fires on transmission lines.

Outage management leveraging smart meters

SDG&E has installed a new outage management system that leverages their 2.3 million smart meters.  The major advantage that the new system provides is that they can detect an outage before the first customer calls in.  They can also differentiate without rolling a truck between outages due to customer problems and those caused by their own network.  The net effect is that it reduces the number of outages that SDG&E needs to respond to and reduces the average outage time (CAIDI and SAIDI).

New technologies can mitigate nationwide power grid blackouts like India's

Monday of this week about 370 million people experienced a power outage, though because outages are common in many parts of India, critical facilities like the Delhi Indira Gandhi airport, hospitals and police stations, and large commercial and industrial users had backup generators.

Then, on Tuesday, there was a 20-state blackout that cut power for between 620 and 680 million people, by far the largest blackout in history.  Only about 40 percent of power was back up by mid-afternoon on Tuesday.  At this point it is not clear what the cause of the outage was, but power grids are complex and this will take time.  I remember that it took months to determine what caused the Northeast power outage of 2003.

In some countries the grid is becoming much more flexible as a result of smart grid and distributed power generation technologies.  New technologies make it possible to restore power faster, track outages and restoration in real-time, and isolate sub-grids ("intentional islanding"), even at the home level, which can be kept them going with local power sources when the central grid goes down.  Home networks that incorporate renewable energy sources and power storage batteries enable homes to function off the grid.  In countries like Bengladesh with a limited central power grid, a significant amount of electric power is completly local and not connected to a central grid, which means that these power users are unaffected by a nation wide outage.

Monitoring outages and restoration

April of last year thirty tornados hit Alabama Power's operating area completely destroying two substations, flattening transmission pylons, breaking 7500 poles, and leaving 400,000 cutomers without power.  Fortunately, Alabama Power had installed more than a million smart meters in its service area.

By looking for smart meters that were read the day before and comparing them with the meters that could not be read after the tornados, Alabama Power was able to put together a detailed map of where power had been lost, without making telephone calls, which is what utilities normally do in such cases.  They could also tell emergency response officials whether the power was on or off in specific buildings - critical information that first responders need before entering a damaged building.  In addition, they could also track power restoration trends as customers started coming back on-line. The smart grid may not be able to prevent an outage caused by this type of event, but it can help get power restored faster and more safely.

The University of Tennessee Power Information Technology Laboratory has used a network of small, low-cost devices that plug into wall outlets to show the electric system dynamics of the Western Interconnect during the San Diego blackout in September of this year.  The devices record frequency, phase angle, and voltage every few seconds and transmit the data via the internet to the University of Tennessee and Virginia Tech. GPS-synchronization of the network made it possible to show geographically how the system disturbance propagated.

Intentional islanding

The combination of an intermittent energy source like solar or wind together with a large electric power storage battery (a 36 MWh battery park was recently commissioned in China) represents a source of power that could function independently of the central grid and provide power to a local community.  Intentional islanding can be used during a widespread outage like that in India to create power islands which can be designed to maintain a continuous supply of power locally during disturbances to the central grid.   Critical facilities like airports and hospitals already employ a form of islanding, taking themselves off the central grid and using emergency backup generators.

Home energy management

A large manufacturer, Panasonic Corporation, has announced that it will start mass-production of a lithium-ion battery energy storage system for homes, specifically for the European residential market.

The battery system consists of a battery cell with a capacity of up to 1.35 kWh and a battery management system designed to control battery charging and discharging.  When the sun is shining the battery stores energy generated from solar photovoltaic (PV) panels. At night when the PV system is not generating power, the battery provides up to a kWh of power.

Decentralized electric power

In Bangladesh, renewable energy, primarily solar, is providing access to electricity for rural villagers, who are not likely to have access to the central grid in the near future.  The Globle Environment Facility (GEF) is helping to accelerate rural electrification through solar home systems (SHS) in rural areas where people live too far from the main electrical grids. The Renewable Energy and Rural Electrification project seeks to reduce barriers to the use of these climate friendly energy systems and grow the market for renewables.  Currently it is estimated that some 80,000 SHSs are installed each month and in the last seven years, over 1 million rural homes in off-grid areas have got electricity through SHSs.  Since SHSs are entirely off-grid, they are not affected by nationwide outages like that in India earlier this week.