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.
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.
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.
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