Laos dam construction and collapse

A dam under construction in Laos as part of a hydropower scheme has collapsed, causing flooding and damage.

At issue is the Xe-Pian Xe-Namnoy project, a 410-megawatt hydroelectric power project under development for Xe-Pian Xe-Namnoy Power Company (PNPC). PNPC is a joint venture among the government of Laos and construction and power companies from South Korea and Thailand. The project, whose construction costs are estimated at about $1 billion, involves the construction of three primary dams to form reservoirs. Construction of the system was reportedly 90% complete, with commercial operation projected for 2019, and an agreement in place agreement to export 90% of project power to Thailand. The project has been touted for the degree of international investment involved, although some have criticized the project for insufficient local benefits.

From an engineering perspective, the project's primary dams impound water in a large reservoir. The project also includes three auxiliary "saddle dams" near several heads of the reservoir, essentially to prevent the reservoir from spilling down the impoundment's back side as it fills.

A map of the project, found at http://www.pnpclaos.com/index.php/en/project/maps

Project maps posted online by PNPC show saddle dams on three of the main reservoir's western branches.

Another project map found at http://www.pnpclaos.com/index.php/en/project/maps

One of these smaller saddle dams reportedly failed on July 23, 2018, allegedly due to severe rains. Saddle Dam D -- a facility 8 meters wide, 770 meters long and 16 meters high -- was built to support water diversion around the project's reservoir. But the structure reportedly fractured, causing water to spill downstream to the Xe Pian river outside of the project's intended path of water flow. According to the prime minister of Laos, at least 26 people have died and 131 are missing from the resulting flooding, and several villages .

Response and recovery actions are ongoing. The dam collapse highlights the importance of safety in dam construction and reservoir operations, as did the February 2017 failure of the Oroville Dam's spillway in California.

Super Bowl 2013 power outage

The National Football League held Super Bowl XLVII last night at the Mercedes-Benz Superdome in New Orleans, Louisiana.  The game was interrupted by a power outage just after the second half started, which caused many of the stadium lights and systems to go dark.  Play was delayed for 34 minutes as workers scrambled to resolve the problem.  What happened to the lights at the Super Bowl?

Electric utility Entergy supplies electricity to the Superdome.  According to a statement issued jointly with Superdome manager SMG, load-monitoring equipment sensed "an abnormality in the system".  To protect systems and isolate the issue, that equipment opened a breaker and partially cut the power feed to the facility.  While backup generators kicked in, the backup supply was insufficient to fully power the Superdome's lights and systems.

The Mercedes-Benz Superdome is a significant consumer of electricity.  Statements issued by the Super Bowl New Orleans Host Committee suggest that energy usage for major Super Bowl venues including the Mercedes Superdome, Morial Convention Center, Team and NFL hotels, will consume up to 4,600 megawatts of electricity.  (Note that this statement is improbable - it should likely read 4,600 kilowatts or 4,600 megawatt-hours.  4,600 megawatts would be about 15% of Entergy's 30,000 MW total generating capacity, and represents more power than 4 typical nuclear power plants can produce.  In any event, the Superdome clearly drew a lot of power from the grid.)

The Super Bowl power outage will focus attention on professional sports' approach to energy.  NFL teams and stadium owners have been exploring alternative energy for some time; for example, last year the Philadelphia Eagles considered developing solar panels and wind turbines on their stadium.  Even the Superdome has invested in energy efficiency, developing an efficient exterior LED lighting system in 2011. 

While alternative energy efforts can reduce operating costs and environmental impacts, they are unlikely to completely displace reliance on the utility electric grid.  Stadiums' significant power demands during games far outstrip their electricity consumption at other times.  This means that stadiums would need to install sizable distributed generation to be self-reliant, but would only need to run that generation for a limited number of hours per year -- making the economics of a distributed generation project challenging.

Traditional, utility-supplied power may remain the most cost-effective basis for large stadium electricity supply for now -- but leaves stadiums, players and fans reliant on their public utilities to keep the lights on.  Team and stadium owners eager to avoid the embarrassment and cost of an outage will continue to look for solutions, including more backup generation and more robust grid connections.