Technical ProgramJulian LamyPh.D. Candidate
Carnegie Mellon UniversityPittsburgh, PAjlamy@andrew.cmu.edu
At the 33rd USAEE/IAEE Conference in Pittsburgh, delegates from across the globe (U.S., Europe, Asia, and the Middle East) met to discuss and exchange ideas about the most pressing energy issues of today. This is no surprise given the group’s reputation. However, one of the unique elements of the conference was the setting: the historic city of Pittsburgh, which has transformed from an industrial powerhouse led by the steel industry, to the center of U.S. natural gas production and a test-bed for new energy technologies. Delegates took advantage of this venue by attending two technical tours hosted by USAEE: a visit to a local wind farm and to a shale gas well-pad, both just outside of Pittsburgh.
Wind Farm Tour
Somerset County, about 100 miles South East of Pittsburgh, is home to the 139 megawatt (MW) “Twin Ridges Wind Farm” owned and operated by EverPower, an independent power producer based in Pittsburgh. EverPower owns and operates 752 MW throughout Pennsylvania, New York, California, and Illinois, and has over 2,000 MW of wind capacity under development across the U.S. Built in 2012, the Twin Ridges Farm contains 68 REpower MM 92 turbines, which sit on a ridgeline overlooking Somerset County’s landscape. Thus, the USAEE delegates on the tour (15 in total) not only learned about wind power, but also witnessed the picturesque views of Western Pennsylvania’s autumn leaves (Picture 1).
Picture 1. Twim Ridges Wind Farm, viewed through autumn foliage. (10/25/2015)
The tour began with an overview of the project and the history of its development by the site manager which lasted about an hour. USAEE delegates had many questions about the farm, leading to an interesting discussion about wind power benefits and externalities. One main topic was, as expected, economic factors. The site manager explained how this project is merchant, meaning that it bids into electricity markets like other power plants as opposed having a power purchase agreements (like most wind farms). EverPower does this by providing forecasts of its production as well as bids into the day-ahead market. If wind production is lower than expected, EverPower fulfills their obligation by purchasing energy on the real-time market. Thus, there is significant planning and analysis that informs their market participation each day. Further, on the technical side, the wind project contains some features that make this task easier. For example, wind turbines automatically curtail when real-time prices are below $0/MWh (which happens due to transmission constraints). They also stop when wind speeds are too high (25 meters/second) for safety concerns, and optimally operate between 3 and 11.5 meters/ second. Regarding total power production, the Twin Ridges project’s capacity factor can be as high as over 50% in winter months, and as low as 20% in summer months. Further, the turbines have unique ability to control reactive/ active power, frequency, and power factor very quickly, which benefits the PJM grid in times of unbalance.
Delegates also asked about some of the externalities of wind farms. First, the site manager addressed questions about negative impacts to bird and bat populations. He explained that projects require rigorous monitoring of birds for two years before built, and subsequent monitoring once constructed. Further, there are several hours of the year (between 30 and 50) in which turbines are shut down due to bat migration. The most compelling statistic presented (also available on EverPower’s website) was how wind turbines are the lowest source of bird deaths (<0.1 %), especially when compared to routine bird deaths like, for example, death resulting from cats (10.6%).
Another topic that came up was annoyance factors such as noise and flicker effects of the project. For noise, the site manager explained that projects are required to produce lower than 50 decibels (low level of ambient sound) at all surrounding households. Therefore, a humming sound can be audible to those closest to the project, but is extremely low. In rare cases in which people complained, EverPower worked with the homes to upgrade windows to eliminate any noise. Similarly, all projects must show little flicker/ shadow effect (intermittent shadows cast by the rotating blades); less than 30 hours per year. At projects where homes expressed concerns about these effects, EverPower agreed to shut off turbines during certain hours to eliminate the impact.
Lastly, before heading out to see the wind turbines up close, delegates asked about subsidies to wind projects and how they affect project economics. The site manager explained that when compared to the billions of dollars spent on the nuclear, oil & gas, and biofuels industry, renewables (wind and solar) have received the lowest government support. Further, the uncertainty about the continuation of the production tax credit has made it very difficult to make long-term investment decisions in the wind industry.
In the final (and best) stage of the tour, delegates got to see the project up close and personal as a bus drove them to multiple locations on the wind farm. Picture 2 shows the project’s substation, which connects it to high voltage transmission lines (138 kV). Picture 3 shows the turbines along the picturesque ridgeline and Picture 4 shows a group shot of the delegates. All agreed that the tour was fun, informative, and a great opportunity to see the Western Pennsylvania landscape; or in other words, they were “blown away.”
Picture 2. Substation at Twin Ridges Wind Farm. (10/25/2015)
Picture 3. Twin Ridges Wind Farm, view along the ridgeline. (10/25/2015)
Picture 4. Conference delegates on tour at Wind Ridges Wind Farm. (10/25/2015)
Shale Gas Tour
The tour was hosted by Range Resources, one of the most active drillers in Pennsylvania (> $1 billion invested) and a pioneer of the Marcellus shale, the most productive gas field in the U.S. The tour was therefore a great opportunity for USAEE delegates to learn more about unconventional natural gas drilling and experience what it’s like to be at a well-pad. Being that it was a nice day with only a slight breeze, it was also a great chance to be outside after many productive days at the conference.
After an introduction to the company and a safety briefing, the delegates (30 total) traveled by bus to a drilling site in Washington County. The tour guide explained that Range plans to drill 5 directional wells (like spokes on a half wheel) and at some point in the future, 5 more in the opposite direction. The drill rig itself was massive, and looked quite impressive especially when standing next to it (see Picture 5). However, the guide explained that after several weeks, the drill rig will come down once complete leaving limited infrastructure needed to actually produce gas. He also explained that Range uses a third party company to conduct the drilling, and has one Range employee on site to monitor their progress 24/7. Further, like many drilling sites, this one was in a remote location and thus required onsite generators, which were mostly fired by natural gas (and also diesel as backup).
The next stop on the tour was to a production platform, which was far less imposing than the drill site. It had 5 wells on it each with a short (3-4 foot) assembly of valves and fittings that the industry refers as “Christmas trees”. These wells mostly produced “dry gas” (methane), with some “wet gases” (such as butane and ethane) which are separated out. Also on-site was equipment to strip water out and place it into holding tanks, which are emptied once a day. The guide explained that production at the site is similar to a manufacturing process, rather than a surge of production followed by a steep decline. Range plans to produce gas from these wells for about 50 years, albeit production will decline over that time period.
A surprising observation was that there is no immediate security at the production platform (no fence, no guards, and no cameras). However, the guide explained that the wells would shut down if the equipment was disturbed. Further, since the pad is on private property, the expectation is that the local community knows that the site makes them money through royalties and therefore has little incentive to disrupt the site, and much incentive to ensure it isn’t interfered with.
The Range guide demonstrated an outstanding grasp of drilling and production technology and answered all questions directly. These included questions about disturbance of local water supplies, gas leaks, earthquake susceptibility, and other environmental matters. Overall, delegates were very pleased with the visit. Picture 5 shows the delegates posing in front of the drill rig.
Picture 5. Conference delegates on tour at one of Range Resources' drilling sites. (10/29/2015)
Contributor to this article: Michael Canes (Logistics Management Institute) and Past President, USAEE.