In a Dec. 12 update, Invenergy Thermal Development LLC told the Rhode Island Energy Facility Siting Board (EFSB) that it is making progress securing needed water suppliers for the up-to-1,000-MW Clear River Energy Center (CREC) combined-cycle project.
The board on Oct. 13 decided to suspend the review proceedings for this project for ninety days in order to allow Invenergy the time to remedy its application regarding the project’s water source and a water supply plan. The board also ordered Invenergy to provide a written status update in sixty days, which is the Dec. 12 filing.
Invenergy reported that it is working with representatives of the City of Woonsocket to review the feasibility of purchasing water from Woonsocket for water supply to the Clear River Energy Center. Invenergy’s engineering consultants are working with the city’s Department of Public Works on developing the details and data to be included in the new water supply plan. The proposal Invenergy is discussing with the city would have water supply in the form of potable, treated water, and the design that is being worked on involves a new dedicated water pipeline from the city’s water supply to the CREC project.
This change in water supply source would result in slight changes to the design of the project’s water treatment system. For example, the Woonsocket water has a different chemistry associated with it than that of the Pascoag Utility well 3A, and as such, its use is expected to require a slight change in the design of the onsite water treatment system with the addition of a green-sand filter to remove iron.
This plan is expected to lead to minor adjustments of the daily water flows for the power project. This new design plan is not anticipated to change the water demand for the limited instances where the project will need to utilize back-up oil as fuel, as Invenergy believes it can configure the system to maintain the original flow. The proposal would involve the installation of a dedicated new pipeline from Woonsocket to the project that would be constructed on state highways and roads. The approach that is being developed by Invenergy’s consultants proposes the installation of a new, 14-mile-long pipeline from the city’s water system from Woonsocket, with a new pumping station to be located in Woonsocket.
For the water discharge/wastewater, Invenergy continues to work on the wastewater characterization based on the revised water quality and the supply and discharge quantities.
Alternatively, Invenergy said it is exploring the option of reducing the water needs of the project by reducing and recycling its wastewater. This would be accomplished by using demineralized water treatment trailers (included in CREC’s initial design), which do not create onsite wastewater, but rather generate treated water for process use without generating a wastewater stream from the demineralized water treatment system, unlike the reverse osmosis system that CREC is currently employing. This would be combined with a new treatment system that would be added to treat other wastewaters that are generated (steam-cycle blowdown and oil-water separator water discharge) and would create additional process water. The net effect of using this approach would be a significant reduction in daily water demand by the project, to the point that trucking water for process use may be feasible.
In other developments, the company reported that:
- On Nov. 3, the Burrillville Town Council unanimously voted to approve the following negotiated agreements reached between the town and Invenergy: Tax Agreement; Decommissioning Agreement; Property Value Guarantee Agreement and the Opt-Out Agreement.
- The configuration of the fuel oil storage tanks for CREC is being modified to relocate the tanks closer to the administration building and away from the wetland buffer area. The revised design will include a single tank of two million gallons, instead of two tanks of one million gallons each.
- The aqueous ammonia design will be changed to reduce the size of the tank from 40,000 gallons to 27,000 gallons. The design of this system will also be modified to include an automatically activated water spray system that will dilute any ammonia, should a rupture or leak occur. This modification will reduce the maximum aqueous ammonia concentration in the event of a spill within the containment area.
- Based on comments received concerning the lighting aspects of the project, CREC is developing a conceptual Lighting Plan for the CREC facility.
- In response to comments and concerns raised by the Burrillville Building Inspector and Zoning Official, Invenergy is revising the Site Plan to avoid any portion of the site being located within a designated aquifer recharge zone.
In an application filed with the board in October 2015, Invenergy sought the approval of the board to site and construct the Clear River Energy Center, a combined-cycle facility of 850 MW to 1,000 MW, and associated facilities and structures, on Wallum Lake Road in Burrillville. The plant is intended to fire natural gas as a primary fuel and ultra-low sulfur diesel fuel as a backup fuel.
The facility will be configured as a two-unit one-on-one (1×1) combined-cycle station. Each unit will consist of an advanced class combustion turbine operated in a combined-cycle configuration with a heat recovery steam generator, a steam turbine and an air cooled condenser for each train. The combustion turbine, steam turbine, and generator of each unit will be connected via a common shaft. The power generated will be transmitted through a new 345-kV transmission line to be installed from the facility through an existing National Grid right-of-way to the Sherman Road Substation in Burrillville.