GUC pursuing pilot project to reduce peak energy usage
By Ginger Livingston
Friday, September 20, 2019
The Greenville Utilities Board of Commissioners awarded a nearly $1 million contact to build an energy savings system that relies on a battery and not a generator.
GUC is launching a pilot project where it will use a 1,000 kilowatt/2,000 kilowatt-hour battery energy storage system to reduce the electricity it buys from Duke Energy Progress during high-demand hours.
GUC is undertaking the pilot project to determine the technical needs and financial feasibility of utilizing battery energy storage systems for future energy saving projects.
The utulity spends about $130 million annually purchasing electricity from Duke Energy Progress through its membership in North Carolina Eastern Municipal Power Agency.
GUC's energy rate is typically 2.5 cents per kilowatt hour, said Kyle Brown, electric planning engineer. During peak hours, when customers of Duke Energy Progress are using larger-than-average amounts of electricity, called the coincident peak hour, GUC's rate increases to $22.52 per kilowatt.
Brown said coincident peak demand charges account for 50 percent of GUC's wholesale cost of power.
To reduce the amount of wholesale electricity GUC needs to purchase during peak hours, large electrical users such as industries and large commercial sites, temporarily draw energy from generators, which are usually fueled by diesel or natural gas. The customers receive credits for using the generators and GUC avoids an estimated $1.2 million in monthly wholesale electric purchases.
Battery energy storage systems aren't powered by fuel. Instead the batteries are charged from the grid during off-peak hours and then turned off during peak hours, Brown said.
These storage systems are advancing because increasing reliance and investment in renewable energy generation requires larger storage systems. Because more systems are being built, the cost is coming down, said Tony Cannon, GUC general manager and CEO.
Brown said the system's length of life also is increasing. If it is charged and then used daily, its life cycle will be shorter. However, the system GUC is investigating retains 80 percent of its output after 20 years of periodic use.
Six businesses submitted bids for the project, which will involve designing and building the system. GUC awarded it to Solar Strata of Durham, which bid $996,200 on the project.
GUC also received a $125,000 grant from the American Public Power Association's Democrat of Energy & Efficiency Development program, which funds research, pilot projects, and education to improve the operations and services of public power utilities.
GUC has budget $1.6 million for the project. Brown said beyond building the system, GUC will have to cover the cost of connecting it to the electric grid, which he estimated to be about $2,500.
Cannon said it will be about 18 months before the project results are known because the system needs to be built and then operated for 12 months.
Water line repairs
The board approved a resolution directing staff to apply for a $1 million loan from the State Revolving Fund to rehabilitate portions of the city's cast iron water distribution system.
Parts of the system date back to 1905 and cast iron was the predominant material used in water lines until the 1960s. Today about 12 percent of GUC's the total distribution system piping is cast iron pipe and much of it needs rehabilitation.
GUC is rehabilitating the piping in sections. The work is done by cleaning out existing pipes and installing a liner, said Scott Farmer, water resources engineer. Rehabilitation is more cost effective and is less disruptive because long lengths of pipe aren't being dug up and replaced. The first project, which was completed in 2018, updated 2,800 linear feet.
Greenville City Manager Ann Wall, who sits on the GUC board, asked why GUC wasn't fixing larger amounts of piping. Cannon said GUC's five-year capital plan is focused on improvements to its water and wastewater treatment facilities. Undertaking more distribution system improvements will change the current rate plan.
The financial services division received three recent honors from the Government Finance Officers Association: Outstanding Achievement in Popular Annual Financial Reporting, Certificate of Excellence in Financial Reporting and the Distinguished Budget Presentation Award, Chief Financial Officer Jeff McCauley said.
Sandy Barnes, retiring director of information technology was recognized for her 16 years of service with GUC and 41 years of contributions in the field of information technology.