Through and attractive pricing arrangement, the Woodruff Electric Cooperative has enticed nearly 85 percent of area farmers to allow their irrigation systems to be shut off when electricity demand is high. The program certainly benefits the participating farmers but the other member owners also save since the cooperative can reduce its need to purchase expensive peak power during critical times of the year.
Woodruff Electric Cooperative Corp, located in Forrest City, Arkansas, is the leading utility of 17 distribution-only electric cooperatives in Arkansas controlling the time when electric power can be used to save their customer’s money. The member-owned electric cooperatives are using load controls to reduce peak demand by a total of 110 megawatts (MW). The cooperatives calculate that the program has allowed them to defer approximately $125 million in infrastructure costs they would have been incurred if their systems had to accommodate the extra demand. Woodruff Electric’s unique cooperation with area farmers has accounted for nearly half (51 MW) of the statewide reductions, preventing its 19,000 customers from paying an additional $5.1 million in 2006.
Woodruff Electric offers a load control electric rate of 11 cents/kWh to members that allow their irrigation systems or air conditioners to be taken off the grid for up to 5 hours per day. The rice, cotton, and soybeans in the area require heavy irrigation, and allowing the irrigation systems to be shut down between 2 and 7 p.m. trims the utilities peak demand. At the end of 2006, Woodruff Electric was able to control electricity to 84% of area irrigators (out of about 5,100 total irrigation accounts). Farmers who do not participate pay the non-controlled rate of 16.5 cents/kWh and typically grow crops that cannot bear fluctuations in water supply.
Currently there are 4,365 radio-controlled boxes in Woodruff Electric’s coverage area. Each box is connected to the control unit of the irrigation or air conditioning equipment. A computer at Woodruff Electric’s headquarters generates a radio signal that is relayed to the devices to control the power supply. The installation of these boxes takes about an hour.
Woodruff Electric’s wholesale billing from its generation and transmission partner, Arkansas Electric Cooperative Corporation, is based on how much Woodruff’s customer base contributes to the peak demand of that year. Therefore when Woodruff can eliminate its contribution to the peak, it can save its members money from reduced wholesale power costs.
Arkansas Business reported that, in 2006, Woodruff Electric’s engineers kicked in the load control systems and prevented the utility from peaking at 124 MW and brought the load down to 72 MW.
- Demand Response and Dynamic Pricing Programs, Policies and Enabling Technologies Publications – Lawrence Berkeley NationalLaboratory