Three energy suppliers

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1 Delaware

Regulating growing volatility

Delaware Elec­tric Coop­er­a­tive (DEC) sup­plies approx­i­mate­ly 84,000 cus­tomers in Kent and Sus­sex Coun­ty, Delaware. More and more cus­tomers are adopt­ing res­i­den­tial solar ener­gy feed­ing into the grid, and switch­ing to elec­tric vehi­cles, which is putting an increas­ing strain on the con­sumer side of the grid. Troy W. Dick­er­son, Vice Pres­i­dent of Engi­neer­ing at DEC, remarks: “We were look­ing for solu­tions to com­pen­sate for these fluc­tu­a­tions and came across the VRDT with the Rein­hausen tap-chang­er. We were con­vinced by the fact that the tap-chang­er is built into a trans­former with exact­ly the same foot­print as a con­ven­tion­al trans­former, and is there­fore no dif­fer­ent in terms of instal­la­tion.”

The Delaware util­i­ty has com­mis­sioned two VRDTs at strate­gic loca­tions, each with high fluc­tu­a­tions due to PV sys­tems and EV charg­ing sta­tions. The instal­la­tion was com­plete­ly seam­less and indis­tin­guish­able from that of a con­ven­tion­al unreg­u­lat­ed trans­former, accord­ing to Dick­er­son. Today, the two VRDTs are oper­at­ing accord­ing to plan, and the engi­neer adds, “We will con­tin­ue to use the VRDTs to expand our dis­tri­b­u­tion net­work in places where there are volt­age prob­lems due to PV sys­tems and EV charg­ing sta­tions.”

2 New Hampshire

Keeping costs and outlays of network modernization low

Fac­ing sim­i­lar chal­lenges to Troy W. Dick­er­son is Mike Jen­nings, Vice Pres­i­dent of Ener­gy Deliv­ery, at New Hamp­shire Elec­tric Coop­er­a­tive (NHEC), based in Ply­mouth, New Hamp­shire. With 250 employ­ees, NHEC serves approx­i­mate­ly 86,000 cus­tomers in the rur­al ser­vice area. To solve increas­ing volt­age prob­lems, Jen­nings looked for a cost-effec­tive solu­tion to sta­bi­lize the chang­ing dis­tri­b­u­tion grid. The dis­tri­b­u­tion sys­tem oper­a­tor explains, “In addi­tion to the ini­tial cost, out­lays for net­work mod­ern­iza­tion play a major role in the deci­sion to pur­chase new equip­ment.”

On this point, Jen­nings is already very sat­is­fied with the deci­sion in favor of VRDT: “The instal­la­tion process was very sim­ple and didn’t pro­duce any addi­tion­al work.” And at the end of the pilot phase, if the improve­ment in volt­age qual­i­ty proves to be in line with the goals set, Jen­nings intends to use the VRDT as a cost-effec­tive solu­tion at oth­er net­work points as well.

3 Tennessee

Maintaining manufacturing production through all seasons of the year without an outage

Jason Brown of Hum­boldt Util­i­ties has used a VRDT to solve a very dif­fer­ent prob­lem than his col­leagues in Delaware and New Hamp­shire. As the Oper­at­ing Super­in­ten­dent for the munic­i­pal util­i­ty, Brown and his 45 employ­ees deliv­er elec­tric­i­ty, gas and water to about 4,400 cus­tomers in the Hum­boldt, Ten­nessee, area. “We’ve been expe­ri­enc­ing grow­ing indus­tri­al demand, which has caused fluc­tu­a­tions in our unreg­u­lat­ed grid. One cus­tomer in par­tic­u­lar was affect­ed, and we worked togeth­er to find a solu­tion.” They found what they were look­ing for at anoth­er indus­tri­al cus­tomer of Hum­boldt Util­i­ties, Rein­hausen USA itself, which oper­ates its plant in Hum­boldt.

“The VRDT con­cept won us over right away,” Brown says, not­ing that “Because this reg­u­lat­ing trans­former is only a lit­tle heav­ier than its unreg­u­lat­ed pre­de­ces­sor, all we had to do was replace the poles and make a new plat­form on which to install the VRDT bank. The instal­la­tion itself was then real­ly very easy.” The affect­ed indus­tri­al customer’s volt­age prob­lems are now a thing of the past, and Brown is enthu­si­as­tic: “Any util­i­ty that has volt­age prob­lems with indus­tri­al cus­tomers can best solve them with the VRDT. We will undoubt­ed­ly use this tech­nol­o­gy again.”