Hundreds of solar power plants are under construction in California today.
But five specific plants, proposed for western Stanislaus and Merced counties, will have a significant impact on the Turlock Irrigation District's high-voltage electricity transmission lines.
“They are significant, because they result in in an overload of the Westley – Los Banos transmission line and certain equipment in the Westley switchyard,” said Ed Jeffers, TID Electrical Engineering Department Manager.
Specifically, the five projects combined would put the Los Banos to Westley 230 kilovolt transmission line and switchyard 289 megawatts over load. Generators plan to sell their electricity to other utilities, but first the power must pass through .7 miles of the Turlock and Modesto Irrigation Districts' jointly owned Los Banos – Westley line.
To accommodate the new power generation, TID will undergo a two year, $4.7 million upgrade of the transmission line – at the generators' expense.
On Tuesday, TID directors authorized the first project, Quinto Solar PV, a 111 megawatt photovoltaic power plant planned more than 1,000 acres near Santa Nella. But before ground is turned, the project's developer, SunPower Corp., must give TID either $4.7 million in cash or secured letter of credit, fully encumbering developers for all costs associated with the upgrade. The four pending generation projects will then repay SunPower, ensuring TID receives funding for the upgrade even if a project falls through.
Should costs exceed the $4.7 million, generators will be required to pay TID for the overage.
“We have the right to go in and collect additional payments if what they've secured is insufficient,” said Larry Gilbertson, TID Assistant General Manager of Electrical Engineering and Operations.
The transmission line upgrade will be performed by TID, replacing three towers, four spans of conductor, and adding a communication line. The switchyard work will be done by MID, replacing two circuit breakers and installing new equipment needed to operate the transmission and communication lines.
The construction work will take the transmission line out of service from October through March for the next two years.
The outages won't directly impact TID customers, but will impact district operations. The reduced transmission capacity will drastically limit TID's ability to buy and sell power.
The new power generators will pay the district a fixed, $1.95 million fee to offset the district's costs due to the restrictions, included in the $4.7 million total cost. That fee represents worst-case scenario losses for the district, Gilbertson said.
All upgrade work will be completed by April 2015.