A top Republican is sounding his displeasure with a two-month electric grid study that Energy Secretary Rick Perry is developing, calling it "hastily developed" and anti-renewable energy.

"I'm concerned that a hastily developed study, which appears to pre-determine that variable, renewable sources such as wind have undermined grid reliability, will not be viewed as credible, relevant or worthy of valuable taxpayer resources," Sen. Chuck Grassley, R-Iowa, wrote in a letter to Perry Wednesday.

He said a study from the Energy Department's renewable energy lab finished a recent report on the subject of grid reliability and renewable energy in two years. Perry's effort is meant to be concluded in mid-June.

The Perry study is meant to "explore critical issues central to protecting the long-term reliability of the electric grid," analyzing "market-distorting effects of federal subsidies that boost one form of energy at the expense of others," an April memo to his chief of staff read.

Grassley's state is one of the nation's leading producers of wind energy. "Not only is Iowa's wind energy reliable, it's also affordable," the senator wrote. Grassley added that Perry should understand that as a former Texas governor who often touts the Lone Star state's success with wind energy under his watch.

"As the former governor of Texas, you surely have an appreciation for the enormous economic contributions wind energy is already providing in many parts of the country," Grassley wrote.

He wants Perry to answer a number of questions on who he is contracting to do the study and if any of the federal grid security agencies are being consulted. He also wants to know if a draft of the report will be made public before being made final. He wants the answers by May 25.

Grassley's letter comes a day after all major renewable energy trade groups sent a letter to Perry contributing detailed analysis on why renewables are beneficial to the grid.

"We believe that, taken together, these reports demonstrate that the U.S. electric power system is more diverse in its energy sources than ever before, and due to the flexible way these resources are now managed, becoming more reliable and resilient as a result," the groups said in their letter.

They said they had attempted to contact the Energy Department and were "disappointed" that no attempt was made to return their communications on how to contribute to the study.

The groups had sent letters to Perry over the last month, asking why the process of devising the study was not made public and was not going through the correct notice-and-comment channels in its development.