A spate of rulings, which tamper with Renewable Portfolio Standards (RPSs) and tax credits for solar installers in three US states, could setback the progress of solar deployment in the region.

The RPS is a regulation that requires a specific level of energy production from renewable sources such as wind and solar from utility companies and sets green targets for individual states.

Texas has a renewable energy target of approximately 10% by 2015, set by the RPS which was first introduced to the state in 1999.

However, on Tuesday the Senate in Texas passed a bill introduced by Republican Troy Fraser, which would scrap the state's RPS at the end of the year as well as undoing a billion-dollar competitive renewable energy zones (CREZ) initiative.

Meanwhile in North Carolina this week, state House leaders also filed a bill to half the state’s RPS target from 12.5% to 6% and cut it short to finish in 2018 instead of 2021.

Ken Johnson, vice president of communications at the US trade group the Solar Energy Industries Association (SEIA) said: “RPSs are still very important to the future development of clean energy in America. What we are seeing, unfortunately, are more and more assaults on renewable energy, including solar, by conservative groups funded by the billionaire Koch brothers. 

“Frankly, we are in for a very long year in many states, but we have our supporters, too – as well as overwhelming public support.”

In the third case, Governor Martinez of New Mexico vetoed a Senate Bill to extend the Solar Market Development Tax Credit last week. The tax credit benefits homeowners, businesses and agricultural entities that install solar, but after the vetoing of the bill this tax credit will expire in 2016.

New Mexico has an RPS green energy target of 20% By 2020.

The Alliance for Solar Choice (TASC), a US rooftop solar industry group, was disappointed by the veto and claimed that it went against strong bipartisan support in both the Senate and the House.

An association statement said: “Taxes will effectively be raised on New Mexicans who go solar after the tax credit expires at the end of 2016. Governor Martinez jeopardises consumer choice and solar job creation, and puts New Mexico out of sync with the national movement to adopt solar.”

Charlie Hemmeline, executive director at Texas Solar Power Association (TSPA), said: "There is always a concern that changing existing policy creates investor uncertainty which could affect the financeability of solar projects currently in development.  A stable regulatory environment is important for all energy industries and provides the foundation for Texas's well-deserved reputation of being wide open for business.  [This bill] would affect existing negotiated contracts between buyers and sellers that formed the basis for Texas being the national leader in wind energy. "

"The Texas solar market is unique from other states in that the RPS here is not what is driving the planned future market growth or the solar capacity that has been installed to date.  We support the competitive market and customer choice, and we see increased demand being driven by economics and key benefits such as solar's minimal to no water use.  However, a stable business environment is critical to any industry and the changes proposed by [the Bill] could dampen investor interest."
This article was updated from its original version to include additional commentary from TSPA.