Renewable electricity generation will have to increase by 50 percent by 2030 to meet ambitious state requirements for wind, solar and other sources of renewable power, according to a new report from Lawrence Berkeley National Laboratory.

The report looked at Renewable Portfolio Standards (RPSs)—commitments set by states to increase their percentage of electricity generated from sources of renewable energy, typically not including large-scale hydropower. Twenty-nine states and Washington, D.C., currently have such standards, covering 56 percent of all retail electricity sales in the country.

“I think that the industry is quite capable of meeting that objective cost-competitively and, actually, then some,” said Todd Foley, senior vice president of policy and government affairs at the American Council on Renewable Energy.

Seven states—Maryland, Michigan, New York, Rhode Island, Massachusetts, Illinois and Oregon—as well as Washington, D.C., have increased their RPS requirements for new wind and solar projects since the start of 2016. No states weakened their RPS policies during this time. Some of the most ambitious requirements are in California and New York, which require 50 percent of electricity to come from renewable sources by 2030, and Hawaii, which requires 100 percent from renewables by 2045.

RPS policies have driven roughly half of all growth in U.S. renewable electricity generation and capacity since 2000 to its current level of 10 percent of all electricity sales, the national lab’s report shows. In parts of the country, the mandates have had an even larger effect—they accounted for 70-90 percent of new renewable electricity capacity additions in the West, Mid-Atlantic and Northeast regions in 2016.

“They have been hugely important over the years to help diversify our power mix and send a signal to investors and developers alike to put their resources in the deployment of renewable energy,” Foley said.

Nationally, however, the role of RPS policies in driving renewable energy development is beginning to decrease as corporate contracts from companies that have committed to getting 100 percent of their electricity from renewables, and lower costs of wind and solar, play an increasing role.

From 2008 to 2014, RPS policies drove 60-70 percent of renewable energy capacity growth in the U.S., according to the report. In 2016, the impact dropped to just 44 percent of added renewable energy capacity.

The increasing role market forces are playing in driving renewable energy generation is seen in a number of states with no RPS policies.

In Kansas, for example, wind energy provided 24 percent of net electricity generation in 2015, up from less than 1 percent in 2005, according to the U.S. Energy Information Administration. Similarly, wind power provides roughly one quarter of net electricity generation in Oklahoma and South Dakota, states that also lack RPS policies. Some of the generation in each of these states may be serving RPS demand in other states, or, in the case of Kansas, may be partly a result of an RPS that was repealed in 2015, lead author Galen Barbose said.

With some states considering further increases in their renewable energy standards, the policies are likely to continue to play a significant role in renewable energy development, Foley said.  

“They have been very important,” he said, “and I think they’ll continue to be.”