April 12, 2016 | By Keith Martin in Washington, DC

Oregon moved to phase out use of coal for generating electricity and to increase the share of electricity that comes from renewable energy.

The effort to bar use of coal may land in court.

Oregon Governor Kate Brown signed a bill in March that bars the two major utilities, Pacific Power and Portland General Electric, from supplying any electricity from coal starting in 2030. Portland General can keep an existing coal-fired power plant in Montana until 2035. The two utilities supply about 70% of Oregon electricity.

The bill also increases the state renewable portfolio standard to 50% by 2040. The current target is 25% by 2025. Only four states have more aggressive targets. California and New York require that at least 50% of electricity come from renewable energy sources by 2030, Vermont requires 75% by 2032 and Hawaii requires 100% by 2045.

There are two safety valves under which the state might step back from the new target. First, utilities are not required to add more renewables if the incremental cost to ratepayers will be more than 4% higher than the cost of drawing from non-renewable sources. Second, the Oregon Public Utility Commission can suspend further progress if the new target causes issues with grid reliability.

The coal effort may lead to litigation. Colorado and Minnesota have already had to face off in court with coal interests and utilities in neighboring states over new laws that discourage use of coal.

A public-interest law institute backed by coal interests argued that the renewable portfolio standard in Colorado has the effect of regulating conduct in other states in violation of the part of the US constitution that forbids states from enacting laws that interfere with interstate commerce.

A US appeals court disagreed in 2015. The law institute is waiting for the outcome of a Minnesota case before deciding whether to appeal.

Minnesota enacted a law in 2007 that bars construction of new power plants of 50 megawatts or more in the state that contribute to carbon dioxide emissions unless an offset project is undertaken at the same time to reduce emissions by the same amount. The statute also bars electricity from being imported into Minnesota from such power plants in other states.

North Dakota and various electric cooperatives sued to block enforcement. A federal district court held in April 2014 that the Minnesota law violates the US constitution because it requires coops in other states effectively to seek approval from Minnesota before undertaking a transaction in another state. The case is now before a US appeals court. (For more details about the Colorado and Minnesota cases, see the September 2015 NewsWire article, Renewable Portfolio Standards.)