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Interactive Map Compares States’ Renewable Energy Goals

By Matt Zonis


Sun, water, waves, wind… no this isn’t the beginning to an episode of Captain Planet or a tour of power plants in Orbit City courtesy of George Jetson, but real sources of energy that are being harnessed and used to greater or lesser extent today. While it’s true that we still heavily rely on fossil fuels, renewable energy is on the rise, now accounting for almost 10 percent of US electricity generation. This number is only expected to increase, in part due to rising demand for renewable electricity from individual states in the absence of a national mandate. For many reasons, including a goal of encouraging economic development and the growth of the clean tech sector, many states have taken it upon themselves to increase their use of renewable energy by implementing policies known as Renewable Portfolio Standards (RPS).

Simply put, an RPS is a goal set by an individual state that requires that a certain percentage of electricity sold to customers within that state be produced by renewable sources by a specified year. Currently, 36 states have an RPS. For instance, in Hawaii, which has the most ambitious RPS, 40 percent of electricity sold to customers must come from renewable sources by 2030.

While the basic idea of an RPS is the same throughout all of the states, no two states have the same exact RPS.

Some states, like North Dakota, Oklahoma, South Dakota, Utah, Vermont, and Virginia, have made their RPS goals voluntary, while the other 31 states with RPS goals instituted mandatory standards.

In some states, renewable energy technologies are not always treated equally. Some states have technology minimums, also known as “carve outs,” which require that a certain percentage of their energy come from a specific source, like wind or solar. In Maryland, for example, in addition to meeting their RPS of 20 percent by 2022, the state also has to ensure that at least 2 percent of its total comes from solar energy.  

Interestingly, the fact that many states are pursuing different RPS goals, while others are holding back from pursuing an RPS at all, is one of the main reasons many energy companies and policymakers say there needs to be a national energy policy to give companies more regulatory certainty to further encourage renewable energy production.

In most instances, states divide their renewable energy sources into separate tiers, with each one allowed to count for a certain percentage of the total RPS goal. Most states divide their tiers into ones that include already established renewables, such as solar and wind, along with other tiers that include a hodgepodge of unproven but promising technologies and more minor renewable energy sources.

As an example, let’s look at the way Connecticut’s RPS, which calls for 27 percent renewable electricity by 2020, breaks down.

Tier Eligible Technology Percent contribution
Class I Solar, wind, fuel cell, wave, tidal, biomass, certain new hydropower plants 20%
Class II Trash-to-energy facilities, existing hydropower plants 3%
Class III Combined heating and power (CHP) systems-installed after 2005. Waste heat recovery systems installed after 2006. 4%


Not all states allow the same energy sources to count towards their RPS goal. For example, some differentiate between large or small-scale hydropower plants, and at least one (Ohio) includes advanced nuclear power in its RPS.

In addition to getting to the RPS finish line, some states have annual or biannual checkpoints that need to be met along the way. Starting in 2009, Illinois made electricity producers begin supplying 2 percent of their electricity from renewable sources, gradually moving the bar higher each year until the goal of 25 percent is reached by 2024.

To help give you a better understanding of how states are doing on their RPS goals, we’ve made this interactive graphic profiling the RPS in each state and providing for comparison the fraction of electricity generated from renewable sources in the state in 2009 (the most recent data available at the time we produced the graphic). Some states have no RPS, but are still generating some of their electricity from renewable sources, as we show in the graphic. 

For all 50 states in the graphic you’ll find links to the Database of State Incentives for Renewable Energy (DSIRE),which is funded by the U.S. Department of Energy. The DSIRE is an ongoing project of the North Carolina Solar Center and the Interstate Renewable Energy Council.

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