The United States could slash greenhouse gas emissions from power production by up to 78 percent below 1990 levels within 15 years while meeting increased demand, according to a new study by NOAA and University of Colorado Boulder researchers.

The study used a sophisticated mathematical model to evaluate future cost, demand, generation and transmission scenarios. It found that with improvements in transmission infrastructure, weather-driven renewable resources could supply most of the nation’s electricity at costs similar to today’s.

“Our research shows a transition to a reliable, low-carbon, electrical generation and transmission system can be accomplished with commercially available technology and within 15 years,” said Alexander MacDonald, co-lead author and recently retired director of NOAA’s Earth System Research Laboratory (ESRL) in Boulder.
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Although improvements in wind and solar generation have continued to ratchet down the cost of producing renewable energy, these energy resources are inherently intermittent. As a result, utilities have invested in surplus generation capacity to back up renewable energy generation with natural gas-fired generators and other reserves.

“In the future, they may not need to,” said co-lead author Christopher Clack, a physicist and mathematician with the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder.

Since the sun is shining or winds are blowing somewhere across the United States all of the time, MacDonald theorized that the key to resolving the dilemma of intermittent renewable generation might be to scale up the renewable energy generation system to match the scale of weather systems.

The continental US is roughly 2,600 miles from east to west. Almost every population center is within 1,000 miles (or far less) of an area with top-notch wind resources. And most are within a few hundred miles of an area with good, if not best-in-class, winds.

HVDC lines are not common in the US, however. Compare the map of HVDC lines in China to that of HVDC lines in the US.

Chile’s solar industry has expanded so quickly that it’s giving electricity away for free.

Spot prices reached zero in parts of the country on 113 days through April, a number that’s on track to beat last year’s total of 192 days, according to Chile’s central grid operator. While that may be good for consumers, it’s bad news for companies that own power plants struggling to generate revenue and developers seeking financing for new facilities.

The main culprit is the northern part of the country, in the Atacama desert. Chile’s increasing energy demand, pushed by booming mine production and economic growth, helped spur the development of 29 solar farms, with another 15 planned, on the country’s central power grid. Now the nation faces slowing demand for energy as copper production slows amid a global glut, and those power plants are oversupplying a region that lacks transmission lines to distribute the electricity elsewhere.
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A key issue is that Chile has two main power networks, the central grid and the northern grid, which aren’t connected to each other. There are also areas within the grids that lack adequate transmission capacity.

That means one region can have too much power, driving down prices because the surplus can’t be delivered to other parts of the country, according to Carlos Barria, former chief of the government’s renewable-energy division and a professor at Pontifical Catholic University of Chile, in Santiago.

Inadequate InfrastructureThe government is working to address this issue, with plans to build a 3,000-kilometer (1,865-mile) transmission line to link the the two grids by 2017. It’s also developing a 753-kilometer line to address congestion on the northern parts of the central grid, the region where power surpluses are driving prices to zero.

“Chile has at least seven or eight points in the transmission lines that are collapsed and blocked, and we have an enormous challenge to bypass the choke points,” Energy Minister Maximo Pacheco said in an interview in Santiago. “When you embark on a path of growth and development like the one we’ve had, you obviously can see issues arising.”