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An interstate for renewable energy could hold costs level, study finds

Photo by Fré Sonneveld

Though it relies on credible data and has a lot of expert number-crunching behind it, you could call it more of an elegant thought experiment than engineering plan.

Still, a paper published this week in Nature Climate Change reaches some striking and encouraging – even compelling – conclusions about finding our way painlessly to an affordable energy future within the next 15 years.

Here’s how researchers at the National Oceanic and Atmospheric Administration and a research institute at the University of Colorado think it could work (my emphasis added):

Our results show that when using future anticipated costs for wind and solar, carbon dioxide emissions from the U.S. electricity sector can be reduced by up to 80% relative to 1990 levels, without an increase in the levelized cost of electricity.

The reductions are possible with current technologies and without electrical storage. Wind and solar power increase their share of electricity production as the system grows to encompass large-scale weather patterns.

This reduction in carbon emissions is achieved by moving away from a regionally divided electricity sector to a national system enabled by high-voltage direct-current transmission.

As the utilities never tire of telling us, The Whole Problem with wind power (or solar) is that – repeat after me, class – it’s only useful when the wind is blowing (or the sun is shining).

Even then its usefulness is further limited, at least in theory, by demand. Because large-scale storage has proved to be such a vexing problem, it is assumed that any wind or solar power that can’t be consumed immediately must be discarded.

The new paper grew from a different assumption: Across an area as large as the United States, shouldn’t the wind be blowing somewhere (and/or the sun shining) at pretty much any given moment?

A research team led by Alexander MacDonald of NOAA’s Earth Systems Laboratory in Boulder, and Christopher T.M. Clack of the university’s Cooperative Institute for Research in Environmental Science (CIRES), gathered weather data and mapped it to very fine scales of space (13 kilometers) and time (hourly variation).

58% renewables without cost increase

They found that, indeed, wind or sunshine or both are blessing some portion of the country all the time, and in sufficient quantity to provide potentially 58 percent of national demand by 2030 without raising costs, under the likeliest market conditions.

MacDonald and Clack argue that the limiting factor for renewables’ contribution to U.S. energy needs isn’t how much wind and sunshine we have, or whether there’s enough demand for the volts the moment they’re made, or whether the excess can be stowed as compressed air, pumped water, hot sand, etc.

Rather, they say, it’s a problem of distributing renewable power from all of the places it could be made to all of the places it could be used.

Correcting that problem could instantly change the U.S. power system from its present shape, where utility-scale wind and solar essentially displace conventional power, to its exact opposite, in which boilers fired with coal, natural gas or nuclear fission could be used to buttress and balance a system driven mostly by the sun and wind. Which means a lot of conventional plants could be retired, and many of the rest dialed down dramatically.

And to put the greenhouse gas impact in perspective, an infrastructure change that delivered a 78 percent reduction in CO2 output from the electric power sector by 2030 would exceed by almost two and a half times the 32 percent reduction sought by President Obama’s Clean Power Plan – without raising the cost of electricity.

Or,  to be more precise, without raising the levelized cost of electricity, which is the best way to  look at these things, and the only fair way to compare the costs of electric power from different sources.

And you don’t need to be an economist or energy geek to get it.

Renewables’ cost advantage

Levelized cost is the number you get, typically in cents per kilowatt hour, if you add up all the costs to make electricity at, say, a coal-fired power plant – construction, coal purchases, payroll, maintenance, fines for violating air-quality standards, etc. – and then divide that total by the plant’s lifetime output.

When you consider the low construction and operating costs, and zero fuel costs, for wind and solar  installations, you can see how renewables gain their cost advantage over fossil-fuel plants that have much larger generating capacities  – and also why the falling prices for solar photovoltaic cells in particular are so transformational right now.

For this study, the researchers used the International Energy Agency’s assumption that the levelized cost of electricity to U.S. consumers in 2030 will be about 11.5 cents per kWh (in 2013 dollars), or about the same as it is right now.

To be sure, the upgraded grid would be a major project, likened by the authors to building of the Interstate Highway System, with a new network of high-voltage, direct-current distribution lines at its core.

I couldn’t find a clear figure in the paper for what the DC project would cost; these guys like to break it down into percentages, rates per gigawatt of generating capacity and so on.

However – and here’s the figure that really matters – they estimate that the improved grid would add a mere 4 percent to the total production and distribution costs.

Apart from avoiding the need to build a storage component that nobody can quite envision yet, the new grid would also provide major gains in efficiency and resilience over the current system of regional grids (think of the blackouts after Hurricane Sandy, or another 9/11 attack).

Water savings, too

And the shift to greater reliance on renewables would pay dividends beyond greenhouse-gas emissions. For example, it would reduce cooling-water consumption in the electric power sector by a startling 65 percent.  

It would take up some land, of course: perhaps seven-hundredths of 1 percent, they calculate, most of it well away from currently developed areas.

The paper has not yet attracted a lot of attention outside the trade and professional press, but Nature did publish a commentary by Mark Jacobson, a professor of civil and environmental engineering at Stanford, who wasn’t involved with the work but found it both novel and important.

In fact, he thought there were additional upsides:

One limitation of the study, which could be addressed with future research, is that it considers the electric power sector before the electrification of other energy sectors (transportation, heating/cooling and industry). Electrification of other sectors has already started, and may occur even more in the future.

Further, it assumes the excess electricity generated by wind and solar is discarded rather than used for some other purpose (for example, hydrogen production or district heating), thereby increasing overall costs slightly.

Which, if other electricity-consuming sectors continue to grow, need not be  the case.

* * *

I really wish Nature were making these papers available without charge, given their policy significance. If you’re willing to pay for access, however, you can find the MacDonald/Clack paper here, and the Jacobson commentary here. You can also see the authors explain their work in this short video.


MinnPost event: On Monday, Feb. 22, MinnPost’s Earth Journal Circle will present its fourth annual event focusing on substantive discussion of critical issues in the environment. This year’s topic is “Land of 10,000 Lakes: Can We Achieve Water Sustainability?” The speaker is Deborah Swackhamer, former director of the University of Minnesota’s Water Resources Center, who will discuss issues threatening regional water quality and quantity. Earth Journal writer Ron Meador will moderate the Q&A session.

Comments (5)

  1. Submitted by Ray Schoch on 01/28/2016 - 10:24 am.

    To an amateur’s eye

    …this looks like a great idea, albeit one with substantial, perhaps insurmountable in today’s political climate, political and practical obstacles. Allow me to exhibit my total ignorance of electrical engineering by mentioning that, while I have no idea what’s happening at the generating end, at the plug-in-the-wall retail end of our current electrical system, we operate on *alternating,* not *direct,* current.

    Do generating plants, at present, produce power in A.C. or D.C., and in which mode is it sent, at present, along the big wires hanging from equally-big transmission towers? Switching over – if that is, in fact, a necessary part of this plan – from A.C. to D.C. entails genuinely huge costs at the retail end.

    If power plants currently (no pun intended) produce power that’s supplied as A.C. already, then none of the preceding anxieties have merit, and we could enjoy the benefits of a national grid as stated in the article. If power plants currently produce power in D.C. and it’s already transformed to A.C. somewhere along the way so that it’s usable in households, it’s also a situation where massive adjustment is not necessary. That said, however, I have no appliances in my home, including the computer on which I’m writing this, that operate on direct current.

    Perhaps more to the point, what are the chances that coal and other fossil fuel companies, and utility executives at the existing regional level, will embrace a change of this type and magnitude? That’s what I think, too. That such a change would likely produce quite a few jobs during the changeover, and that the result would be more reliable and less vulnerable to attack (for those who worry about such things) might not count for much in the face of big contributions to the campaign coffers of politicians already in office, or seeking it. There’s plenty of evidence that fossil fuel companies have far greater influence on legislation and utility rates than individual citizens, or even groups of citizens. We have the pollution problems we do surrounding power-generation precisely because fossil fuels have had a century and more to become entrenched industries, with political clout that overwhelms that of ordinary citizens except in rare instances where there’s enough outrage among the members of the public to overcome other ideological and geographic divisions.

    On the other hand, and because I’m *not* an electrical engineer, maybe the technical issues are relatively minor ones that we already know about. If that’s the case, then the primary obstacle may well be political, which can be, and often is, far more difficult to overcome than any number of technological problems.

    • Submitted by Joseph Senkyr on 01/28/2016 - 12:50 pm.

      Power plants generate AC, and AC is much easier to step up and down to different voltage levels, and, when problems occur, AC faults are much easier to break.

      For this reason, local distribution grids, and even regional transmission grids will always be AC. But, for very long, very high capacity transmission lines, the efficiency gains of DC make it worth it to invest in the conversion equipment at each end. It isn’t even particularly new technology – the two DC lines in Minnesota, running from large coal plants in Western ND to the Twin Cities and Duluth, were built in the 70s. Its just that DC transmission only makes sense if you need to move a lot of power a long ways, AND you don’t need to tap into the line except at the ends. This is pretty much only the case when power plants have to be sited far from the load centers they serve, but with renewable energy, that winds up being the case all the time. It’s definitely more of a political problem than an engineering one.

      Additionally, all electronic devices, like your computer, actually run on DC. It’s just much cheaper and safer to distribute AC around and do the conversion right at the point of use.

    • Submitted by Todd Hintz on 01/29/2016 - 01:48 pm.

      Power Convesion

      If you’re using a laptop, look at the brick that’s inline between your outlet and the computer. If you flip it over and look at the label, it’ll say “AC/DC converter.” Other appliances, such as your desktop computer, have that function built into them so you don’t even see the converter unit.

  2. Submitted by Greg Kapphahn on 01/29/2016 - 08:40 am.

    This Can Be Done

    and would likely be accomplished at far lower cost (figuring in inflation),…

    than the interstate highway system.

    There is, of course, an underlying and very powerful resistance to everything having to do with alternative energy:

    There are a lot of hard working regular folk whose jobs and incomes are dependent on our continuing use of dinosaur energy,…

    and a lot of LESS hard working but very wealthy owners and managers whose much higher incomes are also dependent on our continuing use of dinosaur energy.

    All of these folk are, quite naturally, resistant to having their lives change as our energy use changes.

    It would, of course, be fair and just to assist, retrain and otherwise smooth this transition for those whose jobs will disappear,…

    but sadly, most of those folks live in the very kinds of “conservative” areas where leaders, neighbors, and even those workers, themselves, have always tended to blame the victims of this kind of upheaval for their own misfortune,…

    and figured those other folks should just “pull themselves up by their own bootstraps,”….

    (without realizing that that statement was originally an ironic joke which played on the reality that it is absolutely physically impossible to actually do so).

    Rather than assisting those who will suffer job losses as the result of the regional “outsourcing’ of US energy sources,…

    the political and business leaders in areas currently involved in the extraction and exploitation of dinosaur energy will manipulate regular folk into attacking those whom they are led to hold responsible for that outsourcing,…

    (the same government folk who be most likely to help those in temporary need),…

    convincing them to act against those hard working folk’s own natural interest in accomplishing a reasonable transition from their dinosaur energy jobs to whatever comes next,…

    and their natural interest in leaving a livable planet behind for their children and grandchildren.

    I hope and pray that this manipulatively-and-dishonestly-created resistance to such important and necessary changes in our nation’s energy infrastructures will be overcome,…

    sooner than later,…

    lest we all come to suffer for our willingness to protect the stability of our own lives,…

    and willingness to continue to allow ourselves to be manipulated into ignoring our own self interest by “echo chamber” conservative news sources,…

    who play off our resistance to following the advice of others, no matter how good and reasonable that advice might be,…

    at the cost of creating massive instability in the lives of those who follow us,…

    and perhaps even our own lives (if the “tipping points” of massive climate change arrive sooner rather than later).

    • Submitted by rolf westgard on 02/04/2016 - 01:04 am.

      Many dinosaurs

      were big and powerful like our nukes and coal plants. Prairie Island cranks out 8 billion round the clock kWh. You could cover MN with solar panels and not equal it. On some of these long and quiet winter nights things would be pretty helpless on renewables. They are useful supplements, not base load.

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