If You Like Wind and Solar, You’d Better Like Transmission Lines, Too

If you want more of this....
If you want more of this….

by James A. Bacon

Wind and solar power are becoming increasingly competitive with fossil fuels and nuclear as an electric power source. As Virginia integrates more renewable energy sources into its electric generation mix, a big question is how much can the power grid handle before the intermittent nature of blowing winds and sunny skies threatens the reliability of electric service. The answer, according to PJM Interconnection, is quite a lot.

... you need to build more of this.
… you need to build more of this.

PJM, the Pennsylvania-based entity that oversees the reliability of the electric grid in a multi-state region in the Mid-Atlantic and Midwest, including Virginia, commissioned GE Energy Consulting to examine the issue. The conclusion:

The PJM system, with adequate transmission expansion and additional regulating reserves, will not have any significant issues operating with up to 30% of its energy provided by wind and solar generation. … No insurmountable operating issues were uncovered over the many simulated scenarios of system-wide hourly operation. …

Bacon’s bottom line:

This is not news to anyone in the electric power industry — the study is a year old. But it’s news to me, as I slowly climb the learning curve on this topic, and it may be news to readers who have been moving up that learning curve with me, not to mention legislators who shape the regulatory environment for Virginia utilities.

There is one critical caveat in the quote above that bears close attention: “with adequate transmission expansion.”

PJM’s grid could handle 20% renewable penetration with modest requirements for new transmission lines, the study states, but costs soar at the 30% level. Depending on the scenario, PJM estimates that the regional grid would require construction of between 754 and 2,946 total miles of transmission lines ranging in cost between $3.7 billion and $13.7 billion.

Under the 30% renewable-penetration scenario, PJM assumes that much of the power will originate in Midwest states with strong, steady winds where wind power is most economical, and the grid will need transmission capacity to move electricity to markets in the east. But even with solar-intensive scenarios, new transmission lines also may be needed on a local level as power companies reconfigure the flow of electricity from decommissioned coal, nuclear and, eventually, gas-fired generating stations to the solar facilities.

And that raises a new question: Can power companies build those transmission lines on a timely basis? Environmental and landowner groups put up staunch resistance to the construction of intrusive high-capacity transmission lines through wilderness, countryside and areas of historic value, as has we have seen on numerous occasions in Virginia. These conflicts can be protracted. Friday night, for instance, the U.S. Army Corps of Engineers held another public hearing on the proposed Surry-Skiffes Creek transmission line, even as Dominion Virginia Power warned that the line will take at least 18 months to construct and will create a months-long window of vulnerability when it shutters two coal-fired units at its Yorktown Power Station. Residents and businesses on the Virginia Peninsula face a high likelihood of rolling blackouts in 2017.

The re-engineering of the electric grid to address the global problem of climate change could result in more intense conflict at the local level over disruption to wildlife habitat, soil erosion, water quality and other environmental values — not to mention economic disruption. Virginia has only begun to grapple with this contradiction.

(Hat tip: Kevin Chandler.)

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23 responses to “If You Like Wind and Solar, You’d Better Like Transmission Lines, Too”

  1. I won’t argue that wind farms usually need additional transmission development, especially the large wind farms in the Great Plains. Lack of large scale transmission is curtailing further wind development in some areas now.

    However, in the southeast we don’t have a large wind resource and the developments will be much smaller. Many will be located on ridge tops, so no nearby transmission will likely be available. These smaller developments could probably use lower voltage pole-strung sub-transmission rather than the huge steel lattice towers most people associate with transmission lines. It would depend on the size of the development.

    As for solar development, Dominion’s first installations are proposed for power plant sites to utilize existing substations and transmission lines. If Dominion insists on developing only utility-scale solar facilities that they own, more transmission will be required. However, if policies allow business and residential development of solar – hundreds, perhaps thousands of megawatts of solar can be installed on commercial, industrial and government building rooftops without requiring any land or new transmission lines.

    Developing only large scale solar facilities is an extension of a 20th century central station utility mindset. One of the great advantages of solar is that it can be easily distributed. This increases grid reliability, reduces variability in output (because it is more widely dispersed), and does not require new transmission lines.

    The utility industry is in much the same place as the computer industry in the 1980’s. Most organizations could only envision a mainframe centered world. When distributed computers (PC’s) came on to the scene they were ridiculed as a passing fad with little value. Now we can’t imagine our life without them. The same will probably happen with renewables (and energy efficiency). The world of unsightly huge power plants and transmission lines will be a sign of a less enlightened age.

    The majority of the cost advantage of large scale vs small scale solar is because the cost of transmission needed only for the large installations are not included in the cost of the solar facility. Although fixed costs such as site permitting and planning are lower when spread over a larger facility.

    You propose that the 21st century solutions will only increase conflict. I am very puzzled as to why you would think that is true. First by applying energy efficiency appropriately the economy would thrive without the need for more energy (or new transmission lines). Where new generation was needed it would be sited only on buildings of willing participants. Some adjustments might be required in the distribution grid but no new transmission lines would be needed. Where is the environmental impact or economic disruption? It is this new way of envisioning our energy solutions that Virginia has not begun to grapple with. I believe your blog is serving an important function in beginning the conversation.

    1. As a matter of fact, the proposed Apex wind farm is located right next to a Dominion transmission line, so hooking up to the grid will not be a problem for that particular facility. But on-shore wind in Virginia has very limited potential, so we’ll only see a little of it. It will never account for more than a tiny sliver of Virginia’s energy. Meanwhile, off-shore wind is still massively uneconomical at this point in time.

      You may be right to say that small, distributed solar sources would create less need for added transmission. That sounds like a reasonable proposition, although I would like to hear what the electric utilities themselves have to say about it.

      But where is the solar industry headed? Will it be highly distributed in Virginia, or will it be utility scale? What are the comparative economics of the two paths? I’m still not sure what the economics of solar look like in this state. I’ve been digging into Dominion’s deal to supply solar power to the Norfolk Naval Station, but the Navy has been really unresponsive so far. Hopefully, the Navy will be forthcoming.

      1. Given the decreasing cost of solar and the requirements of the CPP, Dominion is planning to add 3170 MW of combined cycle generation (one plant in 2022 and one in 2030) and 3820 MW of solar by 2030, plus some peaking units.

        Both Dominion and Duke Energy are seeking to use their influence over their state legislatures and regulators to make it difficult for customers and third-parties to develop solar, thus limiting greater adoption of the technology. Utilities want to own it all because they make more money when they do. When a customer installs solar it reduces the utility’s revenue and makes it more difficult to attract investors.

        The SCC is pushing back requiring Dominion to evaluate third party proposals for their 20 MW Remington pilot project. But regulators must find ways to keep utilities healthy so that a more robust intelligent grid can be developed. The path to a more sensible energy will be a delicate one with many need to balance.

        The proposed Surry-Skiffes Creek transmission line is a perfect example where a third way should be found. The two opposing positions of “build-it/don’t build it” will grind each other down until only bad solutions remain.

      2. Jim, I hope you get some answers from the Navy; this would be a terrific case to study on several levels.

        As for the solar path forward, I think we need both DG and central station (CS) solar generation in Virginia, to serve two very different markets. The CS model lends itself to understanding the economics of larger scale projects to serve large commercial customers in the mid-Atlantic, like Amazon and the Navy, but there are many others watching. DG is the future for the small customer who wants to do something green that also saves him money. Cumulatively both can make a huge contribution.

        1. I agree. However, I would characterize a 20-30 MW solar installation located at an industrial or military site as distributed generation – not central station. Although utility scale, it is designed to serve a local load and no transmission is required to distribute it for general consumption.

          1. For what it’s worth, the Navy won’t be using locally generated electricity. The solar plant will be located in Dominion’s North Carolina service territory.

          2. I don’t know any of the details of this project. But locating generation off-site seems to be a lost opportunity. The military is attempting to reduce costs at bases around the world, as well as increase energy security. Check out the energy efficiency project nearing completion at Oceana NAS.

            If the naval base developed a microgrid, plus energy efficiency, and perhaps gas-fired combined heat and power units – a smaller solar installation on buildings, parking lots and open land might be all that is needed to provide nearly all of the base’s energy requirements.

            As you describe it, 10% of the solar energy produced will be lost via transmission. This is an example of the old (non-system approach) thinking that I have been complaining about. Fewer taxpayer dollars would have been used with a more comprehensive solution.

          3. We quibble. Injecting 30 MW into the grid in eastern NC and extracting an equivalent amount from the grid in Norfolk VA is a use by Dominion of PJM’s network transmission service (indistinguishable from any other delivery from generation to retail load) regardless of how Dominion bills its retail customer for it. Someone (the Navy?) will be paid by PJM the locational marginal price for the energy received in NC, and likewise Dominion will pay PJM the locational marginal price for the deliveries in Norfolk; this automatically reflects losses. From that perspective PJM does not care whether Dominion and its customer call this a “microgrid” arrangement or manna from heaven; the microgrid concept is a pure legal and contractual fiction anyway. From a physical point of view, the impact of a 30 MW generator on the transmission facilities in eastern NC is to my way of thinking more akin to that of CS than DG but there is no bright line between these.

          4. Acbar,
            You are exactly right about how the PJM transaction would proceed – as usual. Your experience is a valuable addition to our discussions.

            My comment about the microgrid has more to do with the ability of the base to island itself from the greater grid, so in case of a general outage it could maintain some of its normal operations – if had onsite generation.

    2. “When distributed computers (PC’s) came on to the scene they were ridiculed as a passing fad with little value. Now we can’t imagine our life without them.” Yes, yes! Distributed generation (DG), especially solar, is the way to think about the real possibilities for renewable-resource generation in the mid-Atlantic region. DG spread over a 12-state area the size of PJM has the geographic diversity to match one portion’s cloudy day with another’s bright sunshine, etc.; and DG is located right where you need it, adjacent to loads.

      But, DG of the renewables variety is not going to replace the need for baseload generation; it is a logical, even necessary, component of an efficient Grid, but only up to a point. If we can get folks thinking in terms of even 10% renewables, let alone 20%, that will be huge! And the transmission obstacles to that first 10%, especially if built as DG, aren’t that great, and won’t have that big an environmental impact. That’s the message I hope Jim gets out of this exchange. The Surrey-Skiffes Creek controversy is a product of retiring 40+ year old obsolete (but still-needed) generators, not of decisions to build new ones.

      Energy efficiency improvements are a way to reduce load growth and ought to be pursued for the cost savings that can be achieved there. There too we certainly should go after the low hanging fruit and reap the benefits. But there too the savings become harder and harder to achieve the more you press for greater efficiencies. DG has fewer upside limitations, in my opinion, and deserves greater attention locally if only because DG has been so neglected by Dominion.

      1. Acbar,

        Excellent comments, especially about DG being the wave of the future.

        I take issue with only one point. Designers of energy efficiency measures have found that when designing new buildings or retrofitting old ones, that you can push through the cost barrier so that more energy efficiency actually becomes cheaper. This happens when systems that are merely tinkered with when investing in only a little energy efficiency are substantially reduced in size or not needed at all when more is invested in efficient systems.

        An example would be when energy efficient windows or lighting systems (LED’s) are used heating and cooling systems can be dramatically downsized, saving capital costs and ongoing operating costs.

        1. Yes, I wasn’t thinking about energy efficiency from the new construction point of view but from retrofitting. If you’re talking about long-term impact I agree, building-insulation and design improvements are the way to make the biggest difference, due to the large portion of electricity consumption devoted to heating and cooling. Most electric utility efficiency programs today, unfortunately, focus on the cost/benefit of discrete changes that can be made to what the customer already has in place, like specific kinds of lighting. It’s darned difficult to give a new-home-builder the incentive to install better insulation and efficient-design features unless the customer values the result enough to pay more up-front for the house that has it; the builder won’t pay those utility bills. And there’s a dumb building code obstacle or two out there. The real key is home-buyer opportunity cost awareness — the same educational hurdle, I believe, as for any really decent level of penetration by residential solar DG.

  2. Three quick comments:
    1. “Residents and businesses on the Virginia Peninsula face a high likelihood of rolling blackouts in 2017.” True ONLY IF Dominion doesn’t get permission to delay the Yorktown retirements (they have already asked) AND IF Dominion cannot implement other (expensive) emergency measures such as paying large customers to interrupt loads and strategic placement of portable generators in Newport News in time. I don’t mean to minimize the seriousness of the situation, but cutting off customers involuntarily would be a really desperate last resort for any public utility.
    2. “Even with solar-intensive scenarios, new transmission lines also may be needed on a local level as power companies reconfigure the flow of electricity from decommissioned coal, nuclear and, eventually, gas-fired generating stations to the solar facilities.” Yes, solar and wind generation (particularly wind) have to be placed where the resource is, which probably won’t be where old-style generation is located today. BUT neither solar nor wind is going to bring about many baseload gas and nuclear generation retirements in the near term. Even 30% penetration of “renewable resource” generation by 2025 — a very ambitious goal — means 70% will still be the other stuff (with a higher percentage when the sun isn’t shining and/or the wind doesn’t blow), and that’s 70% of a larger total if there is overall load growth. What the new Grid will have to be is more flexible, to deal with a wider range of generation and load configurations.
    3. You point out the two kinds of transmission improvements needed, interregional (to deliver more midwest power) and local (to receive power from local wind/solar sites). The former are indeed a big deal with long lead times. As for the latter, PJM rules require the generation owner/builder to pay for all transmission improvements needed locally to inject its power into the grid. That means, of course, that the builder first looks for a location that will involve the least expensive fixes — ideally, a location near existing transmission with unused capability. Throw in cheap land and local political support and you’ve got an attractive site! Virginia still has many of these. The crunch to build additional local transmission to reach more such sites will be a few years down the road, when the “low hanging fruit” locations have been taken.

  3. LarrytheG Avatar

    God forbid – you use that blasphemous word – ‘green’. That will make it all the freaking worse!


    did not see the projected date when we’d see 30% “penetration” ..but my guess is there is plenty of time to upgrade the grid and as Tom has surmised – huge additional energy efficiencies… coming onto the marketplace.

  4. LarryG, PJM did not forecast 30%, in fact they focused on a range of outcomes the most reasonable of which it seems to me were “14% RPS” and “20% LOBO” as forecast for 2026. The 30% cases were a look at Grid impacts at the outer limits of feasibility. For all the assumptions and conclusions see: http://www.pjm.com/committees-and-groups/subcommittees/irs/pris.aspx, then click on “Executive Summary” and go to pp. 1-6 or so.

  5. Rowinguy Avatar

    Note also in the quote Jim supplied from the GE study that “with adequate transmission expansion and additional regulating reserves” much more wind can be accommodated on the PJM grid.

    Much of this good discussion has focused on solar, not wind, and little if any on the identified need for “additional regulating reserves.”

    Like many of you, I foresee a steadily increasing presence of distributed solar and even low-grade industrial solar that should require very little transmission or additional regulation, but if we start talking about building 1000 mile transmission lines from the central plains to the Appalachians to bring industrial scaled wind resources, I don’t see that happening anytime soon, maybe when fracked nat gas starts to get questionable.

    Remember, PJM had grandiose plans to bring coal by wire from Ohio and West Virginia to its eastern side a few years ago and most of those lines never got built.

    1. Ah, someone else with a long memory. “Coal by wire”! Be still, my heart. Maybe in the short term Dominion could build a new transmission line along the route of the ACP, in lieu of that underground pipeline, and call it “Shale by wire.”

      You are correct there is an important role for “regulation” power, in the technical sense of that term, in operating a grid with large amounts of wind power connected to it. You undoubtedly know that PJM has a separate market for regulation power already.

      1. LarrytheG Avatar

        re: coal by wire, shale by wire – replacement power to Hampton via wire down I-64 rather than across the James…

        e.g solar on Eastern shore into grid via Delaware… why not wind in the same location – also?

        methinks if moving power across the US – was really feasible – it would be EASY to EXPLOIT the very best power sources where they are – and then just move the power to where it is needed.

        all those windswept wilderness places with hydro and wind in canada – would power the US… Canada would become one humongous pump-storage geography… run the turbines during the day … pump them back at night…. yadda yadda..

        and that’s just for the folks that don’t have on-site capability!

        the “informed” here KNOW what’s feasible and reasonable on these issues and what is not – but it’s not yet quite bleeding through to the less informed like this guy.

        what’s the limiting factors .. that will drive the solutions?

        yes.. we’re up early today -it’s what you do when you start work at 5am… to enable voters to deliver their verdicts…

        1. “Methinks if moving power across the US – was really feasible – it would be EASY to EXPLOIT the very best power sources where they are – and then just move the power to where it is needed.”

          Yes. And yes.

          The problem alluded to here is, how to move massive amounts of new power from a location already exporting power regularly. That’s the Midwest, the old Rust Belt, the new Wind Farm Central. Transmission lines east from there are already massive, and already often fully filled to capacity. They used to call those lines “coal by wire.” A more accurate description would be “baseload by wire” — line constructed to sell and deliver both coal and nuclear generation, originally built to serve Midwest industries that no longer exist, to eastern utilities who could buy it cheaper off the grid than generate it locally. Delivering more Midwestern power eastward would require big new transmission lines.

          You also mention, “all those windswept wilderness places with hydro and wind in canada” — perhaps you did not know, we already have huge transmission facilities devoted to bringing that cheap Canadian hydro power to the US? In fact, those lines are so long, and the current so strong and potentially unstable, that they cannot be operated as alternating current facilities but must convert the a/c in Quebec to direct current, which is converted back to a/c at the destination in New England.

          The biggest limiting factors affecting PJM and Virginia are 1. the up front (capital) cost of the transmission facilities, 2. the cost of permitting, including overcoming environmental opposition, and 3. the electrical losses which will be experienced from transmitting the power.

          You also ask, “solar on Eastern shore into grid via Delaware… why not wind in the same location – also?” Well, yes, you could, assuming you put the wind in the same places as the solar and in similar quantities. Off-shore wind, however, would mean crossing the wide, EPA-protected coastal marshlands to reach the existing grid on higher ground. On shore wind would do better on a mountain ridge in WV. And, any really big wind farm would overwhelm the existing transmission on the Eastern Shore and require significant rebuilding and enlarging of what’s already there. And, there is a wrinkle with wind, moreso than solar, that you need regulating power from another generator nearby to make it all work.

  6. LarrytheG Avatar

    oh – we do have RICHES in informed dialogue on this subject these days and I am most appreciative to you folks for your contributions. Thank you!

    and I hope Dominion is ALSO thankful! 😉

  7. LarrytheG Avatar

    in terms of access to existing transmission lines – there have to be thousands and thousands of existing locations…

    In fact, if not mistaken – isn’t that exactly what PJM does much of the time – i.e. specify to the utilities where new junction points should go to improve reliability?

    they’d be doing that even if there were no wind/solar – right?

    1. True, PJM would specify what transmission upgrades are needed regardless of wind/solar. Not true, they specify “where new junction points should go to improve reliability.”

      The reliability process assumes that anyone who wants to add something incremental to the Grid which causes the Grid locally to move from “reliable” to “unreliable” has to pay to fix that as part of the project. What is “reliable” is determined objectively by studies applying NERC reliability criteria. For example: you want to build an new generator somewhere? You have to submit the proposed location and where you want to tap into the Grid to PJM, and PJM runs studies of the impact of that on existing operations, and if it would degrade the reliability of the grid below acceptable criteria, you would also have to pay for new transmission facilities to cure that. PJM’s role is passive; it does not solicit or reject new generators based on whether they will improve or degrade reliability, but PJM will insist that a new one’s interconnection with the Grid must not degrade reliability below minimum standards.

      Now, short of one of these definitive PJM impact studies, anyone reasonably familiar with the Grid can eyeball things and spot the locations where transmission upgrades are likely to be less expensive than elsewhere, and if they also happen to be where the land is cheap and the fuel is nearby, naturally those are the locations that are going to attract the generation developers. In that sense, the potential cost of keeping PJM happy does help steer new projects to locations where they tend to help reliability or at least don’t harm it.

  8. Rowinguy Avatar

    I do think Larry has inartfully identified one of the many things that PJM does, which is conduct studies of the grid it manages to identify places where improvements are needed to stay ahead of the reliability curve.

    Acbar, you are correct too about how someone adding generation to the grid is responsible for ensuring that new generation does not cause destabilization in other parts of it. If memory serves, Dominion had to pay for some grid upgrades in New Jersey when it added its generating plant in Brunswick County.

    Yet one more thing PJM does is set price signals designed to incent the development of generation where it is most needed, with the highest power prices in areas that have inadequate transmission. The book is still out on whether this price setting mechanism is spurring construction where needed. FERC has recently approved a massive increase in maximum pricing for what PJM is calling “capacity performance.” That is, generating capacity that is capable of actually generating when conditions are tight.

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