Biomass

Published on March 13th, 2016 | by Zachary Shahan

87

US Wind & Solar Electricity Generation Grew By 20,659 MWh In 2015 (2015 US Electricity Generation Report)

March 13th, 2016 by  

US wind and solar electricity generation grew by 20,659 MWh in 2015, compared to the full year 2014. That’s compared to fossil fuel electricity generation dropping by 18,041 MWh. Unfortunately, in part due to terrible drought, hydroelectricity generation dropped 8,199 MWh.

Percentagewise, the total split by energy source for 2015 was:

  • coal — 33%
  • natural gas — 32.5%
  • nuclear — 19.4%
  • hydro — 6.1%
  • wind — 4.7%
  • wood and wood-derived fuels — 1%
  • solar (all types) — 0.9%

As reported last month, 69% of new electricity generation capacity in 2015 came from renewables. Meanwhile, 80% of retired electricity generation capacity was coal power capacity. The story could be even better in 2016. Nonetheless, the US power system is gigantic, and transitioning from dirty energy to clean renewables is quite a long process.

Still, it is happening. In 2014, solar and wind accounted for 5.1% of electricity generation. In 2015, they accounted for 5.6%. And just in December, they accounted for 6.9%, compared to 5.3% in December 2014.

For more info, check out the table and charts below. (For the charts, be sure to note which tab is selected.)

US electricity December 2015

US electricity December 2014

US electricity 2015

US electricity 2014

US Renewable Electricity Generation - December 2015

Source of data: US EIA


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About the Author

is tryin' to help society help itself (and other species) with the power of the typed word. He spends most of his time here on CleanTechnica as its director and chief editor, but he's also the president of Important Media and the director/founder of EV Obsession, Solar Love, and Bikocity. Zach is recognized globally as a solar energy, electric car, and energy storage expert. Zach has long-term investments in TSLA, FSLR, SPWR, SEDG, & ABB — after years of covering solar and EVs, he simply has a lot of faith in these particular companies and feels like they are good cleantech companies to invest in.



  • John_ONeill

    ‘US Wind & Solar Electricity Generation Grew By 20,659 MWh In 2015 ‘
    Any of the four AP1000 reactors under construction in the US could produce more electricity than that in one day. What were you all telling me about nuclear being too slow, again?

    • Calamity_Jean

      “Any of the four AP1000 reactors under construction in the US could produce more electricity than that in one day. What were you all telling me about nuclear being too slow, again?”

      They aren’t anywhere close to being done yet. Renewables will have a massive head start by the time the next completed reactor puts out watt #1.

  • What it look like

    We can do this!

  • Adrian

    If… Utility and rooftop solar, wind and geothermal continued growing as last year, and everything else held roughly steady aside from coal, then by 2025 all coal is retired and renewables > 50% of net US generation.

    Of course, that means installing 18GW of rooftop, 330GW of utility-scale and 105GW of 40% capacity-factor wind in 2025 – probably optimistic…

  • vensonata

    Well this has been a good thread. We are hashing out something here between coal and natural gas…basically both are bad and have to go. And yet there is such a tiny amount of PV installed. Wind at least shows up as a smudge. I have to think like this: “wind, you replace coal. You need to grow at a rate of 40 GW/year to do that in 15 years. Solar you replace gas, you also need to grow at 40 GW/year for the next 25 years.” Well, of course it could happen. But it needs 8 years at least of Democratic majority. Or some green billionaires to bribe Republicans.

    • Bob_Wallace

      Can’t look at that way. Wind can’t replace coal. Neither can solar. We need some combination of wind and/or solar along with something else to fill in the gaps. Natural gas, hydro and storage are our current options.

      If you want to work out ‘how much over how many years’ I’d suggest you start out by assuming a ramp up period, say X years. Then a steady state of installation for Y years.

      Y is probably ~20 years. Long enough that a company can expect a decent return in its investment in factories/equipment. No one is going to build a solar panel plant if we’re only a couple years from reaching solar panel saturation.

      X might be 10 years. Just a guess. Thirty years total would get us to ~zero carbon electricity by 2050 which seems to be the current global goal.

      • vensonata

        Yes, a very important point…we can not plan for exponential growth in wind and pv, because the factories become suddenly useless when they have reached their maximum. Growth in renewable require a very sudden build out of production facilities to allow for even and sustained production of turbines and panels over at least a 15 year period, otherwise the economics of factories becomes ridiculous. But the problem is; look at the time frame for the gigafactory…about 5 years to full production! And that is a drop in the bucket to what is needed. If we are optimistic it will take to 2025 to get the factories in place to stave off CO2, then we need to produce like mad for the next 25 years. It is just barely possible.
        But as to replacement of coal by wind alone…no indeed, it will be the combination of PV and Wind. My image is only to simplify for people to see that we have two substantial technologies to replace two substantial problematic technologies. People need pictures.

        • Ivor O’Connor

          It’s probably an S curve that ends at about 400% of what our current electrical needs are. Since we are only at about 6% now we have a long ways to go…

          • vensonata

            Yes, and it is important to get people off the exponential curve idea for renewables. It can’t work that way because of factory economics. It has not generally been thought through, and needs to be repeated around the web so the picture becomes clearer.

          • Ivor O’Connor

            You realize growth at 20% a year is exponential? SolarCity has been growing at 80% per year for many years now. I don’t think we have to worry about this exponential growth stopping for decades.

          • vensonata

            Exponential is easy at trivial scale, but when 4 goes to 8 the resistance is substantial. We have finally arrived at 1% solar. And we could still get two doublings to bring us up to say 40 GW but at that point it will level out.

          • Ivor O’Connor

            I don’t think we could double every year. Just pointing out that exponential does not mean yearly doubling.

  • Martin W

    You mean 21 TWh more, surely.

    • John Norris

      1st line of article: >>US wind and solar electricity generation grew by 20,659 MWh in 2015<<
      I rephrased it because
      a) I like percentages
      b) I prefer numbers to 2 significant digits not 5
      PS: 21k MWh = 21 GWh. I wish it was TWh!

      • Martin W

        Well, it’s wrong in the headline, check the tables. It’s 21 TWh. 21 GWh would be the annual production of about 2 or 3 3-MW wind turbines, or from 21 MW of PV.

        • John Norris

          My wish came true! You’re right Martin, it is 21 TWh, thanks. Still 10% though. Strange, I thought capacity had increased much more than that. Maybe that was globally and not USA. Will have to check…

          • Martin W

            You’re welcome.

  • John Norris

    US Wind & Solar production grew by 10% (21 GWh) in 2015

  • Ivor O’Connor

    So electrical’s market share of “real renewable energy” grew by .6% and dirty energy’s share decreased by .4%. You could say renewable energy is growing 50% faster than dirty energy!

    Though there was a 5% change in the market as coal was swapped out for natural gas. So it is accurate to say natural gas, which arguably produces magnitudes more green house gases than coal, grew 750% faster than all clean energy combined.

    Since wind is substantially less expensive than natural gas this tells us our politicians are still corrupt beyond measure. They take the lobbyists money in return for crony capitalistic monopolies.

    • Bob_Wallace

      “So it is accurate to say natural gas, which arguably produces magnitudes more green house gases”

      Unless you can furnish proof otherwise I would say that is an inaccurate claim.

      My understanding is that NG produces half as much CO2 per kWh as coal. And if leaks are not mitigated the release methane makes NG about equal to coal in terms of GHG.

      “Not mitigated” is an important qualifier. It looks like the EPA is starting to crack down on methane leaks.

      • Ivor O’Connor

        Magnitudes is too much. But fortunately since our debate a few years back when Obama claimed in a state of the union speech there was very little leakage it has been revised upwards to the point nobody is sure. Likewise as you know we do not have a way to accurately measure NG to CO2 for GHG. They have a very different long term effect. (CO2 lasts longer but NG does much more damage in the short term.)

        I’d rather have the known damage coal does versus the huge unknowns behind the fracking industry. Just being on parity, supposedly, with coal on GHG does not take into account the damage to the water tables across our planet.

        There is no good reason to replace coal with NG when we have so much untapped wind and solar that could do the job.

        • Bob_Wallace

          NG is a great fill-in for wind and solar. As the price of storage comes down we will need less NG but right now it’s very handy.

          • DecksUpMySleeve
          • Brian S.

            From your link: “In the long term, natural gas plants do indeed produce less warming than coal, the researchers found. But that result comes with a caveat: without high-tech carbon storage, neither gas nor coal can achieve the type of greenhouse-gas reductions demanded by international bodies such as the IPCC.”

            People love to use short-term warming factors when comparing natural gas to coal. Global warming isn’t a short-term problem, it’s a long-term problem.

            More issues with the interpretation in that study:
            – Natural gas leakage in the distribution network should not be counted towards centralized electricity generation. Electricity production has no impact on this leakage.
            – They say that the best natural gas is no better than the best coal in terms of immediate radiative forcing. Besides the short-term vs long-term issue, nobody is replacing state-of-the-art coal. They are replacing old, less efficient coal with new state-of-the-art natural gas.
            – They used an emission factor of 191 lbs CO2 / Million Btu for coal when the real numbers are 206-229 lbs CO2 / Million Btu: https://www.eia.gov/tools/faqs/faq.cfm?id=73&t=11

            Getting rid of coal through mandates or a carbon price would have large, immediate benefits as coal was replaced by natural gas. Some solar and wind would be built as direct replacements as well. The large increase in natural gas consumption would push up prices, which would further accelerate wind and solar installation.

          • DecksUpMySleeve

            You’re not educating me.
            Contesting 206-229 vs 191 lbs CO2, trivial and contestable on a plant by plant case by case basis, and nearly a non-point in a multi-faceted particulate discussion.
            You’ll never convince me that building any type of clean fossil fuel will grow TRULY Green technology more than direct investment in it would.

          • Brian S.

            When you add a bunch of 10% errors together, you end up with a conclusion like “natural gas is just as bad as coal”, when the truth is that natural gas is half as bad as coal.

            You are right that direct investment in green technology will grow green technology far more than investment in natural gas. I was mainly trying to correct Ivor, who started this thread by claiming that natural gas was worse than coal. It is not. If the choice is gas or coal, choose gas. If the choice is gas, coal, or renewable, choose renewable. However, do not let your opposition to gas slow the phaseout of coal too much.

          • Ivor O’Connor

            I hope you now understand why NG is much worse than coal…

          • Bob_Wallace

            I see no basis for your claim. GHG emissions, assuming unchecked methane leaks larger than what seem to be now happening, would be roughly the same.

            The pollution/mercury problems and coal ash piles make coal worse.

          • Brian S.

            Not at all. You could argue that natural gas is better than coal, but not good enough. That’s a defensible position. You could say that natural gas is extra dangerous because it lulls us into complacency. I could buy that, too. But you say natural gas is worse than coal, when all available evidence says it is not. As Bob points out, the health effects of coal are terrible, too.

          • Ivor O’Connor

            Just how many tons of CH4 is being leaked and CO2 being produced by NG plants versus CO2 by coal per unit of power? Include all the leakage surrounding the NG industry. That should put an end to this discussion.

          • Bob_Wallace

            No, that’s a dishonest argument.

            Methane leakage in the distribution system that carries NG from the storage facility to homes and businesses for heating, cooking and water heating has nothing to do with electricity generation.

            Take a look at how much leaking is happening in parts of Boston. Those leaks have zero to do with running a CCNG plant.

          • Ivor O’Connor

            No attempt at dishonesty here. How about you simply say X% of the NG is used in power plants. That percentage of the leaks should then be added to the cost of generating power.

          • Bob_Wallace

            Not at all.

            Do you need that explained to you?

          • Ivor O’Connor

            What?

          • Bob_Wallace

            For sake of argument let’s assume 50% of all NG goes to electricity production and 50% to all other used (heating, industrial feedstock, cooking, etc.).

            Were that the case then 50% of all methane leaks associated with drilling/extraction could be charged to electricity production and 50% of all methane leaks to non-electricity uses.

            Then there’s the problem of distribution leaks. All of that has to be charged to heating, industrial feedstock, cooking, etc.

            If that isn’t’ clear to you then read it over slowly several times.

          • Ivor O’Connor

            You really ought to change your tone Bob. Last time we went on for days with you making stuff up swearing and lying and cussing only in the end to delete your BS. You need to watch yourself.

          • Bob_Wallace

            Up yours, Ivor. I’m sick of your attitude and dishonesty.

          • Ivor O’Connor

            I’m honored I can make you so irritable so easily. 🙂

          • Bob_Wallace

            My graduate students had a t-shirt made for me that said –

            Caution!

            Low tolerance for fools

          • Ivor O’Connor

            And you did not read between the lines?!

          • ROBwithaB

            To Bob (and Ivor)
            Not much fun for the rest of us to watch two grown
            men go at it like this. There are no doubt websites for people who enjoy
            that sort of thing, and if that was what floated my boat, that’s what
            I’d be searching. But I clicked on this corner of the internet instead,
            hoping to learn about renewable energy generation.
            Please keep the private bickering private. To air it in public degrades the ethos of the entire website.
            Thank you.

          • ROBwithaB

            To Ivor (and Bob)
            Not much fun for the rest of us to watch two grown men go at it like this. There are no doubt websites for people who enjoy that sort of thing, and if that was what floated my boat, that’s what I’d be searching. But I clicked on this corner of the internet instead, hoping to learn about renewable energy generation.
            Please keep the private bickering private. To air it in public degrades the ethos of the entire website.
            Thank you.

          • Bob_Wallace

            Rob, you and Ivor make moderating this site unpleasant.

            You two babble on day after day with little of value to add. Both of your are massive wastes of time.

          • ROBwithaB

            I didn’t realise it was the job of a “moderator” to make value judgements, on behalf of everyone else, as to the quality of individual comments. Or commentors. Isn’t that what those little voting arrows are for? Everyone is free to click them, after all. Even “moderators”.

            You don’t get to censor opinions that you personally dislike. That is not “moderation”, and it does not add value. And you don’t get to insult people just because you have the hall monitor badge pinned to your chest.

            I learn as much from the comments here as I do from the articles. I have learned much from some of your more thoughtful comments, and I have also found some of Ivor’s comments to be quite informative. Of course, I don’t agree with all his opinions, or yours, but universal unanimity is not a requirement for the advancement of knowledge, as far as I know.
            I have no way of knowing how much “value” people attribute to any of my comments, other than the crude mechanism of the “upvote. By that metric, there are quite a few people who HAVE found value in some of my contributions.
            But luckily we don’t need to indulge in any sort of pissing contest as to “value”, or a philosophical discussion on freedom of speech. It’s only a website after all. It’s not a national election or a talent contest. Occasionally I might say something stupid, and in that event I trust people will politely steer me towards resources to cure my ignorance.
            But if saying something stupid on the internet was grounds for dismissal, there would be no internet.
            Occasionally I might use many words to say what someone else could say more succinctly. To be honest, sometimes I use many words to avoid bluntly telling someone that their opinion is stupid. Like when someone (very succincty) says something ignorant like “It’s just a couple of extra hinges” to wish away the obvious potential for problems with the Model X wingdoors. (Problems which have now become reality.) Of course I could simply insult their lack of understanding. Or perhaps, I could try to help them by providing information to broaden their knowledge.

            But I’m certainly not “wasting” anyone’s time, because nobody is being forced to read any of it. That simple tool called the scroll button will allow you to save whatever precious time you might have “wasted” on me.
            If it ever happens that I commit some egregious violation of the terms and conditions of Disqus, or the comment guidelines here, feel free to call me to order. In fact, If I’m even slightly rude to anyone here you’re welcome to point that out to me. Save for some pointed criticism of Bjorn Lomborg and Bob Lutz, I’ve avoided anything personal.

            In fact, other than the occasional good-natured humorous jibe, I have been unfailingly polite. You’re welcome to be rude to me in return, but let me point out that it just makes you look like a dick, and spoils the experience of everybody else who comes here to learn.
            This sort of personal squabble is what constitutes a GENUINE waste of everybody’s time.
            Please use your powers for good. You have a wealth of knowledge to share. Insulting people is not the best use of your time.

            If you don’t like me or what I have to say, that’s cool. Feel free to ignore me completely and go about your business. The internet is a big place.

          • Bob_Wallace

            Are you so lacking of self-awareness that you don’t realize you started this exchange?

          • ROBwithaB

            Well, I was asking (very politely) that you keep personal squabbles off the public comment thread. Unbecoming of a “moderator”, one would think.
            It was a request. You’re welcome to ignore it, of course.
            And if you feel that I started some sort of “exchange”, then allow me to end it. Right now.

            The end.

        • Brian S.

          There is no possible way to argue that natural gas produces more greenhouse gases than coal. Even if you go with the 2011 EPA estimate of 2.8% leakage (revised to 1.65% in 2013), that amounts to a total greenhouse gas to CO2 ratio of 1.28-1.37 (100 year) or 1.85-1.89 (20 year). Since coal produces about 1.85x more CO2 per Btu than natural gas, emits a bit of methane itself, and operates at lower efficiency, it is absolutely worse than natural gas. Also, don’t forget that plenty of methane leakage occurs in the distribution grid and therefore should be attributed to distributed usage, not centralized electric power generation.

          The known effects of coal are greater greenhouse gas emissions and much greater sulfur, mercury, and particulate emissions. These pollutants are responsible for tens of thousands of deaths per year in the US. The uncertainty of natural gas is whether it’s a little better than coal or a lot better than coal.

          • Ivor O’Connor

            Really?

            On Tuesday, the academic journal Environmental Science & Technology published an issue featuring 10 new peer-reviewed articles investigating the rate of methane leakage from the Barnett Shale region, where the practice of hydraulic fracturing or “fracking” to extract natural gas first took off in the United States. The studies found that the amount of natural gas leaking into the atmosphere during drilling operations is likely about 1.5 times what the U.S. Environmental Protection Agency (EPA) had previously estimated, with most of the emissions likely caused by just a handful of problem drilling operations. The findings indicate that more regulations and controls on methane leakage will most likely be required to realize the potential climate benefits of burning natural gas versus coal for electricity generation.

            http://blogs.scientificamerican.com/plugged-in/methane-leakage-from-natural-gas-supply-chain-could-be-higher-than-previously-estimated/

            I like how you pick a 100 year time frame when comparing GHG from CO2 vs CH4. How about we do a more reasonable 20 year study when they will most likely both be at peak where the real damage happens?

          • Brian S.

            I provided both timescales. If global warming would stop being a problem in 2036, I’d be happy to emphasize the 20 year timescale only, but I’m much more concerned about global warming after 2036 than before.

            Notice that I used the higher leakage rate estimate from 2011 rather than the lower one from 2013. You say 50% higher for upstream emissions from one natural gas field. I used a number that was 70% higher than the latest estimate for all levels and all regions.

          • Ivor O’Connor

            Global warming will probably come to an end around 2036 and certainly by 2050. Then we’ll have to start massive environmental works programs to suck in all the runaway GHG. The problem with CH4 is that it is much worse in the short term and only after many decades does it become the equivalent to CO2. If my memory serves me it is around 17x worse than the equivalent CO2 for the first decade or two. So hopefully now you see why CH4 is so much worse than CO2.

          • Brian S.

            First, no. We will not stop emitting greenhouse gases in the next 20 years. Second, even if we did stop emitting in 2036, the damages would continue accruing until the CO2 was actually removed from the atmosphere. Even the temperature would rise for a bit longer because the climate is not at steady state. Third, if we really do commit to removing all of that CO2, it’s going to be very expensive. If we burn coal there will be way more CO2 to remove than if we burn natural gas. Finally, even on a 20 year timescale, natural gas is better than coal.

          • DecksUpMySleeve

            By current projections yes, it will not be near ending in 20 year, more like a 8-12% decline by then(due to growth). Correct CO2 takes nearly 100 years to cycle down to the surface for absorption, it should be noted the direct climate impact is delayed by ~35 years, until the atmosphere is back down to 280ppm we’re in bad shape. I think it may actually not be that expensive if done right.
            My idea, a fleet Solar powered planes with an onboard algae which can be fed through like a Sharks breathing, then once produced the algae is dropped off by ETFE bag/parachute or picked up by a modified reversed fueler.
            Debating one FF better than another is negated if the latter needs investment and therein will be kept running for a longer period to recap this investment.

          • Brian S.

            True. We do have to be very careful about how much (if any) we invest in natural gas so that we get a net benefit. Actually, just a couple days ago I was ranting a bit too much about how overinvestment in natural gas could delay the transition to renewables.

            The optimal investment in natural gas depends on how hard society is willing to try to fight climate change. If we are only willing to pay a little extra (which is foolish, but likely), we would do best to replace some of the coal with natural gas today and the rest with renewables over the next decade or so. If we are willing to pay a lot more, we could probably skip the natural gas entirely and replace the coal with renewables and storage (batteries and thermal storage).

          • Bob_Wallace

            Remember the Budischak paper that looked at four years of wind/solar supply and load demand for the US’s largest grid? They found a need to turn on a lot of NG plants about seven hours a year. (The orange blips below.)

            We’d need to invest enough in NG capacity to supply those blips.

            With transmission we might be able to lower the blips, but we don’t know that at this point in time. To determine the amount we’d need some full country modeling.

            I hope that’s being done at the federal level. I hope someone is modeling what the best next move is for our energy systems.

          • Brian S.

            I finally read that paper, and it’s quite interesting! Thanks! I hope more modeling is underway in multiple groups to help us plan ahead, as you mentioned. A couple observations from the paper:

            1. They do not do any cost optimization between fossil fuels and renewables. Instead they specify a minimum number of hours of load coverage by renewables, and do cost optimization on the mix of renewables and storage only. Therefore, 7 hours a year of natural gas is not a result, but an assumption (99.9% of hours covered by renewables).

            2. The calculated costs are average costs, but not marginal costs. If the real world were exactly like this model, there is no chance we’d go to 99.9%. In Table 3, moving from 90% coverage to 99.9% coverage requires an extra 73.3 GW wind (all offshore) and 16.2 GW PV just to generate an average of 2.16 GWa. That’s an effective capacity factor of 2.4%. Nobody is going to make that investment.

            3. The model does not require forecasting of generation. With reasonably accurate weather forecasts, we could turn the fossil fuel backup on earlier to precharge the storage before anticipated shortfalls. This would reduce the total fossil fuel capacity needed. We might have enough existing CCNG for backup with decent forecasting.

            To be clear, I think it’s a great study, and none of my points above are intended as criticisms. Assumptions have to be made to turn such an ambitious modeling project into a manageable feat. I just think they are important points to consider when interpreting the results.

            P.S. As the required coverage by renewables goes up, hydrogen looks better and better compared to centralized batteries. The longer storage duration of hydrogen (50 hours vs 6 hours at 99.9% coverage) requires less overbuilding to cover the lulls. It’s not a definitive verdict, because I’m sure we could contest some of the cost assumptions. I just thought it was interesting. At lower levels of renewable penetration, I am pretty sure batteries would beat out fuel cells.

          • Bob_Wallace

            The study is only a first approximation of the sort of complex model needed to show us the optimal way to build going forward. In addition to your #1 and #2 there’s no inclusion of transmission between adjacent grids, no dispatchable hydro, no load-shifting. Adding large numbers of EVs to grids will likely smooth out needs.

            #3, turning on deep backup in anticipation of needs is something I don’t see discussed. Not only turning on deep backup generation early but running it 24 hours a day and letting it recharge depleted batteries would reduce the amount of reserve capacity needed. That deep backup generation could also be biomass. Convert paid off coal plants and stock several days worth of wood pellet fuel.

            Hydrogen, possibly. But it’s very lossy. However if we’re looking at only deep backup then cost is less of a factor. If the total amount needed is relatively small then the H2 could be generated over months at times when the grid is oversupplied with wind/solar,

            Another option might be to create pump-up hydro storage in some of the dams used for irrigation/flood control. Build a ‘dam within the dam’ by sectioning off an area of the reservoir and keeping it full for these infrequent events. The water being held for the ‘summer seven hours’ could be sent through a turbine in to the greater dam area and used for late summer/fall irrigation.

            One of the most interesting parts of the study for me is how infrequently we see a simultaneous low solar/wind input along with high demand. The “seven” hour days.

            Weather is reasonably predictable a few days in advance. Having some sort of dispatchable generation that could be turned on before ‘frequent cycle’ storage is depleted and letting it run 24 hours a day should make those infrequent events manageable.

          • Calamity_Jean

            “We might have enough existing CCNG for backup with decent forecasting.”

            Probably. It’s my understanding that wind power is very predictable 24 hours in advance and almost perfectly predictable an hour in advance. By convenient coincidence, CCNG generators can get from cold standby to full power in about an hour. Could generators designed for natural gas burn biogas? It’s basically the same thing chemically, just diluted a little with carbon dioxide and water vapor.

          • jeffhre

            “That’s an effective capacity factor of 2.4%. Nobody is going to make that investment.”

            LOL, hasn’t a similar investment been made already, in NG peakers?

          • Brian S.

            It’s not the same. NG peakers are installed for their capacity value, not their energy value. It matters WHEN that 2.4% capacity factor is supplied to the grid. We can estimate the capacity value of that investment by looking at how much storage and fossil backup it offsets. However, this isn’t going to be very accurate, because the paper did not include the cost of fossil backup in their optimization problem. Therefore, the renewables and storage mix has not been optimized to maximize capacity value, and each scenario contains a greater-than-optimum amount of fossil backup capacity.

            From Table 3 and Table 8, we see that in this particular scenario, 89.5 GW of renewable capacity offsets 28.6 GW of fossil backup and 17.3 GW (but 0 GWh) of storage. In their model, the storage has power-only capital costs of just $100/kW, so the storage offset isn’t worth much. In other words, to match the economics of gas peakers in the capacity market, this mix of PV and offshore wind would have to cost about 1/3 as much per GW. But again, this mix wasn’t optimized in the first place.

          • jeffhre

            No it’s not the same. The cost of a single cycle gas turbine is rising, the cost of NG is volatile compared to renewables and adds risk, and while right now that cost is rising.

            The cost of renewable energy is falling fast, and lowering risks along multiple fronts. Renewable energy can be distributed to eliminate transmission costs and grid stress, if the right business models are deployed.

            There is no incentive to optimize a renewable/storage mix at such a small part of the grid.

          • Brian S.

            Costs are falling, but until the plants are free, you still have to make money by either a) providing a bunch of energy to offset fuel costs (plus pollution costs with proper regulation), or b) providing reliable capacity to offset capital costs. If you can’t do at least one, you can’t compete against natural gas. At low to moderate penetration, this is easy. But when you are curtailing most of your output, you can’t do a) anymore. You won’t be contributing much reliable capacity either, because the time your output is needed most is when you’re not generating much anyway. Carbon taxes or other pollution measures won’t do much good at that point, because a NG plant that only runs 2.4% of the time doesn’t actually pollute that much or consume that much gas.

            Of course, I’d be thrilled if our most pressing issue were figuring out how to get from 90% renewables to 100% renewables. Instead, we face the easier, but more urgent issue of getting from <20% to 90%.

          • jeffhre

            Long before growth from 16% to over 90% has occurred – reliable availability of capacity will be very apparent IMO. I will term it one of the changing grids emergent properties. Looking toward a grid that is not simply fed by renewable sources but is literally enmeshed with vast numbers of sensors, and informed by data which allows operators to predict, understand and take advantage of dynamic conditions as opportunities and grid resources. In contrast to reacting to seemingly unrelated changes, which have been seen only as restraints and challenges to system balance.

            Five years ago this was in the same category as the fabled butterfly flapping its wings in China. Today, a dozen companies are working to refine the algorithms which make renewable energy predictable, and at large enough scales even dispatchable.

          • Ivor O’Connor

            Why would we pay more? It should be cheaper to go with renewables now than to use natural gas.

          • Brian S.

            The price of renewables is not a constant for all projects in all locations. Wind is cheaper than gas in West Texas. It is a bit less competitive when you have to pay for transmission to get it to the cities. Wind is more expensive than gas in Georgia. Solar is cheaper than building a new combined cycle gas plant in Texas or Nevada, but it is more expensive than simply supplying fuel to an existing combined cycle gas plant. In Ohio, solar is more expensive than either new or existing combined cycle plants. All of this is including the effects of the current renewable energy subsidies, but ignoring the costs of externalities that should be priced in for gas and coal.

            It’s not as simple as renewables are cheaper or renewables are more expensive. Renewables are more competitive than ever, and that is why they are being installed at a record pace. They are still less competitive in many sub-optimal cases, which is why they are being installed at too slow of a pace to avoid 2 degrees of warming.

          • Ivor O’Connor

            Good points which I understand. However there are other points. Kickbacks and crony capitalism plays a much bigger part than anything else in our power sector.

          • ROBwithaB

            The snakeskin boots bit was worth the click.

          • Ivor O’Connor

            True we don’t know exactly how long it will take to go totally green. I imagine we’ll get 100% of our electrical somewhere between 2035 and 2050 with all energy shortly after that. The balance between CO2 and CH4 is not 1 to 1. One gram of CH4 in the first 20 years is worth about 17 grams of CO2. Over the long haul it reverses decades later it reverses. The “Natural Gas” people want you to think 1 to 1 but it is not. So you have to look at the peak production of CO2/CH4. Which will be happening around 2035. Or perhaps sooner. Peak. Not end of. So your second point got off track. Same thing with your third point. You are focusing in on CO2 instead of CH4 problems.

          • Brian S.

            After looking in more detail, it appears that a wide range of studies have found emissions to be about 25-75% higher than the EPA’s most up-to-date inventory. This is consistent with the Scientific American article you linked. There is a good summary in this NREL presentation. http://www.nrel.gov/docs/fy14osti/61686.pdf

            That up-to-date EPA leakage rate is 1.65%, so my simple calculations based on a 2.8% leakage rate are still near the top end of most estimates. In the presentation I linked, NREL reaches a similar conclusion. Look at slide 46. Combined cycle natural has about half the emissions of coal. Using a 20 year horizon (which I strongly disagree with) will reduce the benefit but not eliminate it.

          • Ivor O’Connor

            I don’t see a slide 46 but there is a page 46 titled “Preliminary Results of Gas LCA Meta-analysis (Harmonization)” but the Y-axis is g CO2/kWh. I don’t think that’s relevant to our discussion so I’m probably missing something. Can you elaborate?

          • Brian S.

            It is exactly what we are talking about. It is the combined effect of CH4 and CO2 over a specified timescale (usually 100 years), expressed as CO2 equivalent (CO2e). It shows that when you include the methane leakage, the global warming effect of CCNG is half that of coal. If you didn’t include methane leakage, CCNG would be closer to one-third.

            To be clear, the calculation here is
            grams CO2e = grams CO2 + GWP * grams CH4,
            where GWP is the global warming potential of methane (i.e. how much worse it is than CO2), which is 25-36 for a 100 year basis depending on who’s estimate you use.

          • Ivor O’Connor

            Thanks. I did not understand the ‘e’ at the end. I’m convinced for now.

          • DecksUpMySleeve

            Slightly lesser evils are still..
            Why even try to qoute the EPA on stat revisions when they like any agency can be bought and fixed?
            It’s null to battle which evil is lesser, it’s like the leading republican candidate. Rubbish is Rubbish, we shouldn’t be investing a dime in it.

          • Ivor O’Connor

            It seems there are some people who have interests tied to the republican and democratic parties making them highly dishonest.

          • DecksUpMySleeve

            It’s all more a corporation anymore than a publicly run governing body. Whole things a joke.

          • Brian S.

            Last November in Ohio, a group of 10 investors spent $20 million to put marijuana legalization on the ballot, granting themselves a constitutional monopoly on all production in the state in the process. Corrupt as hell, right? They lost their investment. Elections still matter. Buying elections only works when people don’t care, or people give up.

          • Bob_Wallace

            Are there any other members of your Absolutely Pure and Perfect Party?

          • DecksUpMySleeve

            We’re talking lesser evils and compromise once more.
            Just flip the board on that whole system, require a level of aptitude for voting, fix a broken behemoth.

          • Bob_Wallace

            Something to consider….

            Sometimes at night, during low demand hours, coal plants sell their product at a loss causing wind to curtail. Coal is only marginally dispatchable.

            Natural gas is highly dispatchable and likely to be curtailed when the demand can be covered by wind/solar. Fuel for gas plants costs.

          • DecksUpMySleeve

            I’d rather we cut their subsidies in half, invest it in wind/solar/tidal, cut a massive deal with Aquion or Tesla for storage and not wind them up at all.
            Enough patchy temporary solutions, we’re at sea with so much duct-tape on the hull it’s a wonder we’re still afloat.

          • Bob_Wallace

            Whose subsidies?

          • DecksUpMySleeve

            Fossil Fuels, >500 billion.

          • Bob_Wallace

            I just don’t see political conditions that would make that possible.

            Going forward we’re going to see the fossil fuel industry under more and more pressure as markets shrink. Trying to make coal pay for its external costs would likely cause armed rebellion in coal country. Actually coal may be mostly dead before Democrats could regain control of Congress (and we know Republicans wouldn’t do anything to harm coal).

            Much of the subsidy for petroleum is sweetheart leases and tax treatment. As extraction drops those subsidies shrink.

          • DecksUpMySleeve

            Well, coal prices are down which effects the incentive to mine, but this will mainly effect exports. Mining is down 18% just like the market price, but this won’t stop local demand or close plants, if anything the drop in price makes things cheaper for the Coal Plants. What they lose in business they partially make up for in their power sources commodity price. Helps them from closing but will mean less profit merely for the Coal mines/production.

          • jdeely

            Bob, This is a really good point. In many states Nat Gas will enable faster adoption of wind and solar. By the way, look to CA in 2016 as an example of how states can then begin to replace Nat Gas with Solar. Nat Gas in CA has peaked and there will be a huge drop over the next ten years.

          • Bob_Wallace

            Variable operating costs for CCNG plants can run as high as 6 cents/kWh. Most of this is going to be fuel costs. If a utility has some 3 cent wind or solar they aren’t going to crank up the gas plant.

          • Brian S.

            You can’t just say “everything is corrupt,” discount the experts, and make up your own facts. Tell me who you think is qualified to estimate methane leakage rates from the US natural gas system if not the EPA? Give me the name of one expert or one organization that has better data sources or more expertise.

            The only way we are making any progress is through the political system we have. It has it’s flaws, and the progress so far is disappointing in many ways. There is no alternative.

        • jeffhre

          Look at the work Mark Jacobson did on this. And Jacobson, Delucchi cited by Budischak. Jacobson has had some similar conclusions, but I do not know where he quantified them in his research.

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