Renewables = 13.6% Of US Electricity In October

43 thoughts on “Renewables = 13.6% Of US Electricity In October”

• The hydro drop is probably a semi-random fluctuation, perhaps caused by El Niño. The trend in renewable generation is up. As you say, much of the 11Gwh rise in NG generation offsets the 9 Gwh fall in hydro. So not great numbers, but not bad either. The solar and wind numbers reflect the average generation stock, more or less that of June 2015. The total for 2016 will reflect a whole year’s new capacity, plus reversion to the mean in hydro. My bet would be that 15% is on the cards.

  • The drop in hydro started when the drought on the west coast started. (about 2010). As the drought got stronger water levels throughout the west coast dropped and hydro power production dropped accordingly. Last year at this time there was no snow in the Oregon and California mountains and after several years of drought very little water flow and reservoirs were running dry. this year with El Nino snow in Oregon and Washington are over 100% of normal for the first time in about 4 years.

    • The California snowpack is also above normal. Hydro should be back in 2016.

• So wind has almost passed water. Solar has almost passed wood.

  Basically the truly scalable renewable energy, wind and solar, are at only 6%.

  Six percent may seem like a small amount but it really is huge. Huge because it is scalable, exponentially growing at over 20% or more per year, and currently at 6%.

  Conservative extrapolation shows
  2020: 15%
  2030: 92%

  We need to find the next big solar company and invest heavily in it.

  • Scalability of wind and solar will depend upon the addition of cost effective energy storage. If wind and solar do reach 92% and if it’s night-time and the wind isn’t blowing we all have to go to bed.

    Without storage of some kind, solar and wind will hit a glass ceiling.

    It’s no accident that Musk has introduced storage as adjunct to his vehicles and solar installs.

    • What you say is technically correct, but the “glass ceiling” for solar is roughly 65% of all electricity production, because roughly 65% of usage is during the day. Wind tends to blow more in the dark at evening and morning, so the “glass ceiling” for solar and wind together is more like 75% of all electricity production. Hydro *already* produces about 7% of electricity production.

      So we don’t start to need storage until we’re up to >80% renewables penetration.

      Which will happen in about 7 years, incidentally.

      • I believe the glass ceiling is lower. Here’s why.

        Taken at face value, your number of 65% for daytime electricity use means that solar would need to produce that amount of electricity on the lowest production days in the dead of winter. This means on good solar days in summertime solar would be over-provisioned. Without storage the excess electricity goes to ground.

        Adding storage would reduce the need to over provision. The closer you get to that glass ceiling the more sense the addition of storage makes.

        Same logic applies to wind.

        Without storage the grid cannot afford the worst case scenario to occur. i.e. nighttime, minimal wind. The higher the penetration rate the bigger the risk.

        Some storage will be required well before 80%.

        Another factor worth considering is that some areas get on average much less wind energy, in those areas storage of daytime solar is more critical.

        • 1. It might well be cheaper to over-provision than to store large amounts of energy.
          2. The grid already has significant storage capacity, thanks to pumped hydro. And more capacity is available at little additional cost, by converting existing free flow hydro facilities.
          3. There is also a significant amount of temperature based domestic energy storage already, with hot water tanks, refrigerators, central heating etc. This capacity can be improved if it is incentivised (see below).
          4. With more accurate pricing information, a significant amount of load can be shifted from periods of low production to periods of higher production. This process can be substantially automated.
          5. If the “all go to bed” situation really were to come to pass, I could solve it for my own particular household by spending maybe $5k on a home storage system. And so could anyone in the first world who’d rather watch TV than have sex. The point is that the people who place the highest priority on 24/7 power will be prepared to pay a premium to secure it. Often the heaviest consumers in any case.
          A lot of people might be happy to just go to bed early if electricity supply were curtailed, or prices spiked for a couple of hours.

          Simple market forces would significantly raise the level of your “ceiling”, as long as there some de-regulation of supply chain. I’m not just making this stuff up. In South Africa, our state owned monopoly Eskom has become dysfunctional, to the extent that we are sometimes subjected to “load-shedding” for a few hours a day. People make a plan. Life goes on.
          In the short term, it may be as simple as having a few rechargeable LED camping lights around the house and more frequent barbecues. Or minor lifestyle modifications.
          In the longer term,businesses and rich people spend money to make sure they have a few hours of back-up, often by means of generators, and more recently batteries.
          There is a surprising amount of flexibility in the system.

        • You nailed it on (4) TOD pricing and (3). As soon as there are price signals to shift load, then there will be a lot of load shifting. In Ohio the $0.10 cents to turn your AC off for 30 mins only works on a real green head. But (1) over capacity has been the basic approach of every grid every build that did not have high levels of brown outs.

        • “Without storage the excess electricity goes to ground.”

          Why not send it down some long distance transmission lines to where it’s needed rather than throw it away? The period of Over-production of solar around noon moves around the world once a day so whilst one area may be over producing at any particular moment, another will be just ramping up towards noon.

          If you’re thinking of seasonal supply, then take the excess from those living closer to the equator who are having their summer while we are having our winter. Reverse for our summer and their winter.

          Storage needed? Maybe on a local basis, but not on a global basis with enough transmission capacity.

        • True. The consideration is which is cheaper, storage or overcapacity. Storage is getting cheaper, but IMO, overcapacity is still cheaper. This must be considered in the context is the multitude of sources used, so what blend. I suspect large amounts of pumped hydro will be used, but the time for storage is at least a decade away. By that time, who knows what advances will happen. Right now, storage is not needed. CSP with storage cannot get much traction, and storage needs have been reduced or eliminated in high solar areas, eliminating the day/night arbitrage.

        • I believe based on my analysis of market behavior that we WILL overbuild solar — we will build to produce full daytime production on the lowest production days in the dead of winter, and we will overproduce in the summer.

          The result of this is interesting: it means that storage can compete, financially, in the market, as if the electricity is free. Which is a much better situation than trying to have “solar plus storage” compete versus an alternative.

        • “we will build to produce full daytime production on the lowest production days in the dead of winter”

          I’d guess far less than that. On a heavily overcast day solar may produce only 10% of nameplate. (Maybe 5%). At 10% we’d have to overbuild 10x for the lowest demand of the day. If solar was down to 4c/kWh we’d have to build so much that we’d pay 40c/kWh.

          It’s more likely to work along the lines of calculating how much the next kWh of solar would cost and the percentage of its output we could use over the year.

          Use 90% and curtail 10%? That kWh would cost 4.1c rather than 4c. Use 10% and curtail 90%. Now the cost would be 7.9c/kWh. Might be cheaper to build more wind or install storage/dispatchable generation. The cost cap might be the cost of running a biogas peaker.

    • There’s no glass ceiling. That implies a hard barrier. Maybe there’s a foam barrier, or a marshmallow one, or something along those lines.

      Anyway, here in South Australia we generate electricity equal to 40% of our consumption from wind and rooftop solar. Early this morning wholesale electricity prices went negative for a short period of time because the state was generating more electricity from wind than it was using or could export. But these negative price events will basically go away in March when the state’s remaining coal power plant shuts down for good, but even if they didn’t go away it wouldn’t really be a problem.

      Once the coal plant closes it will still be possible for wind or wind and solar to produce surplus electricity and this will definite happen as our wind and solar capacity continues to expand. But this doesn’t require storage. Currently in South Australia, rather than build grid storage capacity, it is far cheaper to simply curtail some renewable energy production than to build on-grid energy storage. At current costs, it looks like wind and solar penetration would need to be a lot higher before it becomes cost effective. But it all depends on the intersection(s) between the cost of additional renewable capacity, grid energy storage, and the price if any put on carbon emissions.

      That said, we are likely to end up with a lot of home and business energy storage here as at Tesla Powerwall prices it can pay for itself for some people and electric cars, which I presume we will start getting soon, can also provide energy storage.

      So we are likely to end up with a lot of energy storage, but at no point does it become necessary. If we really wanted to we could overbuild wind and solar capacity and capture and sequester the CO2 emissions that result and have a carbon neutral grid without any storage. We don’t really want to do that, but it is technically possible.

      And before I go I’ll mention that in South Australia electricity produced by rooftop solar alone is expected to start reguarly exceeding consumption (or at least today’s consumption) sometime next decade, so there is going to be lots of opportunity for energy storage to take advantage of this free power, but still, storage is not required.

      • What, don’t you have a 24/7, indoor, snowy downhill slalom slope in S. Australia!?

        • We had a train lose control on a slope because of all the millipedes on the tracks. Does that count?

      • ” Currently in South Australia, rather than build grid storage capacity, it is far cheaper to simply curtail some renewable energy production than to build on-grid energy storage.”

        Ah… but think about this. Suppose you already have a big overbuild and a bunch of curtailed renewable energy production.

        Then some entrepeneur can come along, and put in a set of grid-connected batteries. He can fill up those batteries only when the renewable energy would be curtailed — paying nothing for the extra electricity or even getting paid for it — and then wait until the highest-price short-term peak and unload the energy. This would certainly be profitable on a standalone basis, though I haven’t calculated the return on investment.

        This is how I see grid-level storage getting installed. I think you’ve already thought about that.

        • We had a massive 5 hour long period of negative electricity prices in the early hours of the morning here in South Australia due to excellent wind production and a warm Autumn night. So someone could have been paid 3 US cents a kilowatt-hour to store it and could sell it tonight for maybe 4.5 US cents. But that doesn’t happen very often. But it is killing coal generation and our last remaining coal generator in South Australia has only days to go before it’s shut down for good. Once the coal generator is gone it removes the negative electricity prices we’ve had since they are mostly the result of it refusing to shut down, but we can still go to zero or at least close to it at times.

        • Not to zero. If I’m running a solar farm or wind farm I’m not going to give you my electricity for nothing. If you want it then pay me a little something.

          If I’m running the grid I’m not going to ship that power to you for nothing. Pay me something to cover my expenses plus a little sweetener.

        • It doesn’t quite work like that here. Because we have an electricity market, even if our rooftop solar could offer bids instead of just getting an after the fact feed-in tariff, the equilibrium price for electricity in a situation when rooftop solar, or any kind of solar, is meeting all demand is anything that is above zero cents. In other words, since getting something is better than getting nothing, solar electricity suppliers will out bid each other in an attempt to get something until they are making the minimum possible bid. And at the moment I think that’s one hundreth of a cent.

          As for charging for transmission when the price is zero, it is currently cheaper not to in order to ensure people increase there consumption of electricity and prevent over voltage. But I suppose that could be changed. But it is bad for the environment to allow networks to charge to transmit electricity when its market price is zero due to plentiful solar supply and any grid that allows it is horribly organized. Clearly it is best to encourage industry, storage, business, and households to perform their energy intensive tasks when electricity is clean and green.

          Of course, as people take more advantage of periods of zero or next to zero electricity prices, that will have the effect of raising electricity prices. So it’s self correcting, we just don’t know to what extent.

        • You don’t have the feed in subsidy for solar and wind farms. During their first 10 years, if they’ve chosen the PTC rather than the ITC, they can sell for zero pennies and make 2.3 pennies. The thermal boys have to pay the grid to take their power in order to avoid an off/on cycle.

          This is all transition period stuff. Fifteen years from now all the US wind/solar subsidy stuff is likely to be gone. Along with a lot of the coal. The more expensive to operate nuclear plants will likely be shut down. The price floor should always stay a few pennies over zero. In fact, the typical annual/seasonal minimums will likely have disappeared, eaten up by EVs and storage.

        • We have electricity markets, one big long snaky one in the east and a smaller one in Western Australia, so we will end up with zero or next to zero electricity prices when ever rooftop solar production is sufficient to meet all demand in Australia. Maybe the organization of the markets will change in the future, but if the markets are going to be operated as economically efficiently as possible, then we will end up with zero or close to zero electricity prices at times.

          It’s mostly the result of the fact that as the cost of solar comes down we have an incentive to install larger and larger systems on our roofs to reduce our use of grid electricity, which means we have more to export to the grid.

          Of course we will have to wait and see exactly what will happen, but if rooftop solar continues to get cheaper and there is nothing like The Abbott Government Mark II, more or less zero electricity prices is what will happen at times.

          It could happen in other countries also, just probably at a later date.

    • The glass ceiling view depends on the straw-man argument that producing more wind or PV energy than you need at a given moment constitutes some sort of harmful waste.

      As we make the transition to the cheap storage era, we’re at a stage at which the cheapest way to deliver reliable constant electricity is via a lot of production capacity and a little storage. It’s presently cheaper to generate extra than to store it.

      At my house we have a PV system sized to deliver about 2.5 times our total yearly consumption. We produce more than we need in the summer, and in the winter we still produce more than our 24 hour requirement every day, even when the weather is lousy. That means we never need to store more than one day’s worth.

      Where’s the waste in that? It’s like complaining that your water tanks are already full and the extra rain running off your roof is getting away.

      • Stan is correct. Overproduction is a feature of variable renewables. It is just a different way of thinking than electricity produced by nuclear or fossil fuel. We should not impose an inappropriate model on ourselves. Anybody who does the microgrid experiment of living off grid will get the viewpoint for the macro grid, which is soon to arrive. One also thinks up new ways to use excess electrical production. Something like too many tomatoes.
        Aside from this, the commenters are now considering the big view of the “all renewable grid”. I have done the numbers for the U.S. To eliminate nuclear and 99% of fossil fuel requires chemical battery storage of 1% of the entire yearly production of the U.S. grid. 40Twh. That is 3.5 days of running the entire country on battery alone. Why battery, why not hydro or pump up? Because the peculiar requirement of seasonal variation of solar and wind dependent grid means that hydro and pump up could only supply about 15% of peak demand. And that peak can arrive for up to 3 days in certain winter conditions. Therefore a battery is required. The cost, you ask? 66 billion dollars per year. Alarming, you say! No, only the cost of soft drinks per year in the U.S.
        The battery, surprisingly should be only a 1000 cycle battery, and should cycle a maximum of 30 times per year (which means 30% of the entire electrical demand of the U.S. can be supplied every year by battery). The battery needs to last 30 years. It will increase the total grid cost at present by 16% per year…which will vanish since we will increase efficiency by 30% anyway. In the end the grid will be 100% reliable, renewable and cheaper than the present grid. Ta Da.

        • https://en.wikipedia.org/wiki/Butterfly_effect

          I like the idea of doing calculations but I strongly suspect it’s not going to be right.

        • Yes, the weather is a chaos system and can never be less than “infinitely complex”, and the battery to stabilize this infinitely complex system also has a back up. I did not mention that natural gas generators are the back up to the back up. The carbon production will be trivial.

        • We’ll need a considerable amount of battery storage to do the short days fill-in work. But batteries are too expensive for long term storage.

          Probably better to do deep storage with pump-up or flow batteries. When we encounter a day without enough wind/solar to carry us through start filling up the battery storage with deep storage energy. Keep the PuHS/flow running 24 hours a day until we have enough wind and solar back in play. By refilling batteries during low demand times we can make use of their larger numbers during demand peaks.

          Or turn wood waste into pellets and burn them in converted coal plants. Another deep storage possibility.

        • Yes, the maximum effective storage at a reasonable cost is 1% or 3.5 days. In reality it can be less than that because of things like hydro at 7% and pump up which can also be 7%.(Pump up is cheap only if nature helps with the container). So knock off about 15% of our battery needs. Things like hot water heat storage can also reduce the battery needs. And in fact if we want to go Scotch about it, our battery storage can be half of that or only 1.5 days worth (18 Twh). Any shortfalls can be met with natural gas generators easily, and with trivial carbon contributions of less than 1% of present. In that case nobody will notice any economic effect at all, and yet the grid will be stable as a rock.

        • We’ve got thousands of existing dams which can be converted to PuHS. That would be a lot cheaper than building from new. The price estimates I’ve seen assume a new dam and all the cost that involves.

        • Overproduction? How about reserves? Renewables overcapacity is like reserves. The conventional power system always has idle capacity available. But since the wind and solar fuel is free, we don’t need to turn them off. I see many discussions of wind and solar economics that miss this fact. So the economics can be based on load matching, not capacity factor, even without storage. If the economics is good on load matching, then storage is an option. Load matching is potentially cheaper if you can do it. So demand management also makes economic sense. In the real grid, wholesale value is based on predicted available power. Conventional and renewable fast, flexible power like hydro or gas is always available in reserve. So no storage is needed for renewables anywhere in the conventional grid world today, even off grid, but storage is much more useful off grid. 🙂 off grid doesn’t have the benefits of smoothing provided by geographic distribution and transmission lines.
          I don’t have the detailed data runs from the NREL study, but it’s not likely any days load is provided by storage alone unless you consider hydro which is a hybrid source. Geothermal, CSP with thermal storage, and biomass will be sprinkled into the mix in many areas in various ways depending on local/ distant conditions. Transmission from areas of excess to those in deficit is likely in the future.

        • With today’s grid, little storage is needed. (But note it is popping up all over). However by 2035 we will need to have back up for certain weather conditions which may occur. It is somewhere past 75% renewable grid. Of course, if we decide that 10% natural gas is OK then no battery is required at all. And the aim of the most optimistic scenarios is actually only 80% reduction in carbon by 2050. My proposal of 99.9% is close to perfection. It is not necessary, but is actually possible.

        • Yep. There will be storage, for sure by 2050, 2035. Flexible sources, too. I feel less certain about prediction that far out because EVs, storage, and solar have had unexpected gains. So too, we will see other unanticipated technologies develop.

      • Storage costs are going down rapidly when talking batteries. Other types of storage are appropriate as well.

        One can eschew storage in favor of over provisioning solar and wind, but that only delays the day when you can safely decommission the last fossil power station. Why would you want to delay that day?

        The waste isn’t in lost wind or sunlight that ‘gets away’, its the unnecessary cost of the over building of renewable generation facilities and the land they would occupy.

        There are diminishing returns when you reach the glass ceiling with regard to further provisioning wind and solar. It just makes sense to provide storage.

        • There’s no loss in “overbuilding” wind and solar. We’ll find something to do with the electricity. We could manufacture Ferrock and Novacem — carbon-negative concretes. For example.

          The main reason for storage is to use solar energy at night. The Nighttime Problem.

          The secondary reason is to ride out three-day snowstorms and duststorms — but frankly I think for that, transmission lines are a better option. You never have a snowstorm across *the whole continent*.

        • No, there’s some point at which we won’t be able to find a use for the extra. All the EVs will be fully charged. All the storage will be full. All the dispatchable loads will be running full speed.

          Going to the extreme case, it won’t make sense to install a battery that gets charged up only one time a year, cycles once a year. It won’t make sense to expand the synfuel plant just to eat up the very last kWh.

      • I think of the “glass ceiling” more as the “nighttime problem”. Solar hits a limit when all daytime needs are being met, because the sun isn’t out at night. After that, you need storage or transmission (from sunny areas) or wind or hydro in order to provide nighttime electricity.

    • Fortunately battery storage is coming on big.

      There are other types of storage though. I stopped extrapolating at 92% but 400% is where we are headed. 400% to replace the transportation and heating sectors. These sectors are very much like “storage” and can be thought of as dispatchable loads where power is shunted after electrical grid needs are satisfied.

      However there is a “glass roof” and a need of battery storage. The glass roof is the maximum utilities can charge before their customers will switch to battery storage and go off grid.

      • How did you do your heating sector estimate?

        Replacing ALL ground transportation only adds about 10% to US electric usage. (And we don’t know how to replace airplane fuel yet.)

        But I haven’t done the estimate for heating.

        • A while ago there was a video of Musk and the CEO of SCE. I enjoyed the video because they seemed to cover more detail than most of the past videos I’ve seen. They agreed electricity was roughly 1/3rd of the total energy. Heating and transportation each took another third. You may have better data but that’s the numbers they used for their seat of the pants calculations.

    • Demand management and transmission from areas of excess to deficit play a role. Those can be cheaper than storage. Flexible sources like hydro, geothermal, wave, tidal, and biomass will help, too.

      • Agree that there are many ways to approach the task. Diversification is a smart decision.

    • “Penetration” usually refers to share of generation not share of capacity, IIRC. Suppose you are at 90% of generation from renewables. This means that wind and solar are both at over 100% nominal of peak demand. But because of the famous November calm nights, you will need almost equal gas backup capacity. This will hardly ever be used. The problem is not technical but economic: consumers have to pay for it. Since (in the US at least) the gas capacity is already there, utilities will not want to buy masses of dearer storage to allow the gas to be scrapped.

• Now there really isn’t any reason or excuse for USA to not start a carbon fee/dividend system. We have the system primed for a massive build out of solar and wind, all we need is the market signal to get it moving. Yes it will happen with out without the carbon fee, but the timeline is important.

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