Published on December 5th, 2014 | by Zachary Shahan


Solar PV Generation Doubles (Monthly US Electricity Generation Report)

December 5th, 2014 by  

Following up on my first monthly report on US electricity generation by source, here’s the next one. Electricity generation data takes longer to gather than capacity data, so the EIA’s electricity generation information is always from a couple of months prior. In this case, we now have data from September. Check out the charts and a bit of commentary below (be sure to click through to YTD, YTD 2013, and Rolling 12 Months via the tabs near the top of the charts).


Something I noticed last month but forgot to mention was brought up by a commenter: Utility-scale solar PV generation for “YTD” in August was twice what YTD in 2013 was. The same point held true after September’s generation numbers were in, as you can see in the charts above.

As Jake aptly commented via rhetorical question over on Solar Love: “Did you hear that the amount of electricity produced by utility-scale solar had doubled in one year? Is the national mainstream media covering these achievements by the solar power industry?” Indeed, you won’t see this news in the mainstream media, not even the outlets that were so fond of talking about Solyndra!

12,303 GWh were sent to the U.S. grid by utility-scale solar in 2014 through the month of September. For the same period in 2013, that number was 6,048 GWh. The larger figure is only about 0.4 percent of the total amount of America’s electricity, though about 1.5 million US homes could be powered with the 12,303 GWh,” Jake added.

For the most part, monthly generation across the United States doesn’t change a ton from month to month. (The monthly capacity addition report is more interesting in that regard.) Though, renewables have their seasonal shifts. Wind was up approximately 1.3 TWh, giving it 3.38% of the electricity market rather than 2.65%. Hydro, on the other hand, was down nearly 4 TWh, moving it from 5.15% of the market to 4.68%. Nuclear and fossil fuels were also down quite a bit, though, presumably because of cooler temperatures and lower electricity demand.

For the year through September, renewables were up to 13% of the electricity market, and 6.6% if you exclude hydro. The same period last year also saw the renewables total at 13%, but hydro was a bigger share — without hydro, the percentage in 2013 was 6.1%. In other words, wind and solar grew their market share approximately 0.5% in one year. Slow and steady… is not what we need to address global warming and climate change, but I’m hopeful wind and solar will increase at a faster and faster pace in the coming years.

For more number crunching, here are some tables:

US Renewable Electricity Generation - Sept 2014 1

US Renewable Electricity Generation - Sept 2014 2

And, as shared by a reader last month, here’s a graph showing a broader view, followed by another one from a reader shared after publishing this article:

US electricity generation sources


electricity change US

Data Source: EIA

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About the Author

is tryin' to help society help itself (and other species) with the power of the 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 and Solar Love. Zach is recognized globally as a solar energy, electric car, and energy storage expert. He has presented about cleantech at conferences in India, the UAE, Ukraine, Poland, Germany, the Netherlands, the USA, and Canada. 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. But he offers no professional investment advice and would rather not be responsible for you losing money, so don't jump to conclusions.

  • Joseph Dubeau

    Good article Zach, lots of information, read all the links in article and the comments.

    • Thanks! 😀 Wish I had more time to write. Have a long list of more original stories I’d like to do.

  • timpster

    Hydro Electric dams are *REALLY* bad, and do NOT provide a lot of power (DamNation says they could be replaced by 3 wind mills, but I think that’s a bit low — maybe 15).

    Dams suck, and DamNation is the BEST documentary I have ever seen! Highly recommend it.

    Also with our more sedentary life style exposure to lots of bright light is absolutely essential, and gives us better sleep. What hasn’t seem to be doubling is the number of skylight installations. Why can’t we make that cheaper too?

    • Bob_Wallace

      In 2013 the US generated 6.6% of its electricity from hydro.

      Several countries get 100% of their electricity from hydro.

      Paraguay generates 10 times more electricity than it uses with hydro.

      It’s a bit hard to support your claim that hydro electric dams do not provide a lot of power. Even shouting doesn’t make your claim true.

      • timpster

        Watch the documentary DamNation — there are much better ways to generate electricity without fucking up the ecosystem of aquatic — scratch that, of fish, mainly salmon.

        Edit, it’s on Netflix – which is an excellent service!

        • Joseph Dubeau

          You know ground in California shrunk an inch.
          The Salmon had to catch a ride on trucks. Not a joke.

          • timpster

            I don’t follow, could you be more clear?

          • Joseph Dubeau

            In a documentary on water, one scientist showed satellite images of the ground California. Farmers have removed so much water out to ground that the surface height has shrank.

            Along the coast Saltwater intrusion is a problem.
            In Salinas, the county is cleaning waste water and pumping back into wells.

          • timpster

            Why do we have to grow things out of season? That’s what’s wrong. 24/7 fruits, and 24/7 fish etc etc, it’s just not right.

        • Larmion

          Or stick to science (see my post on your earlier reply).

    • Larmion

      Replacing hydro-electric dams by 3 wind turbines?

      A wind turbine has a nameplate capacity of 2-3MW with the largest ones going up to 8MW. Hydro? Typically a few 100MW with many going over 10.000 (the world’s biggest power station is the Three Gorges Dam, at 16000MW). And a wind turbine produces 40% of its nameplate capacity whereas a dam achieves 70% with ease.

      As per the IPCC, currently the reference for all things climate, hydropower has the lowest CO2 emissions out of any electricity source (even after including methane release):

      It’s also cheaper than most other energy sources. Much of the environmental issues associated with it can be mitigated at low cost by using run-of-the-river designs.

      Bottom line: don’t believe everything you see in documentaries. Read scientific studies. Most documentaries are made with an agenda or by people who mean well but don’t really understand the science behind what they are talking about (most film/art school graduates, for example).

      • JamesWimberley

        The really good hydro dam sites have been taken. Brazil, for instance, home to the giant Itaipu dam on the Parana (which with its 75% capacity factor just beats Three Gorges in annual output), is building the very controversial Belo Monte dam on the Xingu, a tributary of the Amazon. Even its promoters claim Belo Monte will only have a 39% capacity factor because of seasonal variations in flow. That’s not significantly better than wind, where the best resources are conveniently close to centres of population in NE Brazil, and not at the end of 2000 km of expensive high-voltage power lines. Other potential megadam sites are even worse, both financially and environmentally. Thankfully. wind at $5.3c/kwh (the latest auction PPA price) is now making them uneconomic. Existing hydro is presumably more than enough for any plausible long-period backup need for variables.

        • Larmion

          Traditional megadams still have a lot of potential in Africa and the Himalaya. But they’re indeed close to maxed out in the developed world.

          However, hydro is so much more than a big reservoir dam.

          – Upgrades and refurbishments at existing dams can add significantly to output (7GW of capacity in the US alone).

          – Run-of-the-river designs allows the exploitation of sites ill suited to reservoir dams due to environmental concerns or local topography.

          – The development of low-head hydro allows exploitation of rivers with limited height differential or allows extraction of residual energy in rivers that already host large dams further upstream.

          A nice example is one of the contenders for powermag’s 2014 Top Plant title, the Ashta low-head hydro dam built by Verbund in Albania:

          At 53MW it’s a far cry from the massive plants the magazine usually nominates, but it deserves the attention: it’s a wonderful example of hydro on a sensible scale and with attention to the environment.

  • Poechewe

    I have a question. In fact, I would like to see a full article on the issue: How well do wind and solar handle bad weather?

    I’m talking about all the forms of bad weather from icing to tornadoes to hurricanes to weeks of fog or still wind to six foot snow storms (I haven’t seen too many pictures of low lying wind turbines and solar panels, and assume offshore wind turbines are designed to handle the worse).

    I advocate a lot for alternative energy and I peddle the ideas of redundancy and energy storage when I find myself not fully informed. But it would be nice to have some of the answers on these issues.

    To be honest, I’ve never seen a news article on weather related accidents concerning wind and solar, though periodically we all see articles on downed power lines whether they come from coal plants or wind turbines.

    • Bob_Wallace

      There’s a video on line of an EF3 tornado ripping through a wind farm. One turbine gets hit pretty much dead on and loses its blades. The other turbines on each side look undamaged.

      A couple turbines at a training college were in an EF5 and apparently suffered no damage.

      Wiki says –

      The survival speed of commercial wind turbines is in the range of 40 m/s(144 km/h, 89 MPH) to 72 m/s (259 km/h, 161 MPH).

      But I’ve read something about one company that builds to a higher standard.

      I haven’t seen anyone pull everything together for turbines.

      There is some issue with blade icing and I think someone was killed when a chunk of ice fell from a blade. There’s some technology that’s either being tested or put into use to deal with the icing problem.

      Snow. Can’t see an issue. Other than the icing stuff.

      Panels are likely to hold up in bad weather until your roof blows away. Here’s a site that has some videos of “panel abuse”.

      I think there are events in which panels were wrecked by hail. But it was the sort of hail that smashes in car roofs.

      I’ve had my ground-mounted panels covered by snow several times and iced over many times. One time I walked over the top of my panels in snow shoes while I was going out to shovel them out. Didn’t realize I was a bit too far to the east.

      If you want to dig around on the web to see if you can find anything else post it. I’ll see if I can find some more.

      • Ronald Brakels

        Nice video showing the sort of punishment solar panels can take. I have lived through one hailstorm where fist sized hail punched through the roof and ceiling. I’m pretty sure that would break solar panels, but on the bright side solar panels should protect the area of roof under them. So if you are unlucky enough to have hail start coming through your roof, seek shelter in a room under the panels. Also, the hail that punches through roofs is not normal hail, it’s a group of smaller hailstones that have fused together to make a clump. So even if there are clumps like this falling, they aren’t that common and your rooftop solar might only take one or two hits, so you should then only have to replace one or two panels. And you’ll have one or two fewer holes smashed through your roof.

        • Indeed. The Perovo Solar Farm built in 2010 or so that I visited had hail storms with similarly sized hail and no damage.

        • Mike Shurtleff

          There’s a good video clip somewhere on golf-ball size ice balls being fired hard at Solar PV panels to test them. Some Solar PV panels are pretty tough.

          • Ronald Brakels

            That’s in Bob’s link above, unless you are referring to another video. Thanks to standards almost all solar panels are pretty tough, although it is possible to get some extra tough ones.

          • Bob_Wallace

            Solar panels can be broken. I wasted six.

          • Ronald Brakels

            I hope you gave them a serious whack.

          • Bob_Wallace

            I contributed.

            My panels are mounted on two racks on the ground. I got up one winter morning and stood out looking at the new laid snow, all smooth and beautiful. Too early to go out and shovel out the racks, 9 am is about when they start performing.

            After a while I realized that the snow looked too smooth. It took another several minutes to realize that there was no hump where my second rack should be.

            We had had a raging wind storm the night before. It seems that when the rack was bolted down a couple of years early I failed to check to see if all the nuts had lock washers under them.

            The one leg that lacked a lock washer was the one most upwind. Over the hours (days?, months?, years?) the wind had caused enough movement to work the nut loose. Then the wind folded 6 of the 8 panels in half.

            Now all bolts have lock washers. And lock nuts on top of the regular nuts.

            I know you aren’t familiar with this stuff called “snow”. I’ll show you a picture of my pickup out in the snow.

            (Hint: The tall green things are “trees”.)

          • Ronald Brakels

            Oh dear. That is some wind you’ve got there. And that’s a nice picture of snow. And actually I am quite familiar with snow. I’ve been snowed on, fallen in it, made snowgonads, made a snowperson, and felt the pain of the bones in my hands expanding when I warmed them up after making a snowperson. I just don’t believe in snow. And I think everyone needs to disbelieve in something that is material and its existence can be proved. Otherwise how can one have any credibility when one claims to believe in things that aren’t material and the existance of which can’t be proved? I’m sure you agree – unless of course this is just a down under thing and people do things differently in the up over.

          • Mike Shurtleff

            You’re right. Missed that. Thanks!

      • Steven F

        Wind turbine deicing can be accomplished using the same systems used by aircraft. Heating the turbine airfoil will melt the ice allowing it to slide off. Once free of ice the turbine can start harvesting the wind. The amount of power needed is trivial compared to output of the turbine.

        Some manufactures have had deicing options for some time others haven’t. Vista recently created such an option:

        Also note wind turbines located in a remote area may not have deicing since no buildings, or people are there.

        • Mike Shurtleff

          Right, icing cannot be too much of a problem. Three wind turbines have been in use on Ross Island in Antarctica for quite a few years now. They can have similar type of electrical de-icing in their blades, to what airplanes have in their wings.

          • Bob_Wallace

            Someone has a blade surface/material solution that causes ice to be sloughed off as it forms, preventing build up.

          • Mike Shurtleff

            Figured that but didn’t know for a fact. Just like fir tree needles. Thanks!

    • Offgridman

      Just letting you know that my experience is about the same as Bob’s, snow and ice is just a pain to clear off at times. Got spooked the first year the panels were up by a freak hailstorm, golf ball size ones put dimples in the car that was out and just bounced off the panels (think the angle helps) while building a layer of ice along the bottom. That was in June, so it really was a freak storm that hasn’t reoccured in nine years.
      Seven years with a residential turbine and a couple of near misses with tornadoes (few miles off) and still haven’t needed to use the replacement blades, but it did top off the batteries very nicely. Never have had icing problems with the turbine, that could be design (taper out to thin ends), or because it is spinning and the blades flexing whenever that type of weather comes through. It rotates faster than commercial types too so that could help.
      I think that most decent brand name equipment has been built to a standard where weather is not going to be an issue, unless like your home it was to take a direct hit from a twister. A relatively new industry giving 20-25 year warranties doesn’t want issues like that.

      • Poechewe

        Thanks to everyone on the answers to weather issues!

    • AltairIV

      The great thing about solar and wind is their distributed nature. Instead of one large centralized plant that would cause a big disruption in supply if forced offline, you have hundreds and thousands of smaller generators spread out over large, diverse areas. It’s generally very hard to damage more than a couple percent of the total installed base at a time, and the rest will keep on humming, still supplying power while you go out and repair/replace the broken ones.

  • Doug Pearson

    You said, ‘“12,303 GWh were sent to the U.S. grid
    by utility-scale solar in 2014 through the month of September. … [About] 1.5 million US homes could be powered with the 12,303 GWh,”
    Jake added.’

    I seem to recall Arnold Schwarznegger, as governor of California, targeting 1 million homes with solar PV power. If that actually happened, the EIA’s practice of ignoring residential distributed solar PV is missing a lot more than a rounding error. Do they also ignore commercial distributed installations that don’t qualify as utility grade?

    • Bob_Wallace

      The EIA includes end-user capacity in their reports but does not estimate end-user production.

      The NREL (another part of the DOE) does estimate end-user production.

      • Jeff Cadman

        Thanks for the chart, Bob.

        That’s a pretty sizeable and growing gap in estimates. Doesn’t seem reasonable for EIA to continue excluding non-utility (especially given NREL has a methodology to estimate).

        Any insight into EIA’s decision?

        Any insight into why NREL data lags so far behind (last data in 2012 vs 2014 for EIA)?

        • Bob_Wallace

          I don’t know what the EIA will do down the road. There’s no way to accurately measure the amount of electricity that’s generated behind the meter and the EIA generation numbers are based on fairly tightly gathered data. The NREL is making estimates.

          The NREL seems to not do regular annual reports on solar.

          I would expect as end-user grows we’ll start to see better reporting.

          • Jeff Cadman

            Thanks for the answer.

            It seems like it would be possible (and worth EIA’s effort as the installed capacity increases) to either capture some representative numbers through surveys (much like the household survey data on employment, as compared with the payroll employment numbers) or to install some sample meters at the PV rectifiers.

            I also thought many (most?) PV systems already included power & energy stats (often web-based); not sure why EIA and NREL wouldn’t be trying to tap into that data (unless they are concerned about data quality/accuracy).

        • RobS

          Remember that the demand destruction we are seeing in total consumption in the EIA reports is in large part the result of behind the meter solar. Might not be a direct measure but it’s certainly kg an indirect one.

  • JamesWimberley

    The complete absence of growth in geothermal in the YTD comparison is disappointing. In the USA, it suffers more even than wind from Congress’ stop-go incentives. Projects take 5 years or so and the policy uncertainty is crippling. The worldwide growth is a decent if not explosive 4%-5% a year, concentrated in poor countries; East Africa, Central America, East Asia. That’s still without the potentially game-changing EGS.

    Terminological proposal: hydro is a renewable source of energy, full stop. It has to be isolated to look at growth rates, but being despatchable, it fills a very important slot in the sustainable energy portfolio. The crucial distinction for the future is not between old and new renewables, but between despatchables (hydro, geothermal, biomass) and variables (wind and solar). Tidal is the one that straddles the divide, as it’s 100% reliable but not 100% despatchable, but is clearly closer to the first group.

    • Yes, geothermal has been shafted. Not sure if that will ever change, but it should, and I think the now-much-larger wind and solar industries should help to get it growing, as the dispatchable supply will be very useful to them down the road. Someone recently noted in a comment here (or maybe that was the Twitter #SolarChat) that it’s high time we have an overarching National Renewable Energy Association. i’m not sure about that or not, but SEIA and AWEA should team up with GEA more.

      Hydro: yeah, there are a few factors to consider here. 1) when trying to identify growth, hydro muddies the water. solar and wind are growing fast, hydro isn’t, but it’s much larger, so including it hides their growth a bit. 2) new hydro isn’t particularly green. (i’ve even heard small hydro is just as bad as large hydro… just, naturally, on a smaller scale. but haven’t dug into the matter in depth.) and not only is it not very green, a number of studies have found it can be horrible for the climate (depending on certain factors). 3) but all that said, it is a renewable, it is dispatchable, and existing hydro is a great help. my understanding is that it has dropped off a lot because of drought. and who knows what’s causing that (jk), but my guess is it’ll only get worse as time marches on… a bit of a challenge many of us would rather not think about.

      • RobS

        I’m not a climatologist but as an Australian I would say that long term trends not withstanding droughts will always come and go, they may become more frequent but the current one will break and then we will see the US’s renewable generation soar as hydro returns to its long term average whilst solar continues to grow at 100%+ and wind 20%+ annually. When that happens coals true collapse will occur.

        • Larmion

          And perhaps hydro will do more than recover. The US still has over 100GW (!) of hydropower potential that could be exploited at reasonable cost and environmental impact (or at no environmental cost if run-of-the-river is chosen).

          The US, like most countries, is so busy drooling over wind and solar it is forgetting that the ‘old’ renewables (geothermal, biomass and hydro) still have vast potential for low-cost growth. They deserve much more support than they currently get.

          • Joseph Dubeau

            Not in the Southwest.
            Rivers, where do you find one of those these days?

          • Larmion

            No, but the Southwest has massive geothermal potential. And CSP of course, another one of the old renewables that’s back in the news.

            That’s the wonderful thing about renewables; everyone has something.

          • Bob_Wallace

            Existing dams.

            Run of the river.

          • Mike Shurtleff

            Pumped hydro for seasonal storage! Just use, or create, two lakes at different altitudes and connect with pipes. Good seasonal solar storage. Tap off of river for initial water supply and good seasonal water storage.

          • Bob_Wallace

            PuHS may turn out to be our best solution for long term, what you’re calling ‘seasonal’, storage. I’ve seen no need for storing power from one season to another, but there is a need for storage for several days in a row and it would be expensive to use today’s batteries.

            If PuHS makes cost sense for rapid/daily cycling then the basic costs (dam/reservoir, pump, turbine, transmission) are covered. Making the storage area larger in order to hold days rather than hours of water is generally a lesser cost.

          • Mike Shurtleff

            You’re probably right. Seasonal storage is probably over-the-top when you can just use wind in the Northern winter months …particularly if we a few days of storage for windless days. Your concept of using PuHS to do this sounds good to me.

          • Bob_Wallace

            Here’s a year’s wind and solar performance in Germany.

            To me it looks like a combination of over-building a bit along with some storage could make those bars even up without the need for very long term storage.

            When you extend the ability to swap power with other parts of Europe even more of the variability should go away.

      • Mike Shurtleff

        Wind, Solar PV, and now Battery Storage are the lowest cost. Hydro too, but geographically limited. Pumped hydro for storage less so, but high initial project cost makes it hard to get past political blocks. Don’t see it being pushed. Geothermal is great, but believe the cost is simply higher. Why bother? Sorry.

  • Eric Gerber

    Anyone know why the coal to natural gas ratio moved in favor of coal this year? I thought coal was declining on cheap natural gas. Any estimates for how much sub 5MW solar systems are contributing? Renewables still have a long way to go…

    • Bob_Wallace

      Increase in NG prices. We’ve burned our way through the supply glut of a couple years back and the price of NG rose. Plus some cold winter weather drop use up a bit.

      We should see a move the other way now as we close coal plants.

      Renewables are starting to count coup….

      • Did you create that? Would like to throw it into the article as well, but says 2004 instead of 2014, and would be nice if it went through September. Email me if it’s your handiwork and you could update it. 😀

        • GCO

          The EIA ‘data browser’ can produce similar charts; you can then provide a link to your creation, and others can play with it further if they like…

        • AltairIV

          Notice that it says “change from 2000-2004 BASELINE”, the period just before the graphed range to which the deviations are being compared. It would probably be clearer to understand if the parts inside and outside parentheses were swapped.

          • AltairIV

            Doh, failed to notice myself that Mr. Wallace had already pointed it out below. 🙂

      • Bob_Wallace

        No, 2000-2004 is the baseline range I used. The data lines start in 2005 when wind and solar started making their debut.

        (Don’t cha like my color choices? ;o)

        • Sorry about that. Skipped reading the first part of the title 😛

    • David in Bushwick

      But it looks like September had NG usage up a larger percentage over coal. I can’t find an article that pointed out several dirty coal plants are to be shut down in the coming year. It’s probably too late for the new Republican Congress to stop the closures. But status quo is their game so at least the PTC is probably safe for just another short year.

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