How Unsustainable is PV Solar Power?

27 10 2015

Hot on the heels of yesterday’s post about renewables being unable to even keep up with the growth of the internet’s energy consumption, along come a couple of other articles I just had to share…..

From Low Tech Magazine yet again is an article about the mushy numbers used to ‘prove’ PVs are the way to go in the future. Most followers of this blog will already know how I feel about this, however, this item has some interesting factoids I was not aware of that make a most interesting point.

Lower costs have spurred an increase in solar PV installments. According to the Renewables 2014 Global Status Report, a record of more than 39 gigawatt (GW) of solar PV capacity was added in 2013, which brings total (peak) capacity worldwide to 139 GW at the end of 2013. While this is not even enough to generate 1% of global electricity demand, the growth is impressive. Almost half of all PV capacity in operation today was added in the past two years (2012-2013). In 2014, an estimated 45 GW was added, bringing the total to 184 GW.

Solar PV total global capacitySolar PV total global capacity, 2004-2013. Source: Renewables 2014 Global Status Report.

According to these numbers, electricity generated by photovoltaic systems is 15 times less carbon-intensive than electricity generated by a natural gas plant (450 gCO2e/kWh), and at least 30 times less carbon-intensive than electricity generated by a coal plant (+1,000 gCO2e/kWh). The most-cited energy payback times (EPBT) for solar PV systems are between one and two years. It seems that photovoltaic power, around since the 1970s, is finally ready to take over the role of fossil fuels.

But, as the article goes to great lengths to explain, manufacturing has moved to China, and as was recently revealed, the biggest eighteen ships produce as much CO2 as all the cars in the world……… so shipping those panels (and inverters) from China to Australia, Europe, and the Americas is unbelievably polluting.

Less than 10 years ago, almost all solar panels were produced in Europe, Japan, and the USA. In 2013, Asia accounted for 87% of global production (up from 85% in 2012), with China producing 67% of the world total (62% in 2012). Europe’s share continued to fall, to 9% in 2013 (11% in 2012), while Japan’s share remained at 5% and the US share was only 2.6%.

Price of silicon solar cells wikipedia

Compared to Europe, Japan and the USA, the electric grid in China is about twice as carbon-intensive and about 50% less energy efficient. Because the manufacture of solar PV cells relies heavily on the use of electricity (for more than 95%) this means that in spite of the lower prices and the increasing efficiency, the production of solar cells has become more energy-intensive, resulting in longer energy payback times and higher greenhouse gas emissions. The geographical shift in manufacturing has made almost all life cycle analyses of solar PV panels obsolete, because they are based on a scenario of domestic manufacturing, either in Europe or in the United States.

Compared to the original manufacturing scenarios of Germany, Japan, Spain, and the USA, the carbon footprint and the energy payback time of Chinese PVs are almost doubled in the asian manufacturing scenario. The carbon footprint of the modules made in Spain (which has a cleaner grid than the average in Europe) is 37.3 and 31.8 gCO2e/kWh for mono-Si and multi-Si, respectively, while the energy payback times are 1.9 and 1.6 years. However, for the modules made in China, the carbon footprint is 72.2 and 69.2 gCO2e/kWh for mono-Si and multi-Si, respectively, while the energy payback times are 2.4 and 2.3 years.

Carbon footprints solar cells produced in china and europe

At least as important as the place of manufacturing is the place of installation. Considering that at the end of 2014, Germany had more solar PV installed than all Southern European nations combined, and twice as much as the entire United States, this number is not a worst-case scenario. It reflects the carbon intensity of most solar PV systems installed between 2009 and 2014. More critical researchers had already anticipated these results. A 2010 study refers to the 2008 consensus figure of 50 gCO2e/kWh mentioned above, and adds that “in less sunny locations, or in carbon-intensive economies, these emissions can be up to 2-4 times higher”. Taking the more recent figure of 30 gCO2e/kWh as a starting point, which reflects improvements in solar cell and manufacturing efficiency, this would be 60-120 gCO2e/kWh, which corresponds neatly with the numbers of the 2014 study.

Solar insolation in europe

Solar insolation in north america

Solar insolation in Europe and the USA. Source: SolarGIS.

So far, I expect most DTM readers already knew this….. but now for the clincher, and it’s growth, yet again totally unsustainable. The author calls this Energy cannibalism, a term I just love!

Solar PV electricity remains less carbon-intensive than conventional grid electricity, even when solar cells are manufactured in China and installed in countries with relatively low solar insolation. This seems to suggest that solar PV remains a good choice no matter where the panels are produced or installed. However, if we take into account the growth of the industry, the energy and carbon balance can quickly turn negative. That’s because at high growth rates, the energy and CO2 savings made by the cumulative installed capacity of solar PV systems can be cancelled out by the energy use and CO2 emissions from the production of new installed capacity.

For the deployment of solar PV systems to grow while remaining net greenhouse gas mitigators, they must grow at a rate slower than the inverse of their CO2 payback time. For example, if the average energy and CO2 payback times of a solar PV system are four years and the industry grows at a rate of 25%, no net energy is produced and no greenhouse gas emissions are offset. If the growth rate is higher than 25%, the aggregate of solar PV systems actually becomes a net CO2 and energy sink. In this scenario, the industry expands so fast that the energy savings and GHG emissions prevented by solar PV systems are negated to fabricate the next wave of solar PV systems.

Several studies have undertaken a dynamic life cycle analysis of renewable energy technologies. The results — which are valid for the period between 1998 and 2008 — are very sobering for those that have put their hopes on the carbon mitigation potential of solar PV power. A 2009 paper, which takes into account the geographical distribution of global solar PV installations, sets the maximum sustainable annual growth rate at 23%, while the actual average annual growth rate of solar PV between 1998 and 2008 was 40%. [16] [21]

This means that the net CO2 balance of solar PV was negative for the period 1998-2008. Solar PV power was growing too fast to be sustainable, and the aggregate of solar panels actually increased GHG emissions and energy use. According to the paper, the net CO2 emissions of the solar PV industry during those 10 years accounted to 800,000 tonnes of CO2.

Which totally puts paid to the hopes of ‘green people’ wanting a quick transition from coal to PVs. The faster it happens, the worse greenhouse emissions are…… Is this the ultimate limit to growth? I find the irony almost too much to bear. I heartily recommend reading the article at its original source where all the facts and figures are referenced. It makes for sobering reading……..

But wait there’s more. Just last night on TV I saw an item on 7:30 on ABC TV showing some guy who built a modern mansion with all the bells and whistles, 300m from the grid. he claims it was going to cost $200,000 to connect to the grid (seems rather excessive to me…) so decided to go off the grid. The TV item was about how we will all go off the grid within ten years, and look at this guy’s amazing green bling…… four inverters no less! Anyone with four inverters is using four times too much power (and hence energy), and he proudly claimed to have batteries capable of backing the whole lot for…. three days. I can guarantee he will soon be disappointed. Anything less than a week would not suit me, I’d opt for ten days. But then again, I don’t need four inverters, we’ll only have one. Watch it here.

Why am I so certain he will be disappointed? Well Giles Parkinson and Sophie Vorrath are, like me, not convinced your average electricity consumer understands any of the dilemmas they face.

So for those of us left, and interested in battery storage as a means of saving money, how do the numbers stack up?

Before tackling those numbers, it is worth noting that the numbers for battery storage are more complex than they may first appear.

Making the economics work will depend on how much your household consumes and when, the size of your solar array, if any, and the local tariff structure. Then you have to consider how you will use that battery, and how the grid might use it to.

Because batteries are left lying around doing nothing much of the time, ‘the sweet spot’ for consumers lies in the range of 3.5to 5.0 kWh/day. Or less, I would add. And that, my friends, leaves out 90% of the electricity consumers as they stand right now. That Adelaide guy in the 7:30 show is well out of his league, and when he’ll have to replace his underworked Li ion batteries after just 10 years, if he can still get some, he will be wondering why his green bling is so expensive to keep running… and to top it all off, the article raves about what will happen way out to 2030, assuming that business as usual will continue forever, and that there will still be a grid to hook up to, unlike Gail Tverberg, the optimist!




20 responses

27 10 2015
John Doyle

Thanks for this info. More ammo to set the records straight.
As for all these products the external costs are just as lacking as they are for coal.

27 10 2015

Mike, while I agree that there is not a way to run the world energy demand on alt
energy, the whole point is that ;
1. The population is already too big and still increasing rapidly.
2. Our way of life is ridiculously profligate and we could and should manage with less.
3. If we do not cut back on population and energy use it will all go to hell anyway with runaway global warming.

What we should be doing is educating people about population control and sustainable living.
The rest would take care of it’s self and if it does not, it won’t matter in the long term anyway cos we will all be rooned.

27 10 2015
Chris Harries

Interesting. Those who have a passion for renewables will tend not to take this in, seeing it as an annoying conspiracy. When I try to raise the issue of cradle-to-grave energy analysis the stock replies are:

• After the period of growth, followed by a flattening off, the solar panels and wind turbines will come into their own, providing free power with no further input. I suspect, though, that if coal mining is to be abandoned and renewables are to take up all that slack, then the rapid renewables growth period (where no net energy is produced) would have to be carried over many decades, ultimately running beyond the total lifespan of the earlier solar installations. In which case there would never be a plateau.

• It won’t be too long before breeder solar systems are developed (solar producing solar). This has a little bit of validity, though I know of no plans to take this beyond solar panels on top of solar panel factories. The mining, mineral processing and transport energy inputs would still have to be oil based for several decades one presumes.

I was interested to read that “the production of solar cells has become more energy-intensive” in recent times owing to the transport factor. As solar panels have plummeted in price I’ve been wondering if the net energy return (ERoEI) has been plummeting at the same time, but haven’t been able to find recent figures on that. It could be that mooted newer solar voltaics, for instance using very thin coatings adhered to construction materials) may reduce some energy inputs such as for aluminium framing and so forth?

But the overall take home message for anyone should be that renewable energy technologies may be gleaming beacons of hope but they have very limited capability to maintain society as we know it. I think society is going to learn that the hard way, it’s not a popular message at this moment in history.

27 10 2015

> For the deployment of solar PV systems to grow while remaining net greenhouse gas mitigators, they must grow at a rate slower than the inverse of their CO2 payback time. For example, if the average energy and CO2 payback times of a solar PV system are four years and the industry grows at a rate of 25%, no net energy is produced and no greenhouse gas emissions are offset. If the growth rate is higher than 25%, the aggregate of solar PV systems actually becomes a net CO2 and energy sink. In this scenario, the industry expands so fast that the energy savings and GHG emissions prevented by solar PV systems are negated to fabricate the next wave of solar PV systems.

Which is what I’ve been telling you since 2007. It isn’t just the ERoEI that matters, its the time difference between the EI and the ER – the EI has to be spent all up front, and then the ER trickles in over the next 25 years.

L = lifetime of panel in years
EI = energy invested in making the panel
ER = energy returned by the panel over its lifetime
EPBT = energy packback time = L * EI / ER
MGR = maximum growth % per year = 100 / EPBT = (100 * ER) / (L * EI)

So if (L = 25 and ERoEI = 3) then (MGR = 12%)
Any growth rate bigger than MGR will need external energy subsidy until the growth stops.

27 10 2015
Chris Harries

The problem as I see it is that most Australians are not going to sit down and try to nut out numbers like EPBY and MGR and ERoEI. To the average citizen you can buy solar pv system, put it on your roof, it works, you get money for the electricity. All is good. Don’t need coal any more. “Down with dirty coal!”

They may gripe a bit about the low feed-in tariff, but this is just to do with the greedy power companies.

Accepting that massive PV power is non sustainable is a virtually impossible sell, because if you take that belief away the perception is that there is no solution at all. May as well keep o burning coal. Maybe nuclear power at a pinch, but how many will support that? And if you do the same sums on nuclear you get the same sort of end result…. oil is irreplaceable.

I think a digestible message for the times is that dilute renewable energy is great, but that it has severe limits and simply can’t sustain anything like the industrial / consumer society that we live in. If we don’t match renewable energy technology with dramatic social change then renewable technology just forces us into a tighter and tighter corner.

That seems a slightly easier sell than to argue to give up on renewable energy because it doesn’t work. How do the sums work out for low key solar?

27 10 2015

As I was writing this up, I was thinking about you . It’s only taken me a few years to get a handle on what you were on about……

27 10 2015
Graham Palmer

Today we had the newly appointed Chief Scientist, Alan Finkel, advocating the need for the end to coal fired power and earliest uptake of renewables and on Lateline he was suggesting nuclear energy needs to be on the table at least for discussion. I find it hard to believe that that the dreadful conundrum outlined above would not have not been thought through by a man of his intellect? Perhaps the ‘elephant in the room’ is that no one is willing to canvas even the possibility that it is our standard of living which is not sustainable.

28 10 2015

I saw that. No one has a clue of what the future holds…..

29 10 2015

This new computer is useless without the cloud and I do not see how the cloud model is in any way sustainable for domestic users. Stupid modems take forever to reboot if you switch them off, TVs loose their programming if switched off for too long. Negawatts (saving power) is so much cheaper than renewables, but so much is going the other way.

We need more exercise, but do not dare let your child walk to school. We wrap our children in cotton wool then we complain that young adults have no sense of risk.

We cannot get that the future will not be better, that we cannot keep getting more and more. Unfortunately capitalism needs that belief. We are running on smoke and mirrors and only willful blindness keeps it going.

Progressives are also willfully blind, as you point out so regularly. I used to visit the Climate progress website so often, but Pollyannaism gets so tiring. Two degrees is not safe and already blown, if humanity stopped today two degrees will still happen.

I seem to remember that Gail the Optimist line.

1 11 2015

Regarding the usage of power on a battery/solar system. We had a guy at work with a 6kw solar system and large battery array. He said he used 8kwhr a day in total, but when pushed admitted this was overnight and he did not record his day time use as the panels covered that and did not effect his battery life.
Turns out he used a system of solar panel, regulator, battery and then inverter. Every bit of power he used effected his batteries as he was either cycling them (overnight) or pouring his electrons through them to power his inverter during the day (heat and resistance).
His battery life was just under three years instead of a possible 15 years expected as the daily use wore the batteries out.

I convinced him to use a panel, inverter, house usage, inverter charger and finally batteries system like the sunny island product range and he has now had 5 years of operation without battery degradation.
With proper monitoring it seems he has been using around 35kwhr + a day all along. Not really compatible with off grid use and will eventually come crashing down again.

This is on top of a large standard brick and black tile house in an urban area with minimal insulation (don’t need it, got rev/ac) large sun exposed windows and no eaves.

If I expanded from 1kw to 2.5 kw, with batteries etc I could go off grid with no bills, still might do it.

2 11 2015

None of this surprises me, which is why I am certain most people who end up off grid not understanding energy will be very disappointed…

6 11 2015
kent crispin

I’m new to this, and I may be overlooking something. But if current installed PV capacity is 1% of total demand, at a 40% growth rate PV would account for 100% of total demand in a little over 12 years, right? The point at which PV generating capapcity is able to cover the energy cost of manufacturing would happen sooner. So, after a decade of excess CO2 production there would be a precipitous drop, and in another decade after that the excess would be more than compensated for. That doesn’t seem so bad…

6 11 2015
6 11 2015

> Kent: So, after a decade of excess CO2 production there would be a precipitous drop, and in another decade after that the excess would be more than compensated for. That doesn’t seem so bad…

Sure, if you actually have the fossil resources and can extract them at a sufficient rate, over and above everything else we are currently using them for. But we can’t. We get so used to thinking that if we need more energy to build more stuff, we can have it – we only have to pay for it (and we can even borrow that).

But now we have entered the Peak Oil and Peak Coal period, with Peak Gas not far behind, the ability to keep FF production rates growing is over. The task of making enough solar panels to produce 100% of demand in 12 years is a colossal one, far bigger than anything we have undertaken throughout history.

By 12 years, the very first solar panel will only have captured half of the energy it will ever capture, and all the other new panels even less. So the fossil fuel subsidy will be huge. And the faster you try and grow the production of panels, the harder the job becomes.

It is hard to visualise this, but it can be done. You need to draw up a table with a row for each year, and columns to show the amounts of energy needed for producing panels at the chosen growth rate, say 40% per year, and the amounts of energy (solar electricity) produced by the previous years’ production. You can then add up all the rows items to give you the net energy each year, and the sum of all those is the energy subsidy needed from FFs.

You need to know the ERoEI of solar panels to do this, but you can do it for a number of different values. The answer is always the same – there’s enough energy available to start the transition, but there is not sufficient to finish it.

If we had started 30 years ago, we could have completed the transition, but now we can’t. The longer we kid ourselves that we can do it, and avoid cutting back on energy consumption, the harder it will be for our children.

6 11 2015
Chris Harries

That’s a great line, Dave. “…there’s enough energy available to start the transition, but there is not sufficient to finish it”

But I think your comment that if we had a started 30 years ago we could have done it is not the case. The problem here lies in social values not technology. Society is at present trying to make an energy transition so that it can maintain a consumer based, growth economy. I don’t think this can be done under any energy scenario.

This dilemma points back to your limiting growth rate of solar in your earlier comment, above. A graded implementation of renewable energy in a low key economy would theoretically allow a net dividend from solar panels. But that wouldn’t solve energy demand in a business-as-usual economy. Check mate.

Trying to beef up renewables to match the society we live in can never work.

7 11 2015

So for the people who say that renewable are not worth the effort what now?
Do we just keep on with coal, start nuclear or do without electricity?

It is better to have tried and failed than to have never tried at all.

7 11 2015
Chris Harries

That’s a very valid point, Seawork. If you interpret this article and comments in that way, then others will too. I think the last thing this site and its followers want to do is to allow the inherent limits of renewable energy to be used as a sop for coal fired power. But we also have to be honest about what’s real.

Doing without electricity is an extreme, I don’t think anybody advocates that. What we don’t do is live within limits. Our society is way, way overpowered. Overpowered to the extent that we become ill through lack of physical activity. So overpowered that the average Australian is satiated in consumer goods, live in 300 square metre homes, buy 500 litre fridges, drive huge lumpy 4WDs and flit off on overseas flying holidays without a thought.

This website is about limits and values and chosen lifestyles. It is also about tipping points. If modern society has overshot its survivability and faces collapse what should individuals do? Pressing the accelerator but in a slightly different direction gives us more of the same, and pushes us into a tighter corner than ever.

What do you think? I am very interested in the mathematics of the possible role of renewables in a moderated society, where we do live within means. Like you, I find it a bit disconcerting that exposing the limits of renewable energy can be too easily interpreted as an advocacy for business-as-usual, especially by those who benefit from BAU.

7 11 2015

Seawork, the key point is to NOT build lots of new stuff, so nuclear it out. Nuclear suffers from exactly the same problem as solar, except some of the EI comes at the end of the life cycle – decommissioning the plant and disposing of the waste. Sadly this is not going to be dealt with properly due to lack of energy.

If we stick with the existing infrastructure and modify lifestyles to suit, knowing that in the end FF energy will go to zero, that is the best we can do. The Powerdown theories make a lot of sense, but won’t be popular, least of all with politicians – “Vote for me, and I will give you LESS!”

19 11 2015

You are incorrect in stating that; “and as was recently revealed, the biggest eighteen ships produce as much CO2 as all the cars in the world”.

It’s not CO2 but nitrogen oxides & sulfur oxide pollutants that they produce at a greater amount.

11 12 2015
Chris Harries

Ah, that makes more sense. I found the CO2 statistic unbelievable.

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