Is the Renewable Revolution Over?

All graphs in this blog post are from the Renewables 2014 Global Status Report. A link to the full report can be found at the bottom of this page.





It is obviously premature to declare the renewable revolution over, however, the latest data on the subject does indicate a substantial deceleration in investments as well as on new installed capacity.

Below, we show some highlights from this report:

For the second year in a row, investments in renewables dropped. 

It could be argued that part of the reason for this drop is that prices of these technologies have been dropping, however, the growth year over year of Solar PV (photo-voltaic) and of Wind are beginning to moderate.

In Solar PV, the percent growths year over year have been:

2005: +38%

2006: +37%

2007: +29%

2008: +78%

2009: +44%

2010: +74%

2011: +75%

2012: +43%

2013: +39% (+26%)

In Wind, the percent growths year over year have been:

2005: +23%

2006: +25%

2007: +27%

2008: +29%

2009: +31%

2010: +25%

2011: +20%

2012: +19%

2013: +12% (+7%)

Sure, the bigger the installed base the more difficult it it to maintain youthful growth rates.

On the other hand, it was China, almost single-handedly that supported the growth of both PV and Wind in 2013. The numbers above in parenthesis don't consider China.

On the positive side, Solar + Wind + Geothermal + modern biomass have finally exceeded 1% share of global final energy consumption: 

Here is the link to the full report:

http://www.ren21.net/Portals/0/documents/Resources/GSR/2014/GSR2014_KeyFindings_low%20res.pdf

Solar Photo-voltaic: Let's Get Real

This exercise is a simplification in which we try to explain why solar photo-voltaic (PV) has difficulty in living up to its hype.

Let's consider an isolated country that consumes on average 40 GW of electricity.

To simplify things, let's consider they consume this amount of power 24 hours a day. In real life, consumption has peaks and valleys.

They plan to install enough solar PV to supply 100% of the electrical energy of the country at peak solar production.

Again, to simplify, let's consider a perfectly cloudless day during the spring or fall equinox. The output would look like this:

So, from midnight to 6 AM, another energy source would supply 100% of the electricity.

Then again, from 6 PM until midnight, another energy source would supply 100% of the electricity.

Then, from 6 AM until 6 PM solar would provide continually variable production and will reach 100% of this country's energy needs at local noon. In other words, at local noon, solar PV would be producing 40 GW of power. (8)

What would happen if this country decided to go above 100% solar at peak production (as an isolated country, they couldn't "dump" the excess production into another country. Also, we are not considering storage that could be an article in itself).

Then, they would have to curtail (disconnect) solar capacity at peak production hours. This is how the graph would look (100% peak vs. 125% peak comparison):

As we may see, there is not too much sense in taking the PV capacity above the peak requirements.

Now, how would the production of the "other" sources (usually fossil fuels) look to compensate for the variable nature of PV. Here we can see it:

In other words, from midnight to 6 am, and from 6 pm until midnight, the other source would supply 100% of the electricity. Then from 6 am to 6 pm it would have to continually adjust its output to compensate for the PV production. 

If the Earth were a perfectly cloudless planet, this sort of arrangement would allow PV to provide close to one third the energy requirements of a country. What would be the carbon intensity of such electricity? Here we calculate it:

According to the table referenced below, solar PV has a carbon intensity of 46 grams per kWh, and let's say the rest of the electricity is produced by natural gas (469 grams per kWh), thus the combined carbon intensity would be:

     46 x 0.33 + 469 x 0.67 = 329 grams per kWh.

However, in real life the Earth is not cloudless and thus the actual annual capacity factor of solar PV is closer to 15%. If we re-calculate with this more realistic number, we get:

     46 x 0.15 + 469 x 0.85 = 406 grams per kWh.

If a component of coal is used in the "other" energy then the emissions would rise even higher. 

Again, this article is a simplification, but the point is to explain in simple terms why solar PV is not living up to its hype.

Thank you.

Notes:

1. In real life, clouds reduce the output of the solar panels.

2. Seasonality also greatly impacts power generation: winter days are shorter and possibly cloudier.

3. The "other" power plants need to be idled, modulated, shut down, restarted and this causes inefficiencies in the system and additional emissions.

4. From a purely operational point of view, "nothing would happen" if all solar capacity were disconnected.

5. Yes, a solar + fossil fuels system produces less emissions than a purely fossil fuel one, but at the cost of duplicated investment.

6. Yes, excess solar energy could be "dumped" into another country, but if that country also installed significant solar capacity, this wouldn't be an option anymore. 

7. The other option is storage but currently this (expensive) technology hasn't been widely deployed. Also, storage would add to the emissions per kWh (once life-cycle emissions are taken into consideration).

8. "Local noon" doesn't happen at the same time in all the country, so the curve would be a little bit flattened. 

References:

http://gnwr1.blogspot.mx/2013/01/clean-energy.html 

Renewables for Australia

Let's make our homework at what it would take to convert Australia to 100% renewable energy.* Not to make the exercise extremely complex, let's simplify it a bit by using only solar photo-voltaic (PV) in our calculations.

According to the IEA (International Energy Agency) Australia's electrical energy supply in 2013 was 228,152 GWh. To convert this to average power consumption we divide it by 365 and then by 24 to arrive at a figure of ~26 GW average power consumption.

If we consider that the capacity factor (CF) of solar PV in Australia is 20%, then the solar PV capacity that needs to be installed is:

26GW / 0.20 = 130 GW.  At $2 dollars per watt that would add up to $260 billion dollars (~$11,000 per person).

Let's also consider that at peak hours, Australia actually consumes 50% more than the average power and thus their typical peak consumption would be 26 GW x 1.50 = 39GW.

This means that, say, at noon in central Australia, we would have a surplus of 130 - 39 = 91 GW.

Thus, at many instances during the year most of the solar capacity would have to be disconnected to prevent destroying the electrical grid. This would mean that the effective capacity factor of solar would be considerably lower than 20% and thus more capacity would need to be installed but this would make the excessive production at many instances during the year even more problematic.

On the other hand and obviously, during the night there would be no energy production.

So, OK, by themselves the solar panels would not be able to supply the energy Australia requires but we can always use storage to smooth the power delivered.

Considering that in winter days are shorter let's add enough storage for 14 hours of the average consumption. That would be 14 x 26 GW = 364 GWh. 

Considering Tesla S grade batteries for the above, a total of approximately 2,330,000 tons of batteries would be required. The above would represent ~100 kgs per person. Sure, lithium batteries are among the lowest weight technology, other chemistries would be heavier.

According to IEA's latest electric vehicle report, the cost of this type of battery could reach ~$200 dollars per kWh by 2020. That would represent a total cost of ~$73 billion dollars. Sure, other chemistries might be less expensive. This would represent ~ $3,100 dollars per person. 

Adding the panels ($11,000) plus the storage ($3,100) gives a total of $14,100 per person. Sure, this is only the upfront investment. Every so many years the batteries would have to be replaced, as well as the panels. 

However, the above system wouldn't provide reliable electricity on an annual basis, as we know the insolation in Australia is relatively low from April to August. More storage would make it somewhat more reliable but the total cost would increase. 

Feel free to make your own calculations and share your comments if you get different numbers.

* We are considering only electricity which is a fraction of Australia's total energy consumption that includes fuel for transportation, for industrial processes, etc.

References:

http://www.iea.org/stats/surveys/elec_archives.asp

https://www.iea.org/publications/freepublications/publication/name,37024,en.html

http://www.teslamotors.com/fr_CA/forum/forums/model-s-battery-0

http://www.gaisma.com/en/location/sydney-au.html   (data for individual cities).

Going Green

More and more we hear people getting impatient with their governments and demanding them to implement the right policies to "go green."

Is this possible?

If by "going green" we mean moving to a less carbon intensive economy then the answer is that technically it is completely feasible.

So then, what is the catch?  The catch is that a low carbon economy today would be more (actually much more) expensive than the current one.

This is something we all have to understand when we demand our governments to act. Actually our demands should be preceded by deciding how much each one of us is personally willing to sacrifice in the form of higher (much higher) energy prices. 

How much are we willing to pay for the liter (or gallon) of gasoline, for the kWh, for our airplane tickets and even for everything else? In a low carbon economy almost everything, including food, would be more expensive.

There are many half truths out there that are really complete lies.  For example, we hear that solar photo-voltaic (PV) has already achieved "grid-parity", but obviously these calculations do not take into consideration the extra costs that the grid has to absorb to deal with the intermittent / unreliable nature of solar.

As long as solar PV is a small part of the energy mix, the grid can (grudgingly) accept it.  Conventional power generators adjust their output to compensate for the fluctuating nature of solar.  However if solar were a main component of the grid  (as many environmentalists propose) then the equation changes completely and vast amounts of storage would need to be installed.  On the one hand this storage will be an additional investment and on the other it won't be particularly kind to the environment whether it consists of vast warehouses full of batteries, gigantic hydrolysis plants with their respective hydrogen storage tanks or hydraulic reservoirs.

The issue does not stop here, because now we would have to decide for how long we want to store the solar electricity: for eight hours? For eight days? For eight weeks? Costs rise exponentially with each step. 

So, let's make no mistake: the reason we have not moved yet to a low carbon economy is because the fossil fuel economy is much, much cheaper (sure, without pricing the effects of climate change). It is NOT a philosophical choice but an economic one.

Environmentalists challenge this point but you just have to look around and ask why if renewables are as cheap as they say they are, they need subsidies to survive? And even with subsidies they are a minute portion of the global energy supply.

The bottom line is that our governments CAN grant our wishes to move to a low carbon economy BUT at least in the short term it would translate into much higher energy prices and thus a considerably lower standard of living for most of us. Are we willing and ready now to sacrifice in this manner to prevent a global climatic catastrophe?

This is the most important real question that we need to answer in the energy debate.

It is a fact that we have to move to a low carbon economy, but we need to understand and accept the consequences beforehand.