Is Storage the Solution?

In the energy discourse we hear often that once the challenge of grid scale energy storage is implemented, wind and solar energy will be able to fully replace fossil fuels for generating electricity.

Instead of just staying at this philosophical level, let's make our homework.

This exercise is an oversimplification to illustrate the challenges of relying on intermittent sources for all of our energy.

Let's take Germany as our working example.

According to the latest report by the IEA (International Energy Agency), Germany consumed 551 TWh during 2013*. To convert this amount into average power we perform the following calculation:

     551 TWh / 365 days / 24 hours = 0.63 TW = ~63 GW.

The actual energy consumed by this country fluctuates hour by hour and seasonally. Germany tends to consume more energy in winter than in summer. However, to simplify, we'll make our numbers with the average power consumed.

Let's consider a solar capacity factor (CF) of 12% for this country (a little generous).

Also (and again with the purpose of simplifying our homework) we'll consider that every day of the year is exactly the same and thus that the daily capacity factor is equal to the annual one.

Thus, the installed solar capacity we would need is (considering 90% efficiency in the battery / inverter system):

     63 GW / 0.15 CF / 0.90 efficiency = 583 GW 

     (Today Germany has ~36 GW of solar installed capacity).

At the very least, the batteries would need to store 12 hours of power and this translates into:

     63 GW x 12 = 756 GWh

According to the Guinness Book of World Records 2013 edition, the largest battery in the world** (pictured below) can store 36 MWh. Thus, we would need this many to store 756 GWh:

     # Batteries = (756 GWh x 1000) / 36 MWh = 21,000

According to the Energy Information Administration (EIA), by 2040 global solar electricity production will be 452 TWh. This would be 82% of the 551 TWh Germany consumed in 2013 (and would "leave" nothing for the rest of the world).***

To calculate the required investment we need to multiply the cost of the solar watt (including inverters and installation) by 583 billion (see installed capacity above). Additionally, the cost of the storage needs to be added. We are easily talking here of more than a trillion euros.

However, these "rosy" numbers won't pass muster in the real world. Why? Because in the real world we have sunlight variations between days and, even more important, seasonality. Germany, for example, tends to consume more energy during winter when there is less sunlight.

Thus the above amounts would have to increase significantly. In other words, in real life we would need considerably more than the 583 GW of installed solar capacity and at the same time the batteries would need to store not 12 hours of electricity, but full days or even weeks. The required investment would thus be much higher than in the simplified case we presented above.

Conclusion: storage for renewable energy is not a silver bullet and it is doubtful that a fully renewable economy (solar and wind) would ever make sense in financial or even environmental terms.

Feel free to add to the conversation on Twitter: @luisbaram

Thank you.

Notes:

1. Sure, the renewable energy doesn't have to be 100% solar. We could have a combination of solar and wind. This would obviously make the exercise much more complicated but would make more sense in the real world. However, solar and wind are not fully complementary. Solar (obviously) operates only during the day. Wind is more random. See graph below for the first months of 2012 where we can see that solar / wind do complement themselves somewhat. We can see that in January there was little solar production but was a very good month for wind. Then, July was a very low month for wind but had substantial solar production. However February (a full month) was low on both. More storage would be required for compensating those long lulls. Additionally, February was the month with the highest consumption in the first 7 months of 2012. (If somebody can share the full year statistics, they are welcomed). Let's bear in mind that the randomness of wind can only be somewhat compensated by solar during the day, so for half of the year (nights) wind is by itself.

2. Another concern is the variability of wind, here we can see annual variations (solar is more stable although its CF is considerably lower than wind's in Germany):

Both graphs are from the last reference below.



References:

* http://www.iea.org/statistics/relatedsurveys/monthlyelectricitysurvey/

** According to the Guinness Book of World Records, this battery is "larger than a soccer field."

*** http://www.eia.gov/forecasts/ieo/

German capacity factors for solar and wind:
http://cf01.erneuerbareenergien.schluetersche.de/files/smfiledata/1/1/2/2/4/7/WindPVProductivity1to712.pdf

A Tale of Two Countries

In the energy discourse we hear a lot about renewable energy, zero emissions, Energiewende, installed capacity, etc. However, today we are trying to clear the air a little bit by publishing the results. Yes, here we are removing the hype and the wishful thinking and presenting just the results.

Luckily, we do have two countries that pursued different paths toward a low carbon electric generation system.

The first is Germany that committed to eliminating nuclear and producing most of its electric power with renewables (sun and wind), the other is France that decades ago decided to go mainly nuclear.

Here we can see the latest report from the IEA (International Energy Agency) in which we can see the actual energy generated during 2013 by each type of fuel. First we have Germany:

As we may see, combustible fuels continue to lead in German electricity production. Nuclear is still in second place. Sun + wind, on the other hand, barely increased their actual output in spite of the fact that their installed capacity continued to increase.

Now, let's take a look at France:

Think what we may about nuclear, it is a low carbon electricity producer. So France overwhelmingly produces its electricity via low carbon means and it shows.

If we now take a look at the ultimate climate result, we may see that German electricity is more than six times more carbon intensive than the French one.

This Tale of Two Countries is trying to point out which approach is actually working in the real world.

Thank you.

Do We Need Subsidies for Solar and Wind Power?

Well, "we" don't need the subsidies, only the solar and wind companies need the subsidies. 

However, let's face it, these industries are pretty much mature and there is really no reason to continue subsidizing them. Spain and Germany are a perfect example of where this road leads to: very expensive energy, loads of debt and then a very difficult uphill battle to remove the subsidies once these industries get used to them. 

Besides, "renewable" installations for the most part are NOT replacing conventional energy installations or preventing additional investments in conventional energy (because "renewable" energy is not constant or reliable). So at the end of the day, "renewable" energy installations are just surplus capacity that makes life more difficult for conventional generating plants (that have to adjust their output to the variability of "renewable" energy).

Let's analyze the German example. First, yes, it is true that a substantial share of this country's electricity is produced with renewables: biomass, hydro, wind and sun. Solar photo-voltaic panels, however, represent only close to 3% of the total and they have been receiving most of the subsidies for renewable energy.

For anyone interested in the facts, we would kindly recommend the main story in Der Spiegel English Edition of October 10, 2012. The story is titled: German Energy Plan Plagued by Lack of Progress.

A few excerpts below:
"With the new rates, German citizens will be paying a total of more than €20 billion ($25.7 billion) next year to promote renewable energy. This is more than €175 for an average three-person household, a 50 percent increase over current figures."
And by the way, even before these price increases, Germans were already paying +37% more per kWh than the average in Europe (as a comparison, the French pay 23% less).
"The rising cost of electricity is also a burden on businesses. According to Oettinger, energy costs now represent the biggest liability for Germany as a place to do business, especially in light of the marked increase in the number of blackouts and voltage fluctuations in the grid."
"As long as there isn't enough storage capacity, virtually every solar plant and every wind turbine has to be backed up by a conventional power plant. Without this double structure, the power supply would collapse."
And finally: 
"At the same time, however, the boom in subsidized renewable energy is ensuring that conventional power plants are no longer profitable. Since the law requires that preference be given to green energy, if it's available, gas-, oil- and coal-fired power plants frequently have to be shut down to avoid overloading the grid. This reduces their revenues while increasing costs because powering plants up and down consumes a lot of fuel and inflicts additional wear and tear on the equipment."

So in summary, no, we shouldn't subsidize "renewable" energy. Being fair, we shouldn't be subsidizing any other energy source, either.

Greenpeace

This blog entry is dedicated or at least directed to Greenpeace.  It is unbelievable that such an important global organization can be so naive.  It seems that for them all the solutions to the main energy problems of humanity start with a) attacking large corporations and b) converting everything to "renewable" energy.

For example, this Arctic drilling thing.  Why are oil companies trying to do business in one of the most expensive and risky places on Earth? Because of the hunger for oil WE the people have.  If we tamed drastically our craving for oil, then no Arctic oil production would be needed.  As long as humanity doesn't curtail it´s oil use, the Arctic will get more and more attractive.  Why? Because the more difficult it gets to supply the demand, the more the price of oil will increase and the more interesting it will get to drill in the Arctic despite its inherently higher costs (and risks).

So Greenpeace may win this round with the oil industry BUT if we the people don't reduce our oil use, next time drilling in the Arctic will be unavoidable.

Now, with respect to "renewable" energy, it is and it will continue to be a niche energy source.  Why? Because it is not reliable (aaand it is more expensive than conventional energy).

Let's start with solar: sometimes there is sun, and sometimes there is no sun.  By definition at night there is no sun, and in winter the days are shorter than in summer, but at any moment of the year we may have cloudy skies and then the output of the solar panels can drop by as much as 90%.  Bottom line: we need to backup all solar energy with conventional energy, so solar does NOT replace conventional generating capacity.

With wind it is exactly the same thing but the variations are even more dramatic in the sense that significant variations can happen in the span of a few minutes.  And again, all wind capacity needs to be backed up with conventional generating plants.

Sure, renewable supporters are going to say that sun and wind, specially if interconnected to a very large grid will pretty much even out and thus somehow provide base power.  Well, this is just not true and for example in the UK, the coldest days of winter (when the demand for electricity is the highest) have almost no sun and might have no wind either.

Now, for the conventional generating plants, renewable energy is a head ache.  THEY are the ones that have to continually adjust their power generation to adapt to the renewables.  And they cannot shut down and tell their employees to go home because in the next 10 minutes they may need to be back in the generating business.  They need to continue paying the salaries of their people and end up producing less than the capacity of their plants.  Yes, their fuel costs go down, but their costs per kWh go up.  Will they absorb the loss or pass the extra costs to the consumers?  Try to guess the right answer.

Renewables (solar panels and wind turbines) are mature technologies but even today need subsidies to survive and this is one of the reasons electricity rates in Germany are close to TWICE those in France.  Why the subsidies?  Well, first because in most first world countries very little new generating capacity is needed and thus renewables are almost completely surplus (in other words unneeded) capacity.  Spain is the perfect example, at peak hour they need 44 GW but they have a total of 100 GW of installed capacity.  In other words all their renewable capacity was nothing more than an expensive luxury.  Spain has already stopped the madness and thus have pretty much eliminated subsidies for renewable energy.  Germany is still going full steam ahead in this orgy of subsidies but sooner or later they will be forced by reality to change their ways.

So, if we really want to make a dent in humanity's carbon emissions what should we do?

1. REDUCE our energy consumption by a very substantial amount, say 40%.

2. Convert coal electricity generating plants to natural gas (where feasible).  This would reduce emissions by 50%!

3. Long term, the only solution for very low carbon electricity generation is nuclear (sorry, Greenpeace, but these are the facts and no amount of feeling will change them).

4. Buy only hybrid cars, or even better, buy no cars.  (Electric cars are NOT ready for prime time).

5. Commute and travel less (much less).

6. Buy less things (much less).

7. Go vegan.

8. Have less children (why not follow the Chinese in having only one per family?)

Greenpeace, IMHO, should focus its marketing muscle, which is considerable, on the true culprits of global climatic disruption and the destruction of the Earth: we the people.

Only if billions of people change their behavior would we be able to improve the road ahead for the planet and all of us that live on it.

Thank you.

Dose of Reality

All decisions have advantages, disadvantages and consequences.

The only thing that is important is to face reality and not try to hide behind wishful thinking.

For example, Japan: they decided to shut down all their nuclear plants (at least for the moment) and that is OK.  What is NOT acceptable is to say that they will replace nuclear with “renewable energy”.  That is just not possible.  Period. End of story.  Elvis has left the room.

Here is the real data from the real world of the real consequences of shutting down nuclear plants:

http://www.world-nuclear-news.org/EE_Fossil_fuels_rule_Japan_3105121.html

And again, it is OK, each country has to make their own decisions, but everybody needs to know the consequences.  In the case of Japan, they are:

a.      Increases in CO2 emissions.

b.      Electricity will be more expensive.

c.      The balance of payments of the country will be affected.

d.      Japan will be even more dependent on ever more scarce (or at least more expensive) fuels.

e.      Additional capital investments will be required.

f.       The energetic security of the country will be at greater risk of global happenings.

If all the above compensates for the “peace of mind” of politicians and other people, then it is OK.  But things have to be put out in the open.

P.S.  and the ONLY reason Germany will not go EXACTLY down the same road as Japan is that France is its immediate neighbor and it will certainly be willing to sell them more nuclear electricity.  ;-)