Freitag, 20. Juli 2012

Is German Special?

Germany is the country with the largest relative (4%) and absolute (27 GW) share of solar energy in the grid. The reason is not the nice sunny weather in Germany, the reason is a strong subsidies policy called EEG (Renewable Energy Law). It gives the producer of photovoltaic (PV) electricity a good, fixed price over 20 years. Did this really have an impact on the growth of photovoltaic installations?
German was leading the growth rate, now the world has changed!
At the end of the 90s, the growth of PV installations grow with a rate of about 30%. This is quite a lot. With the start of the EEG in 2000, the growth rate in Germany leap jumped to more than 100%. At the same time the rest of the world has even seen a decrease in the growth rate, down to 20%. During the last two years things have changed again. The World, without Germany, has now 2011 a growth rate of 80% in PV installations, while Germany has fallen back to 40%, half of the global speed.

Why this Change?

The reason for this change lays in the price of PV-systems. During the last decade, the price declined from somewhere above 5000 $/kW down to 1000 $/kW due to the strong market in Germany. This low price makes PV economical within most of the sunny countries like Italy or India. Most countries have about double the sun radiation during the year than Germany receives.  
It seems so, that the growth of the solar installations is now market driven and therefore sustainable. But be aware, what 80% growth means, within 11 years, if the trend continues, the world may have changed to a complete solar energy driven world. Today, only 0,4% of the electricity is from solar, but in 2023 it could be near to 100%!



Donnerstag, 19. Juli 2012

Storage Maters


Fuel is Stored Solar Energy

We live in a world, where the energy we consume was stored eons ago by nature. The conversion efficiency of solar energy into oil was really lousy, only a fraction of the solar radiation was converted to biological mater, only a fraction was laid down into the ground and only a fraction is now available. If we do the math, we find, that less than one billionth (10E-9) of the solar energy, which reached the earth within the last 100 million years, is stored in our fuel resources. This leads to the idea that we can do better than nature!Using solar radiation energy conversion systems like photovoltaic or concentrated solar power, we end up near 20% conversion rate, which is sufficient for economic land use and by a factor of 100 better than plants, who only convert 0.1% of the energy in usable fibers or sugar. It should be mentioned, plants need water and solar cells love deserts! Resulting in no competition of land use if we are smart and don’t plant for energy but plant for food.

The Storage Problem Remains

There remains a problem, storage! Storage was never an easy business, but if solved it changed the world. Inventing hey for example was necessary to conquer the north hemisphere, where in winter time is no food for the livestock. Storing information in books was the breakthrough for the industrial age and unlimited computer storage capacity is essential for our information age.   

The upcoming renewable power age lacks of efficient and cheap storage capacity for electricity. Knowing this, we could visit the known technologies and there potential to solve the problem if further developed. Best known to the public are batteries. This is by the way a big problem, because our politicians, driven by their simple mind and the public, believe in batteries. Batteries are fine for mobile applications like cell phone and laptop. Cars using batteries are still expensive, but it may be within the reach of our technology to power them by batteries. Things get much more difficult, if we want to use batteries for grid scale applications.

Batteries are expensive, and need some more or less rare and expensive metals, they use processes which are not perfect rechargeable, this is the reason that batteries run out of business after a few thousand charging cycles. All this does not matter, if we use a mobile phone, live time is limited, the price of the battery is not the main value of the device and we don’t care to much on the environmental impact on the small scale that is involved.

Grid Scale Storage is Different

If we need storage for large scale, and grid technology is always about GW and TWh, values, which are trillion (10E12) times above the mobile phone and laptop scale. This is by the way easy to guess, as long as billions of consumers are out there. There are three different questions, how expensive is the storage capacity, how many times can we recharge it, and how efficient is the process. The reason why price matters is we can only earn a limited amount of money on every charging cycle. If the battery lifetime is already finished, before we have earned enough money to pay for the battery itself, it is useless to buy the battery at all.  The situation for the efficiency is in some way similar. If we have to pay more for the energy to charge the battery as we earn during discharge, the system doesn´t work either. The problem of efficiency is not the core problem of batteries, but of many other storage concepts. Batteries suffer from the price per storage capacity. 

Why Batteries don´t Work

Price of storage capacity for many batteries is above 200$/kWh, even for the very simple and widely used lead acid battery. Lithium based systems are often above 1000$/kWh although prices were dropping during the last two decades. Let´s do a simple calculation; our battery should be charged every day, as it makes sense in solar power systems. During nighttime the price of power should be 10ct/kWh more expensive as at daytime. If we discharge the battery, we earn 10ct every day and within six years we have a return of our investment into the lead acid battery. But this does not hold due to the fact, that our battery dies after about 1000 cycles. Using the Lithium system, things are even worse, we have to wait about 30 years for the return of our invest without any interest rate, this does not attract many investors.

More Storage Technologies

We visit other techniques of storage in the next blog posts

  • Methane
  • Pumped Hydro
  • Hydraulic Hydro Storage


Donnerstag, 12. Juli 2012

Global Growth of Growth of PV

The global volume of installed photovoltaic installation is growing fast, this is a well known fact. But not so widely known is the exact growth rate, so I will give some figures for a deep insight.
Different countries are different, so have a look into different countries.
A incredible dynamic in the growth of PV-installations
Fifteen years ago, the USA was the leader in PV-installations. In the year 1996, Japan became the leader but in 2005 another change at the top happened, Germany, supporting PV with high subsidies, took the leadership. But the PV-market has a very high dynamic and in 2011 Italy installed already more PV-panels than Germany. This race is interesting, but not the core of the global chance in the PV market. Lets have a look at the growth rate itself:
The growth rate is growing with 3% per year!
If we plot the growth rate between two years, we find an astonishing plot. Beginning in the mid ninety's, the growth rate was about 20% per year. And sometimes I have the feeling, many people have adapted this and believe in a moderate growth of PV. The last 15 year show a very different picture. The growth rate itself was growing. And a simple linear approximation results in a slope of 2.9 percent points (absolute!) per year, resulting in an approximated growth of the PV installation 2011 compared to 2010 of 67% (the actual value was even higher with 76%)

Reasons for the PV Growth

This mind-blowing effect is not widely anticipated. The reason for this effect is not longer the high subsidies of German PV-installation, the reason is, more and more countries start installing PV at a very high rate, as the first graph shows. And the reason behind this is, that many countries have much more sun as Germany combined with the hard drop of PV-prices. This results in an unprecedented dynamic, higher market volume results in higher production rate, higher production volume results in lower prices due to a learning curve.
The learning curve tells us, if we double the production, the price will fall about 20%. The dropping price opens more markets, if the price is below the power price at the consumer, he will install PV soon. 
Where will this growth end, this is not clear, but I will write about that topic soon.

Dienstag, 10. Juli 2012

The Energy Age

Within human history, we have seen four times, where the primary energy source changed.
The first and most significant moment in energy history was the control of fire. It gave us something, no animal ever had, heat and light, independent from the environment. But as burning wood was the widespread source of energy, it got rare and to expensive for burning anywhere.
The second change was the move to coal, including the development of the steam power engines. It gave us independence from location for mechanical work. Before the steam power age, at some places, water power had some impact on production. Burning coal is cheap, but coal is finite and the carbon dioxide emission seems to be a serious threat for the climate.
The third change was oil. Combined with the ford car, it gave us mobility on land, and a bit later, in the air. The 20th century was the golden age of stored energy in mineral oil. After peak oil at the beginning of the 21st century, it is not a good idea, to relay on this energy source for ever.
The fourth change never made it to the top level, it is nuclear power, a very strong power source, but also a very dangerous fire. It started with the atom bomb, and was controlled to some level in nuclear power plants.  Due to human frailties resulting in design and operation errors of facilities, some power plants failed disastrously.
With the upcoming of the silicon age for semiconductors, a small niche appeared for the use of silicon. Solar cells on satellites for energy supply. Invisible small amounts of energy were generated in the 70´s, first attempts for commercial use started in the 80´s, continuous growth began in the 90´s and as a trend, every 18 month since then, the global photovoltaic installation doubled. This is called an exponential growth. You see jest nothing at the beginning, and after some time astonishing things happen.
This fifth energy source is different to the accustomed energy sources we have seen in history, it does not contain an inherent storage system, so we have to care about energy storage!
Concluding this, my thesis is:
  1. Within the next 20 years, photovoltaic will be the primary energy source of the globe
  2. Energy storage will be the most critical point of this change
Keeping this in mind, my blog will tell you the story of this fascinating change in human energy generation. You have the chance, to watch live the biggest and last change in energy supply of mankind!