Montag, 24. Oktober 2016

Global Demand for Energy Storage

Energy Storage Demand in a Sustainable World

The global transition to renewable energy production is in progress. Last year, 2015, more renewable power capacity, like solar and wind power, was installed as conventional capacity like coal and nuclear. Beside this nice development, there is a weak spot, the installed solar and wind capacity produce only when the sun is shining or the wind is blowing. For a full change to an emission free world, we need energy storage.

How big is the storage demand on a global scale, this is hard to guess, because it depends on a lot of assumptions. I will try to make a good guess within this post.

The Global "Energiewende" 

I will not describe the "Energiewende" (change of the energy system) in Germany, I will focus on the global change. This makes sense, because we have to change the energy system on the global scale to stopp the carbon problem and limit the exhaustion of the scare fossile fuels. 

The strong growth of PV installations, about 70 GW are expected for 2016, continues the long term trend of constant fast growing installations over the last decades. 

This trend will change the energy system as we know it today within two decades, to understand this lets look into the near history.

Growth of the energy consumption and the installed renewable energy production.
Consider the logarithmic axis of the installed power. Data source BP 
The first thing is, the electric power demand has a constant annual global growth of 3%. The installation of wind and solar power combined grows every year with 22%. The result will be, that somewhere around 2025, more fluctuating renewable energy is installed as conventional power plants. 

But be careful, the produced energy of wind and sun will still not match the demand, because they only produce energy when sunlight or wind is available. Resulting in the green line, which represents the mean renewable power generation. This line hits around 2030 the demand.

The result is, the next century will be dominated by the installation of storage to match the flucuating production at any time with the global demand.

Influence to the Storage Demand

The main impact for the storage demand has the electric grid infrastructure. The reason is, that the grid is the most efficient way to transport the electric power from the source to the customer. Is the sun shining in the southern part of a country, it is efficient to bring the energy to the cloudy northern part. And similar, if the northern part has a lot of wind during the night it makes sense to bring the energy with the same grid to the customers in the southern part.

This results in a competition between grid and storage.

To find the economic optimum between power grid size and storage is complex
Theoretical, it would be possible, to span a global grid around the globe and connect this grid with all solar power plants. This would result in a perfect 24 hour solar power supply without any energy storage at all because the sun shines always at some places on our earth.

The main problem seem the high price of such a grid and the energy loss in the power line. The other extreme case is a power storage at home with a seasonal capacity (only necessary in the northern region) of 1000 kWh for every person in the house. Then we can go off grid, sufficient PV on the rooftop assumed. The price for the batteries may reach a million dollars, not affordable.

If we dive into detailed computer simulations as done by J. Tambke und L. Bremen [1] we learn, that a country like Germany needs a storage capacity of seven days after a complete conversion to wind and solar has happend and there is a perfect power grid, often called a copper plate. 

Expanding the area of the perfect grid connection to an area like Europe only two days of storage is necessary. If we are optimistic and assume a perfect grid of this semi continental scale we need only a storage capacity of two days.

Further Chances to Optimize

Beside the grid, another chance to minimise the storage demand is the so called smart grid. Whenever possible, a energy consuming element in the grid goes offline if the power price is high or goes online if the price is low.

We dont know the exact possible amount of energy demand that can be shifted to other times but a optimistic guess might be, that 50% of the demand can be shifted in a way that the storage demand is halved.

Asuming this, we need only one day of storage if a smart grid and a comtinent size grid is available.

Adding up the Numbers

The energy consumption in the world in the year 2030 will be around 4,000 GW. To store this energy over one day, we need a 24h storage system with a capacity of 96,000 GWh. Keep in mind, the Gigafactory of Elon Musk may produce 100 GWh per year. If all the storage is used for the global Energiewende, the production for this demand needs about 1000 years.

But be careful, other solutions may be available.  The energy stored in the lakes of Norway contain an astonishing amount of 80,000 GWh, although there is no pump, the stored volume can only be used once in a year and has to be refilled by natural perception.
Pumped hydro technology may be a good solution, especially the Gravity Storage system, a typical site can store about 8 GWh. We still need 10,000 Sites, but tis seems to be more within practical reach, than a bure battery solution.  


Montag, 17. Oktober 2016

World Energy Council Meeting 2016

World Energy Congress 2016 in Istanbul

From 9th-13th October 2016, the World Congress on Energy was held in Istanbul. It was the 23rd Congress since 1923.

The topics of the congress were distributed over the entire energy area, including the oil and gas production and renewable energies. There were many important statesmen like Russian President Vladimir Putin and the Turkish President Recep Erdogan, including many other government members from different countries, including the visit of Israeli Energy Minister Yuval Steinitz, the first official meeting after six years frozen relations between Turkey and Israel.
Side by side, Putin and Erdogan at the conference in Istanbul

Vladimir Putin talk was about the importance of energy and the price of oil, a remark about a co-operation with OPEC during the speech has moved the oil price to rise by 2 $! He was the only statesmen, who included the words "exponential growth of solar energy".

The issue of energy just brings together not only scientists and engineers, but also politicians and diplomats. The global linking of energy distribution, especialy natural gas, plays an important role and Turkey was presented as a hub between Asia, Middle East and Europe and the Mediterranean.

The world's energy

All participants have concluded, that the energy transition towards renewable energy, particularly solar and wind, is on the way. However, the completeness and how fast that arives is controversial. While I am convinced that before the end of the next decade the significant change of the energy system has been completed, Marie-José Nadeau, Chair, World Energy Council believes that in 2060 the share of renewable might reach only 50% of total energy production [1] ,
Marie-José Nadeau, Chair, World Energy Council

This is understandable from the perspective of the energy industry. They trade with oil, coal and natural gas. Should the change take place quickly, the oil and the coal is not any longer requested by the market. The industry worries about stranded resources. This means the oil in the ground, on which the wealth of large companies and nations is based, may become worthless.

Key issues in the energy transition in the coming decades

The importance of the Paris Convention for the CO2 reduction was repeatedly stressed. Generally, however, many see only a shift from coal to natural gas, as is well known, natural gas produces half as much CO2 when it is converted into electricity than coal! This is due to a fact that a methane molecule consists of one carbon and four hydrogen atoms, but also to the better efficiency of gas power plants.
Key finding: the phenomenal rise of solar and wind energy will continue!

Power Turntable Turkey

At the conference in Turkey, the geo- (energy-) strategic role of  Turkey was stressed by Erdogan.

Important oil and gas pipelines connect large resources of Asia with European customers, more gas and oil pipelines are planned.
Strategic position of Turkey

Finally, the construction of a new gas pipeline connecting Russian and other Asian gas fields to Europe by crossing Turkey, were one reason why Putin, but also the President of Azerbaijan, Ilham Aliyev, showed up in Istanbul.

The Importance of Hydro-Power

It's a certain irony, the most important renewable energy in the global mix, providing at least 71% of all renewable energy is hydro-power, or 6.8% of global electric energy production, is a often forgotten big player.

The importance of hydro-power may lie in a combination of solar, wind and hydro-power. At the conference solar power as named a water saver, in the form that during the day the turbines are shut down at the dam resulting in increasing water level, during the night, with redoubled turbines, water can be used for power generation. Thus normal dams are important energy storage elements for the energy transition. ot to forget pumped hydro storage or even the new technique of Gravity Storage .
A nice photoshop picture used as advertising billboard in Istanbul

There are, at least in Africa and in South America, still many untapped hydropower "reserves". However, anyone was well aware that each dam has also an enormous impact on nature and very often engages in the habitats of people! Especially in India, the water of the rivers is sacred and thus hardly the construction of dams possible as mentioned by Richard M. Taylorlearned Chief Executive, International Hydropower Association.

Africa to get electricity

While the inhabitants of the Americas and Asia are almost completely supplied with power, in Africa there are still 600 million people without electricity. This means no light, no easy way to charge a mobile phone, no fridge and no welder.

The last day of the conference was therefore devoted to Africa. In Africa, here essentially black sub-Saharan Africa was meant, you have to think about the huge areas and the still sparsely populated countries. This makes the construction of a conventional electric grid network uneconomical and therefore solar energy stand-alone systems and microgrids are very important.
The forum "Talent and Capacity Building" moderated by Samir Ibrahim from Kenya, right Sanjit 'Bunker' Roy from India, next to Andreas Spiess, Solar Kiosk , from Germany.

The practical implementation requires some knowledge of electricity and solar energy. Bunker Roy helps the people with his Barefoot College to teach this to everyone. While he teaches women worldwide (Grandmothers) to practical issues of the use of solar energy, an impressive project!

Andreas Spiess tries with his, as he stressed, commercial solution of the solarkiosk promoting the dissemination of locally adapted use of solar energy in Africa.

The Exibition

There was a international exhibition were companies and countries presented interesting ideas and investment opportunities.
Booth of Heindl Energy GmbH

The Heindl Energy GmbH has presented the "Gravity Storage" technology on its exhibition stand. Unfortunately, very few companies from Europe were represented at the fair. The booth was right next Aramco, the largest oil company in the world from Saudi Arabia. As far as I have observed, our stand had awakened almost more interest.

A 600 MW power plant on the water for emergency cases

There were of course many other interesting exhibition stands, I found the idea of ​​"power ship" interesting, which is a ship with a complete power plant (up to 600MW), inclusive substation, which anchors in a port and supports the local power generation, after a natural disaster or for other reasons.