Samstag, 14. April 2018

Big Picture of Energy Generation 2030

Electric Energy Generation till 2030

We can read every day about the change in the energy market. We hear about the year 2050, a time when most of our politicians are no longer with us. 
But is the Big Change to renewables so far away? 
There is only one way to understand the change, and that is, read the data we have. And I did this and present them here. The source is from BP energy statistics, you can download the data there.

Solar and Wind

I concentrate on two sources of energy solar power and wind power. Both are renewable and have the potential to power our civilization. I take the sum of both to get a more smooth picture because there is some change between wind and solar shares, that obscure the real change. The result in a logarithmic graph can show us the long-term trend:
Figure 1: (click to enlarge) red: global electric power consumption; blue: global installed solar and wind power; yellow: global mean power from solar and wind. Data source: BP

The mean global electric energy consumption is about 2000 GW, shown as the red dots, which align in the plot and show a constant growth of 3%.

All installations of wind and solar power are shown as blue dots and have an astonishing constant growth over the last 20 years in the range of 22% per year. 

The mean energy production of this fluctuating sources is much smaller as the installed capacity due to the fact, that the sun does not shine at night and the wind does not always blow. A good estimate based on data from BP shows a factor of five between the blue and yellow line. This means the wind and solar production is only 20% of the time as strong as on the nameplate. Of course, this is a statistical value and may differ between different installations.

The most interesting point is somewhere at 2030, the yellow line crosses the red line, in other words, the generated electric energy over one year from solar and wind power is larger than the electric demand in 2030!

Could this be true  

Today (end 2017), only 2% of the global electricity is from solar power, but remember only 1% was from solar power 3 years ago. In 2020 we will see 4%, 2023 we see 8%, 2026 there are 16% and 2029 32% and 2032 64%, this is the rule of exponential growth, as we all have seen in electronics. 

Figure 2: Solar energy share in different countries and the world. Source: IEA PVPS, shown in pv-magazin.

The remaining 36%, oh sorry I did not include wind power in this very short estimation!

But there is one thing, that may stop this trend. It is not the price of photovoltaics because photovoltaics is now below 3ct/kWh and thereby cheaper than any other energy source. There is a so-called learning curve that gives in the future even lower prices due to high production volumes.

The roadblock could be energy storage!

If we find no way to store the energy cheap and on the huge scale, we cannot go far beyond 50% of fluctuating renewable energy in the electric grid. And the storage demand is in the range of 24 h global electricity production, 60,000 GWh!

To imagine this number using batteries, think about the Gigafactory built by Elon Musk. If it reaches full capacity it may supply 100 GWh of batteries a year. If we install all the batteries in the grid, we need 600 years until we have enough storage. This works only out when the batteries have a lifetime of at least 600 years. 
Figure 3: Gravity Storage, a large-scale electricity storage system.

We need new ideas, my concept of a Gravity Storage may show a way out of this problem. One Gravity Storage site can store up to 8 GWh of energy, and we don't need expensive raw materials only rock and water.

But this is another story.