“An Unprecedented Test for Europe’s Electricity System”

And we will not be able to contribute – by a hair. We have just ordered our photovoltaic generator, and installation is planned for April.

It is the (partial) Solar Eclipse on March 20 that made Europe’s Transmission System Operators (TSOs) release an announcement:

Under a clear morning sky on 20 March 2015, some 35000 MW of solar energy, which is the equivalent of nearly 80 medium size conventional generation units, will gradually fade from Europe’s electrical system before being gradually re-injected: all in the space of two hours.

Managing this event on the world’s largest interconnected grid is an unprecedented challenge for European TSOs. Solar eclipses have happened before but with the increase of installed photovoltaic energy generation, the risk of an incident could be serious without appropriate countermeasures

This paper shows the grid operators’ model and calculations.  20 GW would already correspond to a shift in frequency of 1 Hz – which is huge (from this German article on control mechanisms in the EU power grid). The TSOs’ benchmark is the speed of the  sunrise / sunset, and the solar eclipse’s shadow is faster.

I mentioned before on this blog that I think the power grid is a remarkable and most underestimated achievement in engineering as well as in the design of associated financial markets. In every single instant supply and demand of power have to be balanced exactly – so turning on and off an appliance immediately has to trigger a change in power provided by generators.

Grid operators today emerged from the split of monolithic power companies that integrated both power generation and distribution. Monopolies run by government, allegedly privileged and maybe as ‘popular’ as the stereotype ancient evil telephone company, emerged into a set of distinct players – operators of power plants and operators of the grid. They are now part of a complex market comprising also consumers, different kinds of traders, and agencies. Regulators needs to make sure that there is both fair competition and safe supply of electrical power to anyone in the long run.

For decades the grid had to deal with centralized, large generators only, and both the physical infrastructure  and the smartness of control systems needs to be continuously adapted to deal with a huge number of small, dispersed generators whose output is volatile. Commentators stated that unbundling of grid operations and power generation  caused players in the market to focus on their individual goals whereas ‘thinking holistic systems’ in not fostered anymore.

So TSOs might be concerned about the rapid increase of the number of generators of renewable energies as they are not the ones profiting most from energy sold anymore (their fees are regulated), but they need to care for safe and reliable distribution nonetheless. The development of the smart grid had been called the largest global IT infrastructure project ever – and this is perhaps not even doing the electrical engineering part justice. In Europe nearly all homes need to be equipped with smart meters until 2020 – which is a challenge given restrictive data protection laws and logistics.

It is  impressive that German TSOs can handle this today in such a reliable fashion:

At noon more than one third of power generated – about 20 GW  –  can come from photovoltaic generators, and some of that has to be exported to other countries. But this has to be compared to energy generated, that is power integrated over time: About 6% of all energy generated in a year is from solar generators – 32,8 TWh (Solar power in Germany, data for 2014).

Since a year has 8.760 hours, the average power is thus

32.800 GWh / 8.760 hours = 3,74 GW.

So the average solar power is only a fraction of peak solar power. And this is, unfortunately, why we should not over-hype record powers in solar energy generation. The challenge of the near future is storing, intelligent re-distribution, and management of consumption of electrical energy.

11 Comments Add yours

  1. Joseph Nebus says:

    I hadn’t realized solar power had gotten to be important enough to make eclipses a significant problem for power grids. That’s a heady though.

    1. elkement says:

      I hadn’t realized either – given the huge daily changes in power (on some days, in some places in Europe). It is hard to judge how critical it really is – and/or if TSOs also piggyback on the solar eclipse’s media coverage to raise awareness for the challenging job they do.

  2. Many years ago–1979 to be precise–I first became acquainted with advanced analysis of AC. I learned of, among other things, advanced applications of Kirchhoff and Phasors (and, for any non-Elkes reading this, the term has NOTHING to do with the weapons used in Star Trek. It is a complex number representing amplitude, frequency and phase of an AC feed). One thing I gained a huge appreciation for is the incredible complexity associated with balancing loads in order to maintain a reliable feed of energy. Yes, Elke, I do agree that the grid is one of the great (and under appreciated) achievements of our time.
    There’s still so far to go, though. Presently my home is supplied with electricity generated in a nearby thermal plant. While it’s cheap ($0.12/kWh) the whole notion is ridiculous in an environment that has an ABUNDANCE of hydro, wind and wave energy. Fortunately in a few years the enhanced hydro unit currently under development on the Churchill river will replace the thermal plant. That said, the provincial energy body NALCOR is not even seriously considering wind at this point, even though all of the data indicates ideal conditions here. Too bad–one can hope I suppose.

    1. elkement says:

      Thanks, Maurice! Yes – electrical engineering is really fascinating. Two years ago (as a non-traditional student) I did a photovoltaics project – planning an off-grid solution. This stuff is much more complicated if you have to forecast and balance load and supply – compared to just feeding in your power into the grid.

      Currently I see lots of new commercial PV solutions which comprise batteries and energy management for private homes – but currently they are still far from economical. And fuel cells are announced every year to be available as off-the-shelf solutions within the next year. But I really think within several decades every home will serve as its own power plant most of the time … and I am curious how utilities will react to this.

  3. howardat58 says:

    This is probably the most distributed of all distributed control systems. The main problem is due to the speed with which a change in voltage resulting from a load change propagates throughout the system. Every generating station sees this more or less at the same time, and if they all react quickly and together then we are in the danger zone. This can work either way, and poor design can lead to serious instabilities. Remember the big blackout in the northeastern USA, must be at least 10 years ago.

    1. elkement says:

      Yes – I remember the 2003 blackout… actually not the blackout itself but it is often used as a ‘textbook example’ in cyber security / risk management as it was due to an issue with the monitoring software that should have sent alerts.
      Our (Europe’s) last major blackout was triggered by a – planned! – disconnect of power lines in Germany, allowing for a ship to pass: http://en.wikipedia.org/wiki/2006_European_blackout

  4. My sister actually works for the Austrian Power Grid. And on March 20th, she won’t be in for work because of our dad’s birthday

    1. elkement says:

      I associate two things with APG:
      1) Their head quarter looks like spaceship Enterprise.
      2) I like their X-Mas lighting on a utility pole near the highway, and I miss to take a photo of that every year.

      1. Maybe I should seek to work there. I’d go to work wearing a Klingon costume ;-)

        1. The “phasor” would fit right in :-)

          1. elkement says:

            I should link to this conversation on my previous post – the blogging manifesto: ‘Such discussions are why I like WordPress’ :-)

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