I like silly Top Something Lists. In a more serious state of mind I wondered what a list of the top inventions or top innovations of humankind might comprise.
Random googling yields list items such as The Internet, Money, Plumbing, and The Power of Story.
This list contains what my biased mind was searching for: Electricity, Water Power, The Light Bulb, The Steam Engine, The Electromagnet, The Electron, Semiconductors, The Transistor, and of course again The Internet. I argue the greatest innovation uses all these and is as important as Plumbing – actually our toilets and water supply would not work without it today: I nominate …
The Power Grid
(If this were TV, you would now see this.)
You might say that I am cheating because the power grid is not a singular invention but rather a conglomerate of diverse inventions, held together by the glue of standardization, politics, and committees. I picked the grid for that very reason.
The more I learned about the power grid the more I wondered that it works at all – at that amazing level of availability. In Austria the average downtime per customer is about 45 minutes per year, that is electric power is available 99,99% of the time. Experts state that this even has a negative impact of our ability to cope with sudden blackouts. This is called the paradox of vulnerability: the less vulnerable you are as per statistics, the less you care about very improbably but disastrous events.
At every moment the consumption of electrical energy needs to be balanced with the demand. This sounds trivial but it means that if you turn on your oven, somewhere in your country (actually: in your control area) a gas turbine needs to spin a bit faster. In Austria the gates at a pumped-storage hydropower plant will open a bit more.
If you turn on your computer or other electronic device the compensation needs to be more sophisticated as modern devices distort the nice sine function that alternate current used to be in the old times.
If consumption rises faster than demand the frequency of AC power decreases. All generators rotate in sync – most of continental Europe is one large synchronous area. The energy ‘stored’ in rotation is proportional to the square of the frequency. If the energy is not consumed the rotating masses can’t get rid of it. Since the factor of proportionality is the moment of inertia you can compensate for changes in demand by tweaking the generator, e.g. by controlling the flow of water. The grid codes agreed upon by all countries in a control area state that the operators of generators need to respond within seconds.
If something goes badly wrong the synchronous area would split into regions where generators spin with different frequencies – preventing to flow energy between these areas. This had happened in a blackout in 2006 in Europe, which was triggered by a – planned – disconnect of power lines in Germany: allowing for a ship to pass.
What amazes me even more is that the system does still work so well, even after introducing feedback loops governed by a ‘capitalist’ market. I consider the power grid a combination of at least three networks: the network of electrical power, the communications network (stuff for cybersecurity nightmares), and a market of suppliers and customers. We can expect many new types of participants in this market as the producing consumer – the prosumer – and intermediaries aggregating demand and supply.
I am sometimes worried about the consequences of adding more smartness, intelligence and automation for technical and, above all, for commercial reasons. I am not that concerned about hackers changing the frequency of generators, but about perfectly well-controlled computers running mad at the electricity stock exchange (or by some harmless test command wreaking havoc – as described at the bottom of this post.).
In February 2012 is was really cold in middle Europe for about two weeks, and basically all power plants were up and running – not much reserve left for controlling frequency and power. There had been rumors on speculations impacting the stability of the power grid in Germany: Since the stock exchange prices of electricity were high, the balancing group representatives were said to have tweaked their forecasts. As a result the power needed was not standard power to be purchased on a market designed for that but precious energy that should have been dedicated to providing stability. The German regulator explained later that these alleged speculations had not made sense in hindsight but it cannot be ruled out that representatives were tempted to do that beforehand.
The blackout in California in 2003 is often quoted as a textbook example of a software bug affecting infrastructure, as well as the market manipulations causing the Californian ‘electricity crisis’ have been considered an unintended side-effect of market liberalization.
This is all very interesting for the engineering, physics, and IT geek (even including the geek who indulges in applying physics-style differential equations to economics). But the consumer of electrical power in me simply concludes that at all odds you should try to make yourself as self-sufficient as possible.
For German readers – and actually in order to keep track of that myself – I add some sources only available in German:
Statistics of disruptions by the Austrian regulator, incl. exact definitions for calculating the minutes of disruption quoted in the post.
Stability of the German power grid in February 2012:
Austrian newspaper article – translating to ‘Gambling until Blackout’, a bit sensationalist.
Evaluation by the German regulator, see page 61. They really use the term temptation.