Supergrid - turning wind into firm power
It is a while since we wrote about the European Supergrid. This is one fault that can be corrected today.
Creating the Supergrid has been my most cherished dream for the past decade. Perhaps I should explain why this is.
When I came into the wind business, I was constantly berated by the non wind community (which was almost everybody) that I was backing the wrong horse. The storms that beset northern Europe and are the main drivers for our wind power. They arrive in an unpredictable manner. “It can’t be relied upon”. Nor did I find much encouragement from the official promoters of wind energy. They seemed happy to connect wind farms to the distribution system, to be small, peripheral. Interestingly these proponents of wind energy allowed wind to be seen as negative load; not as generators in their own rights.
So wind is variable, does not deliver firm power and is not very predictable in the long term. The more wind that is put on the system the less firm it became. I had some knowledge of weather systems from a previous employment, and had some idea that the wind was always blowing somewhere. With the assistance of Brian Hurley, the great wind analyst, manager, and fellow founder of Airtricity, we quantified the wind systems around Europe, and so the idea for a Supergrid was born.
Using the Supergrid, it is possible to utterly transform the role of wind energy on the electrical system. Put another way, if wind energy is regarded as a continental phenomenon, rather than a national one, wind becomes firm; it can be relied on.
One of the interesting studies we did resulted from my chairmanship of the EWEA wind conference in Madrid in 2003. I recall looking at the Red Electrica (the Spanish Grid company) screen and seeing that there was a contribution of 300MW being made by all the wind farms in Spain. At the time there was about 6,000MW installed there. During this time Spain, along with the rest of Europe, was suffering a heat wave and demand for electricity was at a peak. Brian did a study to find a place in Europe which was negatively co-related with Spanish wind. In other words we tried to find a place on or off shore where the wind would be blowing if there was a calm in Spain. In fact we found such a place, in the Bay of Biscay - fairly far out.
So the proposition was good that wide geographic diversity leads to smoothing out of the wind variability.
The next step was to examine the grid technology to see if it could meet the technical needs of a Supergrid. When moving large quantities of electricity over long distances, underground, the only possible technically feasible solution is DC or direct current. The cable technology for long distance high voltage DC has existed since the 1950s; from the time that Scandanavia sought ways of moving its huge hydro generated electricity to market in Denmark and Germany in fact.
Next blog explores the difference between the old fashioned point to point HVDC connections and the Supergrid.