Around the world, utilities and government regulators are watching very closely the first mass energy storage device to be tied to a windfarm - VRB Power Systems flow batteries and Sorne Hill in the Republic of Ireland.

If you want to know why Ireland is the first country in the world to pioneer energy storage by wind farms this seriously, I reckon there are three reasons;

i) They have pretty much (except possibly New Zealand) the best sites in the world for windfarms - where windspeeds are so high, load factors of 35% are commonplace. So wind is cheaper in Ireland than almost anywhere else, incentivising developers to build more of it.

ii) A few years ago, TSO, who were in charge of Ireland's national grid (they are now called Eirgrid Plc), demanded a moratorium on new grid connections to wind farms at 775 MW to overcome the technical challenges of integrating large amounts of unpredictable power. So in order to progress, energy storage started to loom far larger in the minds of irish developers than in other nations, where it has clearly not actually happened at all.

iii) Ireland has grown by on average 7.5% per annum for each of the last 10 years and they need lots more power, which as island they can't easily import from abroad. Dell's Computers European headquarters are run out of Ireland and the country has been a magnet for foreign investment, requiring even more power.

So there you have it - if Sorne Hill's energy storage is seen to work, I can well imagine regulators around the world will be tempted to start mandating some degree of energy storage for future wind farms.

And it's hard not to see VRB Power Systems doing well out of that.