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.

Prometheus Energy - a grand-sounding name for a company that deals in waste gas from trash - has just started producing LNG from natural gas emanating from the Bowerman Landfill in California, which will be used to operate public transportation vehicles in Orange County, California. This is a big site - just take a look at these pictures. Landfill gas by the way typically peaks in output over the first 5 years, after which it goes into the "exponential decay phase".

There is a view that biomethane has much more potential than bioethanol or biodiesel. As I remarked here before, I like the low-tech approach to Prometheus; get the lowest cost methane possible and turn it into fuel. Some people find landfill intrinsically wrong, but I think they are wrong. You can only go so far with recycling and the other alternative, incineration, is much less desirable.

Alkane Energy - a company that specialises in the capturing of waste coal methane and turning it into power - is trading up on the completion of 3 new projects.

Given that there's so much coal left in the world and India and China's clear intention not to decouple economic growth from rising carbon emissions, there ought to be a a good opportunity for Alkane to go international. Right now, they've only got one plant in Germany and 3 more on the way.

It's a shocking figure that China produces 35% of the world's coal but over 80% of the mining deaths - more than 6000 a year. I have heard that this is because Chinese miners like to smoke on the job, igniting any waste methane that may arise.

So there's a real opportunity for someone to get some carbon credits, set up a waste methane plant and save some lives into the bargain. China plans to increase electricity production by 6 times by 2020, so they need all the power they can get.

Oil prices have taken a tumble and the alternative energy IPO boom so strong earlier this year has dried up. So it's encouraging to see that Prometheus Energy is planning to list on AIM. Like many of it's American brethren, it is being drawn to London's AIM market, because of the high cost of regulatory compliance following the Sarbanes Oxley Act - something I've written about here before.

The company plans to extract waste methane from landfill and coal mines, liquefy it and turn it into transport fuel. This is all pretty low-tech stuff and I like it. Air pollution in cities would end in short order if cars, trucks and buses ran on natural gas rather than petroleum and especially diesel. Methane - the most powerful greenhouse gas - has very few impurities which create the particulates, or in layman's terms, the black stuff in your nostrils.

The environmental priority for cities is to reduce air pollution - not reduce carbon emissions which perversely encourages diesel. That's why companies like Prometheus are a step very much in the right direction.