Looked at crudely, the world's solar pv industry is mass manufacture in Germany, Japan, and to a lesser extent in China and the USA for module sales and installation in Germany, Japan and the USA. By and large, when you strip out China, most of the production tends to be for the domestic marketplace.

The wind industry I would argue is a lot more globalised.

Take today's news of 2 Big orders for Vestas and Repower Systems in Greece and Japan.

A Danish company selling to Greece and a German company selling to Japan. There's no equivalent kind of interplay going on the international solar scene on that scale.

An exception though might be the extraordinary size and success of Renewable Energy Corp from Norway - the world's biggest alternative energy company by market capitalisation.

A very informative article here about the effect of venture funding for clean energy technology companies.

Although venture funding for environmental technologies doubled in 2006 to $1.28 billion, this is still a fraction of what was raised through IPOs in 2006. Of course, stockmarkets and venture capitalists are not usually competitors. That's because VCs tend to get involved early on in a company's formation whereas the IPO is - quite often - the crowning glory of a company's history. So for successful firms, venture funding very frequently preceeds IPOs.

Take Trina Solar for example. As the article reports, Trina received the third largest venture financing - $40 million ahead of its initial public offering late in 2006. Since going public, a lot more money has been raised. The stock is now worth $240 million.

We should not take this as a given though. At the end of the dot-com crash, VC funds were sitting on a lot of cash with very few opportunities, whilst the IPO market took years to recover. If - as some believe - we are in an alternative energy bubble today - it is quite possible this will happen again and VCs will be a lot more powerful than they are today.

You can't ignore the volatility that is so prevalent in the alternative energy sector.

Take today's biggest winner and loser for example.

Repower Systems AG, usually referred to by the media as just "Repower", jumped 27% today, because Suzlon Energy, an Indian wind turbine manufacturer, has just offered a 40% premium over Areva's buyout price for Repower - fixed on Jan. 19, the last trading day before Areva made its approach. . This is no question, an exciting story. Indian industrialisation has largely been ignored in the West, who have assumed that it is all about China, and India was all about call centres and software. With an economy of 1 billion people growing at 9% a year, we can expect to hear much more of India in the years to come.

Now the loser, Energy Conversion Devices, down 16%, because revenues came in $10 million lower than expected. According to this article, the company said that it does not expect to achieve sustainable profitability by the end of the year as previously projected, partly due to the longer-than-anticipated delay in securing additional funding for the company's emerging technologies.

To pick just one angle, the contrast between the two is really one of marture and developing technology. Repower and Suzlon represent off-the shelf profitable alternative energy technology which works. ECD's basic problem is that it is visionary - the technology is always beyond the horizon.