Top 10 Most-read News Stories of 2011

The Peak Oil Catastrophe-in-waiting: The United States continues to slumber while a catastrophe lies in wait. Increasing numbers of analysts and policymakers are warning of another super price spike for oil and the likelihood of "peak oil" more generally. Peak oil is the point at which global oil production reaches a maximum and then declines. The speed of the decline is a key unknown and if it is relatively fast, the results could be truly dire for economies around the world. Read a recent follow-up here.

Solar Energy Becoming Cheaper than Gas in California?: We hear it every day: "Solar is too expensive." Well, not according to the California utility Southern California Edison. In a recent filing to the state's Public Utilities Commission, SCE asked for approval of 20 solar PV projects worth 250 MW – all of which are expected to generate a total of 567 GWh of electricity for less than the price of natural gas.

Calculating the True Cost of Solar Electricity: It goes without saying that solar investors want a good cost and performance analysis before deciding whether to pump money into a project. What many may not realize is the numbers they get often are superficial and too basic, said researchers from Argonne National Laboratory.

Germany-Greece in Talks Over Massive Solar Project: Greece is looking to the sun for a plan that will help it emerge from its deep economic troubles, and solar giant and EU powerhouse Germany may be the beneficiary. According to a report in Greek daily newspaper Ta Nea, a $29 billion project (€20 billion) could create as many as 60,000 positions in jobs-starved Greece by harvesting its abundant sunshine and shipping it to Germany, which has committed itself to moving rapidly away from nuclear power following Japan’s earthquake and nuclear crisis.

Wind Becomes Spain's Biggest Energy Source: Spain saw wind power become its main source of electricity generation last month, underscoring the country's progress in becoming one of Europe's greenest nations. Power network operator Red Electrica (REE) said Iberian wind farms generated 4,738 GWh of electricity in March to meet 21% of demand, 5% above the year-ago monthly rate, fueled by heavier winds than usual.