In my previous Post I looked at the potential and problems of supergrids. The basic idea is that, since, in various parts of the EU, there will be times when there is excess electricity generated from wind etc over and above local demand, this excess can be shunted to regions which are short and have high demand, using low-loss HVDC supergrids. Would it work on a large scale?
There have been reports that the Desertec Industrial Initiative (Dii) had abandoned its plan to help support the development of solar power in the Sahara and the export of some to Europe, since it looked as if the EU could meet most of its green energy needs indigenously, without significant imports. So is the desert CSP/supergrid idea dead? Continue reading →
The previous few posts have looked at the state of play with renewables in some key countries. In many cases an urgent issue is grid integration and balancing. The variable outputs from wind and PV solar outputs are balanced on some grid systems by using existing fossil-fueled plants, but the later are having a hard time competing, now that some of their peak market has been taken over by low marginal cost (zero fuel cost) wind and PV. To ensure that there is enough capacity still available capacity markets have been proposed, offering extra payments. Some critics don’t like the sound of that- it’s yet another subsidy, in effect for fossil fuel. However, the proposed UK version includes payment for energy storage and demand management options, as well as for gas-fired back up plants, and longer term, fossil gas might be replaced by green gas in the latter. There again there are other balancing options- supergrid links for example, which would open up a new multi-national balancing market. Which option is best? Continue reading →
If you’re fed up with floods in England, sick of snow in the US or mystified by mild temperatures in Scandinavia, blame it on Santa Claus. That’s the message coming from atmospheric scientist Jennifer Francis, whose “Santa’s revenge” hypothesis suggests that the weather weirdness that we’re currently seeing at middle latitudes could be linked to recent warming in the Arctic.
Francis’ theory begins with the polar jet stream, the high-altitude “river of air” that flows over parts of the northern hemisphere. This jet stream owes its existence to the temperature differential between the Arctic region and middle latitudes: because warm air expands, that temperature differential produces a “hill” of air with (for example) England at the top and Greenland at the bottom. The Earth’s rotation means that air doesn’t flow straight down this hill; instead, it curves around, producing the west–east flow seen in animations like the one in this video from the NASA Goddard Science Visualization Studio.
The light from natural gas flares burning in North Dakota’s Bakken oil field can be seen from space. (Courtesy: NASA Earth Observatory)
By Margaret Harris in Chicago
The environmental risks of shale-gas production are real, but the things people worry about most aren’t necessarily the ones that cause the most damage. That was the message of this morning’s AAAS symposium on “Hydraulic Fracturing: Science, Technology, Myths and Challenges”, which featured talks on the social implications of hydraulic fracturing as well as the risks of water and air contamination.
Hydraulic fracturing, or “fracking”, involves drilling a well and filling it with a high-pressure mixture of water and other chemicals. These high pressures cause nearby rock formations to fracture, releasing trapped oil and gas. According to the first speaker, energy consultant David Alleman, fracking and horizontal drilling have “revolutionized the energy picture in the US”: a few years ago, the country imported 60% of the oil it consumed, but today the figure is just 30%.
For the moment Scotland is still part of the UK, but perhaps not for long, with energy issues being part of the reason why some want a split. Scotland has ambitious plans for green energy. It already meets over 40% of its electricity needs from renewables now, far ahead of the rest of the UK. So getting to 50% by 2015, its interim target, seems credible, whatever happens about independence. But what about its ultimate goal of 100% by 2020? Continue reading →
The share of renewables is growing in the United States, up from its current 13%, although the US does not have a nationwide renewable electricity target. However 30 individual states and the District of Columbia do, adding up to a cumulative target of about 18% by 2025. Continue reading →
While Germany currently generates about 23% of its electricity from renewable sources and aims to expand that in stages to over 80% by 2050, with all nuclear phased out by 2022, France is not doing so well, arguably since it has the dead weight of a large nuclear capacity to contends with- still supplying around 74% of its electricity. Nuclear still dominates energy policy thinking and public debate.
The interim energy policy outline that emerged in 2012 after the Fukushima nuclear disaster envisaged getting between 25% and 35% of Japans electricity from renewables by 2030, with wind and solar playing major roles. A new fuller plan is expected soon, but in the meantime progress is being made with renewables, with the Japan Renewable Renewable Energy Foundation claiming that ‘Japan will be able to increase the electricity from renewables to at least 20% of its total consumption by FY2020 without putting an undue burden on corporations or on households’. Continue reading →