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Balancing renewables in Denmark

By Dave Elliott

Denmark has been at the forefront of the renewable energy revolution and although it has seen some political retrenchment recently, it is still pressing ahead with the next phase- which includes the need for more grid balancing.  It’s mainly a problem of over-supply. Wind and other renewables now supply over 43% of annual power, and that at times means there is too much electricity available.  How is that dealt with? Continue reading

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Supergrids revisited – but for desert wind not PV solar

By Dave Elliott

Dr Gregor Czisch is a pioneer for the idea of using long-distance supergrids to allow power from widespread sources to be traded across long distances, for example delivering renewable energy harvested in Africa to the EU. Unlike Desertec’s solar-based supergrid plan, his 2011 supergrid plan focused mainly on using wind, which he saw as the best source. That idea has yet to be taken up and Desertec’s CSP/PV plan is also now defunct, but with solar PV costs now having fallen, Czisch has looked at PV again to see if it was now an option. However, he has still found it wanting. And he still looks to wind, including power imported from North Africa, as a better bet.  Continue reading

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Are we really all going to go off grid?

By Dave Elliott

In 2014, the US Rocky Mountain Institute (RMI) released a ground-breaking analysis of the potential for ‘grid defection’, looking at when and where it might be economical for customers to disconnect from their utility in favour of using on-site solar-plus-battery systems. With PV solar and batteries getting much cheaper since then, it has become a hot issue. However, fully off-grid options still seem unlikely to be attractive or needed for most people – a grid link allows you to top up when there is a solar input lull and your battery is drained, and to sell any excess at other times. In the US this “net metering” approach is quite widespread, although there are disputes about the prices paid by utilities. In the UK the FiT system has an export tariff. Will consumers be willing to forgo that? Would that be wise? Continue reading

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The limits of PV solar

By Dave Elliott

Solar PV has been talked up a lot of late. Its costs have certainly fallen and it has expanded to reach around 300GW capacity globally so far. But is it really going to be the dominant renewable as some have suggested? For example, a recent report from the Grantham Institute/Carbon Tracker has PV supplying 29% of world power by 2050 (PDF), with a massive 10,000GW or so in place. Is that realistic?

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Election promises on energy

By Dave Elliott

In the UK general election run up, with consumer power costs rising provocatively, there had been talk of a cap on energy prices and, in its election manifesto, although specifics were absent, the Conservative party certainly focused on economics. It said Our ambition is that the UK should have the lowest energy costs in Europe, both for households and businesses’ and it would aim for ‘competitive and affordable energy costs following a new independent review into the cost of energy’. Continue reading

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In praise of auctions

By Dave Elliott

IRENA, the International Renewable Energy Agency, seems to have been won over to competitive price-based project auctions as a way to stimulate rapid take up of renewables.  It says ‘the main strengths of auctions relate to flexibility, price and commitments. The flexibility of design allows policy makers to combine and tailor different elements to meet deployment and development objectives, while taking various factors into account, such as the country’s economic situation, the structure of its energy sector, and the maturity of its power market’. That’s a bit of a shift: in the past much attention has been paid to guaranteed price Feed in Tariffs (FiTs). Continue reading

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100% Renewables? Mostly nonsense!

by Dave Elliott

So says a new study by a group of mostly pro-nuclear academics, who look critically at some of the many ‘100% renewables’ global or regional energy scenarios that have emerged in recent years. 24 were deemed to have forecast regional, national or global energy requirements in sufficient detail to be considered potentially credible but, on inspection, none were considered to have provided convincing evidence that basic feasibility criteria, in relation to energy supply reliability, grids and balancing, could be met. Continue reading

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Renewables – now 70% by 2050 is the low estimate!

by Dave Elliott

In a joint report, the International Energy Agency and the International Renewable Agency present their views on how to comply with the Paris COP 21 Climate protection aims. The pathways that they describe both have renewables expanding rapidly, but differ in pace and level. As might be expected, IRENA sees renewables as being able to deliver significantly more power by 2050 than the IEA – 82% of global electricity by 2050, compared to the IEA’s estimate of ‘near 70%’. However, it is striking that, whereas previously, renewables had often been seen as perhaps able to deliver 50% by 2050, we have now moved on to debating whether 70% is too low. With costs falling, the supposed limits are being pushed back continually… Continue reading

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Emission Reduction Plan

By Dave Elliott

Between 1990 and 2015, UK greenhouse gas emissions fell by 38% and should fall by 48% by 2020 on current policies, within the framework of carbon budgets established by the Climate Change Act. Looking further ahead, the UK has committed to a 5th carbon budget (for 2028-32) which requires greenhouse gas emissions to be reduced by 57% by 2030 (against 1990 levels), on the way to at least 80% by 2050. But there is still a way to go.

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EGU 2017: New atlas shows polar seabeds

by Liz Kalaugher

Frost polygons: This polygonal or geometric patterns on the shallow seafloor (10-17 m water depth) here shown on a side-scan sonar image, were formed when the area was emergent (land) during the last glacial and was permanently frozen but not covered by glaciers.

Frost polygons: This polygonal or geometric patterns on the shallow seafloor (10-17 m water depth) here shown on a side-scan sonar image, were formed when the area was emergent (land) during the last glacial.

Wednesday saw a team of geophysicists at the EGU meeting present their new Atlas of Submarine Glacial Landforms. Four years in preparation, the atlas is the work of more than 250 marine geologists and glaciologist and is the most comprehensive and high-resolution atlas to date of the seafloor of both polar regions. The last such atlas was created 20 years ago.

Kelly Hogan, one of the Atlas editors, detailed at a press conference how the atlas reveals how ice has shaped the sea floor. Scientists will use the atlas to interpret the history of Earth’s large ice sheets and examine how environmental change reshaped continents.

Iceberg ploughmark showing rotation amongst a field of pockmarks from the central Barents Sea. Red 240 m water depth, purple 252 m.

Iceberg ploughmark showing rotation amongst a field of pockmarks from the central Barents Sea. Red 240 m water depth, purple 252 m.

The atlas assembles images of the sea floor that together cover an area the size of Great Britain. Modern acoustic mapping from onboard ship can image glacial landforms that are as much as five times smaller than earlier methods. Multibeam bathymetry, for example, creates a fan of sound and measures the return time of each ping to measure water depth across the fan. The researchers also used seismic reflection to look at sediment and remotely operated vehicles to take pictures from the seafloor.

These techniques revealed permafrost patterns on the floor of the Laptev Sea that became submerged when sea-level rose. The patterns are well-preserved because of the absence of weathering and human activities like road-building. In the Barents Sea the atlas shows ploughmarks on the seabed caused by the keel of an iceberg, in what’s one of Hogan’s favourite pictures.

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