Category Archives: Renew your energy

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? (more…)

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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.  (more…)

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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? (more…)

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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’. (more…)

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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). (more…)

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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. (more…)

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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… (more…)

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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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Nuclear Power: Past, present and future

By Dave Elliott

I have been looking at some early, novel, nuclear ideas and how some of them are being re-explored. Thorium, molten salt reactors, high temperature reactors, fast neutron reactors- they have all been tried earlier on, with mixed results. In a new book for IOPP I ask, will the revamped variants, including smaller versions, do any better? And more radically, do we actually need any of them- has nuclear really got a future?

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