Friday, February 15, 2013
The Pugwash High Renewables Scenario
It was with some trepidation that I accepted the invitation to help Pugwash with its 2050 UK Energy Pathways project.
Firstly I was asked to produce a ‘low nuclear’ scenario, to go alongside its planned High Nuclear and Intermediate nuclear scenarios. That made me worry about the mindset of the British Pugwash group! I said no, it had to be a non-nuclear mix, since, unlike the UK, that was what many countries around the world were now aiming for, or already enjoyed. So we agreed instead that I should produce a High Renewables scenario.
Secondly, I was asked to run it through DECCs Pathways 2050 Calculator. I said I wasn’t a great enthusiast or practitioner of modeling, but NATTA member Dr David Finney helpfully stepped in and so we tried.
Thirdly, I was aware that there were already many dozens of studies based on achieving 100% renewable futures, including some for the UK, Germany, Denmark, the EU as a whole, the US, Australia and the world – I’ve counted 60 or so. More are emerging. Why do another? But we did and it has I hope been a worthwhile exercise.
Much as I expected, it proved to be relatively easy to meet projected electricity demand by 2050 from renewables, mainly offshore wind (76GW) and onshore wind (30GW) but also wave and tidal stream, biomass and geothermal CHP and solar PV, plus hydro. I based our scenario on an existing one from Poyry which generated 94% of UK electricity from renewables by 2050 although we cut its offshore wind allocation by a half, to be cautious.
Heat was relatively easy too, given that we assumed a significant energy saving programme, cutting demand by 40% by 2050. That of course is much lower that Germany’s energy saving plan (a 50% cut by 2050), but we wanted to be cautious. On the heat supply side, along with solar and geothermal CHP/DH, biomass-fired CHP and district heating then played a key role, which meant that although we would use a lot of food and farm wastes and forestry residues, we needed quite a lot of land for biomass fast-growing SRC and the like, about 10% of UK land area, with consequent changes in farming practice and possibly diet.
We wanted to avoid biomass imports, so dealing with transport demand was harder. The DECC calculator would not let us replace fossil fuel with hydrogen produce using excess electricity from wind- it just exported it all. That was fine, up to a point. It meant the UK would earn £15 billion a year by 2050 from selling it, but it would require more interconnectors; we included 15GW worth.
What we would have preferred is to be able to convert some of the excess wind derived electricity to hydrogen, use some of it of it for transport (rather than oil) and store the rest for electricity generation when the wind input was low. That was because, although we had included some storage and some demand-side management, plus interconnector imports, we were worried about the needed to back up renewables when they were not available and demand was high. It turned out that we didn’t have to worry. With its large wind element, our scenario happily passed the DECC Calculators ‘stress test’, meeting demand peaks even when the proportion of wind etc was low. It just meant we couldn’t export any excess then.
I have to admit to being surprised. The Poyry scenario had found that by 2050 there would be a need for 21GW of fossil backup plant.What this outcome suggests is that, if we could use the wind-to-gas idea, which is now being pushed hard in Germany, then we could get to 100% renewables fully backed up with no need for any fossil input at any time.
Leaving that aside, what we do have is a Pathway which reduces emissions by 82%, meets demand at all times and has a capital cost that is slightly lower than the rival Pugwash scenarios, with, unlike them, no biomass imports, very little CCS and no nuclear. The details are in the report.
Pathways to 2050: three possible UK energy strategies: http://www.britishpugwash.org/
Saturday, February 2, 2013
Given the very positive prognosis for renewables reported in my last Blog, I thought I would take a new look at the state of play with nuclear power. Judging by several critical, independent reports, it’s pretty grim. The World Nuclear Industry Status Report 2012 portrays an industry suffering from ‘the cumulative impacts of the world economic crisis, the Fukushima disaster, ferocious competitors and its own planning and management difficulties’.
Key results of the assessment include:
• Only seven new reactors started up, while 19 were shut down in 2011. On 5 July 2012, one reactor was reconnected to the grid at Ohi in Japan followed another on the same site. However, it remains highly uncertain how many others will receive permission to restart operations in Japan.
• Four countries announced that they will phase out nuclear power within a given timeframe- led by Germany.
• At least five countries have decided not to engage or re-engage in nuclear programs.
• In Bulgaria and Japan two reactors under construction were abandoned.
• In four countries new build projects were officially cancelled. Of the 59 units under construction in the world, at least 18 are experiencing multi-year delays, while the remaining 41 projects were started within the past five years or have not yet reached projected start-up dates, making it difficult to assess whether they are on schedule.
• Construction costs are rapidly rising. The European EPR cost estimate has increased by a factor of four (adjusted for inflation) over the past ten years.
• Two thirds of the assessed nuclear companies and utilities were downgraded by credit rating agency Standard and Poor’s over the past five years.
• The assessment of a dozen nuclear companies reveals that all but one performed worse than the UK FTSE100 index. The shares of the world’s largest nuclear operator, French state utility EDF, lost 82 percent of their value, that of the world’s largest nuclear builder, French state company AREVA, fell by 88%.
In contrast, it says renewable energy development has continued with rapid growth. Installed worldwide nuclear capacity decreased again in 2011, while the annual installed wind power capacity increased by 41 GW in 2011 alone. Installed wind power and solar capacity in China grew by a factor of around 50 in the past five years, while nuclear capacity increased by a factor of 1.5. Since 2000, within the European Union nuclear capacity decreased by 14 GW, while 142 GW of renewable capacity was installed.
To balance that assessment I looked at the World Nuclear Association’s web site, and their views on the long term potential for nuclear. A key issue must be uranium reserves- if they are not sufficient then there is no future economic or otherwise for nuclear. They reported that the World uranium resources are ample to meet requirements for the foreseeable future but timely investment in facilities will be needed to make sure production keeps pace with growing demand, based on a new edition of the ‘Red Book’, the Nuclear Energy Agency’s biannual Uranium Resources, production and demand survey.
It said that total identified uranium resources had increased by over 12% since the last edition, although lower cost resources have decreased significantly because of increased mining costs. However, the total identified resources stand at 7,096,600 tU recoverable at costs of up to $260 per kg. An additional 124,100 tU of resources have been reported by companies but are not included in official national figures. So-called undiscovered resources - resources expected to exist based on existing geological knowledge, but requiring significant exploration to confirm and define them - currently stand at 10,400,500 tU.
It noted that 440 commercial nuclear power reactors were in operation around the world at the end of 2010, representing 375 GWe of capacity and cumulatively requiring 63,875 tU per year. By 2035, the report found, this can be expected to grow to between 540 GWe of capacity requiring 97,645 tU and 746 GWe needing 136,385 tU.
It claimed that currently defined uranium resources are "more than adequate" to meet the high case demand to 2035, but not without "timely investments" in uranium production facilities. ‘Significant investment and technical expertise will be required to bring these resources to the market and to identify additional resources. Sufficiently high uranium market prices will be needed to fund these activities, especially in light of the rising costs of production’. Secondary sources of uranium (stockpiles of natural and enriched uranium, downblended weapons-grade uranium, reprocessed used fuel and the re-enrichment of depleted uranium tails) will still continue to be required, although their role is expected to decline post-2013 when agreements between Russia and the USA to downblend ex-military highly enriched uranium for use in nuclear fuel expire.
Well if we really do get to 764GW by 2035, then, at say an averaged 100,000 tU per annum over that period, we would then have about 30 years worth left, assuming no further nuclear plant expansion or new uranium finds. Using lower grade, higher cost ores might extend that a bit, but mining and processing it would increase the production of CO2, assuming that fossil fuels had to be used for this energy. And using nuclear energy for this would just exhaust the reserves faster. It doesn’t sound like nuclear fission has much of a long-term future, unless new breeder technologies and/or thorium based systems are developed, or, perversely, we use renewables to provide the power for uranium fuel extraction and processing! Otherwise, 2070-75 or so, and then that’s it…
So what about thorium? I turned to the Weinberg Foundations website, which was set up to support the idea. It would be cheaper, safer and cleaner. www.the-weinberg-foundation.org/ But I also looked at a briefing by Oliver Tickell. That challenges the idea that thorium as fuel might provide a viable alternative to reactors using uranium. This he said had become something of a rallying cry for those who assert that conventional nuclear technologies are in terminal decline – including a handful of environmentalists who believe that thorium could provide some kind ‘silver bullet’ solution to the nuclear industry’s woes.
He says that they are deluded and highlights many drawbacks facing thorium reactors, including
· the very high costs of technology development, construction and operation;
· marginal benefits for a thorium fuel cycle over the currently utilised uranium / plutonium fuel cycles;
· serious nuclear weapons proliferation hazards: the molten salt reactor (MSR) technology promoted for thorium could be used to produce fissile uranium and plutonium at very high purities well above ordinary ‘weapons grade’;
· the danger of both routine and accidental releases of radiation, mainly from continuous ‘live’ fuel reprocessing in MSRs;
· the very long lead time for significant deployment of MSRs of the order of half a century – rendering it irrelevant in terms of addressing current or medium term energy supply needs. It claims that it ‘will not be deployable on any significant scale for 40-70 years.’
Well, so it could be that they might possibly be ready when the uranium runs out! But at what cost? And with what safety and security implications? See http://www.nature.com/nature/journal/v492/n7427/full/492031a.html
Overall, on the basis at least of this survey, I don’t see much a future for nuclear.