The Combined Heat and Power Association (CHPA) was delighted. It said that 'the Strategy points the way to a major expansion of new district heating networks in towns and cities, driving a multi-billion pound investment programme in green infrastructure and creating an additional 40,000 jobs in construction and engineering'.
The CHPA noted that previous Government studies had suggested that 8 million dwellings could be connected to district heating at reasonable cost, along with a major share of commercial and public buildings, through a 25 year capital programme, investing £2bn p.a. in new district heating infrastructure. Through this programme carbon emissions from heating would be halved and reduced to around 9 million tonnes per annum. It added 'Networks could adapt to obtain heat from gas-fired CHP plant, biomass and biogas, heat pumps, energy-from-waste, solar thermal, along with heat rejected from industrial processes and power stations. This approach, which is commonplace in continental Europe and Scandinavia, delivers reliability and security to energy users and provides a credible and practical pathway to decarbonisation.'
However the policy shift wasn't that large: the Heat Review still backs electrification as the main supply focus, since 'electricity is universally available' and, in well insulated houses, heat pumps can make using it for heating relatively economic. But it did admit that gas grids act as energy stores and are better at coping with variable demand, so that there would, in an electrified system, be more need for storage and demand management, as well as a lot more green generation capacity- almost double the present amount, given electrification of transport as well! Basically from nuclear and offshore wind, plus gas CCS.
Even so, it looks to biomethane and hydrogen, as new fuels, sourced from biomass, that could be used for heating, although it warns that biomass resources will be 'constrained and contested' and probably best used for industry and transport, where higher energy intensities are important. And, a little provocatively, it says large-scale biomethane injection into the gas grid is not realistic 'when efficiency losses are taken into account'.
So, apart from some direct use by industry for process heating and for local district heat networks, it sees gas delivery on a national scale is being phased out, with cooking being done by electric hobs and perhaps induction heaters. A big change for many people. Interestingly, micro CHP is seen as just a transitional option, but solar heating is seen as valuable, especially if combined with interseasonal storage, implying large scale 'heat accumulators' /community heating systems. The industry section is useful, with, in addition to improved process efficiency, gas and biomass CCS seen as a possible option.
Overall interesting then, still wedded mainly to electricity, plus some heat networks. But there are few actual commitments or future supply numbers, just a general plan: a full policy is promised within a year.
www.decc.gov.uk/en/content/cms/news/pn12034/pn12034.aspx
Things do seem to take time! The Renewable Heat Incentive for example- which was meant to start the ball rolling. It was set up in two parts, with support of larger business schemes already established, along with an interim domestic-scale grant competition, the Renewable Heat Premium Payment scheme (RHPP), offering one-off payments for homeowners wishing to install green heating systems. DECC had been expected to launch the full domestic RHI in October this year, alongside the Green Deal loan scheme, but it has now decided to delay it until summer 2013, and will instead inject an extra £10m into the budget for the interim RHPP, taking it up to £25m, while reviewing cost control measures.
After its run-in with the PV solar Feed-In Tariff, the government is clearly worried that the projected costs of the RHI scheme, which unlike the FiT, will be met out of government funds, i.e. from taxes, will need to be controlled and kept below the fixed £860m budget. So it's launched proposals to carefully manage the RHI budget. For the existing business scheme, as a temporary measure, it will suspend registrations at one month's notice once 80% of the budget has been allocated. DECC said it will introduce proposals for a permanent cost-control mechanism by the end of the financial year, which could see tariffs fall in line with increased uptake.
Meanwhile, under the new extended RHPP, for the first time, communities seeking to install renewable heating systems will be able to take advantage of the scheme, with around £8m of the budget set aside for local projects. DECC has also earmarked £10m for social landlords to upgrade heating systems, after the social landlord competition last year received such a strong interest that DECC increased the initial £3m budget to £4m.
The Government said it wanted at least 25,000 households to take up RHI offers in the first year. So far, under the first phase of the RHPP, £4.8m has been cashed in by housholders, and 37 social housing schemes have also registered But, given the new review, Gaynor Hartnell, Renewable Energy Association CEO, feared the market will be killed off before it even starts: 'To launch an official consultation on bringing the shutters down, having only just fired the starting gun on the RHI, is premature to say the least'.
www.decc.gov.uk/assets/decc/11/meeting-energy-demand/heat/4805-future-heating-strategic-framework.pdf
Some of the heating issues were followed up in the subsequent DECC, DEFRA and DfT Bioenergy strategy, which backs the 'use of biomass to provide low carbon heat for buildings and industry (process heating), through either biomass boilers or through use of biomethane'. It adds 'Use of recoverable waste heat from low carbon power generation or industrial processes is also an important component of this pathway', noting that 'combined heat and power generation offers more efficient use of the biomass resources and should be promoted where possible'.
It also notes that Bioenergy carbon capture and storage (BE-CCS) offers net carbon removal from the atmosphere or 'negative emissions', which 'could then be used to offset fossil fuel emissions from other harder to decarbonise sectors. This makes BE-CCS an exceptionally valuable technological option'
The Combined Heat and Power Association was again delighted, noting that the stress had shifted to the use of heat networks rather than individual boilers to provide domestic heat, and the recovery of waste heat when used in an industrial setting. www.decc.gov.uk/en/content/cms/news/charleshbgbio/charleshbgbio.aspx
It does seem that, for once, new ideas are beginning to be listened to. I will be exploring some of them in my next Blog.
]]>It sets the scene by pointing out that 'If space heating could be decoupled from water heating it would change the selection criteria for heating appliances and boilers. There would no longer be a need for the heating system (as opposed to the hot water system) to be on standby during summer months or to be capable of operating at a sufficiently high temperature to prevent Legionella developing in water systems. All domestic heating is currently thought of as low-grade heat requirement, but there is a case for distinguishing space heating as low grade and hot water as medium grade. A policy for heat should separate these two different uses'.
It looks at heat pumps as a possibility, but is not too convinced. 'While the general reduction in carbon intensity of grid electricity makes the use of electric heating (direct or via a heat pump) more attractive, peak heat loads tend to coincide with peak electricity loads. There is, therefore, a significant likelihood of heating demand being met by high carbon electricity generation brought onto the system to meet peak loads over and above the capacity of low carbon generators'.
It goes on 'Air source heat pumps have been rising in popularity for new build in the UK, but this is partly an effect of the way in which electrical energy is treated in the regulations that makes CO2 targets more lenient than for gas systems.' While it admits that 'Air source heat pumps integrate well with well insulated dwellings, if properly sized and installed,' and it suggests that 'micro-CHP complements and could balance some of the properties of heat pumps', it also notes that 'several reports discuss inadequacies of the application or system engineering in heat pump installations. It is clear that heat pumps are not forgiving if installed inappropriately.'
By contrast, it's much happier will larger-scale communal system. 'Communal air source heat pumps are an interesting area of development with some new configurations of systems coming to market. Central systems may be more efficient and are likely to offer much greater energy storage than do systems designed for individual household'.
It adds 'Larger district systems, incorporating a CHP facility and providing heating are significantly more efficient than domestic level installations. This is because waste heat can be used in district heating after it has generated an element of electricity. Such district heat is therefore always of significantly lower CO2 emissions than any heat only production utilising the same fuel'. And that, it seems, includes domestic scale heat pumps.
The RAE does seem to been moving towards community- scaled system across the board. However, it is less happy with renewables. Although it sees some potential for bioenergy e.g for CHP/District Heating , it is not very impressed with solar, and overall treats renewables as problematic in terms of grid power supply, reverting to the traditional RAE line on the problems of intermittency and the delights of nuclear: 'During the summer months, most of the night-time load could be provided by nuclear power with renewables providing additional power during the day', while in winter 'we would need sufficient renewables to guarantee 40GW during the evening peak. As wind, tides and the sun are intermittent, that would require significantly higher installed capacity of renewables or thermal back-up capacity, much of which would be unused for long periods in the summer' making renewables uneconomic.
Nevertheless, it does look at smart grid /load management options which might change the situation radically, helping to deal with intermittency. A bit grudging, but at least there is now some recognition that a new interactive supply and demand system might be viable. It's taken decades to get the community CHP/DH message across to the traditionalist engineers, so maybe it's too early for idea of smart dynamic grids to have got through! And it may take even longer for them to give up on 'baseload' nuclear, which they still see as essential, rather than as getting in the way of a more interactive flexible system based on renewables ( which is the view emerging from Germany) .
However, as far as CHP/DH in concerned, the RAE is now full of praise. It says that 'CHP plants, biomass combustion, and heat pumps are more efficient, reliable and cheaper at scales larger than a single dwelling. The costs of large scale heat pump installations per kW are a quarter of that for domestic-scale installations.' It adds that 'it is more efficient to use the available skills for fewer large systems than for many individual units', and that, since energy storage will be needed 'district heating systems have another important benefit - the mass of water in the underground pipes provides a heat store that evens out daily peaks and troughs in demand. This can be supplemented by hot water tanks to increase energy storage'. And taking it one step further, it points out that 'well insulated hot water tanks or underground inter-seasonal thermal stores will be simpler to provide on a community basis given the small (and reducing) size of most UK homes'.
Some sense last! And DECC seem to be taking notice, in their new Heat strategy- see my next Blog.
'Heat: degrees of comfort?' Royal Academy of Engineering www.raeng.org.uk/heat
]]>When it comes to solid biomass for heat and power production, things get a little easier in terms of land use. CCC say 'Our core scenarios focus on the use of abandoned agricultural land', with a range of energy crops being viable: 'We assume in the longer term dedicated energy crop feedstocks are a mix of fast growing trees and grasses, as these crops are potentially more suitable to land of low productivity, have low lifecycle emissions and can be converted for use across the range of sectors'. But CCC see Carbon Capture and Storage as vital in many cases: 'If CCS is not available at the scale envisaged, the amount of bioenergy required to meet the 2050 target would have to be significantly higher than 10% of primary energy demand, and would imply land use change exceeding currently estimated sustainability limits.'
They also warn that 'given limits on domestic supply, much of the forest biomass for power and heat used in the UK will have to be imported'. Nevertheless they feel able to conclude that 'Scenarios for global land use which take account of required food production suggest that a reasonable UK share of potential sustainable bioenergy supply could extend to around 10% (200 TWh) of primary energy demand in 2050. However, it would be unsafe at present to assume any higher levels of bioenergy supply, and even the 10% level might require some trade-offs versus other desirable environmental and social objectives (e.g.through energy crops production encroaching on land of high biodiversity value).' But they want tighter limits: 'the threshold for use of biomass to meet the RO should be tightened to 200 gCO2/kWh. This would represent a significant enough saving relative to gas-fired generation, allowing a margin for emissions from possible indirect deforestation.'
Clearly they do not see biomass as likely to play a major role, although they suggest that there might be range of 'sensible smaller-scale local uses' - such as making use of old cooking oil to run buses, using food or farm waste in anaerobic digestion plants, or using woodchip from tree surgery waste in biomass boilers. Pretty marginal then, with CCC concluding 'The role for use of biomass in heating buildings is likely to be relatively limited in the longer term, given alternative low-carbon options such as air-source and ground-source heat pumps. Where these are not feasible, there may be opportunities for district heating using waste heat from large-scale low-carbon thermal power plants (potentially including biomass CCS) or CHP using local waste or biomass, and for biomass boilers using local biomass in rural homes.'
This may be too dismissive a view. Certainly, in practice, biomass/biogas energy options are still struggling to get going on a significant scale in the UK, with objections still emerging to some large-scale power projects, but some are still moving ahead.
E.ONs controversial 150MW biomass power station in the Royal Portbury Docks, near Bristol, has got the go ahead, despite concerns about its part reliance on imported virgin wood. It will also use dedicated energy crops, and locally sourced waste wood. E.ON has said it would set up a community investment fund, contributing £50,000 per year for charitable and educational community projects in the area, while a further £75,000 would also be set aside to trial green buses and improve cycle routes in the area.
However, E.ON told BusinessGreen that it was reviewing its plans for this and other renwable energy projects, in light of proposed changes to subsidies offered under the government's Renewable Obligation scheme. Drax also seem to be having second thoughts again about their biomass co-firing projects, complaining that there was not enough RO support
Meanwhile, Sheffield Council is looking at plans for a £20m waste wood CHP project in the Holbrook area , following on from the agreed E.ON's £120m 30MW waste wood biomass plant on the site of the old Blackburn Meadows power station next to the M1, now under construction. In addition, RES has plans for a 100MW biomass plant in Northumberland on Blyth River.
An energy from waste/biomass complex has also been proposed for the Ince Park development located at the Manchester Ship Canal, as a joint venture between Peel Environmental and Covanta Energy. Construction of the EfW facility is set to begin soon aiming for operation in 2015. Peel Energy has also got planning permission for a separate 20MW biomass energy facility on the site, with construction scheduled to start early next year. Plants like this, which involve combustion, are often opposed by environmentalists due to possible emissions (especially if wastes are used) and also the land-use/ biodivesity implications of large scale biomass growing/importation
In Wales, in a novel project which should avoid these issues, BiogenGreenfinch have been appointed by Gwynedd Council as the preferred bidder for the construction of a new green energy plant which will take council collected food waste and turn it into renewable energy via Anaerobic Digestion. The new AD plant, which should be running soon, will process around 11,000 tonnes of food waste each year; converting it into renewable electricity and biofertiliser for use on nearby farmland. The food waste will be collected from local homes and businesses via a collection scheme run by Gwynedd Council. The new plant will replace the existing landfill site currently situated in Llwyn Isaf and should play a major role in helping the Council meet their statutory recycling targets. It will be the second waste-fed anaerobic digestion plant built in Wales, following the construction of the Premier Foods plant last year near Newport.
In this case, the biogas is burnt to produce electricity, but AD biogas can also be added to the gas main, with, despite CCC's rather negative assessment, the prospects for 'green gas' from waste AD being increasingly seen as a new possible direction for green heat supply-in Germany especially. For more: www.biogas-info.co.uk.
While CCC may be a little sniffy about biogas, the new DECC/DEFRA/DfT Bioenergy Strategy is a lot more positive, as is the parallel DECC Heat Strategy. Although they do not see biogas playing a role in domestic heating directly, they do envisage biomass and biogas being used for community heating via CHP plants linked to district heating networks. I will be exploring this, and the green heating options. in my next few Blogs.
CCC report: www.theccc.org.uk/reports/bioenergy-review
]]>Here is the book's story. 60% of the world's population live in Asia, and Asia is the epicenter of the global urbanization wave. Asia is also the focal point of incredible motorization with China alone being projected to have in 2050 nearly as many cars, as the world has currently on its roads, in totol: 700 million cars. An Asian city also gives its name to one of the key concepts I extracted from the book: the Bangkok syndrome. Similar to their OECD counterparts, Asian and African cities start with dense, walkable city cores. At the beginning of the last century, OECD cities invested in the then upcoming rail-based transport infrastructure, shaping cities profoundly. With the relatively slow but profound rise of automobility, American cities developed into low-density automobile cities, while European cities kept their inner cities served with public transit. Asian and African cities seem to be mostly on a different trajectory: They skip the stage of public transport infrastructures and move directly into individualized motorized mobility. This is too some degree quite surprising: Relative to their GDP, cities of the developing world invest much more into highways, citizens proportionally much more into personal transport than their OECD counterparts do and have done (see e.g. Jeffrey Kenworthy's contribution). Inversely, these developing cities have high population density and are unsuitable for car transport. As a result, especially Asian cities develop into 'motorcycle' cities (Barter, 2000): motorized two-wheelers are best adapt to navigate the traffic disasters, but are subject to high accident rates and still face congestion.
Distribution and accessibility is another, related theme that develops continously across chapters. As the introductary statement indicates, paraphrased from Setty Pendakur's chapter, non-motorized transport is the starting point of analysis, for transport efficiency and transport equity matters alike. Urban transport planning is often technocratically framed as 'apolitical intervention' (Eduardo Vasconcellos), where in fact it is top income segment who by driving their cars consume 10 times more space than the urban poor, consume a largest part of transport energy, and are responsible for most of street-level air pollution. It is then quite clear that a suitable normative objective for urban transport is reasonable accessibility for all, possibly emphasizing the urban poor (the concept itself actually may need to be qualified, see Xavier Godard's chapter). Accesssibility itself is a highly interesting concept: Some cities, such as Dakar, seem to have high accessibililty - walkability - for the poorest quantile. In contrast, in cities like Buenos Aires the lowest income quintile pays proportionally to income much more than the richest quantile. Poverty may also directly reduce social contact by rendering visits to family or friends infeasible.
In line of the this comprehensive analysis, it then follows naturally to require comprehensive assessments of urban transport projects and plans, relying on strategic environmental assessments (Michael Replogle), inclusive equity evaluation (Eduardo Vasconcellos), and context-specific economic appraisal (Walter Hook). The key conundrum, however, is then in the meta-level of institions (Elliott Sclar and Julie Touber). In the dense urban environment of Asian and many African cities, the traffic disaster of the Bangkok syndrome can only be tackled with efficient public transport. But public transport can be regarded as a quasi-public good, and will not emerge from demand-side focussed market outcomes. Hence institutional capacity, a governance framework of promoting public goods and better public transport and non-motorized transport system need to coevolve simultenously. Transport planning alone is not enough.
]]>To try to help, an independent voluntary Green Energy Supply Certification Scheme was set up for domestic consumers and small businesses, and has been running since Feb. 2011, with 13 UK green electricity tariffs certified by August 2011. The Scheme is bound by Ofgem's Green Supply Guidelines. It is overseen by an independent panel of experts with the National Energy Foundation as Panel Secretariat.
The Scheme awards a 'green label' to electricity tariffs that deliver a real, measurable green gains. Not all tariffs marketed as green in the UK are certified by the voluntary Scheme but evidently all those who have applied has been given certification without the need for major adjustments. However, despite relatively high public awareness of environmental issues, green tariffs still account for only 1% of demand. In part that is because of some confusion- and cynicism- as to what green power really is.
The basic initial idea was that suppliers would contract with consumers to match the electricity they use with electricity from renewable sources, and set green tariff rates, which were likely to be higher than normal rates. So it was voluntary scheme for those who wanted to support renewables more, since they cost more at present.
However it was complicated by the advent of the Renewables Obligation (RO) which requires suppliers to source increasing proportions of the electricity they sell to all consumers from renewable source, with the extra cost passed on to all comsumers. It would be unfair for the same electricity also to be sold under the voluntary scheme- those consumers would then in effect be charged twice. So it was proposed that the electricity had to come from projects that were outside/additional to those operating under the RO scheme. The problem was that there weren't many of them and they tend to be the higher cost projects, so pushing the voluntary green tariff level even further up.
Some critics also argued that, as far a developing renewables rapidly on a large scale was concerned, it was far better to go for the RO, which passed the extra cost on to all electricity consumers, than the rely on voluntary support from a small minority, who would otherwise be in effect subsidising others not to bother. But then that's the nature of charity, and if some are willing to pay more, altruistically, then it all helps. A more fundamental issue was that, as a Datamonitor Survey reported, 27% of respondents did not trust their energy company, and did not believe that their energy would actually come from (or be matched by) a renewable source. The Green Energy Supply Certification Scheme aimed to try to resolve that credibility issue.
In terms of the green tariffs on offer now, what has emerged is something of a compromise. Some green suppliers do supply 100% green power at a premium price from fully additional sources, or like Good Energy, 'retire' the ROCs they get from RO credited projects. But some don't charge more and don't use additional sources- in which case additionality is achieved by offering other, indirect, green benefits- specially established funds fed from a percentage from the sales receipts, for the development of renewable energy projects (e.g. the Juice fund for marine renewables) energy efficiency projects or eco/offset projects e.g. reafforestation.
The Green Energy Supply Certification Scheme requires that these projects must result in the abatement of at least a minimum level of carbon dioxide equivalent (CO2e) emissions- set at 50 kg p.a per tariff for funds/efficiency projects and 1 tonne for offsets. There has recently been a consultation on whether these levels should now be raised, and on other aspects of the scheme. The main concern however for it to be better known and used!
For example from 2006-2010, around 200 Gigatonnes of ice per year melted from the Greenland ice sheet while the equivalent figure for glaciers and ice caps in the Arctic was 160 Gigatonnes. That said, there is considerable variability around the Arctic region, with some glaciers and ice caps losing mass rapidly and a few growing slightly.
As part of the ice2sea programme, Hagen and colleagues have taken continuous GPS measurements on two fast-flowing outlet glaciers of the Austfonna ice cap in northeastern Svalbard since April 2008. The data indicate that the ice is now moving between two and three times faster than four years ago.
What's more, around 30-40% of the total ice mass loss is due to calving. Hagen said the ice cap is exhibiting unstable dynamics and the study shows the importance of monitoring calving. ]]>
The research indicates that growth-rings from trees at the far north of their range may not have picked up the fast cooling caused by major volcanic eruptions in the past. Such trees are particularly sensitive to temperature change, which is why they are used so often in palaeoclimate reconstructions. But there's a snag - temperature drops of a couple of degrees may push them outside their growth range. That could mean a year without growth and a missing growth ring. Not only does this fail to record the temperature drop but it can also "smear" the chronology, explained Mann.
Mann, however, feels his research shows dendroclimatologists are doing a "good job" at reconstructing long-term temperature changes in the past - it's only detection of short-term cooling responses to volcanic eruptions that is an issue.
"Ironically this points to some past work [on climate sensitivity] as biased on the low side and maybe contrarians don't like that," he said. Mann believes the work indicates that climate sensitivity - the increase in temperature for a doubling of atmospheric carbon dioxide - is closer to 3 °C than 2 °.
• Mann was awarded the EGU's Hans Oeschger Medal.
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Rahmstorf calculated the monthly heat record ratio - the number of records divided by the number expected in a stationary climate - for the last 131 years of temperature observations. The global mean ratio was roughly five, but parts of Africa and South America experienced 20 times more records than expected.
The high number of records in the tropics is because these areas normally experience a small temperature variance, even though the trend in temperature rise in the region is relatively low, Rahmstorf explained. The Arctic also has a high record ratio, but this is due to its larger temperature trend.
Rahmstorf's analysis showed that the increase in heat extremes can be explained by a simple stochastic model - a linear trend of increasing temperature combined with uncorrelated noise.
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As detailed in a publication in Nature today, of which Vaughan is a co-author, in West and East Antarctica ocean-warming caused by wind changes is melting ice shelves from below. And where ice shelves have thinned, glaciers inland have accelerated as the buttressing effect of the ice shelf is removed.
On the eastern Antarctic Peninsula, on the other hand, it looks like wind-induced atmospheric warming is the culprit - it's melting snow on the surface of the ice shelves. Some thinning in this region is also due to loss of air compacting the ice.
The team used laser measurements from NASA's ICESat satellite for 2003-2008 to look at 54 - almost all - of Antarctica's ice shelves. Warm ocean currents were pinpointed as melting 20 of the ice shelves, mainly in West Antarctica. Indeed the researchers ascribed the majority of Antarctica's ice loss to ocean change.
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Mernild studied the mass balance of 124 glaciers and 19 icecaps worldwide, using three averaging methods. The results compared well with earlier studies, which incorporated fewer glaciers, he said.
In Central Europe, Svalbard and Greenland, glaciers and ice caps were more out of balance with their surroundings than the global average. Mernild reckons that glaciers in the Alps are likely to lose most of their mass by 2100.
If recent climate trends continue, by around 2040 glaciers and ice caps will lose at least half of their volume. ]]>
The incident contaminated an area of more than 100 km diameter with radioactive materials, releasing 10-20% of the radioactivity of Chernobyl. Yamauchi and colleagues used measurements of atmospheric electric field at Kakioka, 150 km southwest of the plant, in combination with a radiation dose measurement network and soil samples to assess dust transport.
After the first problems at the plant on March 11th, the potential gradient measurements at Kakioka dropped by an order of magnitude; ionising radiation increases atmospheric electrical conductivity and decreases potential gradient.
The potential gradient also dropped on March 14th and March 20th. Yamauchi believes the March 14th drop was due to contamination by surface winds, which left radioactive fallout suspended near the Earth's surface. This is potentially a health risk, especially for children as they breathe closer to the ground.
The March 20th drop was probably down to transport by a relatively low-altitude wind followed by rain, which caused the dust to settle on the ground.
Yamauchi and colleagues recommend that all nuclear power plants are surrounded by a network of potential gradient measurement stations.
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As Teh explained in a talk at the EGU meeting, the gradient of much of his route, which started at an altitude of 3500 m and headed down to the Amazon basin, was too steep to use Eddy covariance sampling. Nothing daunted, Teh went "back to basics" and used chambers to gather his data.
Teh was hunting for the "missing" sources and sinks in the tropics that regional atmospheric budget discrepancies indicate might be located in South America. Along his transect lay Puna grasslands at the top of the mountain, cloudforest at around 2800 m, then mid-elevation forest followed by foothills.
The findings? Altitude had a massive effect. At lower elevations the ecosystems were a sink for methane, but at higher elevations they acted as a methane source. The situation for nitrous oxide was more complex - low, mid and high elevations acted as a source, but the cloudforest at around 2800 m acted as a sink for the gas.
Now Arn Teh would like to work with colleagues in modelling and remote sensing to build on these findings. ]]>
Indeed, governments received a call for action within the first half hour of the conference opening, with Millie Basava-Reddi of the International Energy Agency Greenhouse Gas R&D programme (IEAGHG) stressing the need for investment in carbon storage, in her talk presented by session chair Michael Kühn due to a delayed flight.
While the G8 nations would like to see 20 carbon capture and storage projects up and running by 2020, the IEA target is 100 by 2020 and 3,400 by 2050. The agency's latest assessment, however, indicates that while 20 projects are feasible for 2020 its own roadmap isn't, with just 50 projects likely by 2025. Worldwide there are currently 14 large-scale integrated projects in operation or execution; 2011 saw 74 large-scale projects in at least the planning stage. Basava-Reddi called on governments to allow for long project lead times - up to fifteen years - and to help to provide up-front investment.
The challenges for carbon capture and storage in many cases mirror those for other subsurface technologies such as geothermal energy. Indeed Kühn's group at the Helmholtz Centre Potsdam, Germany, is researching how brine extraction from saline aquifers could help reduce the pressure rise induced by the addition of carbon dioxide, whilst at the same time providing geothermal heat.
There are a large number of issues in geothermal energy that need substantial research efforts, explained Adele Manzella of CNR Institute for Geosciences and Earth Resources, Italy. The upper 3 km of the Earth's crust could provide 60,000 times our current power consumption; the only snag is where and how to access that power. The up-front costs are high and it's hard to forecast production, especially since there is a lack of data on geothermal potential. But once systems are set up the energy produced is cheap compared to other types of renewable energy, since power is provided 24 hours a day.
The European Energy Research Alliance has set up a Joint Programme on Geothermal Energy, said Manzella. Areas under study include assessing Europe's resources for geothermal power, how to mitigate induced seismicity in reservoirs, and high-performance drilling. ]]>
Germany now gets around 20% of it electricity from renewables with 28 GW of wind and 25 GW of photovoltaics, plus biomass and hydro. But it's aiming to expand that dramatically, in stages, to 35% by 2020 and 80% by 2050. Can it be done?
Germany can currently meet about 40% of its of its domestic power demand from PV solar on sunny summer days, while wind can supply a significant amount in winter when its strongest. In addition, within each season, both sources obviously vary from day to day and from hour to hour- and solar is always zero at night! These basic characteristics are the first key things you might need to know when considering if renewable can take over the bulk of power production. The second key thing is to do with location- most of the wind sites are in the north, the best solar in the south.
Given these two factors (timing and location) you can see why Germany is very focused now on energy storage and transmission issues. The basic energy resources are not the main problem - there seems to be enough to support a vast expansion: see www.uba.de/uba-info-medien-e/3997.html.
But the overall energy system will have to be radically revamped in order to use them effectively, with upgraded grid transmission and new storage capacity. However it goes beyond that. What is needed is a new engineering philosophy for the energy system design.
At present most power grid systems around the world are built on the basis of having a few large power plants feeding electricity down the grid to a large number remote consumers. Some of these plants, often nuclear plants, are kept running continuously to meet 'baseload' demand i.e. the minimum level of demand, while other plants are kept ready to ramp up to full power to meet the daily peaks in demand. For the moment renewables have simply been added on to this centralised system. But they don't fit very well. They are often variable, smaller scale and distributed around the country. They need a different, more decentralised and flexible system. And it has been argued that we need to decide which one we want to use in future.
Germany has already decided. The German-Federal Minister of the Environment Norbert Röttgen said in 2010: 'It is economically nonsensical to pursue two strategies at the same time, for both a centralized and a decentralized energy supply system, since both strategies would involve enormous investment requirements. I am convinced that the investment in renewable energies is the economically more promising project. But we will have to make up our minds. We can't go down both paths at the same time'.
On this view baseload isn't a help, in the new decentralised flexible energy supply and demand system, it's an inflexible hindrance. In the new system, rather than having 'always-on' baseload (e.g. nuclear) plants, and then following any extra load with peaking plants (usually gas), in the new system, variable loads and variable supply (from renewables) are balanced via a smart grid with demand-side measures, load peak shaving/delay, energy storage, and backup sources. That's just what Germany plans to move to.
The backup/balancing power will, for the moment, mostly be from natural gas plants, although later geothermal or biomass plants could take over. In addition use can be made of hydro reservoirs for storage/balancing- and that's going to be expanded in Germany. But the really interesting new idea is to use surplus renewable electricity to make green gasses, hydrogen and then also possibly methane, using some CO2, and store it for later use for generation to meet peaks. See www.fraunhofer.de/en/press/research-news/2010/04/green-electricity-storage-gas.html
All this means that there's no need for nuclear baseload and that the use of natural gas can gradually decline. The Fraunhofer Institute modeled the renewables projected for 2020 and found that the need for baseload power will fall by half by then. Depending on how fast biogas substitution for natural gas can expand, that could mostly be coal fired by then. Ideally, given their carbon emissions, Germany should of course phase out coal plants before nuclear plants, or fossil gas use, but coal and fossil gas will be needed for a while for balancing.
There are of course other ideas. Nuclear supporters may say that, rather than going to all the bother of having wind plants backed up, why not stick to the old system and keep nuclear for baseload, and dump coal, while using renewables when they are available, storing any excess renewables as gas to meet peaks. In addition some new nuclear plants can load follow, to a some degree. They also point to the alleged wonders of Liquid Flouride Thorium Reactors, claimed as a safer nuclear option. But these are long shot ideas, decades away at best, and few in Germany will now look at nuclear. It is out, full stop. Instead it's pushing hard for a decentral system based on renewables and energy efficiency.
That has social and political attractions, as well as reducing carbon emissions and the threat of nuclear accidents. As Craig Morris has commented in an interesting review of the German programme, 'Germany is replacing central-station plants that can only be run by large corporations with truly distributed renewable power. While Germany's Big Four utilities make up around three quarters of total power generation, they only own seven percent of green power. Roughly three quarters of renewable power investments have been made by individuals, communities, farmers, and small and midsize enterprises'.
He notes that a 'a small-town energy revolution is going on in Germany, with more than 100 rural communities becoming 100% renewable.', and concludes 'so one reason why Germans might not mind paying a little more for green power is that they largely pay that money back to their communities and themselves, not to corporations'.
Will it work?
Phasing out nuclear by 2022 is a bold move. The opponents have painted grim pictures of prices hikes, blackouts, increased use of coal, with more emissions, and massive imports of nuclear electricity from France and gas from Russia. But in March 2011 the Federal Environment Agency, said that in principle 'all of Germany's nuclear power stations could be taken offline permanently by 2017,' without resulting in 'supply bottlenecks or in appreciably higher electricity prices.' Furthermore, it claimed 'Germany's climate protection targets would not be compromised and Imports of nuclear power from abroad are not necessary'. Given the 2022 closure date in the event chosen, although it will clearly involve major challenges, there should be fewer problems.
And certainly, in reality, the lights have stayed on, emissions have fallen (by 2.2% in 2011) and the small prices rises don't seem to have led to much opposition given the wide scale opposition to nuclear. In addition, Germany is still exporting power (net) to France, and as Craig Morris notes, if excess renewable power is converted into green gas and stored, then it won't have to worry too much about imports, or interruption due to the weather. He says that German researchers have estimated that getting 100% renewables would only 'require up to two weeks at a time to be bridged during the winter,' far less than the 4 months gas storage already available.
It looks like they can do it.
Craig Morrison's article: www.renewablesinternational.net/the-german-switch-from-nuclear-to-renewables-myths-and-facts/150/537/33308/ See also David Roberts helpful review: http://grist.org/renewable-energy/why-germany-is-phasing-out-nuclear-power
German Renewable Energies Agency report: www.unendlich-viel-energie.de/en/details/article/523/renewable-energies-and-base-load-power-plants-are-they-compatible.html The Federal Environment Agency's 2011 report 'Restructuring electricity supply in Germany,' is available from: www.umweltbundesamt.de
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