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April 2012 Archives


Some consumers have been able to make use of the 'Clean Energy Cashback' Feed In Tariff scheme to get paid for generating their own renewable electricity , and exporting any excess to the grid. Around 1GW of solar PV has now been installed in the UK as result. But not everyone can afford the large capital outlay for PV solar or other domestic-scale renewables. For those still keen to use green energy, one option is to buy it in via a green retail scheme. There are a lot on offer, but it is sometimes hard to decide how reliable they are- how can consumers be sure they are really getting green power?

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!

www.greenenergyscheme.org.

  • Next year consumers should be able to get support for installing heat producing renewables, under the proposed Renewable Heat Incentive domestic tariff scheme, but there are already some voluntary green heat retail schemes on offer.

EGU 2012: Arctic vies with Greenland on sea-level

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Arctic glaciers and ice caps cover an area of 402,000 square km, roughly 55% of the world's total. But they're punching above their weight when it comes to sea level rise - although Greenland's ice sheet is four times larger, it contributes roughly the same amount of melted ice to the world's oceans. That's according to Jon Ove Hagen of the University of Oslo, Norway, speaking at the EGU meeting in Vienna.

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.

EGU 2012: Mann upsets dendroclimatologists

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Michael Mann of Penn State University, US, is used to attack from climate contrarians. But his latest work, as he told environmentalresearchweb at the EGU 2012 Assembly in Vienna, has received more interest from dendroclimatologists who "feel our paper [in Nature Geoscience] exposes a problem with their approach".

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.


This year's EGU General Assembly in Vienna is not currently experiencing heat extremes. But worldwide the number of local monthly record-breaking temperature extremes is now five times on average what would be expected if the climate was stable. This means that four out of five recent records would not have taken place without climate change, said Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research Germany, in a meeting presentation so early in the morning that he dubbed the attending delegates "heroic".

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.

Changes in the wind circulation around Antarctica are causing the region's ice shelves to lose ice, explained David Vaughan of the British Antarctic Survey to journalists at the EGU 2012 assembly in Vienna. But the mechanism is different, depending on where the ice shelves are located.

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.

For the world's glaciers and ice caps to catch up with the temperatures of the last ten years, they need to lose 38% of their ice volume, on average, and 30% of their area. That's equivalent to 228 mm of sea-level rise over the next few decades, even without any additional climate change, according to Sebastian Mernild of Los Alamos National Laboratory, US, who presented his work at the EGU 2012 meeting in Vienna.

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.

EGU2012: tracking Fukushima's radioactive dust

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As the first big nuclear accident in the vicinity of a good measurement network, the events at Japan's Fukushima Dai-ichi power plant in March 2011 enabled scientists to find out more about the spread of radioactive dust and its associated health risks. That's according to Masatoshi Yamauchi of the Swedish Institute of Space Physics, speaking to the press at the EGU 2012 meeting in Vienna.

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.

 

EGU 2012: an uphill fight to measure greenhouse gases

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Field work can be tough - especially when there's no power, bad roads and your transect line is too steep to use your favourite measurement methods. That's what happened to YIt Arn Teh of the University of St Andrews, UK, when he studied methane and nitrous oxide fluxes in the Kosñipata Valley in Manu National Park, southeastern Peru.

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.

EGU 2012: going green on (and under) the ground

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The thousands of delegates congregating in Vienna this year will find the EGU making further efforts to "green" the meeting - badge lanyards are made from bamboo fibre rather than PET and the conference schedule is smaller to save paper. It seems only appropriate, since many of the sessions at the conference will focus on the cryosphere (shrinking), climate (warming), natural resources (under pressure) and energy. But are such measures just a drop in the ocean, especially as environmental issues appear to have fallen down the priority list for many governments?

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- to the max

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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


As a self-proclaimed energy dork, it's somewhat exciting to see so much discussion of oil and gasoline (and petrol!) in the news recently. The discussions range from indicating that The Limits to Growth is still basically correct to how technology is trumping all limits to enable the United States to soon be the world's number one oil producer and start exporting oil within 10 or 20 years. Non-energy adept or interested persons can be confused easily, and unfortunately this is many. Of course, energy 'experts' don't agree.

But the lay or 'expert' person can read recent articles from Time magazine ("The truth about oil," cover article April 9, 2012) and The Economist ("Keeping it to themselves," March 31, 2012) that are good for thinking about the situation relating to higher oil prices: increased demand from developing and exporting nations, and a lack of any practical increase in gross global oil extraction the last 5-7 years. Basically the oil discussion, at least in the United States, seems to be comes down three camps.

(1) Those who think that limits from natural resources and technological progress will bring peak oil production relatively soon (for crude oil we can say global production has been statistically flat from 2005-2011; see the US Department of Energy's Energy Information Administration's International Energy Statistics). Here, 'relatively soon' means within a decade from now, but possibly even 1 year. Unfortunately, we won't officially be able to declare a sustained drop in global crude oil production until a few years of statistically significant lower oil production rates. One year does not make a trend. As a subsidiary but economically important concept to this peak oil camp, is the total exported oil available for purchase around the world. The world's exporting countries and growing economies (mainly China and India) are significantly consuming more oil each year for the past decade - leaving less for the traditional oil consumers of Europe, U.S., Japan, and Australia. This camp is largely composed of system-thinking academically-minded physicist/engineer/ecologist types that might get some money from oil and gas companies or are retired from the oil and gas industry.

(2) Those that think technological progress that is enabling oil production from oil sands (Athabasca, Canada), pre-salt formations and/or deep offshore (Brazil, Gulf of Mexico), oil from shales using horizontal drilling and hydraulic fracturing (North Dakota, Texas), and possibly offshore arctic if sea ice does not actually form for significant time during the northern hemisphere summer. Thus, oil production is up in many places, and higher prices make this production possible - the market system at work. This camp is largely composed of those who make some portion of their living from selling, producing, or researching how to sell or produce oil and oil products.

(3) Those that think market speculation by entities that do not produce oil or sell refined oil products. People bet that the price of oil will go up, and therefore that indeed makes the price go up. This camp is largely composed of a subset of persons thinking about getting elected to public office (or staying elected).

As far as my position, I'm in camp #1 above as far as being the overwhelmingly most important factor - for main reason that I believe the world is spherical. For fun and interesting takes on being in camp #1 and talking to those who are not, see this blog by Tadeusz Patzek and this one by Tom Murphy. The point isn't so much if peak oil production will occur, but whether or not you should take anticipatory action.


From being in discussions with a few persons of camp #1, I can say that the projections for the ramifications for peak oil production are quite varied. All believe, including myself, that some form of easily noticeable lifestyle adjustment will occur for Americans and most citizens of developed countries. Arguably we are seeing this in the form of fiscal and budgetary difficulties in the European countries you've been reading about in the news since 2008 (Greece, Portugal, Ireland, Spain). In the U.S., this budgetary difficulty is being seen at the municipal/city level.


But I might disagree with some of the peak oil (camp #1 above) about what we can know about the severity of lifestyle adjustments over time. As oil production decreases to a point where most recognize it has occurred (say being below 5% of the peak for a few years in a row), I think we'd continue to see similar but slightly expanded trends as we've seen the last 4 years: less travel in developed economies, higher unemployment (but not crippling), and a limited number of governments at various scales defaulting on debt. Good things that will start to occur are more walking, biking, and conceptualizations about less consumption (but that will be hard to act upon for most).

At the next stage 'solutions' will be flowing like Spindletop. We will be told to believe that many elixirs will cure our 'ill', but we will be wise to prioritize our wants to those that are more crucial to social cohesion. There could be increased thinking about making sure all infrastructure (cities, buildings, homes, water infrastructure) is built in a way to maximize access and resiliency instead of sprawl and expansion. The idea of transition engineering (as discussed by Susan Krumdieck) and the Transition Town movements (just search the word) will become more mainstream models for learning to consume less energy in a more core manner. I myself look to learn more from these existing movements and look to apply their principles to understanding energy transitions in a fundamental manner as to how they represent increasing or decreasing complexity (a la Joseph Tainter). Luckily for me that somewhat fits my job description ...

Wire or Pipe?

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The UK's current energy plan envisages electricity being the main focus, with excess power from offshore wind and nuclear being used to run heat pumps and to charge batteries in electric vehicles. Natural Gas takes a back seat as a heat source, but is used in CCGT plants to supply some electricity, and these gas turbines also act as back-up plants to balance the variable renewables, although gradually some may become biomass fired. All of this will require new grid links, possibly also to the rest of the EU. So that's the 'wire' view.

It's the dominant one at present. The new DECC Heat Strategy review says 'electricity is universally available' and, in well-insulated houses, it says heat pumps can make using it for heating relatively economic.

The rival 'pipe' view is that electricity is a poor energy vector, since its transmission is lossy and it can't easily be stored, except via pumped hydro. Also domestic scale heat pumps are not that reliable, especially in cold weather.

By contrast, gas can be easily stored and transmitted: we actually already have an extensive low loss, high transmission efficiency gas grid, which handles around four times more energy than the electricity grid. Moreover, the gas grid acts as an energy store helping us to cope with variable demand. And we can produce biogas from municipal and farm wastes to provide a carbon neutral replacement for natural gas. In addition to its use for heating, some of this green gas could be used for local electricity generation, where needed, in CCGT or fuel cells. Some could even be used for vehicles, as a better option than mostly imported biofuels.

The weak point in this argument is that there probably won't be enough biogas to replace all the gas used for heating (National Grid says about 50%, optimistically), much less transport and electricity generation. There are land-use constraints to biomass production and limits to how much waste is available. Moreover, biomass and wastes are, in any case, more suited to local use e.g. in local Combined Heat and Power (CHP) plants, or heat only plants. That would avoid having to shift biomass/wastes in bulk around the country. It's not quite the same for biogas: although that's best generated locally from farms and municipal waste, and some could be used locally, some could also be distributed via the gas main, to power electricity generation plants where needed, as well as being use directly for heating in homes, as at present.

However the use of gas by consumers directly for heating may not be the best bet. Natural gas fired plants, and increasingly biomass fired plants, linked to district heating (DH) networks, could be more efficient option and play a major role, as elsewhere in the EU. Indeed solar-fired DH is now moving ahead across the EU, usually linked to heat stores, and in some cases inter-seasonal heat stores. So that's an extension of the 'pipe' view- we can distribute heat as well as gas. Clearly DH only makes sense in urban and perhaps suburban areas, and it also make sense, if we are burning gas, whether natural or bio, to use medium or even large scale high-efficiency combined heat and power plants. Then we also get some electricity, with the ratio of heat to power being adjustable.

The 'pipe' view is that this make much more sense, in efficiency terms, than installing micro CHP units in individual homes- with large CHP, the heat and power produced can be better balanced against the varying demands of large numbers of consumers. And big CHP/DH systems with heat stores can also help balance varying power grid inputs from renewables

Even so we may not have enough biomass or biogas to run this system- and any solar input will inevitably need backup. That's where the next element in the 'pipe' argument comes in. We can produce hydrogen gas, using electricity from excess off-peak wind and other variable renewables via electrolysis, store it and then add it to the gas main for distribution, or use it for electricity production when needed. Some also look to syngas production from renewable electricity for vehicle fuel.

There are some quite severe efficiency loss penalties with some of the energy conversion processes required for making, storing and using 'green hydrogen', but the technology is improving, with Germany taking a lead: see my next Blog.

So why not consider the pipe option? Certainly the 'wire' option looks tricky. It is likely to be hard to get enough electricity generation from renewables, like offshore wind, to meet all (or most) of the UK's power heat and transport needs. We are talking of perhaps, by 2050, 180-200GW of offshore wind, including floating wind farms further out to sea. Plus maybe some wave and tidal stream. If nothing else, the grid connection costs and problems for renewables on this scale look very serious. But the 'pipe' approach also has its limits. If we really are to avoid the biogas limits by producing hydrogen from
offshore wind (etc) for the gas grid, then we would come up against the same problem with getting enough offshore capacity. In both cases, with high costs - and a need for gas plant backup.

In a way then the two approaches are not that different, at least if we are talking, in the pipe version, about large scale generation of green hydrogen: they both rely on having lots of renewable electricity. But they do differ in the main transmission vectors - electricity or gas pipes or wires.

In theory we could have a mix of both: there could be some useful complementarity between the wire and pipe approaches, reducing some of the constraints. But in practice, under present competitive market approaches, there can be conflicts. For example, it's been said that in Denmark there is a danger that wind energy will drive CHP systems out of business: electricity production from local CHP systems in Denmark went down by 24% from 2000 to 2009. And in the UK, large scale CHP has hardly even started- we have had so much cheap gas. That may not change, if shale gas turns out to be plentiful and cheap, despite its alleged environmental risks. But in that situation, emissions aside, providing backup for wind would be easier, although the pipe lobby might still argue that gas should be used for heating rather than electricity generation.

Technological advances may help change the picture-if we adopt sensible approaches to infrastructure, so that new supply systems can be plugged on to the heat and power grids. Large scale heat pumps linked to DH systems, or large hydrogen or biogas fired fuel cells for urban CHP, are amongst the options. But cheaper offshore wind would be the key breakthrough. Or for that matter, cheaper wave or tidal power. Some also see PV solar as emerging to cut across much of this debate. Then again there's Carbon Capture and Storage. If that proves to be viable (and acceptable) on a large scale, then both the Wire and Pipe lobbies benefit, although the gas/pipe lobby might have an edge, since then the combustion of green gas/biomass would be carbon negative.

The DECC Heat Strategy Review looks at some of these options, but basically still comes down in favour of electrification of heat supply, with the role of gas diminishing, although it does also back district heating networks in urban areas. The debate continues!

www.decc.gov.uk/assets/decc/11/meeting-energy-demand/heat/4805-future-heating-strategic-framework.pdf

A History of Energy

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Bent Sorensen, a leading Danish alternative energy pioneer, who wrote a seminal and massive text book on 'Renewable Energy' and many other important research papers (see http://energy.ruc.dk), has turned his hand to a slightly different project and produced a 'History of Energy' (Earthscan). It looks in fascinating detail at the history of energy production and use, mainly in Denmark, from the stone age to the present day, linking that to social, economic and political developments and influences. So we move through early pre- history, the middle ages , the industrial revolution, the second world war and then on to the more recent battle against nuclear and the dramatic growth in the use of renewables.

In each era there is a detailed analysis of Danish energy generation and use, with, through most of history, ambient energy sources, food and muscle power inevitably playing the dominant role, but fossil fuels then rapidly taking over, leading to massive increases in energy use in recent decades- much of it based on imported fuel.

The historical details and interactions are well developed and it's inherently fascinating to view history from a national perspective other than one's own. Although academic historians might not be happy with the story telling and commentary, especially as the author was directly involved with some of the more recent events, that actually makes it very interesting. Indeed it might have been good to have more reminiscences, but then perhaps it would be too autobiographical. As it is, the marriage of energy and history, although strained in places, works well, leading to some interesting insights e.g. into why Denmark has been so progressive in relation to renewables and so hostile to nuclear- as symbolised by the ubiquitous 'Nuclear Power, No Thanks' smiling sun logo.

The 'bottom up' grass roots resistance to nuclear led to a decision to abandon plans for nuclear power and spilled over into practical 'bottom-up' support for the development of renewables. One factor in this seems to have been the existence of a national network of libertarian Folk High Schools. Starting in 1975, one radical school, Tvind, even built giant 2MW wind turbine themselves, completed in 1978- an amazing feat; well ahead of its time. It's still running: www.tvind.dk/TextPage.asp?MenuItemID=55&SubMenuItemID=160

It helped stimulate the boom in grass roots developed and co-operatively run wind projects in Denmark- with around 80% of Denmark's wind projects being locally owned. And the Danes continue to be innovative, with a plan from the new Centre-left government to get 50% of Denmarks power from renewables by 2020, with coal then being phased out from electricity generation by 2030, and all power and heat coming from renewables by 2035. All of course with no nuclear. www.europeanenergyreview.eu/site/pagina.php?id=3417.

That's not to say there are not problems. Sorensen ends the book with a look at globalisation and consumerism, highlighting the 'enough is enough' view, but in true Danish style, in a non-dogmatic way.

With many other countries around the world now also looking to a non-nuclear future, Denmark is inevitably seen as something of a template, so this book could become very valuable, even if it doesn't provide much detail on the contemporary battles. For example, wind already generates about 25% of its average annual electricity output. But not all of it can be used in Denmark- at times there is too much and excess electricity is exported e.g. to Norway. At other times, when there's not enough wind, Denmark imports power back from them- e.g. from their large hydro plants, some of which can be used for pumped storage - in effect an interim store for Danish wind power. Overall it's roughly balanced, though Denmark gets charged more for the imports than it gets for its exports- so making its wind energy more expensive. But all this energy is non-fossil, so, wherever it's used, there's no carbon emission.

However energy demand in Denmark is still rising and national fossil fuel use hasn't reduced significantly yet, with as elsewhere, transport being a key issue. But they're clearly trying to tackle that and to get to zero net carbon, with increased commitment to energy efficiency and more use of renewables, including heat supplying renewables. Around 60% of Denmarks heat is supplied via district heating networks, some of it from biomass, and the aim is for around 40% of the district heating to be supplied from solar inputs, backed up by heat stores, by 2050.

Germany of course has a somewhat similar plan, following the decision to phase out nuclear entirely by 2022. It aims to get 35% its electricity from renewables by 2020, 50% by 2030 and then 80% by 2050, with parallel development of heat supplying renewables. Following the referendum last year, in which 94% opposed nuclear, Italy's new government is pressingly ahead with renewables strongly, PV especially. And with the Presidential elections soon in France, nuclear is a key issue: opposition has reached 70% in some polls, and the socialists have called for a phase out, with 24 nuclear reactors (nearly half the current fleet) being closed by 2025, and a commensurate expansion of the renewables programme. A similar phase out programme has emerged in Belgium, while Switzerland is not going to replace it nuclear plants- so in effect opting for a phase out.

With much of the rest of western Europe having long standing non-nuclear policies, and the UK nuclear expansion programme looking decidely shaky after the withdrawl of E.ON and RWE, it could be that, when and if a new 'History of Energy' is written, Denmark's pioneering stance may turn out to be the one that dominantes.

Of course the situation elsewhere is different. For example, in Asia. Although Thailand, Malaysia and the Philippines have all moved away from nuclear, India remains committed to nuclear expansion, as is China, and we still await Japans new plan. However, at present only one reactor is operating in Japan and it is far from clear if any of the closed plants will be allowed to reopen, given the widespread and expanding opposition to nuclear power following the Fukushima disaster.

Maybe times are changing. They do seem to be in Europe. For example, when E.ON pulled out of the UK nuclear programme, its CEO explained that "We have come to the conclusion that investments in renewable energies, decentralised generation and energy efficiency are more attractive - both for us and for our British customers".