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July 2011 Archives


The White Paper on UK Electricity Market Reforms emerged in July, just after the last minute withdrawl of the new Energy Bill, which contained the proposals for the much-touted Green Deal, offering (commercial) loans for domestic energy improvements. It seems there was Treasury concern about the cost- and no time for parliamentary scrutiny before the recess. It will be back later though. The EMR White paper, like the revised National Policy Statement on energy, evidently had priority- perhaps because of their relevance to the 'urgent' nuclear programme. The NPS was duly agreed, confirming the eight new nuclear sites.

The final EMR plans are much as in the initial proposal- a carbon price floor (allegedly giving more certainty to investors in low carbon tech); a capacity support mechanism (though it won't be firmed up until the end of the year); a long-term 'contracts for a difference' (CfD) system, possibly with auctions (replacing the Renewables Obligation, and also covering CCS and nuclear); and new emission performance standards (effectively blocking coal without CCS).

Energy Secretary Chris Huhne said the aim was to get to low carbon in a cost effective way by increasing market competition, but with extra support being available for key new technologies- he announced a special £30m allocation for offshore wind subject to cost effectiveness assessment. He saw the EMR as the biggest change since electricity privatisation.

So what will change? Well, when and if it all rolls through the parliamentary process in 2012/13, from 2014, the CfD would mean that technology choice will be even more driven by the market, with no set capacity obligations, but a claw back mechanism to avoid wind- falls if prices fell. The fixed price Feed-In Tariff system, seen by most people as favouring renewables, was not adopted. So nuclear may well benefit most.

In the Parliamentary debate on the White paper, Huhne was upbeat about offshore wind (so sidelining fears that it was to be cut back- though that may still be the result of the CfD). He backed on-land wind (against objections from a back bencher), saying it was about the same cost as nuclear, but was unrepentant about blocking large PV solar projects- 'the size of tennis courts'. There was a fixed budget and we had to avoid 'boom and bust'. Coal had a future via CCS and he thought tidal was promising 'around the country.' As for energy efficiency -well he alluded to the Green Deal and the Smart Meter programme.

British Gas, which had posted profits of £742m last year, had just announced gas price rises of 18%. So the mood was very much one of looking at what it would all cost. Huhne said £110bn, but the EMR would reduce uncertainties for investors and protect consumers from the vagaries of the market, though he said that prices would have to rise- but by less than they would have without the EMR. Maybe 1% extra on bills by 2020.

The details

The Carbon Price Floor (CPF) will replace the Climate Change Levy, building on the existing EU Emissions Trading System. It will provide 'a transparent and predictable carbon price which will make investment in low-carbon generation relatively more attractive, encouraging increasing amounts of investment as the carbon price rises and ensuring that the costs of carbon emissions are reflected fairly'.

The Contract for a Difference (CfD) system (which DECC still labels a Feed-In Tariff, though it's not a guaranteed-price FiT), will provide 'low-carbon electricity generators with increased confidence in their revenues through agreement of a long-term contract. If the wholesale electricity price is below the price agreed in the contract, the generator will receive a top-up payment to make up the difference. If the wholesale price is above the contract price, the generator pays the surplus back. This means that, as the CPF gradually increases the wholesale electricity price, the support needed for low-carbon generators is reduced.' Crucially 'to reflect the different commercial and operational behaviour among different classes of generation, the Government will tailor the design of the FiT CfD for different generation types'.

On the EMR consultation, DECC says that 'the majority of respondents were sceptical about the use of auctions to set the level of support for low-carbon generation' but notes that the government is still keen, though to ease the transition, it is 'minded to move from administrative price discovery processes for low-carbon technologies to more competitive forms of price discovery such as auctions or tenders when the wider conditions in the market will support their successful deployment. In the medium term, technology-specific auctions or tenders for commercially deployable nuclear and CCS generation should be possible. The Government intends to introduce an auction or tender process for price-setting for specific technologies from 2017. Tariffs for generation that will be commissioned prior to 2020 are most likely to be set through an administrative price setting process'.

There's a new consultation on the design of the Capacity Mechanism- to protect security of supply by maintaining a plant margin. It could be targeted, with payments 'to secure only the amount of generation capacity required to make up the expected shortfall in the market', as a strategic reserve, or via a capacity market, with perhaps CfD interactions. Storage, Demand Side Management and interconnector options might play roles.

Finally there's the Emission Performance standard, which is seen as the regulatory 'decarbonisation' driver for the market, 'complimenting' the CPF. Quite a package. [www.decc.gov.uk/en/content/cms/legislation/ whitepapers/emrwp2011/emrwp_2011.aspx]

Routemap

In parallel with the EMR, DECC's new UK Renewables Roadmap sets out a 'comprehensive action plan to accelerate the UK's deployment and use of renewable energy, and put us on the path to achieve our 2020 target, while driving down the cost of renewable energy over time'. It identifies eight technologies that have 'either the greatest potential to help the UK meet the 2020 target in a cost-effective and sustainable way, or offer great potential for the decades that follow'. These technologies are: • onshore wind • offshore wind • marine energy • biomass electricity • biomass heat • ground source heat pumps • air source heat pumps • renewable transport

DECC says that 'of particular importance is offshore wind - of which we have abundant natural resource and already the world's largest market. Our intention is to maintain this position, ensuring the full economic and energy security benefits of our offshore wind resources come to the UK rather than go to our competitors'.

Clearly then, publicly at least, DECC is not taking that much notice of the Committee on Climate Change which recommended a cut back on offshore wind since it was deemed to be expensive. Indeed it says 18GW is possible by 2020, up from 13GW in previous plans.

The Ministerial Preface to the DECC report says 'The UK Government will respond to this advice by the end of the year; this response, alongside the Annual Energy Statement and policies to meet the 4th Carbon Budget, will place renewables firmly within the energy mix'. In the meantime DECC notes the decision to 'provide up to £30m of direct Government support for offshore wind cost reduction over the next 4 years'.

While approximately 90% of the generation necessary to meet the 15% 2020 energy target can be delivered from its chosen subset of 8 technologies, it says 'the remaining renewable energy generation necessary to meet the 2020 target will come from technologies such as hydropower, solar PV, and deep geothermal heat and power. These will generally qualify for renewable financial incentives and will benefit from action to unblock cross-cutting non-financial barriers, including those set out in the recent Microgeneration Strategy for England. Microgeneration technologies will also benefit from the Government's commitment to Zero Carbon Homes'. Note the lowly position of solar.

The report then reviews the potentials for the eight selected technologies, including cost estimates, and outlines a range of actions designed to help progress their development, e.g. using the Renewables Heat Incentive. DECC will produce an annual updated edition of the Roadmap www.decc.gov.uk/en/content/cms/meetingenergy/renewableener/reroadmap/reroadmap.aspx

I'll review reactions to the EMR package in next week's Blog.

Since Newman's and Kenworthy's work in 1989, the role of urban density has been controversely discussed as a mean to reduce gasoline consumption. Newman and Kenworthy's results are very suggestive - see figure below: With higher urban density, fuel consumption goes down with 1/x. Numerous studies have confirmed the basic relationship in different settings. However, the causal relationship still remains illusive (note that transport economists have worked on this issue since the 1970ties, but communities use different language and communicaton between communities remains sparse).

A key criticsm affects not the general results but the proper role of control variables that may co-correlate with urban density (e.g. Mindali et al., 2004). Karathodorou, Graham, and Noland recently published a paper that looks more closely on how a number of variables - including urban density - influence fuel demand. They decompose fuel demand into car ownership, fuel efficiency, and distance traveled by car, and look how each of these factors is influenced by urban density. Fuel efficiency seems to be not significantly correlated with urban density, perhaps because stop-and-go efficiency loss of denser urban areas is compensated by smaller cars more suitable for parking in dense urban areas. However, car ownership and transport activity are both significantly correlated to urban density. Using the Millenium Cities Database for Sustainable Transport, the authors find that the elasticity of car ownership with respect to urban density is around 0.12. The elasticity of distance traveled with respect to urban density is around 0.23-0.24.

While these numbers still not reveal causal relationships, this refined analysis sharpens the intuition on the role of urban density. 

Major cities - per capita petrol use vs. popul...

Image via Wikipedia

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Within Europe, the wave of popular resistance to nuclear power seems to be unstoppable, with, as I reported in my last Blog, even France now joining in the debate about whether to phase it out completely. Austria, Denmark, Greece, Ireland, Norway, Portugal and now Italy are all non nuclear, while famously, Germany, along with Spain, Switzerland Sweden and Belgium all have, or had, phase out plans (Belgium's was postponed but it currently has no functioning government to decide on what happens next, Sweden's has been abandoned but no new plants are likely). That leaves the UK as something of an exception, at least within the western EU, Finland apart, although they are having major problems building their new EPR.

Although the UK government is still pushing ahead, depending on which poll you believe, opposition is now (narrowly) in the majority (51% according to IPSOS Mori), and it is far from clear if EDF, E.ON and especially RWE , will be willing to invests in UK nuclear projects, even given the government strong support. RWE npower said the Electricity Market Reform (which in effect proposes more support for 'low carbon' options like nuclear) 'does not yet provide enough clarity for customers or investors'.

Outside of the EU, the collapse of support for nuclear is a bit less marked, with popular resistance perhaps less effective or viable in Russia, China, and also Vietnam, who are all still pressing ahead. Russia still aims to increase its nuclear share to around 25% within 10-15 years, from the current 16%. Vladimir Putin said its reactors were 'the safest in the world' and it needed 'to produce as many units, I mean big units, as in the entire Soviet period,' but added that that 'our energy should be balanced; it should be based on several sources: nuclear, hydrocarbon, hydro power, wind, solar panels.' China has been reviewing its nuclear programme but seems likely to continue with it, along side its much larger renewables programme, although at a reduced level. A review by the Economist Intelligence Unit (EIU) put China's likely 2020 nuclear capacity at 63 GWe, compared to the current target of 80 GWe. Vietnam has decided to continue push ahead with its plan for 14 nuclear plants by 2030.

There's been plenty of resistance in India, but they too are still going ahead with their expansion programme- it wants 20GW by 2020 . Saudi Arabia is also still pushing ahead with its plans for 16 plants by 2030, in a $100bn programme. The UAE too is planning to build nuclear plants However Kuwait and the Philippines have now joined Malysia and Thailand, and backed off their nuclear plans. The Philippines government says it may 'rechannel' its £100m nuclear budget to renewables. South Korea is rethinking their nuclear expansion plans.

As well as abandoning plans for new plants, Japan is now talking of an ultimate phase out even of its existing plants, with in July Prime Minister Kan saying he believed 'Japan should aim for building a society that is not dependent on nuclear power.' He wanted to reduce the use of nuclear energy 'in a planned and phased manner, so that future society will be sustained without it.'

This clearly rattled some nuclear apologists, with chief cabinet secretary Yukiyo Edano then clarifying the government's position: 'I think the prime minister's announcement outlined a plan for the country to reduce its dependency on nuclear energy in stages. I understand that it is a starting point for launching a national debate on the issue.'

Kan has faced calls for his resignation after the Fukushima crisis and he has promised to resign once the Daiichi plant is stabilised and people could go home - whenever that is! Over 100,000 look like spending Christmas and beyond in enforced exile.

Globally much of the post-Fukushima landscape continues to be shaped by debates over safety and the impacts of radiation. The data on health impacts coming out of Fukushima is certainly sobering. Although the Japanese government did move quite quickly to limit exposure and administer iodate tablets, there could still be radiation linked deaths. www.irsn.fr/EN/news/Documents/IRSN-Fukushima-Report-DRPH-23052011.pdf

Longer term it is still not clear whether the fuel melt down was just caused by the lack of cooling following the loss of pumps and power after the tsunami, or whether internal cooling systems had been wrecked before then- by the earthquake. That is crucial since tsunamis may be rare but there are many reactors around the world in or near earthquake prone areas. If so, then it's not just a matter of locating back-up pumps more carefully.

The International Atomic Energy Agency sent a team out to study the Fukushima wreck. UK nuclear consultant Dr John Large has taken them to task for not addressing the key issue of internal pre-tsunami damage in their report: 'doubts from a number of usually well-informed sources about possible (pre-tsunami) seismic damage to the reactor coolant circuit, services and containments should warrant further and detailed investigation. This is because the Fukushima Dai-ichi NPPs were designed and (supposedly) maintained to the highest international seismic standards - seismic failure at Fukushima Dai-ichi has obvious implications for NPPs, not just elsewhere in Japan but for all plants located in seismic sensitive regions globally- surprising, therefore, that the IAEA have not expressed interest in this potential weakness of the nuclear safety regulatory standard' http://www.largeassociates.com/3201%20IAEA%20Mission%20Statement/R3201-A1%20Final.pdf

The Japanese government's report for the IAEA ministerial conference on nuclear safety also managed the blank out this issue: "Although damage to external power supply was caused by the earthquake, no damage caused by the earthquake to systems, equipment and devices important for nuclear reactor safety has been confirmed". However, it did provide a let out: "further investigation should be conducted as the detailed status remains unknown."

We await clarification. Meanwhile for a good account of what happened at Fukushima see: www.kit.edu/downloads/AnhangHintergrundinfo023AnalyseReaktorkatastrophe.pdf

What next? A Ipsos MORI opinion poll in May found that 62% of citizens in 24 countries across the world opposed the use of nuclear, with 38% in favour: 26% had changed their minds after Fukushima. The most anti-nuclear, at about 80% against, were Italy, Germany and Mexico. Only three of the 24 countries had majorities in favour: India (61%), Poland (57%) and the US (52%). www.ipsos-mori.com/Assets/Docs/Polls/ipsos-global- advisor-nuclear-power-june-2011.pdf

Other polls came up with different figures. For example, an ABCNews/Washington Post poll found that 64% of their US sample now opposed new nuclear. You do have to be careful with poll data- the results depend on the questions asked, But in does seem clear that nuclear is now much less popular in many countries. Moreover, it seems possible that as events at Fukushima continue to evolve and more information about what happened emerges, opposition around the world will grow.

There are of course other views and the nuclear lobby will naturally try to resist further shifts as best it can, especially in the UK. As the infamous leaked email from a staff member of the Department for Business, Innovation and Skills, put it, Fukushima, 'has the potential to set the nuclear industry back globally. We need to ensure the anti-nuclear chaps and chapesses do not gain ground on this. We need to occupy the territory and hold it. We really need to show the safety of nuclear.'

A Mori IPSOS opinion poll just after Fukushima found that 67% of the French public opposed new nuclear projects, and the long-standing support for nuclear power in the French technocratic elite is showing signs of strain, following Germanys phase out plan. The share price of French reactor vendor Areva dropped by 25% in response to the German nuclear exit. It had already fallen 14% following the Japanese crisis. Then came the news of a new French government review of the future energy mix, which would look at all scenarios 'with total objectivity, in full transparency', including the complete phase out of nuclear by 2050 or even 2040. Reuters reported that an opinion poll in June found that showed three quarters of the French people interviewed wanted to withdraw from nuclear energy, against 22% who back the nuclear expansion programme.

The new critical view is developed in a book 'The Truth about Nuclear', by Corrine Lepage, who served as Minister for the Environment in the government of conservative President Jacques Chirac. It lists a litany of damning allegations about the French nuclear industry, such as the escallating cost of Areva's Finnish reactors which will have to be borne by French taxpayers. She suggests that exiting nuclear power, rather than penalizing the economy, could in fact lead to reindustrialization. If France developed its large renewable resources to replace nuclear power, the country would create new industries and jobs like those seen in Germany. Meanwhile the French nuclear industry could turn its attention to the growing trend toward phasing out nuclear. She proposes that France could become a leader in decommissioning nuclear power plants worldwide.

She is currently serving as a member of the European Parliament and in that role she has questioned France's nuclear choice, calling it a "strategic error" of historic proportions. The new leader of the far-right National Front, Marine Le Pen, has also said that nuclear power is a "dangerous form of energy".

Oddly, in the UK, the far-right has been very pro- nuclear, as witness the strong support recently given by the BNP leader Nick Griffin MEP at a Euro parliament session. But then so is the centre right and centre left!

That seems to be at odds with what's happening elsewhere in the EU. It's interesting that it's been centre-right Germany and Italy who have ended up with solid anti-nuclear policies. Of course in both cases that has been due to massive grass roots opposition to government nuclear policies (and/or leaders) , forcing spectacular U turns. It could be the same in France- Sarcozy is very pro nuclear, and there is a presidential election next May. The center-right UMP party mostly supports the extension of nuclear, the opposition Socialist Party has called for a moratorium on new reactors and pledged a national debate on energy transition if elected in 2012.

In Germany, Merkels right wing government was trying to extend (or even abandon) the nuclear phase out programme inherited from the previous left of centre coalition. However, after Fukushima, massive 250,000 strong demonstrations and major reversal in the polls (support for nuclear, already very low, fell to 5%) , she has had to revert back to the existing 'phase out by 2022' plan. But she is now presenting this as a positive new pro-renewables policy.

Italy chose to phase out nuclear in a 1987 referendum just after Chernobyl, and has not operated a nuclear plant since 1990. But a change in government policy in 2008 led to plans for a programme of nuclear construction, with four large reactors proposed by Enel in cooperation with EDF. This was unpopular and a referendum was planned for June. Legislative referenda in Italy require a quorum of over 50% of all eligible voters to cast their vote in order to be valid. This is one of the highest quora in Europe, and no Italian referendum has been able to reach it in over a decade. So some saw it as having little hope of success.

However then came Fukushima. With opposition rising, the government initially imposed a one year delay on its nuclear programme, and then in effect froze it entirely, making the referendum irrelevant. But it went ahead and was the focus of massive grass roots agitation- as well no doubt of much anti government feeling. As a result, 57% of voters participated, an amazing 94% opposing new nuclear. The government has had to accept defeat and is now pushing ahead with renewables.

For the past 14 years, Italy, the world's seventh largest economy, has done without nuclear, so it should not be hard to maintain this stance. It already gets 22.2% of its power from renewables (the UK is at 8%) and has become a leader in PV solar -Italy is currently the world's second largest market for solar PV, following Germany. Other renewable are also moving ahead in Italy: wind energy currently provides nearly 5% of supply, with 5.8 GW installed by the beginning of last year - more than the UK.

Germany is of course in the front globally in most areas - with for example 27GW of wind capacity already in place . The German energy plan produced in 2010 called for renewables to supply 35% of electricity by 2020, upgrading the previous target of 30% renewable electricity by 2020. But in fact Germany's official National Renewable Energy Action Plan produced for the EU, said it expects to actually generate 38% of its electricity from renewables by 2020.

All that was before Fukushima and the German government policy shift to return to a rapid nuclear phase out - by 2022. It's been said that the aim now is to get to 35% from renewables by then, but clearly it could be more. Indeed an agency (UBA) within the German Ministry of the Environment, has produced a report saying that Germany can close all its reactors by 2017 and keep the lights on by faster development of its renewable sources of energy and the construction of 5,000 MW of new gas-fired generation.

The German UBA Environment Agency estimates that a rapid exit from nuclear will cost ratepayers only €0.006 to €0.008 per kilowatt-hour. This increase is, UBA says, less than the price swings of natural gas and coal during the past year. Interestingly, as energy analyst Paul Gipe has noted, the higher market price for electricity will reduce the cost of Germany's renewable energy programme by decreasing the differential between the market price of electricity and the average cost of feed-in tariffs for renewable energy.

Similar shifts have happened elsewhere in Europe. The Swiss government had backed a nuclear expansion programme but after Fukushima 25,000 Swiss attended an anti-nuke demo, and in June the Cabinet decided against new build- in effect supporting a phase out programme as its old plants retire.

With Austria, Denmark, Portugal, Norway, Ireland and Greece all stead-fastly non-nuclear, and phase out programmes in Spain, and (at least until they get a government back in place) Belgium, that leaves the UK, France and Finland, along with Sweden and some ex Soviet EU countries, as the main EU countries in support. Problems have been mounting in Finland, with its EPR programme being 50% over budget and years behind schedule, and a new tax on nuclear being levied, and if the consensus in France is shifting, it could leave the UK isolated. No wonder then that the French and Germany nuclear companies are looking to the UK as a safe haven for new nuclear projects- with the Con Dem coalition offering enthusiastic support.

In my next Blog I will look at the situation outside the EU.

As electricity generating renewable energy project spread, there will be an increasing need for new grid links, often across remote areas. But pylons are invasive and there have been objections to some new wind projects on that basis. For example, this issue has come to a head recently in mid Wales. See the consultation at: http://www.spmidwalesconnections.info/english/pdf/Consultation%20Strategy-English.pdf

National Grid notes that the total generation capacity of the new wind farms proposed in Mid Wales is 874MW, with start up dates in 2015/16. It says that without 'new significant transmission infrastructure' it is 'highly unlikely that the Welsh Assembly Government's target of 2 GW of onshore wind farm capacity by 2015/2017 will be met'.

It goes on 'Currently there is no electricity transmission system in the region of the proposed new wind farms in Mid Wales. The nearest points of connection to the existing system are in North Wales, South Wales and the West Midlands'. And it then looks at grid connection options, geographically and technically.

Basically, conventional overhead AC links are cheapest, but are very invasive. Underground AC costs a lot more and High Voltage Direct Current grids cost even more, over relatively short distances - the main cost with HVDC is in the AC-DC converters and their losses at each end; the cable link itself is much cheaper/km, and less lossy, than for AC. www.nationalgrid.com/NR/rdonlyres/18E52B43-8AB5-4F0B-95F7 -0BECCA0647BE/46002/MidWalesSORIssue1_110319.pdf

However, Friends of the Earth Cymru has proposed an alternative, potentially significantly cheaper, approach, allowing for underground HVDC, with the capital costs of an under ground link possibly being reduced from around the £600m estimated by National Grid to £300- 390m, depending on revised wind farm capacity, link configuration and whether new energy storage technology was included.

How come? Energy adviser to FOE Cymru, Neil Crumpton, explains 'The existing Grid regulations require two circuits in the link, each of which could carry the maximum output of all the wind farms, to avoid lost production if there is a fault in one or other of the circuits. Yet, load-duration data from a group of wind farms in southern Scotland indicates that the farms generate around 95 % of their annual electricity production at below 66% of their maximum output. So for the wind regime in that region a 66 MW circuit from a 100 MW wind farm would still transmit around 95 % of annual production. The wind profile in Mid Wales may well be similar. So the proposed 800 MW or so of wind farms may well be served by 2 x 500 MW links rather than 2 x 1,000 MW links with little loss of production during faults of several weeks a year on one or other circuit. If so, the HVDC hardware and undergrounding cost might be nearly halved.'

FOE Cymru says an energy storage facility at or near the upland sub-station could minimise production losses during a fault by delaying transmission until the wind eases and link capacity becomes available. Storage would also 'bring wider system benefits in terms of routine demand-responsive supply to Grid and power quality improvements'. The group suggest using vanadium flow cell technology or ABB's battery system which could scale to 50 MW for an hour or more.

Underground HVDC links have been used round the world e.g. in Australia, but usually in larger, longer distance transmission or subsea schemes.

However there may be another, much more radical, approach to energy transmission. Energy transmission by electricity pylon, let alone underground cable, is much more costly than by gas pipeline. Estimates vary, but the costs to transport energy by gas pipeline may be 10 - 100 times lower than electricity pylon and 100 - 150 times lower than underground AC or HVDC cabling. Importantly, as pipelines are underground, they are visually non-intrusive, so route planning is less likely to attract public opposition. Pipelines also have lower transmission losses as no wires are getting hot, and they also offer a degree of energy storage, be it within the pipeline ('stacking') or in purpose built stores, at potentially strategic scale.

But what sort of gas and where would it come from? Well a new 48 inch diameter pipeline across south Wales from the new Milford LNG terminals is now supplying the UK with around 200 TWh/y of natural gas from around the world. One idea closer to home is to progressively switch parts of the UK gas network to hydrogen, or a mix of hydrogen and natural gas, to supply decentralised systems.

The hydrogen could come from a number of sources, be it coal or biomass gasification, natural gas or bio-methane reformation. For example large CCS-fitted gasifiers could be located on brown-field sites near port or rail facilities and carbon dioxide pipelines to the sea. The gasifiers could supply hydrogen by new strategic pipelines to dedicated hydrogen distribution networks, or to the existing gas distribution network, to be used locally in fuel cell CHP schemes, domestic micro-CHP boilers, or in urban areas, in larger scale arguably more efficient CHP /District heating projects.

More radically still, some of the peaking output of offshore windfarms could be converted to hydrogen by electrolysers within the turbine or a dedicated electrolyser platform, and then piped long distance.

Much would depend on the relative cost of electrolysers and hydrogen pipelines compared to HVDC converters and cabling capacity. There would be significant energy losses in converting electricity to hydrogen (25 %), though electrolyser efficiencies are improving and sea water electrolysis is being developed. Re-conversion losses to electricity should be minimised (to 10% or less) by utilising the heat in CHP systems. So given the benefits of storage and lower cost transmission infrastructure, piping hydrogen may be worth while.

Piping pure hydrogen would present problems (e.g with pipe embrittlement for non plastic pipes), but modern gas piping has been designed for higher pressures than the old town gas, since the energy density of natural gas is lower, so running with a mix of hydrogen and methane could be viable. Indeed it is already done widely around the world -it's called hydrane. Some or eventually perhaps all of the natural gas could be replaced by biomethane, produced by AD conversion using biomass wastes. Some biogas is already being added to the gas grid. That way we have a 100% green energy system fed by wind (and possibly also wave and tidal) and biomass. And no unsightly pylons across sensitive areas.

There are plenty of technical and economic details to be considered before this particular 'pipe dream' can be taken seriously, but National Grid is currently consulting on grid connection issues, and their web site has much useful information about he details: see http://www.nationalgrid.com/uk/Electricity/UndergroundingConsultation/

The UKs 'zero carbon' house programme, should see a mix of electricity and heat supplying on-house technologies including photovoltaic (PV) panels, solar heat collectors, biomass-fired CHP units and heat pumps. In addition we now have a Renewable Heat Incentive, which from Oct next year, should also see the wider adoption solar collectors, biomass , heat pumps and so on.

While it is sensible to try to get house energy efficiency up to the maximum possible and to use local energy sources wherever available to meet the needs of individual houses, there are other more collective approaches, supplying groups of houses, whole communities or even cities. The RHI can be used for some community scale projects, so they may prosper, and we might see some innovative ideas.

As I discussed in an earlier Blog, elsewhere in Europe district heating networks are common and some make us of solar and other green energy inputs- and they include systems with inter-seasonal heat stores. http://environmentalresearchweb.org/blog/2011/01/green-heat---district-heating.html

That idea is now being taken up in the UK, for example, for large school premises. ICAX have developed an Inter-seasonal Heat Transfer system, which includes a 'Thermal Bank', used to store heat in a very large volume of earth for a period of months, as distinct from a standard heat store, which can hold a high temperature for a short time in an insulated tank.

The ICAX system involves capturing heat energy from the sun via a collection pipe network just beneath the surface of black tarmac roads , or car parks or school playgrounds, and then storing it in the ground under the foundation of buildings. It is then released to heat the buildings in winter via heat pumps linked to underfloor heating.

ICAX say 'unlike a normal ground source heat pump which typically starts with an autumn ground temperature of 10°C, the heat pump in an Inter-seasonal Heat Transfer system starts with a temperature of over 25°C from the Thermal Bank. This doubles the Coefficient of Performance of the heat pump and allows a 50% saving of carbon emissions compared to providing heat from a gas boiler'. They add 'Where it is not practical to create a horizontal Thermal Bank to store energy, ICAX uses a borehole field to perform the same function.' www.icax.co.uk/interseasonalheattransfer.html

Interestingly, summertime solar heat storage has also been put forward as a way to heat parts of the tarmac at Heathrow airport in winter- to reduce icing up of the aircraft stands. That, you may recall, was a major issue last winter.

However if the UK summer is not seen as reliable enough for winter heating of buildings or whatever, then how about wind-powered district heating? The Danish District Heating Association says that more than 20 partly wind powered heating element systems, with a total capacity of more than 200 MW, will have been installed in district heating plants by the end of this year. They can be powered using surplus electricity from Danish wind turbines- the energy thus being stored as hot district heating water. Heating elements work like giant immersion heaters, which can automatically heat water when there is surplus power. The system regulates itself based on electricity prices. When wind power is available, the heating elements are switched on, the district heating plant's own electricity-generating plants are switched off, thus saving on fossil fuel use.

This may be an advanced idea, but District Heating networks in the EU are increasingly supplied using green sources. For example 62% of Danish households are linked to district heating, supplied from gas-fired CHP plants, but also from surplus heat from industrial production, solar heating and waste combustion. And there are plans to increase to solar share to 40% by 2050. www.solar-district-heating.eu

It's the same in the Sweden. The district heating sector there achieved a market share of 60% during 2008 in the heat market for buildings in the residential and service sector, using a mixture of waste incineration, industrial surplus heat, biomass, with only limited fossil CHP. And in recent years, this fossil CHP has been replaced by biomass CHP. Overall carbon dioxide emissions are now claimed to be more than 80% lower than in other European cities and towns using natural gas and fuel oil to heat buildings. It now supplies over 50TWh p.a. The majority of the plants feeding the DH systems use wood and peat (30TWh p.a). 94% of multi-family houses are connected and 78% of public and commercial premise.

District Heating is cost effective. For example, a paper in Applied Energy 88 (2011) 568-576 puts the marginal capital cost of DH distribution at only 2.1 €/GJ, which means energy at around 4.8p/kWh. And in the Netherlands, CHP/DH was found to be one of the least cost carbon abatement options at 25 EUR per tonne CO2, lower than building insulation, condensing boilers and wind power. www.ecn.nl/docs/library/report/2004/c04040.pdf

We may yet see it in the UK- the Renewable Heat Incentive does support district and community renewable heating, and the UK Energy Technologies Institute is looking at inter-seasonal heating storage systems, as I noted in an earlier Blog: http://environmentalresearchweb.org/blog/2011/01/green-heat---district-heating.html

There are some examples already. The University of Warwick has a 4.7 MWe 14MWTh Combined Heat and Power (CHP) system, linked to an extensive district heating network around the campus, which supplies 50% of campus power and reduces overall energy use by up to 34%, compared to separate electrical and heat generation. It also uses thermal energy storage (in a water tank) to meet peak heat demand and also allow for power generation when demand is low, without any heat dumping. http://www2.warwick.ac.uk/about/environment/energy/chp

Finally, 'DH' may not be the most riveting of subjects graphically, but it's brought to life in a fun, if simple, Danish animated video: www.youtube.com/watch?v=IysslE4OvKI