The amount of travel carried out by people in the UK continues to fall. Whether measured by the number of trips or the distance travelled, people are moving around less. The latest National Travel Survey (NTS) says UK adults made fewer trips in 2013 than they did in 1973. After rising until the early years of the last decade, the average distance travelled has also fallen.

The possible explanations are fairly obvious. The internet has reduced the need for High Street shopping. Working from home is now more common than a generation ago. We tend to meet friends in local restaurants or pubs rather than visiting far-flung relations.

One other potential reason is that people’s real incomes have been dropping in the last few years. And as driving tends to get more expensive, we might expect individuals to drive less if they can. These two arguments sound plausible explanations. But examination of some of the detailed numbers in the NTS shows that they are probably wrong. Surprisingly, the richest 20% have cut their travel miles more than the least well-off 20%. And this reduction is driven mostly by decreased car travel. It’s those who can most afford to drive who have reduced their mileage the most. They still drive far more than poorer people but the difference has dipped sharply. This is additional support for the view that energy use will not rise sharply if incomes rise.

One other striking finding: more young women aged 17-20 now have driving licences than young men in the same age range. This is the first time any age cohort of women has ever had a higher percentage of drivers than men. Read the rest of this entry »

Copyright Karen Pendragon

Copyright Karen Pendragon

Another group of scientists has estimated the environmental burden of beef. The researchers suggest that meat from cows contributes 10 kilos of greenhouse gases (expressed as CO2 equivalents) for every 1000 calories of food. Put in a less scientific way, a Big Mac® a day will represent more than a tonne of global warming emissions a year, using up your entire carbon budget by the middle years of the century.

Seven years ago I wrote an article (covered in the New York Times blog here) that suggested that walking to the shops and then eating beef to replace the calories used would generate more greenhouse gases than driving a car to make the purchases. This little piece of ad hoc research was cruelly dismissed as utter nonsense by all right-thinking people. Well, if you believe the figures published today, I’ve finally got my revenge. Beef turns out to be twice as carbon intensive as driving. Read the rest of this entry »

Last month the headlines excitedly stated that Ofgem had asked the Competition and Markets Authority (CMA) to look at the energy market. Actually, this was a huge exaggeration. Ofgem’s request was for the CMA to examine about 5% of the business: retailing gas and electricity to domestic consumers and very small companies. Sales to large organisations are excluded, accounting for over half the market, as are the upstream activities of energy generation (50% of consumer bills), the transport of energy over wires and pipes (about 20% of the domestic bill) and taxation and social and environmental levies (15%).

Market participants nevertheless genuinely seem to hope that the CMA investigation will change the way the whole energy market works, freeing up investment in generation and improvements in networks as well as stabilising prices. This note looks at how participants, particularly including the new generation of smaller retailers, might choose to respond to the investigation if they want to influence its outcome. (Full disclosure: I was member of the Competition Commission, a predecessor of the CMA, for seven years and a tribunal member on the specialist panel at the Commission dealing with the – very rare – appeals against Ofgem decisions).

The central point I want to make is that smaller energy companies and consumer bodies should understand that a market investigation by the CMA is a mammoth, many-headed process. The CMA is hugely thorough and data-driven and the demands it places on companies are often almost overwhelming. Inquiries can last for up to 24 months, not the 18 months specified in recent press releases.

To be effective, and to get arguments taken seriously by the CMA, participants need to devote resources to the process, almost certainly in a joint undertaking with groups of similar views. Occasional letters to the CMA will not work when the Big Six will be spending tens of millions of pounds on lawyers. Read the rest of this entry »

Sawton Mill near Totnes. Tresoc will buy a share in this if it is fully financed

Sawton Mill near Totnes. Tresoc will buy a share in this if it is fully financed

Totnes Renewable Energy Society (Tresoc) in Devon is trying to raise up to £1.5m to fund a portfolio of six PV and hydro projects near the town.  What makes Tresoc unusual – and perhaps unique in the UK – is that is both financing current projects and developing a wide variety of new ventures, including an innovative waste-to-energy plant and biomass scheme for future investment.

This is an ambitious scheme to create a genuinely local energy company that might eventually hope to directly supply its electricity and heat to investors, rather than selling to a big power company. One day, this may make it an exciting form of new energy enterprise. But therein lies in the problem. Tresoc is asking for investors to back what is, in effect, a renewables development company. Read the rest of this entry »

In the last post I looked at the evidence of the decreasing use of resources in the UK. The Environmental Accounts have just provided a new measure of material use, called Raw Material Consumption, which gives us a better estimate than previous series. The new index includes a figure for the resources used elsewhere in the world to make things that are then imported into the UK.

If we divide Raw Material Consumption, expressed in millions of tonnes, by GDP we get a figure for the weight of physical resources the UK uses to generate a £ sterling of income. The figure has fallen from about 513 grams in 2000 to around 358 in 2012. The average reduction is just under 13 grams a year for each £ sterling of GDP. This is equivalent to a 30% reduction since 2000. (All these figures exclude fossil fuel consumption, which isn’t included in the statistics. However we do know that energy consumption is also falling fairly consistently each year).

Grams per £

Grams per £ sterling of GDP is an important measure and should be targeted. As we move haltingly to an economy that productively recycles everything for ever, we will reduce the volumes of materials harvested or mined. And moving to low carbon sources of energy, whether PV or nuclear also reduces the weight of resources we need to extract, as well as reducing CO2 emissions.


In late 2011 I wrote a paper which suggested that the UK’s consumption of material goods had peaked. I pointed to the evidence from a variety of different statistical sources that the weight of the things we use to sustain a modern economy was tending to fall. This included products such as fertiliser, water, steel, concrete and food. I saw this as very good news; increasing prosperity would not necessarily imply increasing use of natural resources. Recent data support the ‘Peak Stuff’ hypothesis and suggest that economic growth in advanced countries doesn’t increase the use of material extracted from the soil or earth’s crust. I think the ‘dematerialisation’ idea has real strength to it. Read the rest of this entry »

Heating buildings is the single most important use of fossil fuels in high latitude countries such as the UK. In the average British home gas use is almost five times as much as electricity consumption. The Green Deal is a part of the approach to cutting heating demands but ‘the Renewable Heat Incentive (RHI) is the main scheme of the heat strategy’, according to DECC.

The RHI for domestic homes was finally launched at the beginning of April after a gestation period of about five years. According to the most recent data, just 79 homes signed up for the RHI in the first two months. Although the RHI subsidy scheme offers some tempting payments, the signs so far are that this scheme will fail in the same way as the Green Deal has done. Read the rest of this entry »

The UK government is keen to encourage more involvement by communities and individuals in commercial renewable energy projects. In particular, it believed it had made a voluntary agreement with the main developers to offer local people the chance to invest in new schemes. It had hoped that it would not have to legislate to oblige commercial companies to let communities buy shares.

Unfortunately the agreement doesn’t appear to be working. Even big companies are ignoring it. One recent example is the Rhyd-y-Groes wind farm on Anglesey. E.ON, the huge German-owned utility, is starting the local consultation process prior to applying for planning permission to take down the existing turbines and put a much larger wind farm in its place, probably in late 2015. It is not offering a stake to local people. When I asked why the company was ignoring the agreement to facilitate community ownership I was told in an email

‘Every project is assessed on it’s own merits and it also depends on the size of the project’. Read the rest of this entry »

Capturing the energy in the tides is an expensive business. The 340 MW Swansea tidal lagoon project is going to cost the best part of a billion pounds although future UK tidal lagoons will probably be much cheaper. (This project is raising first stage development funding from individual investors. See for further details).

A Dynamic Tidal dam, showing different sea levels on either side

A Dynamic Tidal dam, showing different sea levels on either side

Earlier in the week an even more ambitious scheme took another step forward. A Dutch/Chinese joint venture announced that its $40bn plan to capture the energy from tides off the coast of China had entered formal economic evaluation by the national government after several years of feasibility studies. If you thought you knew what tidal power plants looked like, think again. It isn’t a barrage across an estuary, nor a lagoon and even less like the Marine Current Turbines underwater windmill. It’s a giant embankment heading 40 km out into the sea completed at the far end by a sea wall running perpendicular to the main structure. Read the rest of this entry »


Avedore waste water treatment plant

Avedore waste water treatment plant

In December 2013 wind supplied 55% of Danish electricity. On several days, turbines provided over 130% of the total need for power. The variability and overwhelming scale of wind-generated electricity in Denmark poses problems for the grid operator, Energinet. Other countries hoping to emulate Denmark, such as the UK, will face similar concerns.

The last post on this web site moaned about the lack of fundamental research into energy production and storage. Working out how best to run an electricity system that is dominated by a single and rapidly fluctuating source of power is one obvious area where R+D is urgently needed. In Denmark, the national grid operator has just funded over half the development capital for an advanced Power2Gas project at a wastewater treatment plant in Copenhagen. The crucial advantage of Power2Gas is that it can use surplus power, available when the wind is blowing strongly, to turn electricity into natural gas. By contrast, the UK failed to find the capital for a similar proposal here.

The Copenhagen 1MW project may fail. The technology is new and although it has worked very effectively at a smaller scale, there is no guarantee that it will operate successfully in the larger configuration planned for the wastewater plant. But there is no alternative to Power2Gas as a long-run solution to the energy storage problem. The world needs to invest now in risky projects that will eventually show us how to store surplus electricity in the gas grid.




When the grid has too much power pressing to enter the transmission network, the operator has no choice but to disconnect (or ‘curtail’) some sources of electricity. The power that could have been used is wasted.


One alternative is take the otherwise worthless surplus and use it for the electrolysis of water. This splits water molecules into the constituent hydrogen and oxygen atoms. This is a simple process, carried out in chemistry labs of all the secondary schools in the world. The hydrogen has energy value. When burnt or combined with carbon it can be used as a fuel.


Some people therefore believe that we should run advanced economies on hydrogen. For example, hydrogen can be used in fuel cells for vehicles or home heating. It is perfectly feasible that a large fraction of our total energy demand could be met with H2.


The problem is that the world would have to build huge amounts of hydrogen storage and convert all engines that currently use fossil fuels into machines that use H2 instead. This is almost certainly too expensive and too disruptive to be a realistic option.


An alternative is to take the hydrogen and combine it with CO2 to make methane (CH4) and oxygen. Making methane in this way is also a simple chemical process. Methane is by far the most important ingredient in natural gas.


Since methane can be added in almost unlimited amounts to the natural gas network, it may be possible to convert long surpluses of wind or solar power into an alternative source of power. Germany, for example, has gas storage capacity equivalent to over 200 days of use. It could conceivably store all surpluses of wind or PV electricity in the form of methane, providing a zero carbon source of gas for burning in power stations when renewable energy isn’t sufficiently available.


Among other advantages this might help stabilise the wholesale price of electricity in Germany which has frequently dipped below the production cost of coal-fired power stations in the last few months. On several days power prices have gone severely negative. However much the opponents of fossil fuel may cheer this development, it has had profoundly serious effects on the capacity of electricity generators to fund new electricity generation schemes. The bankruptcy of RWE or E.ON will not solve the climate problem.


Opponents of Power2Gas usually point to the waste of useful energy that is inherent in the two processes of electrolysis and methanation (making methane). Only about 55-60% of the power of the surplus electricity is likely to end up in the form of methane energy. The correct response to this is a) to say ‘so what, it  would have been 100% wasted otherwise’ and b) the waste heat from the two processes and the oxygen derived from electrolysis both have potential value that will reduce the loss from conversion.


Why is the first commercial scale electricity-to-methane project sited at a wastewater treatment plant?


Wastewater treatment plants (sewage farms in ordinary English) take human waste and other organic material and decompose it. One output is a biogas that is part methane and part CO2. The CO2 means it cannot be added to the national gas grid. So the biogas is burnt in a gas engine to generate electricity.

However the CO2 is useful for the methanation stage of Power2Gas. The new technology to be used at Copenhagen puts the entire stream of biogas through a reactor that converts the carbon dioxide, along with the hydrogen from electrolysis, into methane. The output from the process is pure enough to put directly into the gas grid.


The company delivering the technology to the project is Electrochaea, an early stage business developed from research at the University of Chicago, that has selectively breed a type of microorganism (methanogenic archaea) to feed off hydrogen and CO2 to make methane. Electrochaea has completed a pilot plant (1kW) in the US and successfully operated a larger pre-commercial system for much of 2013 at Foulum in Denmark, backed by utilities such as E.ON. The Foulum trial took place using biogas from an anaerobic digester, rather than gas from a sewage farm.


A wastewater treatment plant makes more sense. The surplus oxygen from the electrolysis process can be injected into the waste water to increase the rate of decomposition of the organic materials. The surplus heat from the methanation process can be similarly used to speed up the creation of biogas from the sewage.


Biogas can be stored temporarily at a waste water plant meaning, for example, that the electrolysis may well only take place when electricity prices are low, or perhaps even negative. The plant will also benefit from payments for being available to act as ‘frequency reserve’ to the operator of the national electricity grid. This means it will shut down the electrolysis process when the grid AC frequency drops below a safe level and will increase the electricity it is taking when the frequency is too high


Every wastewater plant in the world will eventually have some form of Power2Gas equipment to upgrade the biogas into methane, using electricity when it is in surplus.


The Copenhagen project


At the wastewater treatment works at Avedøre in Copenhagen, the seven commercial partners will install a 1 MW Power2Gas plant, using the proprietary Electrochaea technology for methanation and electrolysis equipment from the Belgian company Hydrogenics.[1] The plant will be built in early 2015 and will run as a trial for the remainder of 2015. A fully commercial Power2Gas system should be available in 2016.


About half of the €7m cost will be borne by the state-owned Energinet, which operates the gas and electricity grids in Denmark. The rest comes from the other others, including car company Audi. Audi’s interest in this venture, which complements its existing Power2Hydrogen research, arises from its wish to find non-fossil fuel sources for its cars. Liquid methane is a potential fuel for vehicles. Other participants include an energy trader and an operator of biogas plants, both of which would benefit from the success of the Avedøre trial.


The importance of this commercial experiment


Without energy storage, the renewables revolution will fail. Denmark and Germany both know this, not least because of the increasingly obvious impact of wind and solar on the functioning of the electricity market in both countries. But it should also be apparent to other countries that the world will need huge amounts of capacity to store electricity. The companies that create the means to convert surplus power into energy that can then be used when supply is tight will become enormously valuable. They will have solved perhaps the most intractable problem of the conversion to a low carbon world.


The UK has yet to understand this. Electrochaea has made sustained attempts to create a network of partners in the UK. Despite sustained interest from Severn Trent, the water and sewage company, and National Grid, the company told me that ‘nobody  was able to provide the matching equity’ for its proposal for a trial site in central England. Its applications into competitions for grant funding run by DECC and other bodies have been rejected.


As I said in a blog post of last week, spending multiple billions every year on support for existing technologies through schemes such as feed-in tariffs must be matched by financial backing for raw, risky and unconventional technologies that might radically reduce the cost of a full move away from fossil fuels.


I’m not qualified to judge whether Electrochaea’s technology will work but I do know that backing a trial plant in the UK with a few million pounds is an overwhelmingly sensible idea. Isn’t it about time that someone had the courage to invest in companies that could change the energy world for ever?






[1] I believe the 1 MW refers to the energy value of the methane output, which will be substantially less than the electricity used to carry out the electrolysis.

« Older entries