Electricity is expensive to store in large quantities. The largest battery pack in North America has just opened this week at a cost of about $50m for 32 MWh of lithium-ion cells. That’s over $1,500 a kilowatt hour, several times the cost of batteries in electric cars. (I presume the reason for the high cost must be the sophisticated electronics necessary to tie the DC battery system to the local grid).

The new plant is sited at one of the substations serving the huge Tehachapi wind farms in Southern California. 600,000 individual batteries wired together in a 500 square metre warehouse are helping to stabilise the output of the five thousand turbines in this important wind province.

Tehachapi Battery Storage

Tehachapi Battery Storage

The UK’s largest storage battery is being built in Leighton Buzzard, north of London, and is due for completion by the end of 2014. This 10 MWh plant is costing about £20m, partly paid by Ofgem and partly by the local operator UK Power Networks. The cost is over twice the price per kilowatt hour of the Californian battery.

Adding the gigawatts/gigawatt hours of short term storage that we need is going to cost huge sums. Batteries will get cheaper, of course, particularly if Tesla continues to invest in enormous factories in the US. But even at $250 per kilowatt hour of storage capacity – one estimate of the likely cost of Tesla batteries within a few years – a gigawatt hour will require expenditure of $250m. That buys the capacity to store about a minutes worth of UK peak electricity need.

One alternative to lithium-ion batteries is an expansion of pumped hydro. Two water reservoirs at different heights are linked and reversible turbines are installed. When electricity is cheap, water is pumped uphill to the top reservoir. At times of high power demand the water flows back downhill, turning the turbines and producing electricity. The UK has had a large pumped hydro plant at Dinorwig in Snowdonia for thirty years.

A new company, Quarry Battery, has just raised another round of seed money to push its own Snowdonia project forward. £3m will enable the company to carry out engineering costings and other preparatory tasks for its scheme to turn two disused deep slate quarries into the upper and lower reservoirs of a pumped hydro plant. Read the rest of this entry »

At 5.30 in the late afternoon the average UK house is using about 130 watts of electricity to power lights. In the winter months this number rises sharply, probably to around 200 watts. 27 million households are consuming over 5 gigawatts of electricity just for lighting in the early evening of the darkest month.

The maximum need for electricity last year occurred just after 5pm on November 4th when the major generators delivered almost 53 gigawatts. At the moment of highest electricity need, domestic lighting was therefore using about 10% of the country’s power production. The easiest way of cutting this is by banning halogen bulb sales and obliging consumers to replace them with equivalent LEDs.

An LED bulb that could replace a standard halogen ceiling light

An LED bulb that could replace a standard halogen ceiling light

As conventional power stations close, the gap between the total generating capacity in the UK and peak winter demand is narrowing sharply. A ban on halogen lamps will dramatically improve the UK chances of ‘keeping the lights on’ in winter by shaving the top of the daily winter peak of power demand.

Halogens are not quite as inefficient as the old fashioned incandescent bulb but they use far more electricity than LED equivalents. A 35 watt bulb can be replaced by 5 watt LED of almost identical light quality. Many kitchens and living areas contain several hundred watts of halogen bulbs and all this lighting could be replaced by equally effective LEDs.

Cutting domestic lighting demand is the simplest way of reducing the maximum need for electricity. And it would reduce consumer bills and make a substantial dent in the need for electricity users to pay (indirectly via the so-called ‘capacity mechanism’) for fossil fuel power plants to stand waiting just in case the other generators couldn’t supply enough power. In addition, the reduction of peak demand would cut the need for extremely expensive grid upgrades. There is real social value in moving the country off halogen bulbs as fast as possible. Read the rest of this entry »

Schematic of the Joule plant in Hobbs, New Mexico

Schematic of the Joule plant in Hobbs, New Mexico

Scarred by the failure of first generation biofuels and by the increasingly bitter controversy over the burning of imported biomass at Drax and elsewhere, the UK has backed away from research into using biological materials for energy conversion or storage. This behaviour is mirrored across Europe. Outside the US, research into using natural materials has almost ceased as concerns over the diversion of land from food production and low carbon savings have overwhelmed the case for increased renewable energy.

This is a mistake, and possibly a tragic one. In sunny parts of the globe, solar PV may provide the cheapest source of electricity. But PV doesn’t provide either reliable 24 hour power or a source of liquid fuel for transport. Since electricity is typically provides less than 40% of total energy demand, the world needs to find inexpensive low carbon sources to meet other needs. Biological sources of energy are vital, not least because they can both store power (thus complementing intermittent sources such as PV) and can be converted to high density liquid fuels suitable for transport. A piece of wood is a semi-permanent store of solar energy and can be converted – albeit expensively at present – to a liquid hydrocarbon. Algae are similar. But work on even relatively simple technical problems such as improving the slowness of the breakdown of cellulose molecules in anaerobic digesters simply isn’t taking place in the UK.

By contrast, this note looks at Joule Unlimited, a seven year old US company that is making ethanol and other fuels from CO2, sunshine and water. Like many other US bioenergy companies, Joule has raised what to European eyes look like prodigious amounts of capital. But the $160m of investors’ money has bought what seems like exciting intellectual property. If Joule can do as it promises and produce transport fuels for less than $50 a barrel of oil equivalent, it can undermine the conventional supply of oil, a market currently worth about $8bn a day.  Read the rest of this entry »

A wind entrepreneur wrote to me last week pointing to the increased variability of wind speeds over the UK. Until recently, he wrote, average monthly wind speeds only very infrequently departed more than 30% from the norm from the month. In the last year, however, he said that we’ve had two months of very high speeds (more than 30% greater than the monthly average) and one very low speed period (30% less than the average for the month). This matters; greater variability of output from wind turbines means more need for backup resources.

Does the data match the entrepreneur’s instinct that variability is increasing? A quick look at average wind speeds since the beginning of 2001 argues it does. The average month now varies about 13% from the norm, up from 9.5% in 2001. This isn’t a large amount, and the data doesn’t suggest a very clear trend, but if variability is increasing it will add to future problems balancing UK electricity supply. And higher winter wind speeds will cause more destruction, as they did over many parts of the UK in February of this year.

Read the rest of this entry »

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 »

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