It's going to be an expensive winter

If you are already worried about your energy bills, then look at this and weep. Forward prices for gas this coming winter are currently 30-40% higher than they were this time last year. Why? Many reasons, but perhaps in 2011-12 the market is expecting our fifth consecutive colder winter in a row?

I think we'd better make this the Chart of the Month for July 2011, a bit ahead of schedule for a change. The source for those who are interested is here, the latest Ofgem market report.

UK households produce more CO2 than the entire transport sector combined

June 2011 Chart of the Month

This one hardly requires explanation, just look at the chart. Household CO2 is now greater than the entire transport sector. Bear in mind that the transport sector includes:

• All cars, trucks, motorbikes, vans, buses, HGVs, etc
• All trains, rolling stock, etc
• All domestic civil aviation and aircraft support vehicles
• All national shipping and fishing vessels
• All military transport

To me that’s astonishing. Add up the total CO2 emissions from all these things, and you come to a lower number than if you add up the emissions from electricity, gas and heating fuel that we use every day in our homes.

A footnote to the statistics maybe, but a footnote with huge implications: residential carbon is set to become the single biggest environmental pollution problem of our time.

Open publication - Free publishing - More carbon census

We could have saved sixpence ...

"Mr Rooney, we could have saved sixpence. We have saved fivepence. But at what cost?" - All that Fall, 1957

Chart not displaying? Try clicking on the space below, or  here.

Open publication - Free publishing - More carbon census

This month the government published our latest national CO2 statistics. They are quite interesting to look at, you can read the full press release here or just have a quick look at the chart above.

The headline is that CO2 is going in the right direction and everyone is rather pleased. In total we seem to have cut our national carbon footprint by 28%. That's the kind of good news we like to hear, if things are indeed what they seem.

But of course, things are not what they seem. The first big sleight of hand is to have excluded from the data the only 2 major sectors where carbon emissions are growing massively: shipping (up 17% since 1990) and aviation (up 109%). When these are included, the total UK saving falls to 25%.

But 25% is still good right? Well, it sounds good, but what's strange is that a big chunk of this saving (about a third of it, actually, or about 8% points) has been delivered in the last two years. And because the reporting is all a year in arrears, that means between 2007 and 2009. Hmmm. Can anyone think of anything that might have happened from 2007 to 2009 that would have reduced our carbon footprint by about 8%?

So what are we left with? When you include the boats and planes that refuel in the UK and allow for the recession we've just been having, well then you're left with about a 17% saving over 19 years, or about 0.9% per annum. Somehow that doesn't seem so exciting to me.



Here is the data table as published under, I believe, Kyoto reporting agreements. You'll notice it doesn't include shipping and aviation, we had to dig those out of a footnote to come up with the chart above.

Something strange is happening to our weather

Can't see the chart? Try clicking on the space where it should be, or clicking here.

Open publication - Free publishing - More carbon census

Did you know, the Met Office now posts UK weather station data online? It’s pretty easy to rummage around in the numbers, so we've been having a go. Take a look at this, our Carbon Census Chart of the Month for March 2011.

This chart (which is from the Heathrow weather station, but typical of weather stations around the UK) shows three rather strange things, as follows:

First strange thing: our winters have been getting colder. The coldest temp has got colder for 4 years in a row. That's only happened once before at Heathrow since records began. 

Second strange thing : our summers have been getting hotter. The hottest temp has got hotter for 3 years in a row, and that's also only happened once before in this dataset

But the third really, really strange thing is that the first two strange things are happening at the same time, which appears to be a genuinely unprecedented event for these isles.

In the past, when there has been any kind of run of warming or cooling in the weather, it has either got warmer for a few years, or got colder for a few years. There is no previous example of the hottest month getting hotter and the coldest month getting colder, for three and four years in a row, in either the Heathrow data since 1948 (plotted above) or in the data from older weather stations such as Oxford which go all the way back to the 1850s. (Take a minute to look at the analysis we've done of the Oxford dataset, if you like this kind of thing you'll get the idea straight away.)

So the next question is, could this be a coincidence? Well perhaps it could, but to answer that question we would need to have a Theory of the Weather. We would need to say something like this: here is how we expect the weather to behave, here is what it's been up to recently, and here is the chance of that happening for no particular reason, i.e. just by fluke. In statistical terms, in other words, we need a null hypothesis.

Of course, we're not meteorologists over here, so we haven't got a Theory of the Weather, so we haven't got a proper null hypothesis. But heck, let's just make one up and see what happens. Let's assume that there are no long term changes in the weather going on, and so the annual high and lo temperatures just bounce around a bit from year to year, with a normal distribution and standard deviation around some long term average value. We know that's not true, exactly, but it's not far off... and here's the interesting observation: if this cartoon model of the weather were true, then the chance of drawing the chart above by fluke would be less than 1 in 100,000.

So on that basis, I'd like to make a wager. I'll wager that this pattern is not a fluke at all, that it's an extremely unusual anomaly in historical terms, and that within 12 months of today someone will publish a peer reviewed article showing that this is the case. And just a hunch, of course, but I also think we'll hear a lot of news this year that climate change is accelerating and the impacts are worse than we thought. Increasing volatility (widening extremes, rather than rising averages) will be the climate change story of 2011.



For those who are interested, the Met Office weather station data can be downloaded here, and the Oxford analysis going back to 1852 is here. Many thanks to Lora Brill who helped me with a previous draft of this article.

Energy Flow Chart 2009

I've been meaning to post this for a while. If you've been enjoying the blog so far, then you should enjoy this (which comes from here and uses these as units) without further explanation. Click on the image for a full size view. 

It's not a tube map.

October 2010: Chart of the Month

(Looking for the September Chart of the Month? Click here )

At this time of year, everyone is turning the heat on.

I've already written about how we're also turning the heat up. I used some research data from BRE to show that we've been cranking up the thermostat for about 30 years now, and as a result the average temperature inside a British home has gone up from about 13°C in 1970 to about 20°C today. As a result, I said that Britain had gone soft.

But that's only half the story. The truth is, Britain has gone very soft. The part I was missing out is what has happened to the temperature outdoors over the same period.

So guess what? It turns out that, using a more or less accepted method for measuring these things, it is a lot warmer these days than it was 40 years ago - warmer, that is, in the sense of how many days a year you'd need to turn the heating on.

Have a look at the chart below and you'll get the picture. There are about 10-15% fewer heating days per year than when our parents were our age.

Conclusion? We need less heat, but we are using more. If you can figure that one out, please post a comment below.

(Click on the image to enlarge the view.)

The raw data is from the Met Office, although access is only after an authorisation process. And here is a bit more on the methodology for Heating Degree Days. In the chart, I have taken a simple average across all UK weather stations and shown the hi/lo bands in the shaded area.

September 2010: Chart of the Month

For reasons that don't bear explaining I have found myself looking into the latest government data on light bulbs. It was quite an illuminating exercise. For instance, I learned that we have cut our energy usage for lighting by 4% in the last 20 years, although on average the light bulbs we use are 43% more efficient. Hmmm, something up with that. The explanation must be that there are more of us, and we have more bulbs each. I chewed through the data and sure enough, the picture is as follows:

(Click on the image for a full size view)

To me, the column of interest in this chart is the third. It shows that we're each using more light bulbs, which is weird. But sure enough, that's exactly what we're doing. Think of a classic kitchen refurb: you take out a 100 watt centrally suspended bulb and replace it with 8 or 10 halogen spotlights, at 35 or 50 watts each. So the total energy requirement triples, at least. Sometimes it quintuples. There are now 170 million halogen lights in UK homes, more than the total number of energy saving light bulbs in the whole country.


Some people hope to solve this problem with LED lights, but I am not convinced. A 4 watt LED from Philips costs £22, compared to 99p for a 50W halogen spotlight . The LED lasts 20 times as long, and at 10p / KWh I estimate the cost of ownership is 6 times less per hour the bulb is used. But since the halogen spot only costs 0.5p per hour, and produces nearly 10 times more lumens  than the LED version, I'm not surprised if most people just can't be bothered with the calculation.


As usual, the source data is here for anyone who wants to check the maths. But more interesting than the raw data is the moral of the story: to make the kind of reductions in energy usage that we are currently targeting, we need the third column of this chart to start working for us, not against us. In this example, we need to stop ripping out low energy solutions and replacing them with high energy solutions. It just doesn't make sense. Perhaps we should introduce a tax (or a pox!) on halogen spots.

Tax breaks for fossil fuels worth $9.1 billion

You couldn't make it up! A report from the OECD shows we're spending $9.1 billion on tax subsidies for fossil fuels. That's about $7.50 / year for each of us, just in the few selected industries that the report has looked at.

They're still working on figuring out the total, which is likely to be much larger. See the helpful comment below from Ron Steenblik, one of the authors.

Similarly, The Global Subsidies Initiative (an interesting institution in itself ...) suggests that fossil fuel subsidies outside the OECD are worth around $400 million, or getting on for $15 per person every year. As shown in the table, that's nearly 10 times the total subsidy available for renewables.

Finally, the OECD team has also estimated that removing subsidies to fossil fuels across all developing and emerging economies (I think this is the region where they have the best data) could cut global greenhouse gas emissions by 10%. And as we've seen before on this blog there are not many policies with that kind of potential.

Click here for the report this table comes from.

It's official - we've gone soft

June 2010 Chart of the Month


For over 30 years now, our partners at BRE have been collecting data on average indoor temperatures in the UK. What they've found is that over time we're heating our homes to higher and higher temperatures, from about 13° C in 1970 to over 20° C in recent years. And all this during a period where the weather, if anything, has been slightly warmer than it used to be.


Of course, one thing that has changed since 1970 is that a lot more people have central heating. So what I like about this chart is that it separates out this effect: all else equal, the chart shows that the spread of central heating would have increased indoor temperatures only to about 15° C by 1970 standards. The rest of the increase (by rough calculation about 70% of it) is just behaviour. We've gone soft!

The Energy Saving Trust says that turning down the thermostat down by 1° C cuts your heating bill by 10% on average. So what we're really seeing here is the long run trend of rising incomes and falling relative costs of energy. Which if you're worried about these things, would get you thinking again about pricing.


The data source is here for those that are interested. 

First fall in energy use since 1982

The source is BP's Statistical Review of World Energy. You can read an interesting if cynical critique of this report by Jeremy Leggett in the Financial Times, arguing that the statistics are a cover up and that an 'energy crunch' is upon us.

Relatedly, BP do publish some data about Jeremy's area, solar PV. Solar PV grew nearly 50% in 2009, which is surely good news. But total capacity is still only enough to meet about one twentieth of 1% of global demand for electricity. So Jeremy's article just offers a reminder of how little protection we really have against the energy-crunch scenario.

Vive la France!

Congratulations to France, which has de loin the lowest per capita CO2 emissions in the G8. Good news for those who think the future is nuclear. Of course some of us think that the future will not be nuclear. If anyone has a G8 league table of hazardous waste per capita please post the link.

PS I am guessing France benefits from a bit of warm weather too, from a quick look at the Canada column. The dataset comes from here if you are after the source.

We're saving £5 of energy a year - that's all

In March we posted that UK residential CO2 emissions were 500 years off target. Apologies. It turns out that we are in fact only 369 years off target - as shown below. The trend rate of improvement since the year 2000 is 0.4% per annum. In other words, since there are 27 million households in the UK, we're cutting our actual CO2 emissions by about 25 kg per household per year. 

Another way of looking at this: the total impact of all UK energy saving policies is about £5 of energy saved per household, per annum. Now, that's not a figure you'll hear quoted very often in the House of Commons.

Introducing the Carbon Census Rule of Thumb

How much power do you use when you're not using any power? Surprisingly, not zero. Take my house for example: it's a quiet Saturday afternoon, the family has gone out and everything is turned off, but our power monitor is reading 170 watts. How so? After 5 minutes poking around I found the culprits: microwave, radio, TV, DVD and a list of other things.

These devices draw a tiny amount of power, but they draw it all the time. That's the problem. So I spent another 5 minutes figuring out how much this 'background demand' is costing me. According to a really rather elegant coincidence, it turns out that 170 watts of background demand will cost about £170 a year. That's about 1 tonne of CO2 or 30% of the average UK electricity bill, just for stuff I'm not even using.

Let's call this the Carbon Census Rule Of Thumb: 1 watt of background power costs £1 a year.

(Interested in why this works? There are about 10,000 hours in a year, and a kilowatt hour of electricity costs about 10p. Well, just under 10,000 hours actually and just over 10p, but the rounding cancels out making the answer nice and easy.)

10% of households use 1/3 of our electricity

Last week we posted our Financial Times article on reverse pricing. We said this policy could double the marginal cost of energy without making households worse off overall. There would be winners and losers, and people asked us how many: the answer is about 2/3 of households would benefit, and about 1/3 would pay higher bills.

But here's what's really interesting: to get to this answer we had to crunch the data on 26 million domestic electricity meter points, producing the chart below as a by product. Wow. The top 10% of households use nearly 1/3 of all domestic electricity in the UK. The top 20% use 44%. For whatever reason, there are about 5 million households who consume up to 6 times the national average every year. So we really do need policies - like reverse pricing - that make energy saving more attractive for high volume users.


You can see the source data in DECC's Energy Trends, March 2009 (p24 and after).

Household CO2 is 500 years off target

The latest CO2 statistics were published today. Not good news. Residential emissions grew by 3 million tonnes in 2008, despite the economy being in recession for most of the year. This is why we say that current policies are not working in this sector: the average reduction in household CO2 emissions since 2002, when the flagship EEC/CERT program began, is now 0.3% per year, meaning it would take 500 years to achieve an 80% reduction. That's supposed to be our target for 2050, by the way.

You can download the data for yourself on the DECC website. The picture looks better for 2009, but DECC attribute the improvement to warmer weather in 2009 and the full dataset won't be published for another year or so.

What is a tonne of CO2?

About as much as

• 100 trees can absorb in a year 
• Driving across America in a car 
• A 10,000km long haul flight, per passenger
• £175 of gas and electricity at current UK prices

The Carbon Trust publish some useful conversion ratios for this kind of thing. We use a figure of about 10kg per tree which is widely quoted on the internet; the United Nations Environment Programme puts it at about 12kg a year, but 10 kg / tree (or 100 trees per tonne) is a pretty good rule of thumb.