Friday, 23 October 2020

How much water do we use washing our hair?

A friend told me yesterday her lodger spends 20 minutes in the shower each day - but she has long hair. (We were discussing the pros and cons of solar hot water panels). Since I have short hair I am very quick in the shower which I like because it means I have more time for other things. In addition, less time in the shower means less use of water and energy to heat it. Both water and energy are valuable and water can be scarce at times. If you already have efficient toilets it is quite likely that your biggest water consumption is the shower. Try my water calculator to check. So how much water and energy do we use washing our hair? How does this compare to our overall consumption?

Please fill in my survey
It is difficult to find good data on hygiene habits so I have compiled a short anonymous survey. If you wash your hair in the shower please fill this in. In the meantime, here are some estimates and suggestions for how we can be more efficient with washing our hair.

Saturday, 19 September 2020

The Cambridge Climate Change Charter: why the urgency?

Earlier this month Cambridge launched its Cambridge Climate Change Charter, to encourage residents and businesses in the city to reduce greenhouse gas emissions. Alongside this there is a carbon footprint calculator, and a broad menu of suggestions actions you can take with advice and guidance, provided by Cambridge Carbon Footprint. Please do sign the charter and make pledges. This is a follow up to the council declaring a climate emergency last year. It seems this is a good time to remind ourselves of why this is an emergency and how long have we got.

I'd like to show you a graph. This is from the carbon budget report for Cambridge from the Tyndall Centre for Climate Change Research. They have determined science based budgets for cities around the UK based on the commitments made in the UN Paris Agreement. There is a short video about the project here. The graph shows historical emissions up to 2019 and the decreasing budget to 2070.

Carbon budget for Cambridge from the Tyndall Carbon Budget report. In the report the image is interactive so do follow the link. Historic emissions from 2015-2019 dropped around 4% per year, mainly due to cleaner electricity at national level. The budget requires reductions of 12% per year to 2050. That is about an 80% drop by 2030


Sunday, 13 September 2020

The Climate Assembly - values and attitudes

The final report from the Climate Assembly was published this week. 108 members listened to 60 expert speakers over six weekends, deciding how we in the UK can reduce our greenhouse gas emissions to zero by 2050. This is a huge challenge. It will affect our economy, our transport and energy infrastructure, our diets and our homes and involves co-operation between government, business and individuals. There have been many reports on the findings from different angles. I am particularly interested in how the assembly has allocated responsibility and the values and attitudes their decisions reveal. My themes include fairness, personal responsibility, trust and the role of technology.

Extinction Rebellion included having a citizens assembly as their third demand in combating climate change. However they did not approve of this one because the findings are not binding and the target date for zero carbon was not in the scope of the discussion. However, the assembly we had is still a huge step forward in democracy. The members were carefully chosen to be representative by age, ethnicity, education level, region and level of concern about climate change. They were required to listen to the evidence, question the witnesses, discuss amongst themselves and vote on decisions, very much like jury service. By all accounts they took this responsibility very seriously. 

I think we can safely assume that the views of the members are close to the views that we (as in the UK population in general) would think given information and time to think about the issues. However my references to 'we' do not always include 'I'. Text in blue is my commentary, not from the report.

Friday, 28 August 2020

Food and climate change without the hot air by S L Bridle – review


Published by UIT Cambridge Ltd. Available free in electronic form or currently £15.99 from Blackwells

I really like this book. It works on many different levels in different ways, for different sorts of people. I recommend it to all my family and friends, not just the geeky ones.

Saturday, 22 August 2020

Is the gas industry promoting uncertainty as a delaying tactic?

We have to decarbonise our heating systems, but there are competing options as to how this is best done: electric heat or green gas. Whatever happens this is going to be very disruptive for industry sectors including oil and gas supply and appliance manufacturers - some very large corporations face an existential threat. So it is hardly surprising that the gas industry is lobbying our government intensively, arguing that green gas is a practical, inexpensive alternative to electric heat. It is not clear that they have successfully driven policy decisions in their favour, but it is possible that they have achieved delays to measures that are needed urgently. Or are ministers simply putting off decisions that they believe will be unpopular? As one consultant said (of decarbonising heat policy): Anything that puts people’s bills up is a big issue. And anything involving intervening in people’s homes is a big issue. You’ve got them all. It’d be an absolute car crash. [1]

This blog post is inspired by two journal papers by UK academics Richard Lowes and Bridget Woodman from the University of Exeter, and Jamie Speirs from ICL. You can find them here:

[1] Disruptive and uncertain: Policy makers’ perceptions on UK heat decarbonisation (Energy Policy) 2020

[2] Heating in Great Britain: An incumbent discourse coalition resists an electrifying future (Environmental Innovation and Societal Transitions) 2020

As academic papers go, these are very readable. I particularly like the extensive quotes in the first one, one of which you have read in my first paragraph. Both are based around interviews with people who have influence over policy - from Ministers and civil servants to industry reps, 3rd party consultant and NGOs.

Thursday, 9 July 2020

Lessons learnt from the Green Deal Home Improvement Fund

The latest announcement of the Green Homes Grant scheme, with vouchers of up to £5000 for homeowners to spend on energy efficiency measures [1], is strongly reminiscent of the Green Deal Home Improvement Fund (GDHIF). Back in 2014 the GDHIF offered vouchers up to £7,600 per home for measures from a menu of insulation and heating improvements. It was massively popular and sold out in 7 weeks [2]. Unfortunately there was little lasting impact for the industry as insulation rates quickly dropped back to their former levels - as you can see in this chart.

Based on National Energy Efficiency Statistics from [3]

There were many other shortcomings too including:
  • Short timescales to spend the voucher did not allow for inclement weather - it is impossible to do a good job with external wall insulation in a rainy January.
  • Only Green Deal certified installers could take part, and qualification cost time and money, which shut out many small builders who could not afford the investment.
  • The certification scheme was not adequate to protect consumers from rogue traders. In particular, any companies that failed an audit could resurface with another name and get new certification from a different body [4].
Since that time there has been growing acknowledgement of the need for a whole house approach to retrofit, rather than a measure-delivery based scheme. The Each Home Counts report got the ball rolling and now we have started to certify Retrofit Co-ordinators, whose role is to oversee a plan for each case. The goal is to avert unintended consequences from inappropriate measures or combinations of measures. These measures are part of the recently approved PAS 2035 standard and trust mark. At the moment it is voluntary except for government projects - maybe this is a good time to roll it out.

Here are some more suggestions from me:

Sunday, 28 June 2020

Will an electric heat pump increase your energy bills?

For a long time I have bemoaned the fact that while electricity has been getting cleaner and cleaner, it is not getting cheaper. Ten years ago I used to say that gas was a third the price of electricity and a third the emissions. More recently I have been saying that electricity is less than twice the emissions but four times the price. With an electric heat pump you should be able to get an efficiency of 250% or so, but this is not enough to level out the difference. Times have changed.

These days, if you are flexible in when you consume energy, which should be quite possible with a heat pump, you can get electricity at close to twice the cost of gas, so your heat pump really should work out cheaper. I anticipate your next questions are (a) where can I get this cheap electricity and (b) how does having a heat pump mean I can be flexible.