This site uses cookies. By continuing to use this site you agree to our use of cookies. To find out more, see our Privacy and Cookies policy.
Skip to the content

[IOP] A community website from IOP Publishing

Tag Archives: efficiency

ETI on energy saving in buildings

By Dave Elliott

The UK Energy Technologies Institute’s report by Jeff Douglas on Decarbonising Heat for UK Homes notes that ~20% of CO2 emissions are from domestic heating, but says insulation/upgrades won’t cut that enough: ‘the scope for cost effectively reducing the energy demand of existing buildings to the great extent required to meet emissions targets is limited as comprehensive insulation and improvement measures are expensive and intrusive. A several hundred billion pound investment in demand reduction for the entire building stock might deliver less than half of the emissions abatement needed. The most cost effective solutions therefore involve the decarbonisation of the energy supply combined with efficiency improvements that are selectively rather than universally applied, as part of a composite package’.


Posted in Renew your energy | Tagged , , , , , , , , , , | Leave a comment | Permalink
View all posts by this author  | View this author's profile

Green heat: not all going to plan

By Dave Elliott

A new report ‘Policy for Heat: Transforming the System’, from Carbon Connect, follows a cross-party inquiry chaired by Shadow Energy Minister, Jonathan Reynolds MP, and Conservative MP Rebecca Pow. It argues for the better development and greater integration of policy on low carbon heat, energy efficiency and new-build homes. It notes some big problems with current programmes, not helped by the scrapping of the Green Deal and the Zero Carbon Homes policy. (more…)

Posted in Renew your energy | Tagged , , , , | 1 Comment | Permalink
View all posts by this author  | View this author's profile

Saving energy or saving carbon?

By Dave Elliott

The June 2015 Energy and Climate Change report by the International Energy Agency (IEA) has an ambitious ‘Bridge Scenario’ in which the adoption of efficiency measures reduces energy-related global greenhouse gas emissions by 49% by 2030: Does saving energy save carbon, as is usually argued? (more…)

Posted in Renew your energy | Tagged , , , | Leave a comment | Permalink
View all posts by this author  | View this author's profile

Filling the GAP

By Dave Elliott

A group of UK notables, including Sir David King, Lord John Browne, Lord Nicholas Stern and Lord Martin Ryle, has launched a proposal for a 10 year Global Apollo Programme of science-led research and development (R&D) to develop clean energy technology fast to combat climate change. One of the other proposers, former Cabinet Secretary Lord O’Donnell, told BBC News: ‘People never believed we could put a man on the Moon – but we did. People don’t believe we can solve climate change – but we have no choice.’ (more…)

Posted in Renew your energy | Tagged , , , | Leave a comment | Permalink
View all posts by this author  | View this author's profile

Sustainable heating and cooling for buildings

by Dave Elliott

 ‘40% of Europe’s energy use and a third of the greenhouse gas emissions can be attributed to buildings and much of this relates to heating and cooling. For example in the UK, 38% of all CO2 emissions are related to space heating. These emissions can be avoided or significantly reduced through a combination of holistic design, integrated renewable energy and high efficiency.’  So says a report on Sustainable Heating and Cooling of Buildings from Leonardo Energy, the European Copper Institute’s think tank, offering a good analysis of the options for reducing buildings’ energy consumption  and carbon emissions. (more…)

Posted in Renew your energy | Tagged , , , , , , | Leave a comment | Permalink
View all posts by this author  | View this author's profile

Commentary: Public perceptions of energy consumption and savings

An interesting paper has recently been published in the Proceedings of the National Academy of Sciences entitled “Public perceptions of energy consumption and savings” (see by Attari et al. This paper provides insights into how people view the quantity of energy consumed for various tasks that are normal in an industrial society. The paper authors conclude that people generally overestimate the energy savings for changing habits related to saving low quantities of energy while underestimating energy savings associated with saving larger quantities of energy.

This research shows some of the difficulties in using surveys to assess perceptions and reality of how energy impacts our lives. Take for example the following in which the respondent is asked to select how strongly he/she agrees or disagrees with the statement:

“We are approaching the limit of the number of people the earth can support.”

Today, human population is approximately 6.7 billion. If you believe that the earth can only support 2 billion people, then you could strongly disagree with the statement on the grounds that we are not approaching that limit, but that we have far surpassed the limit. However, if you believe the earth can support 12 billion people, then you might also strongly disagree with the statement because you think we are far from the earth’s limits (i.e. we are not yet “approaching the limit”). So two completely different answers might prompt selecting the same response to the statement.

The results for the questions pertaining to values and behavioral questions (e.g. how hard do you think it is to change your energy consuming habits) are not presented in the PNAS paper by Attari, but these are important questions to ask. Many people believe that the vast majority of people will not willfully conserve energy without financial penalties (e.g. high prices or taxes) for consumption. I fall into that category myself. We find ourselves in an interesting time as for only the second time in the last 40 years we (in the US) have reached a point where over 10% of GDP was spent directly on primary and secondary energy.

The first time period was from the mid 1970s-mid 1980s and likely in 2008 as well (see figure). The first time over 10% of GDP was spent on energy was driven by political events – particularly the Arab Oil Embargos and the Iran-Iraq War. This most recent worldwide economic recession starting in 2008 was not driven by a particular political event, but has been a growing trend for almost a decade (at least with particular reference to the US).

The US broke out of the recessions cause by the oil shortages of the 1970s by investing in energy efficiency for vehicles (Corporate Average Fuel Economy, or CAFE, standards), only to find itself equally or more dependent upon oil for economic growth today as in 1970. Important questions are: Will the US meet its new CAFE goals (reaching 35.5 miles per gallon for vehicles sales; 39 mpg for cars and 30 mpg for trucks and sport-utility vehicles) by 2016? This targeted increase is approximately the same percentage increase in fuel efficiency as occurred from the 1970s to the late 1980s in meeting the original CAFE standards. If the US (and the world) is successful in reducing oil consumption per mile traveled by 2016 (or soon thereafter), will we only find ourselves in the same position 10-30 years down the road? In other words, will we just wait until we consume too much gasoline for it to take too much out of our wallets to again think about restructuring the way our economy functions and consumes energy?

There are reasons to think this time is different. This time we are well past peak oil production for the US. Perhaps we have reached peak crude oil production in the US and so far the statistics seem to point to that possibly being true (but it will take several more years to confirm the full truth). In reading the August 15, 2010 issue of Science which talks about scaling up of renewable energy, there are two articles about biofuels. One article in particular (“Challenges in Scaling up Biofuels Infrastructure” by Tom Richard) notes the logistical issues with making fuels out of biomass. Richard discusses much about how we are supposed to create a viable supply chain for the relatively low-density biomass materials to go from the farm to the biorefinery and finally to the consumer. The reason that this is such a hard problem is that the net energy of the biomass fuel is so low that it is not obvious that we can run our current economy as designed if using these fuels to any large degree. That is also a major difference now from the 1970s – we’re actually really trying to grow an economy using biofuels instead of just making cars run on less fuel and importing more oil.

Posted in Energy the nexus of everything | Tagged , , , | Leave a comment | Permalink
View all posts by this author  | View this author's profile

Energy efficiency, conservation and “sacrifice” revisited

A recent article (“Leaping the Efficiency Gap”) in the August 14, 2009 edition of Science discussed the now classic argument of how far energy efficiency takes you to conserving energy.  The general answer is so far, not much.  The article discusses Arthur Rosenfeld starting an energy efficiency program at Lawrence Berkeley National Laboratory in the mid-1970s, and how he and many were convinced that reductions in energy consumption could be achieved by advances in technology.  The article also notes how Lee Schipper of Stanford’s Precourt Energy Efficiency Center took offense to President Jimmy Carter’s 1977 ‘cardigan’ speech in saying that in order to save energy sacrifice was needed and some sacrifices would be painful.  Schipper wrote a letter to a congressman arguing that conservation did not have to be painful. Schipper is then quoted as saying he was wrong and Carter was right.

After 35 years of the efficiency v conservation debate, I think there is much more understanding that energy in the US is still cheap and has not generally dicatated decision making by businesses and citizens.  Perhaps the last few years represent a turning point in that the CO2/climate argument has put a differnet spin on the question.  But when we think of the word sacrifice, particularly in the US, are we really sacrificing to reduce our annual per capita energy consumption from the range of 350–370 GJ/person (330–350 million BTUs/person)? The world average is 75–80 GJ/person, and approximately 23% of the world’s population live in countries consuming up to 100 GJ/person/year.

Since the 1970s the accumulation of statistics on energy and human development have allowed us to see that most human basic needs in terms of food access, health, and longevity are achieved at approximatley the 100 GJ per capita level. There are of course a few exceptions to any rule, but the tendency of diminishing returns on most of the important quality of life measurements when consuming over 100 GJ/person is extremely enlightening and provides great perspective.

As a possible extreme example, I recently purchased a house that had a three-star green building rating (by the local utility) yet has 17 recessed lighting sockets in the main room of approximately 800 square feet. Two light switches control 7 light bulbs each, so there was clearly a need to install low power-consuming light bulbs (or remove some of the light bulbs) so that 400–500 W of power are not consumed just to light half of a room.  When materials and energy got cheaper from efficiency gains and technological advancement, many times people just bought or installed more gadgets.

On the other hand, the per capita energy consumption of the US has remained relatively flat for the last 35 years due to many infrastructural and behavioral changes, even though total energy consumption has gone up due population increase. This same pattern holds for the electricity consumption of the state of California – a point that the Science article makes as the total electricity consumption rose similarly to the rest of the country.

It seems that most of solid energy conservation gains in the US stemmed from actual mandates and legislation, not business operations. After all, we measure economic growth based upon the flow of goods and services, not the amount of resources that we have in stock. Businesses are naturally incentivised to increase efficiency of operations, including using less energy per product, so subsidizing them to do what economics should drive them toward is perhaps a bit ridiculous. Subsidizing them to actually consume less energy, measured as total energy, not energy/product, can make more sense.

Many famous entrepreneurs and politicians have stated their visions in the past, and we have acheived them. President Kennedy targeting putting a man on the moon. Bill Gates (Microsoft founder) targeting a personal computer in every home. But none of these targets have anything to do with using less, they are always for using more. 

I think what we need is confidence that we can actually remove something from our homes and lives (here I’m thinking of the US), because we know that decreasing our energy consumption by 100 GJ/person/yr probably won’t affect anthing fundamental in that Americans will then conserve energy at a rate that is still more than Western Europe. Granted, some things would certainly be hard to give up – I’m sitting in Texas right now where high temperatures of at least 38°C can occur for 3 months of the year, but other regions of the world experience this as well. But do we seriously think that there isn’t the ability to 25% of our per capita energy consumption? Most of the reduction would likely come in the combination of reduced travel and smaller/lighter vehicles. Telecommuting and teleconferencing exist also. Exposing people to the correct prices of energy and food will also help.

So I propose this new challenge of removal, not addition: remove 100 GJ/person from the average American footprint.

The level of ‘sacrifice’ is to be determined.

Posted in Energy the nexus of everything | Tagged , , | 2 Comments | Permalink
View all posts by this author  | View this author's profile