Sustainable views

Green Buildings in Emerging Markets: Where are they likely to succeed?

2011-10-18T07:27:00.000-07:00

In parts of the world with high energy tariffs, like the Caribbean, West Africa, and the Philippines, Green Buildings are a no-brainer because they pay their own way. Similarly, in countries where carbon emissions from electricity generation is high – South Africa, Turkey, Indonesia, India, China, and states in the Middle East and North Africa region – it’s easy to track fast results. Overall, countries with the highest energy costs are likely to have the biggest demand for energy efficiency in buildings.

Note: Why “electricity”?: The largest amount of energy used by buildings is in the form of electricity. Typically 20-40% of the electricity generated in a country is used by the buildings sector. The graph currently does not adequately reflect fossil fuel used for heating.

CHP based district heating: a discussion

2010-07-22T09:20:00.000-07:00

Photo by Julian Elsworth

Max Fordham Consulting Engineers have presented a case in their report- ‘A case against the widespread use of district heating and CHP in the UK’, Issue 2 / May 2010. The report provides analysis to demonstrate that CHP/district heating is not an effective low carbon solution for the UK. The report has been written in order to ascertain the best use of UK's resources and to be fair seems to be open to debate. Such transparent research and evaluation from one of UK’s leading engineering firms is not only greatly beneficial but also highly commendable in terms of the effort that has gone into it.

After many years of being in this field, I am keen to express my view on the assumptions that have been made in the report and also the broader hypothesis.

1. In the section about the carbon intensity of the grid, it is suggested that CHP/district heating should essentially be compared to CCGT rather than average fuel mix. Not sure if it is really logical when in reality 33% of UK electricity supply still uses coal [0.85kgCO2/kWh] and that is what clearly needs to be addressed when mitigating carbon emissions in this context. This argument has been made clearer by Jarek Kurnitski of Helsinki University of Technology [1].

2. The sample calculations have sized the hypothetical CHP unit to meet the monthly average electrical demand and to meet a proportion of the heating in the winter and have a surplus of heating in the summer, which is wasted. The heat deficit in winter is made up by a central gas-fired backup boiler (40% of the heat). This assumption may have substantial repercussions on the final carbon emissions. There is however, the other possibility where the CHP is sized based on heating demand. Rather than plan for one large gas turbine CHP [which is of course very efficient at generating electricity] a set of smaller modulating CHPs would be able to provide a larger proportion of the annual heating demand rather than back-up boilers. For example, a CHP unit which provides for DHW could run throughout the year and smaller machines of different sizes could be installed depending on the demand for space heating. It is doubtful that all of the electricity requirement will be met by doing this but as more of the ‘waste’ heat is used for heating the system, it becomes more efficient on the whole. The economics of having CHPs working for shorter hours [<5000hr] would however, need to be investigated.

The main aim of using CHPs is to reduce carbon emissions arising from heating rather than providing for all of the electricity demand. By sizing the CHP to meet all of the electricity demand, the proposed system within the report, under utilises the ‘waste heat’ from the CHP [even in peak winters!] therefore making it less effective.

3. The focus should also not be on homes alone as there are plenty of commercial and mixed use developments in the UK that could benefit from using CHPs. E.g., Woking Town Centre [2].

4. Heat loss of 32% has been assumed as distribution heat loss in the report. Whilst these high percentages are not unheard of, secondary research suggests that the district heating systems in Norway[3] and Finland [4] are operating with 10% distribution losses.

Sensitivity check

The report suggests that the CHP/boiler will have an emission of 8,500tCO2 compared to 7.500tCO2 for CCGT i.e., CCGT will be 12% better.

Very quick, back of the envelope reworking suggests that:

• If the heat distribution losses are assumed as 10% rather than 32% [see issue 4], CCGT is 6% better than CHP/boiler

• If the proportion of district heat from gas back-up boilers is reduced to 20% [point 2], rather than 40% which is what the report assumes, the CHP/boiler is 4% better than CCGT.

• The above two put together will make the CHP/boiler 6% better than CCGT.

• And finally, if the district heating system is designed based on heat demand rather than electricity [issue 2- i.e., smaller capacity and with modulating units], the CHP/boiler is 13% better than CCGT. This scenario will generate 4GWh of electricity rather than 9GWh, so not all of the electricity demand of the neighbourhood would be met but the mains supply can always meet the shortfall.

• If all of the above measures are implemented then the CHP/boiler is 36% better than CCGT.

The calculations for the above discussion have been done quickly and so might be off by a few percentages. Also there is need to consider the economic implications of the proposed modulating system, added pipe insulation etc. However, 36% of lower carbon emissions instead of 12% higher, as suggested in Max Fordham’s report ‘A case against the widespread use of district heating and CHP in the UK Issue 2 / May 2010’ is a significant difference. This suggests that a more detailed sensitivity assessment (based on the right assumptions) including a cost analysis is needed and would be really useful to logically conclude this discussion.

Reference
[1] Jarek Kurnitski, Accounting CO2 emissions from electricity and district heat used in buildings www.ehpcongress.org/fileadmin/2009/presentations/tuesday/B/JKurnitski.pdf

[1] Jarek Kurnitski, Accounting CO2 emissions from electricity and district heat used in buildings www.ehpcongress.org/fileadmin/2009/presentations/tuesday/B/JKurnitski.pdf
Helsinki University of Technology.

[2] Woking Town Centre www.woking.gov.uk/planning/service/publications/energy.pdf

[3] Norwegian Water Resources and Energy Directorate
www.nve.no/global/energi/analyser/energi%20i%20norge%20folder/energy%20in%20norway%202009%20edition.pdf

[4 ] www.energia.fi/en/districtheating/districtheating/distribution

The Biomass Myth 2

2009-12-10T14:11:00.000-08:00

Some more clarity on limited role of biomass in reducing the UK’s carbon emissions for the following reasons:

To meet the UK’s heating demand we would have to carpet the country with biomass crops and ship more in from countries like Malaysia, Canada etc.
To meet 10% of the UK’s heating demand we would have to plant energy crops on 20% of arable land in the UK, equivalent to 1 million Ha[1]
Biofuels and biomass are both competing for the same resource i.e., arable land, as well as that which is required for food cultivation. The European Council has sets a binding biofuels target of 10% for road transport fuel by 2020[2]. This, if grown in the UK, will require 3 million Ha or 60% of the UK’s arable land area. If one takes into account that there are ambitious plans to scale up the use of biomass for UK power generation (15% from biomass[3]), then the area of arable land required will be much greater than available.
Usually waste wood (e.g., from saw mills) is quoted as a source for biomass feedstocks, however this is not a scalable alternative; the timber for the waste wood would need to be grown somewhere (probably in Canada or Northern Europe). Trees for timber grow more slowly than energy crops do, with a yield of <5t/Ha/yr and assuming 10% is waste wood, then a net supply of only <0.5t/Ha/yr. On the other hand, energy crops (e.g. coppiced willow) provides approximately 10t/Ha/yr. Therefore the same argument regarding availability of land area would apply and waste wood biomass becomes less viable on a larger scale.
Importing biomass from temperate forests such as Canada or Northern Europe is not sustainable for two reasons i.e., impact of transporting the low energy density fuel and when viewed at a worldwide scale the supply from these sources is marginal (115% of the arable land will need to be cover in bio-crops to provide for the world energy demand).
It goes without saying that importing biomass (or biofuels) from tropical areas, either forests or farmed must never be considered, as it will have disastrous impact on biodiversity and land available for people to grown food, especially from the poorer South.

Biomass has a limited role in UK’s fuel mix; because of its low energy density for the area of land available, it should only be used prudently for projects that have limited alternatives for example for displacing fuel-oil in existing sites.

[1]UK Biomass Strategy suggest increasing the amount of perennial energy crops produced in the UK to to around 1 million hectares, equivalent to 17% of total UK arable land http://www.globalbioenergy.org/uploads/media/0705_Defra_-_UK_Biomass_Strategy_01.pdf

[2] www.erec.org/renewableenergysources/biofuels.html

[3] The UK Government’s Department for Energy and Climate Change (DECC) has set a target for 15% of the UK’s renewable energy to be generated by biomass by 2020. www.coaltransinternational.com/htm/w20091113.696970.htm

Do We Have Enough Space for Renewables?

2009-12-07T10:00:00.000-08:00

India's Carbon Emissions Profile

2009-12-03T15:45:00.001-08:00

The above profile is broadly based on the data India submitted to the UNFCCC through the NATCOM. I am working on two scenarios for 2030 i.e., 'Business-as-Usual' and Low Carbon Growth.

Reducing Carbon Output in the UK

2009-12-01T09:47:00.000-08:00

I had made this carbon profile for the UK at Price & Myers soon after the Stern Report came out in 2006-07. I was keen to know if an 80% carbon reduction is technically viable, and if so, what it would potentially look like. The idea wasn’t to create a ‘Transition Plan’ but a potential snapshot of what the future could look like.

Some interesting issues came out of this work, including:
• Carbon emissions from domestic heating is a huge problem, that is not adequately addressed;
• Most of what is typically defined as ‘Transportation’ is just CAR travel and that school runs and journeys to supermarkets were a significant reason for their use;
• Carbon emissions from Air travel has a marginal contribution (but one to watch out for, as it’s a fast growing sector);
• Energy efficiency is quite a tough to implement at a macro scale;
• Decentralised CHP-fed heating has a significant ability to supply heating of homes;
• At a macro scale, Roof-mounted PV do not scale up to provide noteworthy reductions;
• Biomass has a marginal role to play;
• We need significant centralised renewable energy infrastructure.

UK’s Unaccounted Carbon

2009-11-27T15:29:00.000-08:00

We hear in the media that China is now building about two power stations every week. The Chinese are increasing emissions at the rate of 2.8% annually.[1] This is when you begin to wonder whether Britons, who officially emit only 2% of global emissions, should even bother with living in 'zero carbon' homes, giving up their cars and avoiding foreign holidays in order to reduce their carbon footprint.

Ignored embodied carbon

The truth is that there is a fault in the current carbon accounting methodology. The carbon emissions accounting does not factor in the manufacturing of foreign goods consumed by Britons. Over the last few decades a large part of UK’s manufacturing moved offshore to countries such as China and India.

My rough calculation on per capita carbon emissions based on a recent report by the International Institute for Sustainable Development[2] indicates that UK’s per capita emissions which is currently stated as 9.2tCO2/person will actually be closer to 15.4 tCO2 per person, an increase of 40%.

Another report by the Stockholm Environment Institute (SEI) implies that once imports, exports and international transport are included the carbon emissions are almost 50% higher than official figures for UK[3]. Dieter Helm, a professor of economics at Oxford University also suggests a similar increase in his report ‘Too Good To Be True? The UK’s Climate Change Record’[4].

Made in China

Indirect carbon emissions stem from manufacturing of goods that you buy, since the materials incorporated in the products require energy for extraction, processing and transportation, which generates carbon emissions. Globally 36% of carbon emissions are attributable to manufacturing industries.

Industrial emissions contribute 14% of the UK’s carbon emissions [20% if the power sector is included][5] compared to China where they are 70%. Even if you discount the fact that a large component will be to serve its growing domestic market, there is little doubt that a large chunk of the Chinese emissions are for export purposes[6].

Taking some responsibility

Under international agreements such as UNFCCC, nations only have influence and responsibility over their direct national carbon emissions. This is mainly because it is easier to count the emissions at source of generation or production. However this presents the problem that movement of commodities are not fairly accounted for.

To make an analogy, the person who consumes the endangered blue fin is partially responsible for eradicating the fish as is the company fishing it as is the restaurant serving the delicacy. Likewise, a building that uses electricity from a coal-fired power station is as [if not more] culpable for emitting carbon as the power station. Your logic will tell you that it is the demand that drives the supply and not the other way around.

Besides better accounting, which needs to be based on consumption rather than production of CO2, the West could do more to help in the following ways:

Ensure technology transfer in clean technologies [e.g. capture and storage technology] to reduce carbon intensity of energy generation
Investment in low carbon manufacturing plants to reduce footprint of goods [e.g. improvements to motor systems, including variable speed drives and steam systems, including combined heat and power (CHP)]
Regulate the level imports based on embodied carbon of goods
Increase awareness to reduce consumption
Create a market for low carbon goods [e.g. through carbon labeling]

[1] www.eia.doe.gov/oiaf/ieo/emissions.html
[2] Glen Peters et al, 2009. CO2 Carbon Footprint of Nations: A Global, Trade Link Analysis, American Chemical Society http://pubs.acs.org/doi/full/10.1021/es803496a?cookieSet=1
[3] www.businessgreen.com/business-green/news/2223193/firms-urged-address
[4] Dieter Helm et al, 2007. Too Good To Be True? The UK’s Climate Change Record, website: www.dieterhelm.co.uk/sites/default/files/Carbon_record_2007_1.pdf
[5] www.hm-treasury.gov.uk/d/7d_industry_annex_p1.pdf
[6] http://news.bbc.co.uk/1/hi/7947438.stm

The Biomass Myth

2009-11-22T12:34:00.000-08:00

As a long-term source of fuel biomass only has a marginal role and yet the UK's Climate Change Plan relies heavily on it.

Biomass for heating home

The technology is limited in its ability to reduce CO2 emissions. Biomass is generally considered to be carbon-neutral, which is fine as long as we are using waste wood from the timber industry or woodcuttings, but it gets more complex when we consider growing biomass as an energy crop.

My calculations suggest that the UK has around 18 million ha of agricultural land, with 5.5 million hectares [ha] given over to arable. If we assume that 1 million ha — 17% — of that land will support biomass crops (as suggested by Biomass Task Force), then my calculations show that this would only yield a carbon saving of 2.3 million tonnes of carbon a year. Current annual emissions from heating UK homes are approximately 22.6 million tonnes of carbon

As bio crops are essentially solar energy, you get four times as much yield in the tropics than in the UK, so tropical and subtropical countries will switch to biomass crops for export — displacing food crops and clearing forest. If the use of biomass and biofuels were to continue unchecked, it could lead to ecological disaster. George Monbiot has highlighted to dangers of offshore deforestation due to demand for energy crops from the Europe.

Biofuel for transport

The UK Department for Transport expects suppliers of fossil fuel for road transport will be obliged to ensure 5% of total fuel sales are biofuels by 2010. This is set to raise this to 10% by 2020. The political ambition for 10% of transport fuel to be provided by biofuels would need 4 million ha of land. Uk only has 5 million ha of arable land. Where will it grow food? will the people except field after field of bright yellow rapeseed farms

More Information: http://www.bdonline.co.uk/story.asp?sectioncode=453&storycode=3093022&c=1&encCode=000000000137281b#ixzz0XcSJHKSb

Sustainability consultants need a professional body to maintain quality and credibility

2009-11-20T19:41:00.000-08:00

The green industry needs a professional body like the RICS or RIBA to champion quality and consistency. Otherwise, sustainability risked being viewed as an “alternative medicine”, not a mainstream practice.

New effort is required to set and maintain standards within the field of sustainability consultancy. There are many people who say they’re sustainability consultants. If the field is going to have credibility, there must be a professional code of conduct. The main concern is whether sustainability consultants are staying true to the principles that underpin the field.

A structural engineer knows that whatever your client asks of you, the building she designs has to “stand up” The question is, If you are a sustainability consultant, are you doing your job properly if you fail to address global environmental issues?”

To ensure standards are acceptable one would like to see mechanisms introduced and, possibly ,an organisation founded, that would work to ensure that the credibility of sustainability consultancy is protected and enhanced. Universities all across UK are churning out students with a raft of sustainability-related qualifications, but there is no consensus on the principles of sustainability and no standardisation of the way sustainability consultancy is practised.

Clients are being charged anything from £200 to £20,000 for similar work, and the price they pay does not always reflect the quality of the output.

A lot of people believe that in the long term, we must educate the industry so that Sustainability Consultants are no longer needed. Although I agree that this needs to happen, in my view, we may still need the specialization of sustainability consultancy just like the industry needs to appreciate cost in buildings, but still need the services of a quantity surveyor [cost consultant].

See the following articles for further reading:

Green consultants risk ‘witch doctor’ label

http://www.building.co.uk/story.asp?storycode=3128723&origin=bldgweeklynewsletter

WSP director calls for standards for sustainability consultancy

http://environment-analyst.com/index.cfm?go=1164

Obituary: Passive solar architecture. Died 2006?

2007-07-09T15:11:00.000-07:00

Passive solar architecture could be dead in the water, at least in the UK. Today it makes little difference whether one adds south-facing openings so that buildings receive maximum passive solar heat gains. You probably will not get past the building regulations, never mind saving much money or reducing carbon emissions.

Reducing heat
Until recently, the biggest component of energy consumption in a house was the heating system, which was responsible for more than 50% of a building’s total carbon emissions. But today, with the insulation and infiltration requirements under the new building regulations [Part L2] and with our taste for electronic gadgets rising, this has plummeted to 20%. The biggest carbon emitters now are electrical appliances and lighting; these two components are responsible for approximately 50% of the total emissions.

Light what?
Enhancing energy efficiency through daylighting in new homes is limited, unlike commercial buildings, as a typical family spends less than 50% of their time in the house awake during daylight hours. Considering the fact that most new homes/flats have at least two-thirds of habitable rooms with windows, albeit small, the advantage of adding more is marginal. As a result, we are really looking at low energy bulbs as the only serious option to reduce energy for lighting.
As for electrical appliances, the success of EU Energy Labelling of white goods, which allows consumers to clearly see the efficiency and energy consumption of a product, has meant that most people and developers are already choosing A-rated goods.
In any case, using low energy light bulbs and efficient white goods is not truly ‘Passive Solar Architecture’. Is it?

Over insulation
The new Part L2, which will come into effect in April 2006 and requires about 23% reduction in carbon emissions as compared to building standards in 2005.

Preliminary analysis carried out by the Price & Myers Sustainability team shows that trying to comply with the new Part L using passive solar heating, as well as energy efficiency measures such as super insulation, exceeding airtightness levels and installing efficient boilers system will be challenging and expensive (see graph above).

The analysis also shows that options that were previously considered radical and expensive, such as building integrated renewable energy systems like photovoltaics, wind turbines and biomass boilers could in fact be a more cost effective way to achieve low carbon targets.

Rising Coolth
Although heating has lost its significance in new homes, the risk of overheating has increased with the possibility of hotter summers in the coming years. Government projections of domestic air conditioning, as reported to Parliament, indicate that one in ten of us will install an air-conditioner by 2050 . This could potentially increase carbon dioxide emissions by 1-4 million tonnes each year and in so doing, reduce gains made through present energy efficiency standards.

The new Part L2, however, has tried to address this, and requires us to ensure that internal temperatures do not exceed 28ºC for more than 20 hours.

‘New’ architecture
As the regulations push our new homes towards low carbon emissions, passive ‘cooling’ features such as external shading, thermal mass, and stack ventilation could soon take the place of passive solar heating.

Passive Architecture may not be dead altogether. Architects and engineers will have to take on new challenges waiting on the horizon and resuscitate design of passive buildings. This time, one that reflects the sensibilities of warmer countries.