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

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

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

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.

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[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?

India's Carbon Emissions Profile

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

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

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