Counting the Cost

Source: Flickr

Bloomberg recently reported on an Asian Development Bank (ADB) study which suggested that regional mean temperatures in 2090 for East Asia (China, Japan, South Korea and Mongolia) could be 3.8 to 5.2 degrees Celsius higher than the 1961-1990 average. As a result, the region could be vulnerable to floods that could threaten $864 billion in assets.

Adapting infrastructure to climate change would cost the region $22.9 billion a year in 2005 dollars in areas such as coastal protection. Climate-related natural disasters since 1970 have cost $259 billion to China, $64 billion to Japan, $15 billion to South Korea and $2 billion to Mongolia. It may thus make economic sense for the region to embark on more adaptation measures.

An interesting study was conducted by Rojelj et al (2013) to determine the probablistic cost estimates for climate change mitigation. At present global carbon prices of less than US$1 / tCO2e, the likelihood of limiting warming to less than 2 degrees Celsius is almost zero. However, imposing a carbon price of about US$20/ tCO2e would increase the probability of staying below 2 degrees Celsius to about 50%.

Source: Rojelj et al (2013)

The same paper also found that carbon price would be highly sensitive to political inaction. Should governmental action be delayed till 2030, the probability of global mean temperatures staying below 2 degrees Celsius dropped dramatically from 50% to 15%

Source: Rojelj et al (2013)

In conclusion, whichever energy mix that a country selects, it would be important that adaptive measures are also put in place by policy makers early. It makes economic sense to do so, as illustrated above. 

Wind Power Contributes to Climate Change?

Source: Wikipedia

Amongst the various energy options such as nuclear and fossil fuels, most would likely consider wind power as a relatively climate-friendly technologies. The New York Times in Oct 2013 reported that 12 miles off the coast of Fukushima nuclear power plant site, a giant floating wind turbine has been installed that can generate enough electricity to power 1,700 homes. Japan aims to have 140 of such wind turbines that would generate one gigawatt of electricity. This is equivalent to the power generated by one nuclear reactor.However, the perception of wind power being climate-friendly is now being challenged.

The Telegraph in Apr 2012 reported on a study which postulated that wind farms could result in localised climate changes. The paper by Zhou et al (2012) presented observational evidence for the period of 2003–2011 over a region in west-central Texas, where four of the world’s largest wind farms are located. The analysis revealed a significant warming trend of up to 0:72 degrees Celsius per decade over wind farms. Interestingly, the spatial pattern of the land surface temperature increase (red areas) correlates well with the geographic distribution of wind turbines, as shown in the chart below. 

Source: Zhou et al (2012) 

Most of the wind farms were built around 2005-2008, so the temperature difference depicted is for the years before (2003) and after (2010) the wind farms were constructed.

On a separate note, the US EPA has cited other concerns on the use of wind power. Modern wind towers can be between 60-120m in height and are typically sited on atop ridgelines or in the sea. Wind facilities may sometimes face opposition from local communities due to aesthetics considerations, as well as its impact on wildlife such as birds. Recently, the Washington Post reported that the US government fined a wind farm in Wyoming a hefty sum of S1 million for the deaths of eagles in turbines under the Migratory Bird Treaty Act.

Wind farms are also subject to availability of the wind resource, and consumers have to fall back on conventional sources of power that may contribute GHG when there are no winds*, The latest finding by Zhou et al (2012)  would further trigger the need to rethink the modes by which some of our climate-friendly technologies could create localised impact on the regional climate. 


*Updated on 28 Nov 2013

Fossil Fuel Divestment

Photo by London Commodity Markets

The Guardian recently reported on an Oxford University study that recommended for investors to divest funds away from the fossil fuel sector. While the direct impact of divestment campaigns on share prices and company financing may be small, the study suggests that the reputational pressure could still influence transformative change in the fossil fuel industry.

The researchers nonetheless acknowledged that even with the maximum possible capital divested by university endowments and public pension funds, the total was relatively small compared to the market capitalisation of traded fossil fuel companies and size of state-owned enterprises.

Debates on divestment of university endowments has been on-going within the academic community. For example, Hendey (2012) wrote an article in the Harvard Political Review expressing his view that divestment from fossil fuel companies would deliver a strong signal to the energy industry that the academia takes a serious view of the climate-energy challenge. 

On the other hand, Harvard's President Drew Faust released a statement in Oct 2013 that divestment of its investment in fossil fuel industry may not be warranted. She argued that there are more effective ways for Harvard to address both climate change and to enhance its commitment to sustainable investment.

While we continue to ponder upon the efficacy of such fossil fuel divestment campaigns, I believe that tracking developments in this area would be interesting to see how academic institutions and the industry would respond to mounting pressure from such campaigns.

How Reliable is Solar?

Photo from Flickr

According to the US Environmental Protection Agency (EPA), mankind started using the magnifying glass to concentrate sun’s rays and create fire since the 7th century BC. For the modern photovoltaic technology, one may trace its origins to 1954 when Bell Labs based in the US developed the silicon photovoltaic (PV) cell that was capable of converting sufficient solar energy to run everyday electrical equipment 

While solar technology has since progressed much, challenges remain in terms of efficiency, cost and variability. 

An article by Shaheen et al (2011) cited that PV cell production has been dominated by crystalline silicon modules representing 94% of the market. Limited by thermodynamic considerations, PV cells can likely achieve maximum efficiency of 31%. To this end, Zhou et al (2010) proposed that hybrid solar–wind energy systems could help improve system efficiency and power reliability

In the area of cost, the potential of organic PV cells has been actively researched. Organic molecules and polymer materials are typically inexpensive to manufacture and could offer substantive cost reductions that would make it economically viable for large-scale power generation. The chart below illustrates the cost gap that would need to be covered in order to meet the US Department of Energy's cost goal of $0.33/W for the PV cell. 

Historical and projected costs for wafer c-Si and film c-Si photovoltaic modules
Chart from Shaheen et al (2011)

There is also an added aspect of environment justice (EJ) proposed by Mulvaney (2013).The paper contends that PV technologies use materials and processes that rely on toxic materials and generate waste flows similar to those in the electronics and semiconductor industries which may impact on workers and communities. Enormous land resources to harvest solar energy would also be required that may result in conflicts with other ecological and cultural resources.

It would thus appear that solar energy from a life cycle perspective may not be as environmentally friendly as one would expect. Nonetheless, with on-going research into organic PV cells, hopefully we can one day witness a major breakthrough in PV technology in the areas of cost, efficiency and reliability.

The Irony of Hydropower

Photo from Wikipedia

Hydropower is considered by many to be a strong candidate in the fight against climate change. This is notwithstanding the potential social impacts and habitat destruction that is commonly associated with such mega damming projects. Here is an illustration of how a typical hydropower plant works.

Illustration from Wikipedia Commons

Hydropower will likely continue to play a key role in future energy production. A study by Lehner et al (2005) correlated the potential of hydropower plants to produce electricity to changes in river discharge. Based on findings from their models, the authors proposed the following scenarios for the 2070s in Europe.

• Scandinavia and northern Russia could see an increase in developed hydropower potential (15–30% and above)
• Portugal and Spain in southwestern Europe, as well as Ukraine, Bulgaria and Turkey in the southeast, could see a decrease of developed hydropower (20–50% and more).
• The United Kingdom and Germany's developed hydropower potential would likely remain stable

This leads one to wonder if hydropower may have its limitations going forward? 

There has thus far been a notion that removing trees along streams would increase surface runoff going directly into streams, and thereby benefit hydropower generation. Challenging this notion, New York Times recently reported on a study by Stickler et al (2013) that considered “indirect” rainfall effects resulting from deforestation generation potential for the Belo Monte energy complex under construction on the Xingu River in the eastern Amazon. Deforestation of the Amazon region inhibited rainfall within the Xingu Basin and simulated power generation declined to only 25% of maximum plant output. 

Apart from rainfall effects, Simoes and Barros (2007) also observed that increased temperatures could lead to increased evapotranspiration rates, which would result in reduced power generation for hydropower plants. In 2001, due to an upward trend in temperature, rainfall fell behind evapotranspiration rates, and reservoir levels dropped to 20% of total capacity. The situation was so severe that the federal government announced a national rationing plan to avoid blackouts. 

The authors therefore cautioned that such climatic variability typically do not capture media attention, but the subtle changes over long periods would accumulate and invalidate assumptions on water availability for hydropower stations, thereby affecting electricity generation.

Therein lies the irony. Although hydropower is viewed by many as a potential solution to global warming, the viability of hydropower itself is at the mercy of climate change. Relevant stakeholders should therefore consider undertaking more holistic analysis that factor in climate change impacts as part of their environmental impact assessments for future hydropower projects. 

Dynamic Life Cycle Analysis

Photo by: Wikipedia

Over the past few posts, I have made some references to the use of Life Cycle Analysis (LCA) in determining the viability of the various Alternative Energy Technologies (AETs) that were discussed. For example, Sovacool (2008) compiled the life-cycle GHG emissions from various AETs as shown in Table 1 below. 

Table 1 - Sovacool (2008) : GHG Life-cycle Estimates for Electricity Generators

Meanwhile, Kenny et al (2010) suggested that a more advanced form of analysis called the dynamic LCA should be used as a gauge on the suitability of AETs to drive the optimization of electricity generation for effective climate change mitigation. 

The interesting feature of the dynamic LCA, is that it takes into account the growth rate of the technology, in addition to other critical factors such as emissions arising from plant operations as well as its construction phase. Table 2 below summarises their findings:

Table 2 - Kenny et al (2010) : Rankings of current technologies according to carbon-neutral growth rates

Electric energy technology	Carbon-neutral growth rate (%)
Geothermal	24
Wind	91
Biomass	50
Concentrating solar thermal	43
Small Hydro	43
Solar photovoltaic	41
Nuclear	22
Hydro	5
Natural gas combined cycle	−5*
Oil	−20*

The “carbon-neutral growth rate” is defined as the rate at which the aggregate carbon mitigation of an energy technology as a whole (eg, all wind power projects in the world) is offset by the carbon emitted in the construction of new plants. Negative carbon growth rates imply that adding capacity of that technology to the grid will result in an increase in GHG emissions per unit energy. 

It does not come as a surprise that fossil fuel technologies fare badly in the rankings. The results suggest that wind, biomass and solar AETs could be promising. 

Nonetheless, the authors have also acknowledged that further refinements could be made to their methodology such as the inclusion of economic principles. With these refinements, the new methodology could be of interest to potential investors and policy makers, and could potentially reshape future evaluations of AETs. 

Algae

Photo by: Wikipedia

Since biomass cultivation on land poses competition to food security, perhaps we can consider using other forms of biomass from the sea? Can algae be a promising source of biomass energy, since they generally do not compete with food crops for resources and land?

It appears that there has already been strong interest in algae biofuel development. A recent Time article mentioned that while technology to make cellulosic ethanol or biofuel from algae is available, there are high costs and challenges associated with scaling the production up sufficiently to compete with oil.

Liu et al (2013)'s life cycle analysis (LCA) on  algae-to-energy systems with hydrothermal liquefaction (HTL) showed that substantively lower GHG emissions can be achieved compared to gasoline as depicted by the chart below for various scenarios. Nonetheless, conventional fossil fuels such as gasoline maintain the upper edge as they enjoy a higher Energy Return on Investment (EROI).

Source: Liu et al (2013) 

HTL is of particular commercial interest because it is able to seamlessly integrates with existing petroleum refining infrastructure. During hydrothermal liquefaction, high moisture biomass is subjected to elevated temperatures and pressures, similar to the natural geological processes that has produced existing stocks of fossil fuel.

Apart from cost considerations, one should also consider the CO2 mitigation potential of algae biofuels through a life cycle analysis. Andres et al (2010) compared the environmental impact from algae production with various biofuel crops such as switchgrass, canola, and corn farming. The results indicate that conventional crops have lower environmental impacts than algae in energy use and GHG emissions. It appears that the large environmental footprint of algae cultivation is driven predominantly by upstream impacts, such as the demand for CO2 and fertilizer. To reduce these impacts, wastewater could be used to offset most of the environmental burdens associated with algae.

Looks like it will still be some way to go before algae biomass can become a marketable and truly climate-friendly alternative energy technology.