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October 22, 2009

Why we need renewables?

Dr. Ian H. Rowlands

Dr. Ian H. RowlandsLow-impact, renewable sources of energy are our only long-term hope.

With the Kyoto Protocol's target dates lying between 2008 and 2012, most climate change discussions focus on the coming decade.

The preferred solutions are those, such as energy efficiency, that can deliver the targeted greenhouse gas emission reductions over the next few years at the least cost.

But energy efficiency gains will only take us so far.

Singular focus upon the Kyoto Protocol's reduction targets fails to recognize that much greater emission reductions are actually required if we want to achieve the goal of the 1992 UN Framework Convention on Climate Change (FCCC).

In fact, some scientists estimate that emission reductions of the order of 60 to 80 percent may be required if that goal is to be met.

The Kyoto Protocol, in contrast, calls for approximately five-percent reductions from 1990 levels for industralized countries as a whole and no limits upon global emissions.

Albeit a good starting point for taking action on climate change, the Kyoto Protocol demands only limited changes to what remains a carbon-based economy and society.

Imagine that a firm or a country is growing in economic terms at three percent a year. It is also improving its "carbon efficiency" - its economic output per unit of carbon dioxide released - by four percent a year.

If we take our example from the year 2000, we see that carbon emissions will have declined 9.2 percent by 2010, even though economic output has grown by 34 percent. This is, of course, to be applauded. It even looks like this firm or country could be on track to reach the most ambitious national target set in Kyoto - that is, an eight-percent reduction from 1990 levels by 2012.

A different assessment arises, however, when a target of 80 percent is identified. Given the same trajectory, one might think that an almost 10-percent reduction in 10 years would bode well for achieving the FCCC goal.

The fact is, this 80-percent reduction would not be achieved until the year 2167.

Indeed, it takes a 700-fold increase in carbon efficiency to reduce emissions by 80 percent because of an associated 139-fold increase in output during the same period.

Efficiency gains will clearly not achieve the FCCC goal. They may also make eventual achievement of larger reductions much more difficult, since improvements in the efficiency of the existing system can serve to further lock-in the structure of that system.

Other strategies must be part of the portfolio of responses to the challenge of global climate change.

In the short term, what is known as "fuel-switching" to lower-carbon sources of energy, such as natural gas, has a role to play. But its contribution will also be ultimately limited because the associated carbon reductions are only one-offs.

Renewable energy clearly needs to be part of the response. Its potential is great - estimates suggest that solar energy alone could meet all of the world's present and future energy requirements.

More widespread use of renewables, however, faces two well-known challenges.

First, while some other energy sources can be transported to where the demand is greatest, renewable energy can only be generated where the geography permits it.

Second, while some energy sources can be stored easily, renewable energy sources are intermittent - that is, they vary in intensity throughout the day.

Therefore, continuing advances in energy transportation and storage technologies are critical if renewables are to play a significant role in energy supply.

Promising developments are already underway with pumped-hydro facilities, compressed-air energy collection and, perhaps most significantly, hydrogen generation.

But as it stands today, the contribution of renewables to global energy supply is modest.

In 2000, less than two percent of the world's energy supply came from what are called the "new renewables" - that is, solar, wind, ocean, geothermal and small hydro power.

Even with annual rates of growth well above conventional forms of energy, the small base from which this expansion begins means that the renewable share of the energy market will - in a business-as-usual scenario - rise to only three percent by 2020.

Action needs to be taken now to enable renewables to develop and be disseminated faster. Based on the principle that we learn by doing, the sooner new technologies are being used by more people, the faster their performances will improve and their prices will drop, leading to even more widespread application, improved performance and increased economies-of-scale.

Dr. Ian H. Rowlands is an associate professor in the Department of Environment and Resource Studies at the Univer­sity of Waterloo, Ontario.

Follow up: Canadian Renewable Energy Network is a federal government site with comprehensive details on renewables in use and development in Canada: http://canren.gc.ca

For an analysis of the key barriers to faster renewable energy development in Canada, see the Pembina Institute: www.pembina.org

-- Reprinted from Ian H. Rowlands, "Why We Need Renewables," Alternatives, 30:1 (2004). Used with permission from Alternatives Journal. Subscribe today at www.alternativesjournal.ca.

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