With such a range of possibilities, wherein lies the best approach to the goal of reducing global CO2 emissions? Might shifting perspectives on both lifestyle and technology come to be seen less as a constraint and more as the key to ever greater progress? The response to the current challenge depends as much on the emergence of disruptive innovation as on fresh perspectives toward current modes of energy production and consumption.

ParisTech Review – Between now and the next century a target has been set to ensure greenhouse gas emissions be halved to ensure no more than a 2°C rise in global temperatures. The stakes could not be higher, particularly in developing countries. Which policy levers represent the most promise for achieving this aim?

François Moisan – Essentially our choices can be reduced to three primary approaches: a reconfiguration of the global energy mix to include new sources of energy as they come on-line; optimization of both current as well as future resources; and more investment in CO2 capture and storage technology (CCS).

As a more detailed illustration it may be useful to cast a glance at the figures produced under the IEA’s BLUE Map Scenario (PDF) for global energy-related CO2 emissions. In 2005 global emissions were 28 billion metric tons (Gt) and if the situation remains unchanged forecasts predict totals to hit 60 Gt by 2050. The BLUE Map Scenario proposes to reduce this figure to a mere 14 Gt and the IEA has created a roadmap toward the achievement of this ambitious target. A cross-sector approach must be deployed and involves reductions of: 38% through increased energy efficiency (in transport, buildings, power generation, etc.); 17% through increased use of renewable energy sources; 6% as a result of nuclear technology; 20% by way of CCS; and, a further 20% through other methods. While these figures remain estimates they are an accurate reflection of the current state-of-the-art and thus represent a reliable framework for the creation of a clearer picture of the future energy landscape.

Daniel Clément – Our position has been to make energy efficiency the top priority as this represents the most promising path toward reducing consumption at the lowest possible cost. Following closely behind is investment in renewables while CCS is, at the moment, merely one of many pieces of the current energy policy puzzle.

Keeping the focus on energy efficiency, which options represent the greatest potential for cost reductions?

Daniel Clément - In the vast majority of OECD countries the primary sources of CO2 emissions are the buildings and transportation sectors. Of France’s 374 million metric tons of annual CO2 emissions, 130 million can be attributed to transportation and 88 million to the residential and tertiary sector. Patterns of consumption vary widely and stand in marked contrast to the industrial sector where the bulk of consumption is concentrated in a handful of activities such as steel, cement, and glass manufacturing. Additionally, industry is far more sensitive to price fluctuations, particularly in Europe where regulatory challenges such as quotas on CO2 emissions have pushed industrial actors to the forefront in the battle to drive down consumption.

In light of these facts, it would seem that future progress will depend largely on shifting current assumptions on the basics of daily life: travel and domestic needs … recommendations to dial down thermostats to 17°C (as former US President Carter once suggested to widespread derision) seem poorly suited to long term sustainability. What other instruments might be deployed?

François Moisan - We are fortunate enough to have a wide variety of means at our disposal that avoid the need to intrude into the personal habits of our friends and neighbors and instead seek to harness the power of communities to effect significant change. Transport provides a perfect illustration with three principle levers for action: vehicle improvements, low-carbon fuel sources, and the creation and expansion of new forms of mobility.

Energy efficient vehicles are being developed through a combination of incremental steps and truly disruptive innovation. In the former category better aerodynamics and improvements in tire technology have decreased rolling resistance and limited the effects of friction. In the latter, an exciting new wave of construction materials are leading to ever lighter vehicles perfectly suited for the expansion of the electric vehicle market and well adapted to the urban environment. While a large sedan might consume up to 30 kWh/100 km the next generation of light-duty vehicles, such as those being developed by both Renault and Peugeot, could slash consumption to a mere 8.5 kWh/100 km. The very notion of the somewhat infamous “second car” would be turned on its head and we can start tracing the outlines of increasingly diverse range of options such as lightweight three- or four-wheeled electric vehicles in a range of configurations. That these new fleets would be energy-efficient and perfectly adapted to the needs of city-dwellers goes without saying but what may be even more interesting, and we will revisit this subject shortly, are the possibilities that exist for shared ownership and an entirely new approach toward vehicle usage habits.

In other environments, hybrid and hydrogen-powered vehicles provide an ideal solution to the need for increased autonomy and could conceivably achieve ranges of 500-800 km. In reality, there are some rather significant technical constraints that must be overcome, not least because of the sheer weight of onboard fuel cell and hydrogen technology, and progress will likely be made by combining both strands with other forms of low carbon fuel. Additionally, it must be admitted that some of the solutions being proposed merely create new sets of problems such as how to recycle discharged batteries.

Finally, a wave of 1st and 2nd generation biofuels have reached maturity and have a proven track record in their ability to act as at least partial substitutes for petroleum-based fuel. In fact they are already being blended with gasoline and diesel and future progress will depend on finding the right proportional balance to create ever more efficient forms of fuel. The technology is already well on its way and further advances will only be limited by the availability of a given resource or variations in the life-cycles of different biofuels, particularly in regard to CO2 emissions.

Is the transportation revolution already well under way? How far along the path toward new forms of mobility have we really come?

François Moisan – Things are moving forward in leaps and bounds. Evolving ideas of mobility should not be underestimated as numerous bike-sharing or carpooling schemes have clearly demonstrated. Carpooling is nothing new but its true power has yet to be harnessed and will deserve closer attention in the years to come. The expansion of public transportation options will also have a decisive role to play.

The infamous “second car,” as discussed previously, could be transformed from an individual possession, dedicated to a specific purpose, and come to be viewed as a service. And why not? Options are multiplying and could consist of fleets of vehicles purchased through systems of collaborative consumption and made available through a wide range of schemes (co-op, commercial, publicly subsidized). The knock-on effects would ripple outwards and could be considerable with more flexible usage patterns and more efficient vehicles (as they could be stripped of a surplus of optional add-ons). Moreover, one of the enduring headaches of electric vehicles, namely recharging the battery, would be eliminated as the vehicles would be parked in dedicated facilities.

A reflection on the future of transportation should hinge on more than a simple evaluation of individual choices and must include a willingness to discard certain preconceptions. Discussion must turn on how many daily journeys are actually necessary as well as on the possibilities created through telecommuting or the introduction of more localized consumer supply chains. Ultimately, it is the very definition of urban planning that is as stake.

This leads us to another essential component in the effort to reduce CO2 emissions, the building sector, one which would appear to possess a somewhat more insoluble set of challenges.

Daniel Clément – The overriding constraint of the buildings sector is that, unlike automotive fleets which follow a ten-year lifecycle, we are dealing with a much longer time-frame. Two-thirds of the housing infrastructure in the OECD countries is already in place. This is not to say that we should discount the contribution the remaining one-third can make toward reducing CO2 emissions as “passive energy” construction methods become more widespread. Existing technology is already being deployed to create positive energy buildings (producing more than they consume) at minimal added cost. The commercial sector is demonstrating significant promise and as we move along the learning curve we can expect costs to decrease even further.

Renewables can play a primary role in fulfilling residential heating requirements, most notably by heating domestic water supplies using solar panels, but also through the provision of space heating through both active (sensors, storage) and passive (integrated into construction) techniques.

High-performance wood boilers represent another promising avenue for development, not least for their low emissions but also in terms of scalability. They can be used at the level of individual households as well as for larger industrial concerns or municipalities. Still relatively young, the technology has already helped reduce pollution and we can expect yet further improvements in the future.

Geothermal energy represents another option, particularly as a local solution or in buildings that lend themselves to this option. Networks of subterranean tubing can be deployed to extract low-grade heat energy from groundwater supplies located near the surface (100m or less) and then make use of heat-exchange pumps to extract enough heat, in the form of air or water vapor, to ensure stable heating supplies.

The most pressing concern however is the need to address the shortcomings of the current stock of residential and commercial buildings. The most obvious and efficient solution is to improve energy efficiency through better insulation yet this is not always possible, particularly in the case of older constructions.

What obstacles currently lie in the way?

Daniel Clément - In the short-term current skillsets will need to be adjusted and more professionalism introduced to take full advantage of newly available technology. In a larger structural sense, the buildings sector remains highly compartmentalized and has largely failed to develop a coherent goods and services continuum. One hand acts without knowledge of the other and services often find themselves in opposition with products when what is really required is tighter integration between the two, from the moment of design and conception through to completion of a given project.

Advances in construction materials must also play a role and the sooner technical constraints can be lifted and new products integrated the better. These materials are essential to the refurbishment process of run-down housing stock and can be used to create multi-functional shells and provide improved interior and exterior insulation through such methods as thin-layer technology. Additionally, making buildings more energy efficient requires a wider array of production systems (heat pumps, wood boilers, and cogeneration systems).

What about changing usage patterns?

François Moisan – As mentioned previously keeping the thermostat at 17°C is not the long-term solution our planet needs but nevertheless can be seen to represent the importance of changing perceptions toward energy consumption. At a more subtle level we can suggest less intrusive methods. Few would complain about taking a staircase in place of an elevator when walking down a single flight of stairs … yet architects have a role to play here in designing well-adapted environments where the stairs can be easily found and used with a minimum of fuss! Energy efficiency will rely as much on changing behavior and introducing the idea of collective responsibility as it will on designers creating habitats that both encourage and provide the opportunity for new attitudes to emerge. Evidence also suggests that localized solutions often meet with far more success than broad legislation when it comes to changing behavior.

There is also ample space for discussion over taking a more collectivist approach toward energy resources and increasing cooperation in the use of existing infrastructure. This goes against many more basic instincts but offers some promising possibilities that need to be taken seriously. Constraints do exist, particularly in older constructions, and calculating costs at the level of individual buildings lends itself to only modest progress. What appears more promising is scaling our thinking upwards to the level of districts and neighborhoods. Grid operators everywhere fret over periods of peak-demand when recourse must often be made to high carbon-emitting resources. The question of how to smooth the demand curve has become crucial and positive energy buildings have a significant contribution to make toward balancing the demands made by older buildings. It is from this base that the possibility exists to create improved electricity supplies by exploiting locally produced resources and direct current to store electricity and avoid the negative effects of any temporary shortages. Improvements in flywheels and other forms of storage should ensure continued progress in this domain.

“Smart Grids” have been praised for their ability to optimize the use of energy resources. Do they offer a somewhat simpler solution?

Daniel Clément – The different approaches are not mutually exclusive and intelligent networks represent just one more asset toward the creation of effective local solutions. Depending on how they are deployed, there are numerous possibilities many of which have yet to be fully explored. As mentioned previously, periods of peak demand are a perennial challenge and one that could be minimized through new approaches toward load-shedding. One example might be to shut down heating systems for 15 minute intervals and thus reduce overall demand. Households would be hardly affected but the stability of the overall system could be greatly improved through this simple action. Following a similar logic we could imagine the deployment of intelligent sensors to activate household appliances such as washing machines during periods of low carbon electricity production.

François Moisan - In any discussion over shifting behaviors however it would be remiss to ignore the very real barriers that exist to changing attitudes toward consumption. Smart meters have already met with resistance as they are viewed by many as an intrusion. Households are inherently private and it is difficult to approach them in the same manner as a public space. Among the numerous problems in defining the barrier between private and public consumers have demonstrated their reluctance toward disclosure of what many consider to be personal information. These concerns will only be overcome if some clear benefit can be identified such as a significant reduction in monthly electricity bills of between 10%-15% for example. We can expect utilities to start moving in this direction, not least out of pure self-interest, as managing peak-demand is not only costly but generates considerable risks for grid stability.

In summary, it would seem that what is truly required is the continued elaboration of innovative economic models.

François Moisan – Absolutely, and on this point significant progress needs to be made. Nevertheless, numerous pilot projects have been initiated to demonstrate the feasibility of a new approach toward energy management. One such program is currently underway in the city of Nice, which, like many of its neighbors in the South of France, presents a rather unique set of challenges and possesses only a single high-voltage connection to the national grid. As with many municipalities in the region, electric heating is widespread creating considerable spikes in demand during rare winter cold snaps. Under the leadership of Veolia a new type of grid is being implemented and will integrate many diverse sources of decentralized generation, storage, and consumption. To create a link between producers and consumers a new “energy aggregation” system has been created to monitor local installations and efficiently store power that can be supplied to the grid when necessary. Through intelligent management new sources of value are being created by way of a sort of “virtual grid” in which a known amount of power is available for curtailment from a client base composed largely of the tertiary sector. The goal is to reduce customer costs through aggregating individual cuts in consumption in a way that benefits the entire community. Put simply, the more consumers participate the greater the savings for all. The region also plays host to another pilot project led by ERDF, EDF, and Alstom and constructed around the idea of an intelligent network that harnesses local intermittent power sources such as solar that have already been integrated into the construction of numerous buildings in the both the commercial and residential sector.

More generally, it seems clear that a cooperative approach toward energy would seem to represent the most promising path forward. The notion of collaborative consumption has become so widespread that Time Magazine made it one its “Top Ten Ideas That Will Change The World” in 2010. The outlines of new sources of value are only beginning to be traced and as the shift in usage patterns continues apace we are witnessing the dawn of what could prove revolutionary change.


  • Smart Power: Climate Change, the Smart Grid, and the Future of Electric Utilities
    Peter S. Fox-Penner
    List Price: EUR 32,95
  • ADEME (website)
  • International Energy Agency (website)
  • Smart Grids European Technology Platform

More on paristech review

By the author

  • Energy efficiency: changing habits to create positive energyon April 12th, 2012
  • Gregory James

    this is fantastic