A Global Village
Issue 6 » Planet

The Future Energy Mix

Dr. Gregory Offer, Imperial College London

Society’s use of energy underpins everything we do. We can’t eat, work, travel, drink, wash, surf the Internet or do almost anything without consuming energy, and most of that energy currently comes from fossil fuels. Transport in particular is heavily dependent upon fossil fuels with currently no alternatives deployed at scale capable of replacing them. However, we need to replace them: fuel is becoming more expensive every year, and even big oil companies are predicting difficult times ahead.

The report Signals & Signposts, published by Shell last year, predicts a future described by two extremes: scramble and blueprints. These can be broadly interpreted as everyone working in their own interests versus everyone working together. They also predict a period over the next few decades, called the zone of uncertainty, during which there is huge shortfall in global energy supply compared to currently predicted future energy demand. In their own words, this can be either a zone of extraordinary opportunity, or extraordinary misery, but is more likely to be the latter if everyone works in their own interests.

The other argument for reducing our dependence upon fossil fuels should be well known by everybody by now; that burning them produces greenhouse gases which are driving climate change, and that the consequences of that climate change will, on the whole, be very negative. However, the recent UNFCCC negotiations at Durban ended with little or no meaningful agreements, suggesting that we are a long way from an international agreement on how to manage a transition away from burning fossil fuels.

The problem currently appears intractable: even if we maximise our use of all existing energy resources – something that any agreement on climate change would surely restrict – energy companies are still predicting a large damaging energy gap between supply and demand. In addition, for many governments it seems that the economic and energy security arguments appear more real and more immediate, and that any agreement on climate change could make those problems worse. It is apparent that until climate change, economic development and energy security are dealt with together and consistently, it will be very difficult to counter the economic and energy security arguments for doing nothing about climate change.

The problem currently
appears intractable:
even if we maximise
our use of all existing
energy resources ...
energy companies are
still predicting a large
damaging energy gap
between supply and

The UK is in a fortunate position, in that it has already done some of this work. The Department of Energy & Climate Change’s 2050 Pathways Project last year calculated whether and how the UK could meet its commitment to reduce its greenhouse gas emissions by 80% by 2050. The answer was that the UK could, and there were multiple pathways, but all required a significant increase in effort compared to current policies at the time. However, although the UK is an island, we are part of the global village, and the UK cannot act alone. A global energy crisis or runaway global climate change will affect every country, thus prompting Shell to frame their perspective with two extremes. One sees us work together as a global community to reinvent our economies and take advantage of new energy sources and technologies, and the other sees us compete with each other for dwindling resources down a ‘business as usual’ dead end.

Electricity as a Universal Energy Carrier
Generating the energy in the first place is critical, and it is possible to predict relatively accurately which technologies will be important in 2050. This is because the important thing is scale, and it takes a long time to reach scale. According to Kramer and Haigh1 it takes 30 years to scale up new technologies from pilot plant to making a meaningful contribution, 1-2%, to global energy supply, and then a few more years to establish economic competitiveness at scale. This means the technologies being developed now are those that will be important in 2050, such as wind, solar PV, solar thermal, new nuclear, biofuels, and marine. Others may be important in the long run, such as fusion, but only those that are already being demonstrated are likely to have reached scale by 2050.

Options for Transport
Electrification of transport is probably the most important alternative. We can produce electricity from anything, wind, solar, tides and waves, nuclear, and fossil fuels, and because of this electricity is considered as a universal energy carrier. Even with current electricity generation, based upon natural gas, electric vehicles would reduce emissions by roughly 40% if charged at the correct time. Moving to electricity from renewable sources, zero emissions are possible in the future. Most importantly, there are no limits to the expansion of electricity production.

of transport is
probably the
most important

Chemical fuels will still be important, and in 2050 we will still be able to produce considerable amounts of fossil fuels, but alternatives such as biofuels, solar fuel and hydrogen could all become major players. Biofuels are likely to be cheap to produce, and although second and third generation biofuels based upon crop wastes or salt water agriculture minimise competition with food production, land availability will always impose a natural limit on production. Solar fuels could be important, converting carbon dioxide and water directly into fuels using solar energy.

Fuel cells could also be important, currently powered by hydrogen they are already commercially viable in some niches, such as forklift trucks in distribution centres. They are scheduled to emerge on the mass market in 2015 with major players such as Toyota and Daimler all planning major launches. Hydrogen production could initially limit their market penetration, but in the future they are likely to be more fuel flexible, and could ultimately occupy significant niches where electrification is challenging, for example heavy vehicles and long distances. As costs come down they could even challenge the dominance of the internal combustion engine with their higher efficiency.

Aviation and shipping are likely to consume most if not all of the chemical fuels we can produce, so an astute observer will still ask how cars will be powered. Again, the answer is electrification. Many have already recognised this, for example China has between 120-140 million electric vehicles, mostly scooters, and wants to make a million electric cars a year by 2015, while investing over a 100 billion Yuan over the next ten years. Likely triggered by concerns about air quality in cities, electrification of vehicles in China is becoming increasingly attractive for economic and energy security reasons, as it should for many other countries too.

Challenges and Opportunities
The only certainty is that things will change, and with that change there will be both challenges and opportunities. The challenge for some will be how to sustain their standard of living during a time of competition for resources and energy, for others it might just be how to sustain themselves at all. Alternatively, the opportunity will be to reinvent our society around sustainable energy sources with the potential to deliver improvements in quality of life for everyone and within the boundary conditions imposed by nature. As scientists and engineers this should be our goal, nothing less.

Dr. Gregory Offer is an EPSRC career acceleration fellow at Imperial College London. Greg conducts research into sustainable fuel production and sustainable transport, including electric, hybrid electric and fuel cell vehicles, and spent part of last year on secondment at the UK’s Department of Energy & Climate Change working on the 2050 Pathways Project.


  • Posted by Ms L Offer on Oct 23, 2012 4:07 PM

    Excellent, a very clear message.

    Obviously a lot more work needs to be done and these are the people to do it.

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[1]    Kramer, G. J. & Haigh M. (2009) Nature. 462: 568-569.