There are various ways of interpreting this question, so I will choose this one: "Will renewable energy sources ever be able to satisfy fully the world's energy needs?"
By far the majority view of the energy industry is that ultimately the world's energy supply will come from renewable energy. But opinions diverge on when this day will come. The advent of "peak oil" will hasten it. Safe, cheap carbon capture and storage technology for fossil power plants would push it back. It all comes down to the relative cost of renewable and fossil energy...
technologies.
In many areas of the world, advanced renewable energy technologies can deliver energy to the end consumer at the same price - or cheaper - than fossil technologies. More and more regions of the world will find renewables the cheapest option as technological advances are made, economies of scale drive down manufacturing costs, and fossil energy prices continue their inexorable rise.
Some technologies are further from the market than others and an energy system with a high or 100% reliance on renewable generation will mostly likely be based around a combination of technologies with complementary characteristics. Concentrating solar power (CSP), for example, is expensive today compared to fossil generation even in very sunny climates like the Middle East, but those countries that choose to install some CSP capacity now will improve their understanding of the technology and equip themselves with the means to escape rising fossil electricity costs. The sums of money needed to subsidise the building of this initial capacity, expressed as a proportion of the kWh cost now paid by electricity consumers, are small, but the future savings have the potential to be very great indeed (see graph below from the German Aerospace Centre, concerning Jordan).
Thick line: electricity cost of new CSP plants. Dash-dotted line: cost of new gas-fired combined cycles. Thin line: cost of conventional electricity mix in Jordan. Dashed line: cost of the national electricity mix including CSP. Black squares: installed solar capacity share in the Jordanian electricity mix according to MED-CSP 2005. The circles indicate the cross-over of the cost of CSP versus new conventional power plants (upper) and versus the national electricity mix (lower). Red zone: small additional investment costs to kick-start CSP. Green zone: large savings made thanks to the take-off of CSP. Long-term exchange rate $ / € = 1.
On the one hand, this question should be considered as purely theoretical at this particular stage of technological development of the humankind and able policy frameworks supporting use of 'green' energy. On the other hand, the answer would largely depend on the definition of the renewable energy. For instance, would nuclear be considered as a part of 'green' energy mix? It is likely that fossil fuels or/and nuclear will remain dominant at least until 2050. However, this fact should not stop governments and industry from supporting and reporting...
concrete renewable projects both on policy and technology levels. It would be useful to concentrate both on the 'technologies for the future' and improving traditional energy solutions, especially in the area of energy efficiency, energy saving and developing safer nuclear options.
What needs to be done on the policy level?
In this situation, the leading international players countries should definitely take a lead in creating a new truly global energy organization and make a quantum leap in international efforts to spread relevant technologies. These policies should address global warming and other crucial environmental issues, and promote responsible and market friendly technology sharing in order to accelerate the pace of transition to more environment-friendly low-carbon energy future.
The governments acting together with the private sector, international organizations and the civil society should re-frame the concept of technology and knowledge sharing. Too simplistic, 'one way' understanding of technology sharing/technology transfer may undermine the interest of patent holders and private sector's Research & Development units in developing new technologies for developing countries' energy sector.
Inter-governmental technology fund ("Knowledge bank") based on the private-public partnership (PPP) principle may be an appropriate answer to the above-mentioned challenges. This "knowledge bank" should immediately make available environmentally friendly energy technologies to small and medium enterprises as well as to the state corporations in developing countries, while compensating developers and patent-holders. The financial burden should be shared between the governments of developed and developing countries, international organizations and, on a voluntary basis, the private sector.
We are living in a world where energy needs are essentially covered with fossil fuels. Reserves for these fuels are logically decreasing. Additionally, the development of emergent countries over the next years will increase overall energy needs, reducing fuel reserves at a highest rate. Besides, a traditional energy supply at the present consumption levels, and based mainly on fossil fuels is not sustainable, as it will increase the concentration of greenhouse gases in the atmosphere, producing harmful or even irreversible effects on the climate.
Among...
the energy sources that can be used as an alternative to fossil fuels, there is no doubt that renewables show significant advantages. Besides...contributing to the security of energy supply in Europe, their use do not produce any waste, as it is the case with other energy sources.
Is it possible to completely replace fossil fuels by renewable energy? More important than looking for substitutes for current consumption is to try to see if we can save or (produce and) consume more efficiently. If we reduce our needs, there will be less to substitute. At last at European level, objectives have been properly fixed for both goals (energy saving and penetration of renewables). This last objective is needed for speeding the development and deployment of renewables and to facilitate their integration and progressive substitution of conventional technologies. Some stakeholders have criticized the existence of binding objectives of renewables at EU level. We need to have a longer term vision. Renewables can make supply slightly more expensive in the first years, but they will contribute positively to a higher self dependence in Europe, and to lower costs of supply in the coming years.
Within the three different sectors where substitution can take place, the electricity sector, due to its versatility, is the one which allows for a greater development of renewables. However, the management of an electricity system based mainly on renewable energies is much more complex than that of a system based on conventional energies. Although improvements in network management are foreseen that will allow for the massive connection and operation of distributed and discontinuous sources of energy, present (nuclear) and coming (Carbon Capture and Storage) technologies are also low (almost no) carbon technologies perfectly compatible with the objectives of competitiveness and sustainability, and that can positively contribute to a secure and reliable electricity supply. In the case of the transport sector, probably the more urgent need, is also to increase savings and efficiency. Fossil fuel substitution in this last sector will take place from biofuels, or from alternative sources of energy (fuel cells) which could be recharged from renewable sources of energy. Finally, in the heating and cooling sector, we could use the same type of fuels that we will use in the case of the transport sector.
In any case, should we want it or not, the energy mix currently in place will evolve as prices of fossil fuels surge -making renewable energies more competitive- to shift from a situation where fossil fuels are the basis of our energy supply, and renewables just a mere complement, to one where renewables will be the main source of supply, with fossil or other (mainly nuclear) fuels being the complementary part of it. Substitution can be perfectly done, without shortages of energy, but we must be prepared to produce and consume more efficiently, and above all, to pay for the true price of the energy we consume.
Considering this topic does not directly fall within the immediate policy of Clecat, allow me to respond as a private individual. Clecat Members are direct users of fossil fuels, or are obliged to deal, one way or another, with the indirect consequences of fuel markets.
It is my feeling that the relatively low price of fossil energy has allowed remarkable progress in the XX century. The two main petroleum shocks set shivers up the spine of the western world, but in the end they did not last long enough to create the need for alternatives.
Today’s...
landscape is instead completely different. On the one hand energy demand is soaring and will steadily grown in the years to come and on the other concerns exist about the limits of fossils supply and their environmental impact. It is therefore reasonable to think that the price of fossil fuels and petroleum in particular are set on a steady upward trend.
These elements create a thoroughly new picture and make alternative energy more appealing to our purses, whilst at the very same time they create the conditions for enhanced and urgent research of new sources of energy. When such evidence is used in the transportation industry it is very easy to see that the pressure for alternative fuels and alternative propulsion systems will grow in future in connection with the market pressure on fossils.
One could probably consider the above a disruptive event. Such events historically ignite or foster change in the behaviours and habits of mankind, and such changes in turn have created long and stable periods of progress and prosperity. All in all I am of the opinion we should hope for a relatively short period of disruption followed by a hopefully long period of progress and prosperity, where new technologies will create new business opportunities. As regards renewable energy, it is more difficult to imagine its extensive use in individual transport, because of the problems we still have in energy storage and distribution. This does not mean that renewable energy will not play a major role in all those transport systems which will be in a position to avail themselves of reasonably expanded distribution systems.
The auto industry is long making significant investments in improving the fuel-efficiency of vehicles and the deployment of alternative fuels and alternative energy, such as hydrogen, electricity, compressed, liquefied petroleum gas natural gas and biofuels. The latter are now increasingly seen in a negative light, it seems, with questions raised concerning the production of biofuels, their efficiency in terms of CO2-emission reduction and the possible effect of biofuels on food prices. These criticisms need careful scrutiny.
Biofuels can significantly...
contribute to reducing overall CO2 emissions and they can be produced and deployed in a sensible and sustainable manner. In general terms, all alternative fuels have their advantages and disadvantages and their stage of development and greenhouse gas (GHG) pathways vary significantly. Although there are many studies on “well-to-wheel” GHG emission pathways, further research and real-life testing are still needed to establish which fuel sources will be affordable and practical for daily use in all vehicles. Biofuels must be part of this assessment.
So-called first-generation biofuels, such as ethanol or Fatty Acid Methyl Ester (FAME) for blending in petrol or diesel respectively, will certainly contribute to the general uptake of biofuels and help attain future greenhouse gas reduction (GHG) targets. ACEA supports the application of environmental sustainability certification criteria to provide greater assurance of the sustainability of biofuels.
Also, since the auto-industry develops and manufactures its vehicles for the entire European market, clear and harmonised fuel quality standards have to be established in order to ensure vehicle compatibility with biofuels. The auto-industry needs good quality fuels that are defined and applicable across the EU and which are fit for purpose so the customer can use the fuel in his vehicle without consequences.
The future lies with second-generation biofuels, which are produced from waste, residue, non-food cellulosic and ligno-cellulosic material, and will have a better CO2 performance and greater compatibility with existing cars. The investment in first-generation biofuels was necessary to prepare for the transition to second-generation biofuels. Although they still need further development, second-generation fuels will provide a quicker route to the more widespread and a greater proportion of biofuel use in all vehicles.
Alternative fuels have an important role to play in an integrated approach to achieving the EU community’s CO2 strategy. Combined with further improvements in vehicle technology, changes in driving style, more efficient infrastructure and CO2-related taxation, the use of biofuels is an essential part of such a comprehensive approach.
The European auto industry calls on EU policy makers to sustain a broad and forward-looking policy that will provide for the widespread adoption of sustainable biofuels and give a clear political message to encourage the rapid introduction of second-generation biofuels. The sustainability criteria for biofuels will result in a renewable energy policy that can satisfy all stakeholders and, depending on the biomass raw material source, address concerns about sustainability, CO2 benefits, land availability and impact on food availability. ACEA is ready to support these aims.
Energy efficiency and renewable energy will be vital in curbing emissions. In the longer term our energy production must indeed become 100 percent renewable. But if we are to prevent run-away global warming, we also need - for some decades - to capture and store CO2 from large emission sources such as coal power plants. The Bellona Foundation considers CO2 capture and storage as a key bridging technology to take us from the fossil to the renewable economy.
Climbing out of poverty will in the next few decades require higher energy consumption in...
most of today's emerging economies. Their energy consumption is increasing at a break-neck pace, making even the International Energy Agency (IEA) reference scenario of a 50 per cent increase in global energy demand by 2030 look timid. Coal is the most important readily available and abundant energy resource for many of these countries - including India and China.
While energy demand goes up, emissions must be cut rapidly and radically. Global greenhouse gas emissions must peak by 2015 and be reduced by 50-85 per cent by 2050 (on 2000 levels) if we are to have a reasonable chance of preventing run-away global warming, according to the Intergovernmental Panel on Climate Change (IPCC). Unfortunately energy efficiency and renewable energy cannot alone meet this challenge in the short run. According to the most optimistic scenario from the International Energy Agency (IEA), the Tech Plus scenario the global power production in 2050 will be ~35 000 TWh. Only ~13 000 TWh will be produced from renewable sources, which leaves us with a gap between power demand and renewable potential equal to ~22 000 TWh.
This is IEA’s most optimistic renewable potential. However, IEA states this scenario as speculative and not realistic. Actually, IEA believes the gap will be much larger than indicated by the Tech Plus scenario.
Capture and storage of the CO2 (CCS) emitted from large-scale combustion of fossil fuels (in particular coal-fired power plants) will thus be instrumental as a transitional technology for limiting global warming to 2 degrees Celsius without depriving a large part of humanity of legitimate access to energy.
We in The Bellona Foundation are therefore very satisfied that Chris Davies, the European Parliament's rapporteur on the proposed directive on geological storage of CO2 has announced he wants to make CCS mandatory for fossil fuel power plants in the EU. We also support his proposal to kick-start the building of the first full-scale CCS power plants with an EU-managed incentive scheme in the shape of free emission allowances (to be taken from the proposed cap for EU emission allowances, not to be added to the cap) for such early movers, who could then sell the allowances in the EU emission trading system.
This is not about diverting resources away from renewables or energy efficiency. The magnitude of the challenge of the EU effectively going carbon neutral within 40 years simply gives us no choice but to pursue all options.
The promises of fusion to realize taking at least 50 years, we do have to look closely at the renewable energy currently available. Therefore if we want it to replace fossils fuels we need to consider and solve the following issues: storage in order to fully enjoy the renewable energies by unlocking non continuous production, the principal weakness; improve energy efficiency as well as decrease energy consumption; drastically increase the use of solar energy. This being done, replacement of fossil fuels is within reach.
In its Fourth Assessment Report on Climate Change, the IPCC clearly states that renewable energies are part of the climate change solution, together with many other strategies such as energy savings, Carbon Capture and Storage (CCS) and, assuming constraints are lifted, nuclear energy.
However, at the current state of technology, renewable energies have their limits: solar panels only work in daytime, wind turbines only work when the wind blows, and storing electricity is very power consuming and expensive; photovoltaic panels are still bulky...
and expensive and much more research is needed before they can be widespread; hydroelectric plants and biofuels can have significant environmental drawbacks; geothermal energy is so far effective only in selected volcanic area.
While investing more research into renewables and energy savings will increase the future share of renewables, it is unlikely that these will fully replace fossil fuels in a foreseeable future. To achieve effective CO2 emissions reduction, significant investments are also needed into short and medium term solutions, such as low emission vehicles and other energy savings schemes, CCS and, if acceptable, nuclear power.
Yes, fossil fuel can be replaced by renewable energy sources such as ocean wave energy, wind energy and bio mass - the last in large quantities from the ocean.
You can read in my paper about Ocean energy for IPCC that Ocean wave energy alone can deliver between 8,000 and 80,000 TWh electricity which is between 50% and 500% of the world's electricity consumption of today.
As the time for development of new technologies is strongly dependent of how the public priorities between fossil fuel and renewable energy it may take generations before fossil...
fuel is reserved to areas where it is highly justified to use it: as a valuable raw material for special purposes.
The EU has defined a target of 20% of integration of renewable energy at European level by 2020 and a target of 40% is now envisaged for 2040. This represents a vision that renewable energy can make a very significant contribution to the energy supply of Europe, something that was not foreseen one or two decades ago. On the other hand renewable energy is still in his infancy and history has shown that successful technologies (like those supporting renewable energy utilization) go much beyond what their inventors and first developers (usually very...
visionary people) are able to forecast.
Examples of these are everywhere from airplanes (could the Right Brothers imagine that less than a century after their invention hundreds of ordinary people would be flying between continents in a non-stop flight?) to the recent advances in telecommunications and informatics. So, to put it simple: I would not bet on having renewable energy replacing completely fossil fuels with no other sources being need, but also I would not bet in the opposite.
Global primary energy demand is set to grow by more than 50% over the next 20years according to the IA, meaning that over 5TW of power generation capacity would be required just to keep pace and replace old plant. In order to replace all of this, the current level of renewable energy use -less than 5% of total consumption- would have to rise beyond practical possibilities. The sheer size of the energy requirement suggests that all sources have to be explored in order just to meet demand. But we expect that renewable energy will take up an increasingly...
large share of consumption growth and that it could account for c 20% or slightly more of total energy use.
Some of the key requirements on energy sources are: cost to produce/extract/use, reliability, efficiency and environmental criteria such as emissions and others. Fossil fuels tend to stack up well on the cost and reliability criteria; the current average unit power cost for a fossil fuel basket is c 5-20% lower than that of wind for example, the most economic renewable energy source depending on the assumptions of use and input costs. Yet, considering a scenario of long term scarcity of resource (including fossil fuels) and thus increasing commodity costs, renewable energy becomes an increasingly viable alternative under economic criteria. The economics of renewable energy can further improve if the industry achieves widely targeted cost economics. Much will depend on the degree to which environmental performance becomes a quantifiable cost/benefit. The changes to the EU Emissions Trading System and the outlook for similar schemes around the globe point towards this becoming a reality.
Renewable energy is set to take a growing share of the global energy mix, and around 20% of energy use certainly seems feasible. Yet, no energy mix can depend solely on one source; consumption, security of supply and demand requirement such as seasonal and daily fluctuations require a diversified portfolio made up of several sources. At the same time, not all sources of energy are suitable for all applications (eg large scale or transport etc). Secondary costs, such as for example sustainability issues in the area of bio fuels that are currently being raised, are another consideration. As such, all sources will have to be continuously explored and developed.
David Porter - Association of Electricity Producers
6.05.08
Renewable energy: can it ever replace fossil fuels, or do other sources have to be explored?
Renewables are already making inroads into the energy sector. Today, the share of renewables in EU final energy consumption is 8.5%. In electricity, the share of renewables is almost double that, as a number of technologies have been developed to generate electricity from sources such as hydro, the wind, the sun and the ocean. In the UK for example, there is huge potential to generate electricity from offshore technologies such as wind,...
wave and tidal. The EU has just set itself an ambitious target for 2020: producing 20% of its energy from renewables. The target demonstrates that the political will is there to promote renewables and change the energy system. To do it, we have to be ambitious - but also realistic. It will take time and a 20% renewable energy target will be challenging. In the UK, it probably means moving from a position where 5% of our electricity comes from renewables, to one where it is 45% - in just 11 years. No one should under-estimate the size of that challenge, in terms of financial investment, skills, equipment and planning approvals. Nor, for those who want to invest, the importance of stable public policies.
In the short to medium term, a number of technologies will be needed alongside renewables to ensure security of supply. Energy companies with customers to satisfy want the reassurance of diversity in the fuels that they use to deliver heat, light and power and that includes fossil fuels. This does not mean that the electricity sector cannot move towards a low-carbon future. Already, research into carbon capture and storage is progressing, and the legislative framework for it is being created at European and national level. Carbon capture and storage technology would allow us to use fossil fuels without emitting CO2 into the atmosphere. Equally, companies are having a fresh look at nuclear power, another low carbon technology. In its report on the role of electricity in moving towards a low-carbon society, Eurelectric, the European body representing the electricity industry, showed that using a mix of technologies is the most cost effective way of reducing emissions by the middle of this century.
I am convinced that renewables will play a huge part in Europe's future energy mix and it is clear that energy businesses are developing rapidly their understanding about what renewables can and cannot do. Furthermore, fossil fuels are finite and they have to be replaced. As we make the transition, the energy industry must use the fuels and technologies that deliver the benefits that customers want - within the tightening environmental constraints that will steer us to a greener future.
For some decades we still will largely depend on fossil fuels. But due to their limited availability we will see the decline of so-called ‘production’ rates of oil and natural gas within the next 10 years. As renewable energy systems take longer to be build coal likely must replace much of the decreasing oil and gas production intermittently. So the static prognosis of another 200 years of coal reserves will melt down. Similar will happen with nuclear energy, but much sooner as uranium resources are more limited. As energy is the driving force...
for almost every human activity such as traffic, agriculture, housing, construction, water treatment, or health, this looks like a horror scenario.
Fortunately, I conclude from the research I did regarding availability of renewable resources and my knowledge on energy conversion technologies, that renewables can provide many times more electricity than mankind uses today. Also the complete thermal demand, required for production processes as well as room heating and cooling can be supplied by solar, geothermal and biomass.
In several electrical grids we already see that renewables can provide large shares. Today in Germany on average almost 15% of electricity is provided by renewables, in Brazil it is around 80%. To match demand including base load a well-balanced mixture of different renewable technologies is required. Solar energy well matches the peak during daytime. Wind and hydro often are complementary to solar. The renewable production in a single country hardly can cover full demand unless there would be massive overpowering, which is not cost-effective. However, due to weather patterns lower production in one country often is balanced out by overproduction in others. Further, higher volatility of electricity prices will lead to successful demand side management. Much more storage capacity than we have installed today must be build to cover low production periods. To allow all this, we need a massive strengthening of electricity grids. Today’s technology of high voltage direct current allows far transportation of large electricity amounts with low losses - but also quite expensive. Building many new electricity lines should be forced politically.
The technology to realize the full conversion to renewables is already there. Further enhancing efficiency helps to bring down costs. This is essential as today investment costs for renewables are still relatively high. Wind power, which is in the market for many years, already managed to decrease costs strongly. Other technologies like solar thermal power plants, which have an even higher potential, did not really start the learning curve yet. Through economies of scale, new concepts, and increased efficiency I expect that electricity generation costs will fall below those of coal-produced electricity before 2030 in many regions. Hopefully this will happen earlier, especially if coal facilities get obliged to sequestrate CO2.
Important is to ramp up renewables now, as long as enough fossil resources including metals are available. Bringing more renewables online soon and investing in energy efficiency smoothes the dangers, which the severe drop of fossil fuel production brings. This requires incentives to support deep market penetration of renewables until they are cheaper than fossils. Investments in the energy sector have very long pay-off periods. We will see that many of today’s investment decisions for fossil fuel fired systems are misdirected due to high fuel prizes. Unfortunately banks do not yet force investors to secure the required commodities over the full amortization period, e.g. by futures. Otherwise the market would create a strong boost for renewables much earlier.
… do other sources have to be explored?
In the next decades much money is needed to explore fossil resources, which will get scarcer and scarcer. Even more money is required to build facilities to gain those resources from places which are harder and harder to access. But sharply rising fuel prices will provide the companies excellent budgets to do this. Thus, there is no public funding needed here.
Further, it makes no sense to waste more money to explore nuclear fusion power. Promoters of fusion energy projects predict that this technology could be ready in 50 years, which is much too late. Even if it turns out that fusion power is feasible in industrial scale then, I have some doubts it will be a more cost-effective technology than renewables at that time. So let’s massively push today using the fusion power, which the Sun beams down to Earth every day and almost forever.
Can technology help us to reduce our dependence on fossil fuels?
Renewable and efficient energy technology is going to have to replace fossil fuels far faster than most people currently anticipate. The reason is the combined impact of two megaproblems that will shape the 21st century: peak oil and climate change. A premature topping point in global oil production would wipe out most if not all economic plans currently on offer in boardrooms and finance ministries around the world. This is because such plans routinely assume growing...
supplies of generally affordable oil for several decades to come. But a surprised world, so I and others believe, will instead soon be facing rapidly falling supplies of increasingly unaffordable oil. A growing number of oil industry whistleblowers now predict the early years of the next decade as the most likely time for the peak. As Former US Energy Secretary James Schlesinger recently concluded, "we can't continue to make supply meet demand much longer. It's no longer the case that we have a few voices crying in the wilderness. The battle is over. The peakists have won."
The main potential escape clauses for peaking conventional oil supply, according to traditional energy experts, are mining of the vast Canada tar sand deposits, and coal-to-liquids technology. Using the tar sands will require massive amounts of water and gas to melt the tar. Canadians would have to forget a lot of agriculture if we go down this road, never mind the greenhouse emissions. Coal-to-liquids technology is similarly greenhouse-gas profligate, though here - as with regular coal burning - advocates hold up the prospect of carbon capture and storage, where emissions are buried underground. Of this prospect Schlesinger has concluded, "it will take at least 15-20 years to introduce, if then." Because of the climate crisis, we don't have 15-20 years. That is also why nuclear power is a no-hoper. According to NASA's top climatologist, and many others like him, we have less than a decade to cut emissions deeply. If we don't, we lock in non-linear climate horrors such as an irreversible melting of the Greenland ice sheet, which would lift global sea level by 7 metres. Most of the global economy sits on the coastal plains.
Can renewable and efficient technology replace fossil fuels, and if so how fast? Here there is good news and bad news. Yes, we can run the world on renewables and efficiency. To give a feel for this, any self respecting solar energy company - hooked up with the right partners - can put up zero carbon buildings in a matter of weeks these days. Around half all carbon dioxide emissions come from buildings, directly or indirectly. Meanwhile, as traditional power prices soar, solar manufacturing costs plunge. This kind of potential is attracting a snowballing flood of investment. Even so, solar is no panacea. The twin megacrises demand explosive growth in all renewable and efficient energy markets. In a country like Britain, for example, we have the potential to source all our primary energy from wind and marine technologies. Knowing what the renewables family can do, imagine the frustration practitioners like me feel, having watched the survival technologies held back so badly during the great addiction to fossil fuels.
The bad news is that no combination of technologies, renewable or otherwise, can plug the energy gap if the peakists are correct. There will be a third, and last, global energy crisis. It will dwarf the first and second oil crises of 1972 and 78, and it will happen on the watch of most people at the helm in industry today. Profound economic dislocation will result. The challenge for global human civilisation will be how we rebuild post-peak. If we mobilise with renewables and efficiency, as though for war, we have the potential to achieve renaissance on many fronts. If we forget climate change, discount the future as we have to date, and go for coal and tar sands, we will achieve the opposite. Only a few hundred billion tonnes of unsequestered coal and tar sand would be needed to tip us into economically ruinous irreversible climatic impacts. That would amount to a fraction of remaining coal and tar-sand deposits, even if the experts have over-estimated those "resources" the same way they have conventional oil.
I would change the question slightly from 'can' to 'will' renewable energy ever replace fossil fuels and in that context the answer is an emphatic yes! In a world threatened by the impacts of climate change and where Peak Oil will mean a long slow and potentially painful decline in oil production outputs, rising fuel prices and a complete rethink of the way we generate and use energy we are at a unique crossroads as these two pressures unite. Our challenge is to creatively think and adapt our way out of this 'tight spot'. Essentially we live in...
a world where the our evolved civilisation is built on ludicrous inefficiencies which if we were to return to first design principles for making society function would be laughable. Alas, we must start from where we are in our redesign and grasp the opportunities that are already presenting themselves. As the radical engineer Amory Lovins says 'whoever talks about climate change as a threat hasn't done the maths'. We can reduce overall consumption dramatically through efficiency and change the way we generate our energy through a dual process of decentralisation and decrabonisation. We need to move away from a centralised grid based and dependent system to one where localised, decentralise generation close to point of use supplies the majority of local needs. This will require multiple solutions: solar photovoltaic and thermal, micro-wind, geothermal, small scale biomass, Combined Heat and Power etc working together in complementary fashion to ensure security and consistency of supply. It's a big vision but it's achievable if we really want it, the main barriers being current regulations and the vested interests who profit from the status quo. An integrated renewable energy solution is a big idea. But we never changed the world by thinking small!
In my view , the answer is a clear YES, it only depends on the timeframe we are using. Man discovered oil last century and has since planned the world largely around it.
However, man has also proven to be able to adapt to all circumstances. The big issue for renewables to expand beyond a certain threshold is their intermittant nature. However, I am convicned that If all efforts (R&D, financial,...) were concentrated on renewables rather than on fossil fuels as they are today, more efficient technologies would certainly emerge to allow storage...
and continuous use of renewable power. But since we have wasted decades without making serious efforts in this direction, this is not around the corner unfortunately, but certainly feasible. However, replacing fossil fuels is not as difficult as some people want it to be: for example, by covering just 1% of world deserts with solar modules, one would generate all power needed by the earth. Is this such an impossible task? What are we waiting for? Let's just do it!
The European Commission has set a binding target of 20% of renewable energy by 2020, up from today's 8.5%. The goal gives an idea of the unexploited potential of renewable energy sources in the short and medium term. In the long term, renewable energy sources can go much further still.
Renewable energies, particularly wind, are booming. In 2007, more net capacity was installed for wind power than for any other power-generating technology, including gas. Worldwide, there is now 100 GW of installed wind energy capacity, with new players, such as...
China and India, catching up with the more seasoned users of renewables in Western Europe. The Global Wind Energy Council (GWEC)'s latest report sees the trend continuing, to reach 240 GW by 2012.
The raw potential for 100% renewables and beyond is certainly there. According to the U.S. Department of Energy, the world's winds could theoretically supply the equivalent of 5,800 quadrillion BTUs (quads) of energy each year - more than 15 times current world energy demand. Indeed, a recent study in Germany demonstrated that the state of Hessen could run fully on renewables, and there are areas of Sweden and Spain that already have 100% renewables targets.
Energy use can be broken down into three areas: electricity, heating & cooling and transport. Of these, renewables are currently strongest in the electricity sector, with wind power covering 3.7% of EU demand. In 2030, with an installed capacity of 300 GW - up from the current 57 GW - wind power would provide 21-28% of EU electricity consumption. The renewables contribution to heating and to transport should also increase dramatically.
The European Renewable Energies Council (EREC), in its document Renewable Energy Scenarios to 2040, states that "by 2040, a share of renewable energy of up to 50% worldwide is possible". However, it adds that to reach such a share, "advanced, intelligent and reliable policy measures have to be implemented at least in the majority of countries worldwide."
For wind and other renewable power-generating sources to supply all the world's energy needs, significant barriers must be overcome. There is a need for high energy efficiency, far-sighted, ambitious policy frameworks, the internalisation of environmental costs, stable and flexible support systems, a flexible, correctly-functioning supply chain, increased support to technological development and an appropriate, competitive grid infrastructure. More support could be provided to renewables by redirecting the subsidies received by the fossil fuel and nuclear industries, which account for approximately 80% of total subsidies received by the energy sector in Europe.
Only by moving step by step, by ensuring all the required elements are in place, can a 100% renewable energy future become a reality.
Your Comment
Greg Arrowsmith - EUREC Agency
27.05.08
There are various ways of interpreting this question, so I will choose this one: "Will renewable energy sources ever be able to satisfy fully the world's energy needs?"
By far the majority view of the energy industry is that ultimately the world's energy supply will come from renewable energy. But opinions diverge on when this day will come. The advent of "peak oil" will hasten it. Safe, cheap carbon capture and storage technology for fossil power plants would push it back. It all comes down to the relative cost of renewable and fossil energy...
In many areas of the world, advanced renewable energy technologies can deliver energy to the end consumer at the same price - or cheaper - than fossil technologies. More and more regions of the world will find renewables the cheapest option as technological advances are made, economies of scale drive down manufacturing costs, and fossil energy prices continue their inexorable rise.
Some technologies are further from the market than others and an energy system with a high or 100% reliance on renewable generation will mostly likely be based around a combination of technologies with complementary characteristics. Concentrating solar power (CSP), for example, is expensive today compared to fossil generation even in very sunny climates like the Middle East, but those countries that choose to install some CSP capacity now will improve their understanding of the technology and equip themselves with the means to escape rising fossil electricity costs. The sums of money needed to subsidise the building of this initial capacity, expressed as a proportion of the kWh cost now paid by electricity consumers, are small, but the future savings have the potential to be very great indeed (see graph below from the German Aerospace Centre, concerning Jordan).
Thick line: electricity cost of new CSP plants. Dash-dotted line: cost of new gas-fired combined cycles. Thin line: cost of conventional electricity mix in Jordan. Dashed line: cost of the national electricity mix including CSP. Black squares: installed solar capacity share in the Jordanian electricity mix according to MED-CSP 2005. The circles indicate the cross-over of the cost of CSP versus new conventional power plants (upper) and versus the national electricity mix (lower). Red zone: small additional investment costs to kick-start CSP. Green zone: large savings made thanks to the take-off of CSP. Long-term exchange rate $ / € = 1.