What proportion of the world’s energy supply will be sustainable by 2020?

Mike Childs, head of climate change campaigns for Friends of the Earth 

The next 10 years is not a great amount of time. We’re seeing great strides forward in terms of renewable growth in China, which is clearly leading the way, Europe has set itself a target to get 20 per cent of its total energy requirements from renewables by 2020; and the US, despite its political debates about whether climate change is happening or not, is actually driving forward quite a lot in terms of renewable energy, partly because of energy security concerns. But it will still be a small proportion of the total energy requirement; we’re looking at a maximum of 15-20 per cent globally produced through renewable energy if China carries on at its rate of development, if Europe meets its target, if American development continues and if other developing countries get in on the act. Egypt has recently announced a significant wind farm development partly funded and supported by overseas governments. 

So renewable energy is starting to take off, but the period between 2010 and 2020 is likely to see relatively slow growth. 2020 to 2030 could see rapid growth if that’s what governments choose to do now. In the UK, for example, our greatest potential for renewable energy is from offshore wind. We’ve got some offshore windfarms, and they will undoubtedly grow to 2020, but if you want to seriously scale up there have got to be some infrastructure changes. Ports need to be built, we need to get the barges to help build the offshore wind plants, funding needs to get into place, licensing needs to be in place, we need to work out the grid access from offshore wind. There are lots of challenges that need solving in the next few years that could see a very substantial rise post-2020. 

Friends of the Earth is 40 years old this year and traditionally the role of the organisation has been to wake up the world to the challenges it is facing, from river pollution to climate change and beyond. Over the last four or five years there’s been a much greater global recognition of the scale of the environmental challenges we’re facing. Our role now is less about putting the issues on the agenda, and more about focusing on the solutions and the regulatory framework needed to address the challenges that now top the agenda of virtually every major company around the world. For example, in the UK, Friends of the Earth campaigned for so-called feed-in tariffs. Businesses and householders in the UK can put up solar panels in their roofs not just to produce cleaner energy but to make a bit of money on the side as well.

Royal Society of Chemistry

Deployment of sustainable energy will require a concerted effort from scientists across a number of disciplines to develop current technologies. However, a supportive legislative environment to encourage adoption of sustainable energy is also needed, alongside an emphasis on the education of consumers.

Sustainable energy encompasses a wide range of sources, including solar, wind, tidal, nuclear and biofuels. Increasing the proportionate use of all of these sources will require improvements in materials, processes and waste stream treatment to allow their successful adoption. A central issue in deploying sustainable energy is the efficient conversion and storage of energy. This is particularly pertinent in relation to intermittent sources such as solar, tidal and wind. In the case of solar energy, existing solar panel technologies operate at efficiencies of less than 10 per cent. In order to make increased use of sustainable energy more viable, improvements in fuel cells and batteries must be made. 

The future UK landscape is likely to feature a mixture of nuclear, solar, tidal and wind energy. Current fossil fuel usage may also change, with a move towards co-firing in power stations using a mixture of coal, domestic wastes and biomass. The UK already obtains around a fifth of its energy from nuclear; further investment in infrastructure could see this increase. While wind, tidal and solar covers a much lower proportion of our current energy use, UK research in these areas is advancing, with solar potentially seeing a slightly increased future uptake. Wales is home to a burgeoning solar industry and public demand for solar technology is consistently rising. The number of existing buildings receiving government grants for the fitting of solar panels nearly quadrupled between 2006 and 2009.

While research into practical advances is important, the basic research that underpins improvements in these areas needs to be maintained. Without basic research into photochemistry, solar cells could not have been developed. Further advances in nuclear energy depend on the development of fundamental lanthanide and actinide chemistry. 

Policy on energy must be cohesive and take into account all of the parts of the energy puzzle. No single source of sustainable energy will meet future needs. Instead, policy which allows integrated use of a range of sources must be adopted. Educating consumers on the move towards sustainable energy and the progression of new technology is essential. Scientists and the media must work together to ensure that accurate information on safety, availability and viability of new technologies is conveyed to the public. By implementing a cohesive research and policy agenda, an increased use in sustainable energy could be attainable by 2020.

Duncan Gregory, chair in inorganic materials and head of inorganic chemistry at the University of Glasgow 

The answer rests entirely on political will. If the political will isn’t there, both nationally and internationally, it matters little what scientists might be able to achieve. 

In the recent past, perhaps scientists have struggled to communicate and assert themselves sufficiently. One of our problems is that we are a disparate group. For example, my discussions with climatologists are few and far between; I might meet them occasionally at clean energy conferences but we don’t really interact. A greater interaction between them and physical scientists like us - those of us who make things and try to solve materials problems - could only be beneficial. And then there are the absolutely key people in the mix such as the economists. It’s vital that as scientists and engineers we carry socio-economists with us; they can reinforce to government that there is a financial incentive in driving towards sustainable energy and a wonderful opportunity for social reform. Sadly, I think the move towards sustainable energy is really going to suffer in the foreseeable future, with the focus currently shifting from environmental issues towards economic issues. When that happens, one looks inward and becomes a little protectionist.

With a background as an inorganic materials chemist, my team is interested in understanding various types of materials that will convert or store energy. We focus on lithium ion batteries, hydrogen storage materials for fuel cells, and thermoelectric materials for converting thermal energy to electrical energy. Although funded primarily by the Engineering and Physical Sciences Research Council (EPSRC), we increasingly interact with industry. We collaborate with the global aerospace and aviation company EADS (owners of Airbus), which is interested in reducing the carbon footprint of flight. Alongside this, one of our EPSRC projects is co-funded by the government’s Defence Science and Technology Laboratory (DSTL), focusing on powering soldiers on the battlefield, reducing their burden in terms of batteries, allowing them to perform longer missions by reducing the need to recharge. An added benefit of that project, where we are trying to couple photovoltaics and thermoelectrics, is that any technology we discover will be transferable to the civilian sector - potentially providing power for buildings, for example. 

There has to be a move towards sustainable energy in the next 10 years, but the form that takes is less easy to predict. I suspect that if there is no political will in the West, it will certainly come from countries with growing economies. In India, for example, which has a lot of sunlight, the country can realise a very marketable resource and product - exporting energy generated by sunlight - providing the infrastructure is appropriately developed. The distribution of the world’s energy supply and wealth - bearing in mind that most of the world’s population is outside Europe - will change dramatically by 2020. 

Anthony Harriman, professor of physical chemistry and co-director of Newcastle University’s molecular photonics laboratory 

On the question of how much of our sustainable energy supply will be solar by 2020, since that is my research area, probably only a small fraction. But I suspect it will grow bigger and bigger as perhaps some of the other sustainable energy technologies plateau out. We’re still very early on in the solar world. It looks good; in terms of really producing massive amounts of energy its potential is enormous. But at the moment, if you asked someone to fill a petrol tanker with solar-generated fuel it would be impossible. It’s too big a challenge. It won’t happen in 10 years, but it will happen one day. There are certain areas where other technologies will need to kick in; we will never be able to make petroleum, but we’ll be able to make alternatives. As the technology develops we’ll be able to use replacement fuels. But solar-powered transport is not likely. You’d never be brave enough to leave without petrol. It would be nice in the summer, or if you go to the south of France, but would you ever dare rely on solar power on a ship?

The power you could generate would be extremely valuable around the house. And I think it will drive agriculture. In parts of the world where at the moment it’s difficult to imagine really good quality agriculture, I think you could solve the problems there with a solar-powered system. Even today you could use sunlight to produce ammonia. And from a water supply you could enrich it with the nutrients you need to grow crops in parts of the world where otherwise that’s going to be difficult. 

Given the amount of space you need to generate significant amounts of solar power, it is unlikely that filling a field in the UK with solar panels will be very useful. 

But I’m convinced you can power everything inside a building by using the windows on that building. The technology is there, the justification for doing it is there, but it needs a driver. It would take a lot of education, it would be very expensive, and we’re unlikely to see it in the next 10 years. We need a fantastic demonstration of it; it hasn’t caught the public’s imagination yet. The policies in Europe, where you have your roof coated in silicon and then you feed the energy back into the grid [see the feed-in tariffs mentioned in the Friends of the Earth comment], they’re talking 20 years before you make any money from it, and will the solar panel producers be in existence in 20 years’ time? Probably not. 

In America you see the typical solution to the problem, which is to throw enormous amounts of money at it. The big driver for Americans is security, and they’re talking about a 15 year programme to make solar fuels. Strangely enough they’re using Europeans as all the referees and advisers. A worry for me is that they will license everything, and then we will be no further forward.