New world markets are opening up as the cost of fossil fuels continues to rise and the problems associated with changes in the chemistry of the atmosphere and oceans are recognised. Ways are being found to store energy from intermittent renewable sources, including advanced batteries, hydrogen, ammonia, biomass and synthesised gases.|
The role of innovation
A variety of efficient and renewable energy technologies are under development, but they could not compete when cheap fossil fuels were readily available. Fuel cells are the most efficient means of converting new renewable energy sources to electricity and heat. They convert fuel electrochemically in a process which is generally twice as efficient as combustion. Fuel cells will facilitate the change to renewable energy sources in the electricity generating, heating and transport sectors. Depending upon the fuel used, emissions are minimal or zero so that it is feasible to generate electricity and heat on site, thus obviating expensive infrastructure. With their high electricity to heat ratio, fuel cells will be utilised in the well insulated buildings which will result from the Government’s new Green Deal. Fuel cell combined heat and power (CHP) systems will facilitate the changeover to renewable heat, contributing heat as well as providing some of the electricity to power heat pumps at times of peak winter demand. As electricity supplies are increasingly obtained from intermittent renewable sources or base load nuclear power, the use of electric vehicles will help to balance the electrical load by storing power at times of low demand. With double the efficiency of the i.c. engine, fuel cells could become the most cost effective means of using new transport fuels and minimizing emissions of carbon dioxide and other pollutants.
UK Government policy expediting change
At a recent meeting of the All Party Parliamentary Climate Change Group (APPCCG), Prof Samuel Fankhauser of the Grantham Research Institute of the London School of Economics explained that the UK will have to halve its greenhouse gas emissions by 2025. The 2008 Climate Change Act and the subsequent four carbon budgets were passed nearly unanimously by Parliament. They commit the UK to cutting its annual greenhouse gas emissions by half by 2025, which is not achievable without a power sector that is virtually carbon-free by the middle to late 2020s. It is clear that this cannot be achieved by relying on unabated gas power stations and policy-makers need to anticipate this and avoid locking in high-carbon electricity generation. In addition, the European Union Directive on Renewable Energy requires the UK to obtain at least 15% of its gross final consumption of energy from renewable sources by 2020. In order to comply with the EU Directive, the Government’s Renewable Energy Strategy suggests that around 30% of electricity, 12% of heat and 10% of the energy required by motorised transport should come from renewable sources by 2020.
Cost of renewable technologies
Prof Fankhauser said that a key attraction of onshore wind is that in terms of levelised cost it is currently the cheapest renewable technology in the UK. Levelised cost is an economic measure that takes into account all the costs of a technology discounted over its lifetime. However, it is important to consider the real cost of future energy technologies. The comparison needs to take into account the actual and future prices of energy technologies, including the expected price of fossil fuels and the real cost of climate change. Possible cost reductions for other low-carbon technologies, due to learning and economies of scale, also need to be considered. Sarah Rhodes of the Department of Energy and Climate Change said that on energy grounds there is a good case for onshore wind. The subsidy cost is generally about half that of offshore wind and it will help to ensure future energy security and price stability in the face of rising costs for natural gas. A recent survey found that over two thirds of the population were in favour of onshore wind, so long as local factors were properly taken into account.
Fuel cells with renewable installations
Fuel Cell Power believes that cutting emissions of greenhouse gases is best achieved by deploying both small and large scale energy technologies and that efficient electrochemical conversion can effectively replace the combustion of fuels. The use of fuel cells in combined heat and power applications (CHP) would reduce the waste of much of the 45m tonnes of oil equivalent (toe) which is at present lost in the transformation to secondary electricity. It is estimated that the thermal energy lost in this process, together with grid transmission losses, would be sufficient to heat every building in the UK. The overall efficiency of fuel cells in CHP mode is 85% compared to around 36% for the electricity grid. In order to provide 27m toe of electricity in 2011, 75m toe primary energy was required.
Dealing with intermittent supplies
Dr Robert Gross said that according to a systematic review of the evidence by the UK Energy Research Centre (UKERC), if 20% of electricity were supplied by wind power (or other intermittent renewable sources) by 2020, the additional back-up capacity and system balancing reserves needed would be equivalent to about 20 - 32% of the installed renewable capacity. For example, assuming 27GW of onshore and offshore wind installed capacity by 2020, an additional 5GW to 8.5GW of fossil fuel-fired generation capacity would be required. However, this could be reduced by non-generation methods such as interconnection, energy storage and load management, as outlined in the White Paper on Electricity Market Reform (EMR).
According to the Government’s Digest of UK Energy Statistics 2012 (DUKES), in 2011 fossil fuels supplied approximately 88% of UK energy, nuclear 8% and renewables 4%.
The data are given in tonnes of oil equivalent (toe), where 1 toe is approximately 42GJ. 162million (m) toe were imported and 84m toe exported, so that net imports were 78m toe, or 37% of the energy used in the UK.
The primary energy demand totalled 212m toe, comprised approximately of coal 33m toe, primary oils 76m toe, natural gas 78m toe, bioenergy and waste 8m toe and primary electricity, mainly nuclear, wind and hydro, 17 m toe.
Of the 212m toe, transformation losses comprised 48m toe (of which electricity 45m toe); other losses 4m toe; energy industry use 13m toe; leaving 147m toe for final consumption.
147m toe was utilised for final consumption by: industry 27m toe; transport 55m toe; domestic 39m toe; public administration 5m toe; commerce 9.5m toe; agriculture 1m toe; misc 1.5m toe; and non energy uses such as chemical feedstocks and lubricants 9m toe.
The 147m toe of fuels for final consumption were petroleum 70m toe; natural gas 43m toe; electricity 27m toe; with the balance of 7m toe made up of coal, bioenergy and waste.
Dr Gross said that other countries are benefitting from the manufacture of low carbon technologies and he would like to see the UK taking a stronger role in the new markets which are opening up.
Storing renewable energy
A study by the Bow Group entitled Rescuing Renewables: How energy storage can save green power recommended that in order to solve the problem of intermittency, a Renewable Energy Storage Incentive (RESI) should be introduced to encourage the deployment of energy storage systems, particularly for the use of hydrogen. Storage could be at two levels, on a kilowatt to sub megawatt scale if it is located close to where the hydrogen will be utilised, or up to 50 megawatts near wind farms. It is suggested that 10p/kWh RESI could be added to the Feed in Tariff. The price of electricity at times of peak demand can increase fourfold from the off peak rate and storage would help to contain the price. The problem will be exacerbated as more intermittent renewable energy is introduced and the present storage with ‘spinning reserve’ in coal fired stations is phased out. The report found that the following advantages would accrue if hydrogen were stored locally:
Improved efficiency as supply matches demand
The need for fossil fuel back-up is removed
Lower carbon emissions
Less investment in infrastructure costs
Reduced stress to the system as ramping up and down is minimized
Grid stability and continued freedom from blackouts
Community, business and individual self-sufficiency
30% RENEWABLE ELECTRICITY
In terms of electricity generation or output, during 2010 onshore and offshore wind generated over 10 terawatt hours (TWh), hydro 3.5TWh and 12.8 TWh were generated from biomass and waste. If the electricity from biomass and waste were delivered at double the efficiency with fuel cell technology, this could contribute over 25 TWh per annum. This would give communities a choice between more onshore wind farms and the efficient generation of electricity from waste. In 2007 three times more waste was recycled or composted than was burnt for fuel, but there would be greater public support for generating electricity from waste if the clean, efficient process of electrochemical conversion were available. In addition to obtaining more renewable electricity from waste sources, the process leaves residues for farmers to use as fertilisers. A project is underway to demonstrate alkaline fuel cells which, once economies of scale are achieved, are projected to stabilise the retail price of electricity generated from local waste at 7p/kWh. Another company is exporting to developing countries PEM fuel cells powered by ammonia obtained from waste.
There is great potential for fuel cells powered by energy from biomass and waste, both in the UK and around the world. A tremendous energy store is locked up in existing landfill sites. The clearing, reclamation and restoration of the older sites could deliver massive benefits by recovering and recycling metals and converting all the plastics and other organic material into useful end products. This would be a high value energy exporting, profit making cleanup programme. There are millions of tons of usable energy sources available on our doorsteps. This is by definition a green energy source and converting it into energy has massive benefits by producing green energy locally, reducing traffic to traditional generators, restoring and reclaiming land, removing pollutants and creating employment.
ELECTRICITY GENERATION - CAPACITY AND OUTPUT
Capacity: 1000 watt (W) = 1 kilowatt (kW); 1000 kW = 1 megawatt (MW); 1000 MW = 1 gigawatt (GW); 1000 GW = 1 terawatt (TW). Output is measured in hours of generation at full rated capacity, i.e. 1 kilowatt hour (1kWh)
www.fuelcellpower.org.uk  www.greenmotorsport.com  www.futureenergies.com 
The electrochemical process is not limited by the Carnot cycle and can generate electricity at 60% to 70% efficiency, that is twice the efficiency of generating electricity by combustion.
If fuel cells are powered by energy from waste, this could help to reduce methane emissions and slow global warming. According to the International Energy Agency, methane is a greenhouse gas 25 times more potent than carbon dioxide, so reducing methane emissions will enable important near-term progress toward climate change mitigation. Fuel cells can also be powered from the stored hydrogen which will increasingly become available from intermittent supplies of energy from wind, marine and solar power at times of low demand for electricity. This will smooth the load from intermittent supplies and reduce the investment needed in the electricity infrastructure.
High temperature fuel cells
High temperature fuel cells generate electricity and heat from natural gas or bio-energy at up to 90% efficiency. They also provide cooling and can generate hydrogen to power transport. During the process of generating electricity, the fuel cell automatically separates the carbon dioxide stream and developments are underway which could enable this to be stored or recycled. An extension of the Feed in Tariff (FiT) to 5 MW for CHP systems would encourage the deployment of these clean, efficient technologies until economies of scale are achieved.
Related energy technologies
The UK could lead the world with its small and medium enterprises (SMEs) which are developing clean and efficient energy technologies. Fuel cells work alongside both large and small scale renewable energy systems. The use of small wind energy collectors would complement photovoltaic panels, as they provide peak power during the winter months. Subject to successful development, a 400 watt micro wind energy collector could generate 1000 kWh per annum, similar to that of a 1kW solar panel in the UK.
On a much larger scale, fuel cells could also be powered by synthesized renewable fuels, in which CO2 extracted from the atmosphere is combined with hydrogen obtained from renewable sources. A UK project has successfully evaluated this technology and larger scale demonstration is required. The first units to capture carbon dioxide could be situated at a brewery/distillery, prior to larger scale deployment. It would take decades to replace the existing natural gas pipelines but this technology could be a cost effective way of transporting renewable energy while local hydrogen stations are being built up. The Treasury is making available £1 billion for carbon capture and storage (CCS) projects. Instead of storing the carbon for hundreds of thousands of years, it could be synthesised with hydrogen from wind farms to form valuable gaseous fuels or petrol. The costs of offshore wind will come down as 10 MW units come on stream with a target cost of £100/MW. The carbon neutral gas would be suitable for powering fuel cells, as it would not contain sulphur or other impurities. This would improve the efficiency of hydrogen reformation, which is done internally by the high temperature fuel cells.
12% HEAT FROM RENEWABLE ENERGY BY 2020
The Renewable Heat Incentive (RHI) is supporting the combustion of biomass, the use of solar thermal panels and the introduction of heat pumps, which extract heat from the ambient atmosphere or ground, in a process similar to that of a refrigerator in reverse. The heat pumps will utilise most electricity at times of peak winter demand, which would require very large investment in the electricity infrastructure. Fuel cells can be introduced alongside the heat pumps in order to generate onsite electricity to power the heat pumps, without requiring new electricity transmission infrastructure. The fuel cells will at the same time contribute to the heating requirement. The fuel cells will increasingly be powered by renewable energy, either biofuels or hydrogen from wind, wave or solar power. Fuel cells have a high electricity to heat ratio, so they are most effective in well insulated buildings. It would be beneficial if all users of new heating technologies benefitting from public support should meet minimum insulation standards.
10% TRANSPORT POWERED BY RENEWABLE ENERGY
According to the Evidence Brief prepared by the UK Energy Efficiency Deployment Office (EEDO), final energy consumption by the transport sector doubled between 1970 and 2010, accounting for 19% in 1970 and 37% of final energy consumption in 2010. During this period the electric vehicle industry worked with the road transport industry and the former Department of Energy to develop an efficient hybrid drive system. The hybrid design selected was the load-levelling system, in which a small engine operates continuously at maximum efficiency. Peak power demand is met by a motor and small battery pack, which is continuously recharged when the vehicle requires less power or is braking, in a process called regenerative braking. Early trials suggested that this hybrid design could cut fuel use in urban driving by around 40% and there would be continual improvements as advanced batteries and fuel cells were introduced.
The engines of cars and vans were designed to meet the requirement for 56 mph constant speed, not for efficiency in stop/start driving. The average power requirement in London was found to be only 3.5 kW, which meant that engines were most inefficient and polluting in busy urban centres. Ultra-capacitors can also be used to store the energy from regenerative braking and contribute to the power required for acceleration. There are cost advantages if a fuel cell is used in a hybrid configuration to meet the average power demand. The fuel cell can be rated at 5kW to 6kW, which is about a fifth of the maximum power demand.
One British SME is operating prototype fuel cell hybrid cars and is achieving energy consumption equivalent to 300 mpg on petrol. It is estimated that an 18kW to 20kW fuel cell would be required for a 5 seat family car that can cruise at 75 mph. This compares with 80kW to 100kW fuel cells used to power the heavy, inefficient and expensive cars provided by the motor industry. A unit of biogas can be burnt in a combustion engine or in a CCGT plant producing electricity for an electric car. However, considerably greater range can be achieved if the hydrogen is stripped out of the unit of biogas and used to power a highly efficient fuel cell car. Today’s vehicles were optimised around the i.c. engine, before problems of energy security, resource depletion and climate change were envisaged. Technology alone is not going to solve these problems. Instead of selling vehicles, a mobility service is leased, which changes the attitude to one of optimising resource use, extending vehicle life, recycling and designing the vehicle for value recovery.
Another British SME has developed lightweight power units which are a complete replacement for the engine, gearbox and differential found in conventional cars. The electric drive trains achieve 75% efficiency, which compares with only 15% to 35% for an internal combustion engine, depending on whether it is in stop/start urban traffic or travelling at constant speed. The electric drive trains are quite revolutionary, in that they will enable a new range of long distance eco friendly electric vehicles to be developed that do not rely on the conventional heavy steel bodies used by current car manufacturers. Current designs have to be strong enough to cope with the conventional big heavy engines and gearboxes. It is not the big car companies that will actually deliver the new non-polluting transport solutions. They have already invested vast amounts in conventional vehicle manufacturing technology and need to sweat those assets to remain viable, whereas this solution does not need those manufacturing facilities. The conventional car manufacturing industry in its current form does not have a long life expectancy, and the changes necessary to evolve to new materials, new designs and concepts will need careful nurturing. A transition to an electric vehicle transport infrastructure will require entirely new and different forms of support products and services and new companies will emerge to deliver them.
An EU study entitled A Portfolio of Power-trains for Europe envisages that the world is likely to move from a single power-train (I.C.E.) to a portfolio of power-trains including Battery Electric Vehicles (BEV), Plug-In Hybrid Vehicles (PHEV) and Fuel Cell Vehicles (FCEV). The total cost of ownership of the four power trains is expected to converge around 2025. The study shows that FCEVs are technologically ready and can be produced at much lower cost for an early commercial market over the next five years. The cost of fuel cell systems is expected to decrease by 90% and component costs for BEVs by 80% by 2020, due to economies of scale and incremental improvements in technology.
Cutting the impact of travel
According to the British Social Attitudes Survey 2011, two thirds of respondents agreed that the current level of car travel has a serious effect on climate change and they would like to take action to reduce this. Some would like to walk more, go by bus, cycle more or reduce driving speed. The transition to cleaner, quieter vehicles will make it more pleasant for present car drivers to walk or cycle for shorter journeys, which will lead to further reductions in greenhouse gas emissions. Lower speeds in residential streets could also lead to further cuts in emissions, as more people are encouraged to take out their bicycles. The survey finds that 69% of non cyclists believe that it is too dangerous for them to cycle on the roads. A majority of 70% would like to be able to buy a car with lower carbon dioxide emissions.
The second family car and new local car share groups will be early markets for electric vehicles. In 2011 the average car journey was just over 8 miles and more than a quarter of households had access to more than one car or van. The deployment of electric vehicles in niche markets for urban and local transportation will create a firm basis for the larger scale manufacture of electric vehicles and help to build up the requisite refuelling and servicing infrastructure. One niche market is for company cars and the Committee on Climate Change (CCC) recommends that, given the importance of electric vehicles, their exemption from company car tax should continue after 2015. The CCC envisages that, by 2020, 1.7 million electric vehicles of all types could be on the UK roads.
The Government’s support for the H2 Mobility programme will encourage the greater use of hydrogen fuel cells for transport. The most suitable fuel cell for lightweight cars and vans at this stage is the Proton Exchange Membrane (PEM) fuel cell. For larger lorries and buses a prototype Alkaline Fuel Cell (AFC) powered tram is being developed. It is envisaged that the AFC could be combined in a hybrid configuration with a Solid Oxide Fuel Cell (SOFC) in order to match the low cost of the alkaline fuel cell with the very high electrical efficiency of the SOFC.
INNOVATORS LEAD THE CHANGE
Oil companies will have to diversify into the renewable energy market, as most of the global automotive companies are planning to start commercial production of hydrogen fuel cell powered vehicles between 2015 and 2020. They do not want to lose customers when petrol becomes prohibitively expensive due to the rising costs of oil extraction and government legislation. Lord Nicholas Stern said in a letter to the Financial Times that fossil fuel companies are valued according to their proven reserves, but only half their reserves may in fact be saleable due to legislation on carbon emissions and this should be resolved in the interests of all investors. The benefits to manufacturers and the UK economy as a whole of investment in low carbon technologies are outlined in a policy brief from the Grantham Research Institute entitled A Strategy for Restoring Confidence and Economic Growth Through Green Investment and Innovation. According to an EU study entitled Finance, Innovation and Growth there is little investment available for innovative SMEs in Europe. British engineers believe that the UK could learn from the US model, in which the fuel cell companies have had very considerable value of orders from various government departments. Private finance is also more readily available from US venture capital businesses, which allocate a portion of each fund, usually 5 - 10%, for long term high risk strategic investments.
The Way Forward
Fuel cells complement the new distributed energy technologies which are growing up around the world, powering local industries, homes and schools with energy generated on site. Given similar support to that for competing technologies, they will provide a cost effective alternative as economies of scale are achieved. Should the Government go ahead with a large nuclear programme, this will require base load operation as it cannot be easily ramped up and down. There would still be problems balancing the electricity load with intermittent renewable sources from wind farms, but hydrogen fuel cell systems are flexible enough to store the energy and make it available at times of peak demand. In future there will not be three separate energy streams, with oil for transport, natural gas for heating and a separate grid for electricity. Renewable energy will increasingly power all sectors, providing electricity, heat and cooling, as well as fuel for transport. Efficient electrochemical conversion could double the electricity obtained from renewable sources for final consumption and would also contribute to heating. The use of electric vehicles could halve the primary energy demand for transport.
The UK has leading engineers with expertise in electrochemical energy conversion, hydrogen storage, fuel synthesis, small scale renewables and electric vehicle design. Government departments could lead the way by procuring innovative energy technologies from SMEs. Private investors could allocate 5% to 10% of their investment to longer term innovation, as they already do in the USA. A concerted effort to bring to market a variety of innovative energy technologies will enable the UK to be a world leader in the manufacture of the next generation of efficient, low carbon energy technologies.
The Foundation for Economic Trends in Washington D.C. envisages that the five requisites for a sustainable future are: shifting to renewable energy; turning buildings into micro-power plants to collect energy on site; deploying hydrogen and other storage technologies; the development of an energy internet; and changing to electric vehicles.
A new business model is needed for the development and deployment of clean, efficient energy technologies. Several UK companies are ensuring that the interests of all their stakeholders will be represented, whether they are users, investors, manufacturers or others dependent upon a stable environment. Some companies specify that a proportion of their income will be ploughed back into the provision of clean energy technologies for the local community. These new technologies are often made available to other manufacturers under favourable ‘open source’ arrangements, in order to hasten the uptake of clean, efficient energy technologies around the world. Engineers have been working to find new models to meet the requirements of this century, getting down the cost of renewables, recycling and aiming for zero waste and zero carbon footprint. They believe that the public will vote with their feet for the green operational companies, as they have done with fair trade!
Jean Aldous October 2012