The enthusiasm for alternative energy sources is heating up as carmakers face increased cost, but it seems that solar and wind power can only fulfil their promise if the right subsidies are in place 

Alternative energy. Why is it called that? What is it about sunlight, wind and the other, currently fringe, energy sources that makes them ‘alternative’? Like oil, they are simply energy, and to brand them as alternative can, sometimes, negatively influence people into believing that they are either inconvenient or too expensive. There are, though, examples of cost-effective alternative energy solutions that are now helping companies successfully reduce their energy bills.

UK construction company Gazeley says it is ‘committed to delivering environmental initiatives at no extra costs to its customers’. Although specialising in logistics buildings rather than production facilities, some of the technologies it has pioneered in commercial applications are worth examination. Based on a so-called ‘eco-template’ for offices and warehouses of 100,000 square feet or more, the company aims to address not the minimal carbon impact a building has during construction, but the 92 per cent of total carbon emissions a building emits over its lifetime. Designed from the ground up to be energy-efficient, techniques include stormwater recovery, super-effective insulation, geo-heat pumps and, where appropriate, solar power. Although the UK has yet to embrace solar photovoltaic (PV) electricity, plants in Spain or other sunnier regions could reap considerable benefit.

Pre-heated air
If a new building isn’t in the budget, the SolarWall solution, offered by CA Group in the UK and Conserval in the US and Canada, is said to have the potential to make the most of a building’s existing qualities. “The SolarWall system uses the building’s elevations to pre-heat fresh outside air, bring it in and use it to offset the heating load. It reduces gas consumption and thus reduces the company’s carbon footprint, too,” says Andrew Brewster, Design Engineer with CA Group. The concept is quite simple. A sun-facing wall is fitted with a secondary metal cladding, perforated with small holes and mounted on a spacer system. “The air gap between the original wall and the cladding is 100-300mm. As the sun shines, it heats up the perforated panel, which warms the layer of air, which is then drawn into the building. Even on cold days, which are often very clear and sunny, it can raise the temperature of the air layer by 30-35°C.” It’s not a totally new technology: originators of the idea, Bombardier and Ford have been putting this method into practise since the 1990s.

“Ford has installed (this technology) on seven sites in the US and saved over $10m in heating bills,” continues Brewster. “In the US, GM has, over the past 15 years, used SolarWall to offset over 1,200 tonnes of CO2, as a result of reduced demand for heating.” CA Group first tried the SolarWall on its own buildings towards the end of 2005. “In early 2006 we employed Business Services Research and Information Association to undertake air testing to ensure we met regulations, and to independently monitor the building before we put the cladding on it,” he said. CA had seven years of gas and electricity bills with which to make valid comparisons. “We then installed a 410 square metre SolarWall system on our SE elevation in March 2006. We monitored it for 12 months and the final report showed that we’d saved 50 per cent of our 1,800 square metre building’s gas consumption, and that SolarWall had actually supplied 21 per cent of our heating requirement over the year.” As the building in question is a manufacturing and distribution facility that often has its doors open, this was a considerable boost in efficiency. As well as direct energy cost savings, the SolarWall had another benefit. “It also saved 58.9 tonnes of CO2. Because it performed so well on our existing building, we installed it on our new premises from the outset. We’ve been running it for around 16 months and reckon it has saved us 64 per cent of our heating costs. The new unit is 3,500 square metres, it runs 24 hours a day and our gas bill in September 2007 was £13.”

Living in a material world
In the assembly and production area, one may wonder what can be achieved by switching materials used in auto manufacturing. Everyone is aware of the weight savings offered by plastics and aluminium, making vehicles cheaper to run. Aluminium, though, is expensive to manufacture. Anglesey Aluminium, near Holyhead, UK, uses more than 12 per cent of the total electricity demand in Wales, producing aluminium billets, rolling ingots and pure metal. Considering twice the output uses only 22 per cent more power and the company has improved efficiency by approximately 27 per cent since 1973, it is still running close to the limit of what can be achieved. Having consulted the Carbon Trust and engaged in Six Sigma projects to improve process efficiency, it has switched from a batch furnace to a Hertwich continuous unit. The company receives all its power from a carbon-free source – Wylfa atomic power station – so it doesn’t pay the Climate Change Levy. But Wylfa is due to close no later than 2015 and gas priced at 2005 levels would still be too expensive for the plant to operate economically.

Due to rising demand from emerging economies and the increase of crucial power costs involved with aluminium production, auto manufacturers have been looking for lightweight alternatives. The solution could be the ultralight steel auto body (ULSAB), first unveiled in 1998. Having demonstrated comparable strength with regular body components, including frameless doors, it has already been incorporated in door modules, but a cost penalty of about $4 per door puts off a lot of manufacturers, this despite the cost being related to the technology employed in making the material rather than energy costs. Luxury carmakers may not be so critically affected by rising aluminium prices but mid- and lower-market producers will be, so while the ULSAB project formally ended in 2002, carbon fibre and plastic (recall the Citroën AX with its plastic panels) may still find their time has arrived.

Sunshine came softly
New technologies are becoming progressively more high profile and, while little is as high profile as a few wind turbines across an area of outstanding natural beauty, the breeze isn’t as strong a source of energy – in theory – as the sun. Much has been made of the savings to be achieved from solar power, both thermal and PV, yet much to the chagrin of all concerned, the sun is still strongest where it is needed least, in desert regions, and weakest where its energy would be most welcome, in the populated higher latitudes. “Solar power would have cost us five times as much as wind and would need nine acres of panels to produce the same power as two 1.5mW wind turbines,” says Rick Johnson, Director of Facilities with Varian Semiconductor Equipment Associates in the US. That said, the Co-operative Insurance Services clad its so-called Solar Tower, located in Manchester, UK, with solar PV panels which have the potential to generate up to 183,000kWh a year, saving 78 tonnes of CO2. Part of the equation was that the panels were actually cheaper, at less than £700 per square metre, than either marble or bronze cladding. Inspite of this, solar thermal power is making more headway in the UK, as crucially, it requires only light, rather than direct sunlight to work.

Using vacuum coil technology, solar thermal systems collect solar energy and transform it into heat, which is then transferred to the hot-water tank. It won’t bring water up to full operating temperature, but pre-heating saves precious thermal units of gas or electricity. The technology is well established, a lot cheaper than PV, and it works even in temperate climates.

Geo-heat pumps
Whereas Iceland and New Zealand famously tap into their respective geothermal resources for power generation, geo- heat pumps are far from widespread.

That said, away from areas of permafrost, the uppermost ten feet of the Earth’s surface maintains a locally constant temperature, a resource that once accessed via geo-heat pumps can be used to heat and cool buildings. Consisting of a pump, air delivery system (ductwork) and heat exchanger, the system works in two ways. In winter, the pump removes heat from the heat exchanger and pumps it into the indoor air delivery system. In the summer, the process is reversed, with the heat pump moving heat from the indoor air into the heat exchanger. The heat removed from the indoor air in summer can also provide hot water. Although the technology is not yet capable of providing limitless on-demand heating and cooling for large spaces, it can make a worthwhile contribution by pre-heating hot water, together with cooling in summer. EarthEnergy Systems reports having supplied a number of geo-heat pump systems for commercial applications in the UK.

Shooting the breeze
Construction of the six wind turbines at Nissan’s Sunderland, UK, plant began in September 2005, the £2m project starting power generation two months later. The contribution the turbines make to the company’s total energy requirement is revealing, adding up to a reduction of between 4,000 and 10,000 tonnes from the factory’s CO2 emissions and a reduction of approximately £1m from the overall electricity bill. That, however, only amounts to five per cent of the company’s annual energy bill; to replace gas and conventionally-generated electricity would require several acres of land.

Wind is making a bigger contribution to Michelin’s plant in Dundee, UK, where two wind turbines generate up to 4mW of power a day, enough to meet all of its requirements. With electricity expected to remain up to 30 per cent more expensive in Scotland than in France and Spain, wind power is more than just a nice idea – it’s essential if the factory is to survive. Further south, Ford’s two turbines at Dagenham have the potential to provide enough power to meet all of its electricity requirements – 6.7 million kWh a year. If the turbines ran at peak capacity all the time, every diesel engine produced by the plant would be made entirely with wind power, saving up to 6,000 tonnes of CO2 emissions into the bargain.

General savings globally
GM isn’t being left out, either. Its Canadian plants reduced their collective output of greenhouse gases by 49 per cent between 1990 and 2006, while raising production more than 12 per cent. The biggest impact has come from improved energy efficiency and better housekeeping, but new materials, such as water-based paint and adhesives with fewer solvents, from companies including Henkel, have also played their part.

Additionally, the company has announced plans to build a state-of-the-art $250m research centre in China, focusing on alternative energy and the environment. The Center for Advance Science and Research will be located at GM’s corporate campus in Shanghai’s Pudong New Area. Its focus will be on three main areas: alternative fuels; advanced alternative energy propulsion systems (which the company sees as having particularly strong market potential in the PRC); and manufacturing and supplier energy efficiency. The targets for the third of those objectives is to reduce energy consumption and increase the recyclability of materials, cutting emissions and eliminating plant waste throughout the manufacturing chain.

Government assistance
China has become the world’s second-largest car market after the US and along the way it has become the world’s biggest polluter. With an unprecedented surge in the demand for energy, authorities are aware of the implications. The country has already passed laws concerning renewable energy resources, with a clear sense of urgency. Henan Province, a large agricultural region, is expected to become the home of workable bio-mass energy industries, while the Provincial Academy of Sciences is undertaking studies into bio-mass energy, including the utilisation of crop stalks to produce granular fuels. The Chinese Academy of Engineering (CAE) is investigating coal purification technologies, including gasification and liquefaction.

Energy in new buildings has been moved up the agenda, with the publication by the Central Committee of the Chinese Communist Party of energy usage standards. In a classic case of Chinese CP instruction-speak, senior CAE member Du Xiangwan spoke of the need to develop clean and efficient cars in a lower energy-consuming industry. “We still have something to learn in developing the auto industry. We cannot blindly build inefficient, polluting vehicles. This is not a correct concept of consumption.” Despite apparent inclinations to the contrary, the US Federal government is working to raise its game and improve efficiencies in manufacturing. Initiatives are aimed at the small to medium enterprise sector, and include Manufacturing Extension Partnerships, offering a range of assistance, from consulting to technical guidance, with the goal of improving energy efficiency with the addition of new equipment and implementation of best practice policies.

The Industrial Technologies Program (ITP) plant assessments, available at 26 universities across the country, offer free energy audits conducted by the engineering faculty and students, together with detailed recommendations for improved energy efficiency, waste minimisation and productivity enhancements. Larger companies can qualify for financial assistance under Plant-wide Assessments, which target energy savings in steam delivery, process heating, motor systems, compressed air systems, heat exchange optimisation, and combined heat and power.

Elsewhere, the Industries of the Future Program is a public-private partnership intended to reduce high energy usage through technological innovation in seven key industries: steel, aluminium, metalcasting, glass, chemicals, petroleum refining and forest products. There are also local and regional programmes across the country, including the New York State Energy Research and Development Authority (NYSERDA) Premium Efficiency Motors Programme. This programme awards motor manufacturers up to $80 for every qualifying motor they sell, the idea being that the incentive will motivate vendors to market efficient motors more aggressively, ultimately creating a market independent of state subsidy.

Subsidy, however, won’t win the energy war. The immediate solution is in industry’s hands: plug the leaks, close the doors, turn off the lights and make sure everything is running as it should. In general, those are no-cost options and they are still likely to yield benefits, even in companies that have already undertaken energy audits. The longer-term solutions require more thought, a strategic approach and commitment to the solution.