Time to make your warehouse greener

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Environmental concerns are increasingly coming into play in logistics operations, with more and more companies committing to low carbon strategies for the future of their businesses. One of the biggest energy consumers in the logistics industry is the warehouse.

The retailer sector especially relies heavily on depots, some of which operate day and night. Marks & Spencer, Tesco, Sainsbury’s, Wal-Mart and John Lewis, are among those that recognise the need for action, and are developing energy saving projects that promise significant savings in energy consumption and carbon dioxide output. M&S is investing in a £200 million environmental plan, which will help it achieve its goal of becoming carbon neutral by 2012. Lee Scott, president of Wal-Mart, has promised to use 100 per cent renewable energy, create zero carbon waste and reduce carbon emissions by 2009, through an investment of £255 million. Meanwhile Tesco has solar power projects across the UK.

The bar was set when Adnams Brewery opened its environmentally friendly distribution warehouse, constructed out of hemp and chalk blocks, which absorb carbon dioxide, helping to regulate temperatures naturally efficiently, and reducing energy costs. The warehouse, complete with grass roof, designed to harvest rainwater, was opened last year in Southwold, Suffolk.

However, the financial viability of implementing green initiatives is an issue. Action is apparent in new build warehouses with developers like Gazeley and ProLogis, and designers like sbh.uk committing to eco-friendly initiatives and innovations, and where renewable technologies are integrated during the early stages of the design and build process. But for existing warehouses the prospects seem less certain, as many companies remain unsure of how or where to start the ball rolling.

The costs of running green warehouses are lower than those of conventional ones. Where energy is reduced, cost savings are made. For companies wishing to commit to the low carbon initiative, renewable technologies such as wind turbines and photovoltaic panels are costly investments but will guarantee long-term pay back.

Laurie Sice of sbh.uk says: “In some cases, the additional cost of putting in items means that there is an initial increase in cost but then looking at the payback in running costs, these factors make it worthwhile.”

John Lewis is opening a distribution centre at Gazeley’s Magna Park site at Milton Keynes, which will incorporate an increased range of sustainable design initiatives contributing to a saving of up to 66 per cent on carbon emissions. Jonathan Fenton-Jones, global procurement and sustainability director of Gazeley, says that operational cost savings for John Lewis will work out to £238,000 per year.

Commenting on the project, Dino Rocos, managing director of distribution at John Lewis, said: “It is good for us as a business and the environment – it has shown that the business agenda and the green agenda can run comfortably along side each other.”

Sainsbury’s is soon to open an energy efficient depot at Pineham, Northampton. Its design incorporates environmental features and technologies to reduce energy consumption and carbon emissions, including wall-mounted photovoltaic panels that generate electricity; solar walls that produce heat from sunlight; an on-site combined heat and power plant that reuses the by-product heat from the chilling process normally wasted to the environment; an on-site recycling facility; energy efficient lighting systems; and air-tight construction that minimises energy loss through the external fabric of the building. ProLogis estimates that Sainsbury’s’ warehouse operation will be up to 75 per cent more energy-efficient than a standard warehouse. Ken Hall, ProLogis’ sustainability guru, says it’s also developing ongoing retrofit programmes in the US.

Laurence Duncan, director of renewable technology consultants Ice Renewables, says there is a lot of misunderstanding regarding what type of renewable technology to use and its potential payback. Wind turbines for instance, are regarded as having a rather lengthy payback period, but they can return investment after just four years. According to Duncan, some companies are being ‘muscled’ down the green route as a result of binding legislation such as the Merton Rule, the planning policy pioneered by London Borough of Merton, which requires the use of renewable energy on site to reduce annual carbon emissions in the built environment. Others see it as a way of staying competitive and achieving corporate responsibility objectives.

Yet, for existing warehouses, there are still a lot of grey areas regarding which technologies are worthwhile investing in.

A major source of energy consumption in any warehouse is lighting. In response to this, recent efficiency targets introduced by the national Building Regulations call for electrical consumption and industrial lighting to be reduced by 10 to 15 per cent.

Hugh King of Thorn Lighting says 50 per cent savings can be made by use of currently available energy efficient lighting technologies (products, lighting controls, natural light) all without loss of lighting conditions. Lighting designers have the power to hold down carbon emissions and reduce the carbon footprint of lighting installations, (0.42kg of carbon dioxide is saved for every 1kWh reduction in electrical load).

According to King, choice of lighting varies from high intensity discharge (HID) to advance fluorescent luminaires (complete light units). He says: “With regard to the building regulations we have received some instances of large warehouse projects being given a false impression that to comply, the lighting installation needs to take account of both occupancy and daylight levels and need to be switched as such. This is extremely difficult to do with discharge lighting and hence users seem to be thinking they must go down the fluorescent route…this is not the case.”

He says that the most important point is the provision of switch controls. The most common approach is the use of microwave presence detectors for monitoring aisles and switching 50 per cent of the HID luminaires off after 15 minutes of non-detection.

King says that four types of control sub-systems are usually employed: daylight-linked, occupancy-linked, localised switching and timed controls, although frequently a combination is used.

Future summer temperatures are predicted to rise by several degrees as a result of global warming. Keeping temperatures down, specifically for products that are stored higher up in a warehouse has always been a problem, says Steve Ball, operations director of Jet Environmental.


“Overheating has been the number one critical deficiency in pharmaceutical warehouses for the past five years, but has moved up the agenda because of improvements in the thermal efficiency of warehouses plus the waste heat given off by lighting and materials handling equipment and greater use of mezzanines, all of which significantly increase internal temperatures. Without cooling stratification occurs as hot air accumulates at a high level in the warehouse, making the top levels of racking unusable for temperature sensitive products.”

Air induction technology and controlled ventilation can be used to create greener warehouses which not only require less energy, but also use it more efficiently, he says.

“Traditional heating, ventilation and air-conditioning systems which employ energy hungry mechanical cooling, are not only expensive to run but also pump high levels of carbon dioxide into the environment. They are simply not a viable option when the government is committed to reducing energy consumption and insuring that UK businesses implement low carbon solutions which minimise the impact on the environment.”

Steve Kirkwood of Seeley International, which makes evaporative-cooling and gas heating products, says: “Climate change legislation provides companies with financial motivation to cut carbon emissions in the most cost-effective way. Companies that exceed their emissions limit are penalised while those producing emissions below their limit have the opportunity to develop a new revenue stream.”

Kirkwood points out that evaporative air-cooling is emission free and cheaper to run than refrigerant based air-conditioning. It provides cooling properties and ventilation with minimal energy consumption, using water as a working fluid and avoiding the use of ozone-destroying chlorofluorocarbons (CFCs) as used by compressor type systems. It’s a simple technology which consumes less than a quarter of the energy of refrigerate air-conditioning systems.

Significant savings can also be made by employing building management systems, computer systems which can calculate the pre-set requirements of the building and control the connected plant to meet those needs. Its inputs, such as temperature sensors and outputs, such as on/off signals are connected into outstations around the building. Programmes within these outstations use this information to decide the necessary level of applied control. They are designed to combine maximum building and plant efficiency with minimum energy consumption.


Julian Martin, director of Ice Renewables, says that combined heat and power systems (CHP), initially more well-known in the public sector, are becoming increasingly popular.

It’s one of the cheaper technologies to install and guarantees a fast payback of three to four years, depending on the site. Martin says that retrofitting existing warehouses with a CHP system can be done by running it alongside the existing heating system, with the CHP gradually dominating the original system.

Ultimately, there is only so much the architects and designers can do, it’s up to the end users and their attitudes, to carry on the green effort and ensure that their warehouse operations are environmentally beneficial. As Laurie Sice says: “It’s a matter of money versus social responsibility.”

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