Energy and resource usage
We aim to minimize energy input in all our manufacturing and processing activities, ensuring that glass usage contributes net benefit to sustainability, using as diverse a range of energy sources as practicable
Initiatives to reduce resource usage
Thermo-Photo Voltaic (TPV) Development
A TPV cell is very similar to a solar cell except it uses Infra-Red rather than visible light to produce electricity. NSG, Lancaster University, QinetiQ, CSI, Wafer-Tech, RWE nPower, and Tata Steel have been given £1.5 million by the UK Technology Strategy
Board to develop TPV technology.
A TPV system has been designed by the UK R&D Team and is currently installed in a furnace flue to test the resilience and long-term output of the cells. It is hoped that investment in this technology will reduce environmental impact by generating electricity from our waste heat instead of the current steam turbine system.
Our energy usage
For both environmental and financial reasons and wherever possible, we use natural gas as the fuel of choice for glass melting and convert furnaces whenever practicable.
We used 1,071 million cubic meters of natural gas in 2011. This equates approximately to 37.7 PJ of energy, a 10 percent increase on the previous year.
Heavy fuel oil
Our second most utilized fuel is heavy fuel oil, readily available and relatively low cost. It is therefore used when gas is not available. It provides good heat transfer and is considered a good fuel for glass melting.
We used 237 million liters of heavy fuel oil in 2011, or 9.4 PJ; a 10 percent reduction on the previous year
Diesel oil and liquid petroleum gas
The use of diesel oil and of liquid petroleum gas as fuels for float furnaces is generally limited by cost. Both are used as back-up fuels in case of the failure of the preferred fuel, natural gas. Diesel oil is also widely used to power small engines and boilers.
In 2011, our consumption of diesel oil was 19.8 million liters, or 0.74 PJ (down 8 percent on 2010) and that of liquid propane was 10.5 k tonnes or 0.5 PJ (an 8 percent reduction on 2010).
Electricity is a major resource usage for the Group. The environmental impact associated with electricity is,
of course, dependent on the method used to generate it. During 2011, we consumed 8.7 PJ (2.4 TWh) of delivered electrical energy (a 1 percent decrease on 2010).
The total energy used by the NSG Group in 2011 was 57.12 PJ (15.87 TWh). This represents a 4 percent increase on 2010.
Our resource usage
Some electrical power is directly generated on-site from waste gases or using co-generation installations. In 2011, we received 275 GWh from combined heat and power.
We expect our usage of renewables to increase significantly over the next few years, with projects under way to install photovoltaic arrays and wind generation at some of our facilities. In June 2011 we commissioned a new 3,000-panel solar field at our facility at Northwood in the US. This is now generating 250 kW of energy, or about 7 percent of the facility’s
requirement, every year.
In Europe, much of our glass is transported on steel stillages without packaging, utilizing specialist ‘Floatliner’ vehicles. Outside Europe, more glass is transported in boxes and containers, often made of wood. Although much of the timber we use comes from sustainable forestry, we cannot yet guarantee this worldwide and this remains an area for improvement.
We used 123,000 cubic meters of timber in 2011, mainly in the transportation of glass (up 27 percent on 2010).
In glass-making, water is used for cooling, but most of our plants operate with closed loop systems and so only require top up. Water is also used for washing glass in plants, but there the need is for very high purity, so water is treated and then reused.
Across the Group water consumption can vary considerably according to process and product demands as well as water quality. Typically, ~2m3 are required to manufacture 1 tonne of float glass. ~90 liters are required to process each square meter of automotive product.
We used a total of 20.8 million cubic meters of water in 2011. This was a decrease of 3 percent on 2010 data, despite increased production levels.
Some cullet (recycled glass) is bought in from external sources and remelted to form new glass, so closing the recycling loop.
In 2011 we bought in 200,000 tonnes of cullet to supplement cullet from our own internal recycling.