Beating the levy

As well as minimising environmental impact, the adoption of greener power generation techniques can save money, reports Paul Gay.

The Climate Change Levy, introduced on 1 April 2001 to encourage energy saving measures in commerce and industry, has the potential to increase the average electricity bill by 13 per cent and the average gas bill by 30 per cent.

However, a tax exemption on renewable and combined power encourages the use of these technologies as a means of reducing CO2 emissions.

One approach that could benefit from these exemptions is combined heat and power (CHP) schemes, commonly-accepted as a useful way of hedging against future increases in energy costs, as well as the possible introduction of further energy/carbon taxation.

In addition, because of the pressure on CHP providers to compete with artificially-low electricity prices, the overall cost of CHP-related products and services has been driven to an all-time low, making this the best time to invest in the technology.

RWE npower last month confirmed it had made an application for consent to build a Combined Cycle Gas Turbine power station at its former oil-fired site in Pembroke, south Wales. It is based on power plant configurations of 2,000MW capacity using modern gas turbine technology.

RWE npower has around 8,000MW of coal, gas and oil-fired generation capacity in the UK. It is also the country’s leading wind power developer.

the industrial and commercial retail arm of RWE npower — npower Business — has struck a three-year deal with BT to supply almost 1tWh of green electricity, the equivalent of supplying 100,000 homes with electricity every year for three years.

According to the independent body The Climate Change Group the deal, worth several hundred million pounds, is the world’s largest ever for green energy supply. Seventy five per cent of the total 1.45tWh of electricity will be supplied by npower. Of this, 0.4tWh will comprise green electricity from a range of sources including wind generation, and hydroelectric schemes.

The remainder will be made up of ‘good quality combined heat and power’ (GQ CHP) generation which has a lesser environmental impact than conventional fossil fuel energy generation methods.

The contract will supply BT’s 6,500 telephone exchanges, satellite earth stations, offices and depots. The initiative will save emissions equivalent to the amount of carbon dioxide produced by almost 50,000 homes — or more than 100,000 cars.

In a separate development, Gaz de France purchased the Shotton combined heat and power plant near Chester, north-east Wales, from its receivers in October 2003. This 215MW, natural gas fired power plant, commissioned in August 2002, has enabled Gaz de France to strengthen its position in the UK energy trading market. Its subsidiary, Gaz de France Energy Supply Solutions, already sells around 10 per cent of natural gas to industry and commerce.

A previous acquisition — RWE Trading Direct, a company specialising in the supply of electricity to major energy users in the industrial and commercial market — had already enabled Gaz de France ESS to provide its customers with a dual-fuel, natural gas and electricity offer.

Using patented gasification technology successfully proven in Scandinavia and Germany, Manchester-based Ener·G can now design, build, operate and maintain small-scale energy-from-waste plants which are sited locally and capable of converting non-recyclable waste into energy with minimal environmental emissions.

Developed by Norwegian-based Energos — now a subsidiary of Ener·G — this new energy recovery solution features Advanced Conversion Technology as defined under the UK’s Renewable Obligation Order.

These plants use energy recovered from pre-sorted household and other wastes through a two-stage thermal treatment process, comprising gasification and high-temperature oxidation. This converts local waste streams into a high rate of thermal energy for process steam, district heating, and/or electricity.

The drying, pyrolysis and gasification of the pre-treated waste is carried out in the plant’s primary chamber under substoichiometric conditions. The syngas generated in the primary chamber is transferred to a separate secondary chamber where final high-temperature oxidation takes place.

Recovered energy is then converted into hot water or steam and the flue-gas is passed through a dry flue-gas cleaning system with injection of lime and active carbon.

This process achieves low carbon content in slag (less than three per cent total organic content), CO stability on a low level and a high degree of cracking of organic substances and also low and stable NOx emissions.

Six purpose-built energy-from-waste plants incorporating this technology are already operating in Scandinavia and Germany.

But by making this technology available in the UK for the first time, Ener·G will also enable its customers to meet the EU Landfill Directive requirements, while significantly outperforming the relevant EU emission standards.

These low-cost plants are typically 1,500–2,300 sqm in size and are ideally suited for construction alongside existing recycling facilities. They are designed to handle approximately 30–80,000 tonnes of waste a year, producing up to 0.21TWh of thermal energy.

The small-scale, low-profile construction of this type of plant, its minimal emissions and green energy-generating credentials are all aimed at helping to counter public opposition. At the same time it is a local solution, so the approach should help cut road haulage costs, traffic congestion and associated exhaust emissions.

So the message here is quite clear. As well as minimising environmental impact, the adoption of greener power generation techniques can save money.