Energy Efficiency - Powered for change01 October 2006

The government is now aware we have to take drastic steps both to save energy and find new sources of supply. There are many ways to achieve these goals. Top of the list has to be to take advantage of government-backed schemes that provide free advice on how to reduce energy waste; to adopt every technology available to make best use of the fuels and energy sources we have already; and to convert waste materials into usable energy, both in the form of electric power and heat.

There is no doubt that the UK government is beginning to take energy matters seriously. In his speech to the House of Commons on 11 July, introducing the 218-page report on the Energy Review, Secretary of State for Trade and Industry, Alistair Darling, declared: "We face two major long-term challenges. First, along with other countries, to tackle climate change and the need to cut damaging carbon emissions. And, secondly, delivering secure supplies of cleaner energy at affordable prices. The starting point for reducing carbon emissions must be to save energy. If we are to meet our goals of a 60% reduction in carbon dioxide emission by 2050, we need not just to reduce carbon intensity through low-energy sources such as renewables, but also by saving energy.

"The Government believes that we can do more to encourage the generation of electricity on a smaller scale near to where it is used. Today, less than 0.5% of our electricity comes from micro-generation. Combined heat and power provides about 7%. We need to do more.

"We want to remove barriers to the development of what is known as distributed generation. We can do more to make it more attractive to energy micro-generation and to set up Combined Heat and Power schemes. We will also encourage low carbon alternatives, such as bio-mass, solar and heat pumps," Darling added.

One of the proposals in the report is to establish a new Office of Climate Change, "which will monitor progress towards our carbon goals and ensure coherence of action across government departments to achieve them", said Darling.

While many may suspect that the hot air produced will do little to alleviate future energy shortages, the Envirowise programme already in place offers what we have found to be very sound and free advice - over the telephone, via the Web and in on site visits via a national team of expert advisors. Since 1994, Envirowise claims to have saved UK industry more than £1 billion.

The Carbon Trust, which is funded from the proceeds of The Climate Change Levy, also provides free advice, ranging from energy audits to supporting capital investment in new energy-efficient equipment.

Darling talked of 'Combined Heat and Power' (CHP) and, on this subject, it must be pointed out that this is an old idea that seems to be coming back into favour with the demise of abundant cheap energy. For example, Battersea Power Station used also to heat the apartments in the Churchill Gardens Estate on the opposite bank of the Thames, while combined power generation and district heating systems are still used in many cities in Russia.

Large-scale district heating systems have always suffered from heat losses in pipes, leading to the idea of making CHP plants small enough to power and heat single factories, offices or even homes and fuelling them on locally available, low-cost materials, including those normally regarded as waste.

Talbott's Heating in Stafford, founded by ex-fireman Bob Talbott, has developed a novel biomass generator with an output of 80-100kW of electric power and 150-200kW of heat. The first production unit was installed last September at Harper Adams University College in Shropshire and Talbott tells us that several more units are "under way".

He established his business 30 years ago when he produced a wood-fired boiler, following the oil crisis in the mid 1970s. Since then, the company has sold some 3,500 units, which are installed in the USA, Canada, Europe, Asia, Russia and Australia. The new BG100 unit is the result of some 10 years of development and includes a number of unique features.

For a start, the whole unit comes in two standard shipping containers, plus a bunker. The fuel can be any kind of biomass with a moisture content up to 40% and a particle size up to 30mm3. It uses hot air as its working fluid, heated by the 9000C furnace gases in a heat exchanger. The heated air turns a turbine, which is directly coupled to a high-speed generator to avoid losses that would otherwise arise from use of a gearbox. Using hot air, as opposed to furnace gas, reduces blade erosion, although with some loss of efficiency. Nonetheless, overall system efficiency as an electric generator is thought to be about 20%, which is quite good for such a small unit. If heat is included, CHP efficiency is about 80%. It has a step grate system, with an auto de-asher, and the whole unit is computer controlled.

Typical fuel is shredded 'tops and crops' from forestry, which is normally regarded as a waste product, and either burned subsequent to harvesting the trunks or left in piles to rot. Alternatively, the plant can be fired with short rotation willow specially grown for the purpose. The cost of a system is currently about £300,000, which has until now rendered such solutions economically unattractive. However, with fuel costs expected to continue to spiral upwards and government keen to encourage alternatives, this could soon change, especially at remote locations with no gas supply.

Another old idea that keeps rearing its head is to magnetise fuel in feed lines. The latest company to make claims for the beneficial effects of magnets on fuel to reach our attention is Maxsys with its system Fuel+, which managing director Barry Singh says "is patented for oil and gas on large combustion plant - ie, ovens, furnaces, dryers and boilers".

The unique feature of Fuel+ seems to be to insert permanent magnets in fuel lines, instead of fastening them on the outsides. Clamping them on the outsides, they say, means that pipe walls interfere with the magnetic fields, especially when the pipes are made of steel, and results in some parts of the pipe cross section being subjected to lower field strengths than others.

Walsall-based Maxsys guarantees minimum fuel savings of at least 5% to its end users. If these are not achieved, all money is returned and the plant returned to its original configuration. One company cited as benefiting from the technology is Campbell's Grocery Products, which installed the equipment at its Worksop site in Nottinghamshire. Since commissioning took place some 18 months ago, the company reports a significant reduction in gas consumption and has already recouped its initial capital outlay for the system.

Mick Blackburn, energy manager at the plant, explains: "Fuel+ improves combustion by applying a precisely calibrated magnetic field to the fuel. The unit is installed into the fuel supply line before the burner. Maxsys guaranteed that we would achieve five per cent savings. We agreed that, once it was installed, the effectiveness of the system would be independently monitored and verified by ABB. If the system fell short of a five per cent return, all our money would be returned, so it really was a situation where we couldn't lose."

ABB calculated the savings made after six months, using a statistical technique called CUSUM, comparing predicted and actual steam generation. The cumulative difference was plotted and the chart indicated a rise in steam output. It was concluded that over the post-commissioning period 316,500kg more steam was generated than expected. Prior to installation, the boiler system at Campbell's averaged 13.25kg of steam generated for every cubic metre of gas consumed. Post-installation, this became 14.14kg of steam per cubic metre, a rise of 6.7%.

If magnetising fuel does help, the question is, how? Hydrocarbon fuels are hardly magnetic materials. However, when any liquid interfaces with a solid (or liquid) surface, there is an electrical double layer at the interface between the liquid and pipe wall. As hydrocarbons are insulators, this can lead to the generation of some impressive, and potentially hazardous, static voltages when oil or gas is pumped through pipes made of insulating materials.

While hydrocarbon molecules are normally completely non polar - that is, the charge at one end is the same as at the other - this changes if they are adjacent to a strong charge, where electrons will tend to spend more time near the end adjacent to the positive charge. It is thus possible for a charged surface to line up the molecules. Since anything charged moving through a magnetic field experiences a net force, it is possible that a magnetic field could add to this lining-up effect. Also, it has been found that fluid moving through a steel pipe can pick up iron containing nanoparticles and that a magnetic field adds to the aggregation of these particles, which may also have some effect on combustion. Furthermore, it is easy to show that a magnetic field has an effect on a flame, because of the moving ionised molecules within it, which are also charged. If there are residual magnetic fields resulting from the motion of charged elements of fuel going into the flame, this, too, might have some effect on combustion. However, all this shows is that magnetic fields are likely to have some effect on hydrocarbons flowing through pipes. Proof of the pudding is purely whether magnetic fields improve the efficiency of combustion or not.

SOE

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