http://www.theecologist.org/archive_detail.asp?content_id=832

Less waste, more speed

Growing crops to solve the planet's energy needs doesn't work. 
Recycling the energy in our waste just might have a significant part 
to play. By Jeremy Smith & Jon Hughes

Date:29/03/2007         Author:Jeremy Smith & Jon Hughes

Bush's latest' state of the union speech - wanting 20 per cent 
bio-fuels from food crops to be driving the US fleet in 10 years 
-makes two things remarkably clear. First even the Toxic Texan now 
sees the environment as a vote winner. And second, people such as him 
are still looking for the answers in the wrong place.

To see where the answers might lie he needs to look beyond the 
cornfields of the Midwest. To somewhere aiming to be nuclear free by 
2010 and oil-free by 2020. To Sweden. This radical energy policy, the 
most ambitious of its kind in the world, was introduced by the 
socialists and adopted, after a recent change of government, by the 
equivalent of the Tories. In terms of ecological consciousness and 
seeking bipartisan solutions to environmental problems it affirms 
that Sweden is a good 20 years ahead of either Britain or America.

The country's environmental awakening started in the Eighties when 
two separate but connected events shocked the country. First there 
was the bleached coffee filter paper scandal. People liked the filter 
paper for their coffee machines to be white. But then it was 
discovered that the chemicals used in the manufacturing process left 
cancer-causing residues and were causing environmental degradation 
simply so we could have something that looked aesthetically pleasing. 
Then dead seals started to appear off the north-west coast. The 
Swedes put two and two together and realized that the fundamental 
processes used in manufacturing were having a direct impact on the 
environment. And determined that they were going to do something 
about it.

So they set their minds to addressing these issues, as fishing, 
forestry and agriculture are critical parts of their economic 
portfolio. How best to use their natural resources is tantamount. 
Biofuels there have been used as a fuel extender for petrol-engined 
vehicles for years. Today, almost 40,000 cars in the country are 
powered by some form of alternative fuel. Last year sales were up 168 
per cent. By the end of 2006 sales of alternative fuel cars were 
expected to account for about 20 per cent of all new cars sold.

However, the biofuels approach currently being endorsed by Bush and 
others is already recognised by the Swedes as being an ultimately 
unsustainable solution and of little help even in meeting the modest 
targets for cutting C0… emissions set by the EU. So while the rest of 
the world is only now belatedly jumping on the bio-fuels bandwagon, 
the Swedes have already moved on to the next phase.

Today, they are concentrating on non-food-crop biomass for energy 
production and fuel, in the form of biogas, for cars, both of which 
have far greater potential to play a long and lasting role in 
providing green fuel and green energy. Rather than sow new plants 
that compete for space with food crops, they are using the waste 
products of their society - anything from woodchip to slaughterhouse 
slurry - and turning them into fuel.

In December last year they opened the world's largest biogas plant. 
Costing 3.2 million Euro, the Gothenburg plant will be able to 
produce 1,600 cubic metres (cu/m) (56,000 cubic feet) of biogas per 
hour. This will be done by refining gas from the city's wastewater 
treatment plant into biogas.

Outside of Gothenburg, the government and 25 local municipalities 
have backed an initiative to build 200 new biogas stations over the 
next two to three years. Expansion on this scale and at this speed 
will replace the need for around 35 million litres of petrol and 
diesel fuel, cutting emissions by 50,000 tonnes a year; a clear 
signal to business and the public to have confidence and invest in 
the sector.

Last year Sweden unveiled the world's first biogas powered train. 
Driven by two biogas bus engines it can carry 54 passengers at 81mph, 
and run for 372 miles without refuelling

The country already has 779 biogas driven buses. In the city of 
Linköping for example, all the buses and many of the taxis run on 
biogas produced locally from slaughter waste, agricultural waste and 
other kinds of food/organic waste. Across the country, sales of 
biogas-powered cars increased by 49 percent in 2005.

Not that they've stopped there. Last year Sweden unveiled the world's 
first biogas powered train. Driven by two biogas bus engines it can 
carry up to 54 passengers at 81 miles an hour and run for 372 miles 
before it need refuel. It cost them just 1.08 million Euros to 
develop.

Closing the loop

Biogas is produced in essentially two different ways - by 
biodigesters and bioreactors. From the cities of Sweden to remote 
rural villages of China anaerobic biodigesters are becoming 
increasingly commonplace to see. These are essentially 
micro-generators where animal manure and organic matter (food waste, 
agriculture wastes and so forth) are fed into a chamber. They combine 
with the oxygen in the air and heat up naturally, just as in a 
compost heap. As they do so they produce two things; gas 
(predominantly methane with a small percentage of carbon monoxide), 
and a slurry of sterile (non-toxic) nitrogen compounds.

The gas is then piped to a generator, which uses it as fuel to supply 
power to the village or farm for household appliances and electricity 
driven farm machinery. Anaerobic digestion also removes the need for 
petrochemically produced fertliser, which in the UK accounts for 
around 14 per cent of GHG emissions - the same as industry. The 
result: with the exception of the release of a tiny amount of methane 
gas, a totally green whole cycle power system.

Aside from the climate benefits, replacing costly chemical 
fertilisers with cheap, produced on site ones from an anaerobic 
digesters can also boost farm incomes. In Germany this potential is 
already being harnessed. There, farms with herds of around 500 head 
of cattle are paid to 'biodigest' their wastes, the gas from which is 
then bought and collected. For struggling farmers in the UK, 
biodigesters could make a dramatic impact on their balance sheets. 
For example, an average hill farm in Wales running 500 sheep on 100 
acres - the minimal possible to make it anyway approaching economical 
- would spend around 30 per cent of its annual income on 
petrochemically produced fertiliser.

Bioreactors run on a slightly different principle to biodigesters, 
and use both heat and pressure to speed up waste conversion, like 
giant kitchen pressure cookers. And they do it on a grander scale and 
faster. Where a biodigester would run over a 10 day cycle, a 
bioreactor completes the same conversion of matter to energy in a few 
hours, recycling some of the energy it creates to power its own 
operation. Construction of a bioreactor has recently started in 
Lockerbie. When in operation the plant will generate enough 
electricity to power 70,000 homes, offsetting 140,000 tonnes of 
greenhouse gas emissions each year. The Lockerbie bioreactor will be 
fuelled by biomass, sourced from the waste matter from the nearby 
wood processing and pulping industries; a resource that would 
otherwise by fly-tipped, burnt or landfilled. It's a solution 
suitable to Scotland (and potentially Wales) because of its extensive 
commercial forests.

Closer to home

Bioreacators' potential doesn't stop there. The reactors can process 
practically anything - all human and animal effluent, animal 
carcasses, garden waste - and convert it into energy. So, for 
instance, the effluent in rivers such as the Thames could in 
principle be filtered out to create power, whilst cleaning up the 
river in the process.

The Institute of Science in Society (ISIS) has calculated that there 
are somewhere in the region of 88 million tons of effluent and 
organic waste suitable for anaerobic digestion in the UK. If 
converted into fuel this could provide 11.7 per cent of our total 
energy needs and save at least 15.8 per cent of our carbon emissions. 
Or, create enough liquid fuel to power half our transport needs, 
saving around 50 per cent of our current transport emissions, which 
themselves account for 14 per cent of the UK's total emissions.

Admittedly waste biomass is not quite as clean as carbon neutral 
forest biomass. Nonetheless it is far cleaner than simply 
incinerating our waste. For every ton of waste currently incinerated, 
2.8 tons of C0… are emitted. When converted to energy in a 
bioreactor, the process is 10 times cleaner, as the reactors use far 
less energy than a waste incinerator, and can be fitted with carbon 
dioxide scrubbers on their exhausts.

Furthermore, they are 85 per cent efficient at recovering energy from 
waste: an incinerator is only about 10-15 per cent efficient, or 
less. In sum: you can get five to eight times as much energy, all of 
it green, from bioreactors than incinerators, at a fraction of the 
carbon dioxide output. The same applies to anaerobic digesters, which 
are also very energy efficient.

Another immediate benefit of pursuing the biomass/biogas line is that 
in the UK we already have the infrastructure in place. Gas travels 
through pipes, and the pipes already exist to deliver natural gas. 
Localising production also answers a key question of energy security 
and addresses the problem of energy wasteage, with 7-25 per cent of 
the electricity produced in the UK currently being lost simply while 
being transported around the national grid.

It might also lead to proper funding of recycling services as 
millions of tons of waste and rubbish can be converted into hundreds 
of millions of pounds worth of valuable energy, to be sold back to 
the consumer.

Despite lack of support from central government, across the UK, there 
are several signs at a local level of people taking the initiative 
for themselves. In Nottingham for example, Trevor Hardcastle of 
Hardstaff haulage has developed a simple and effective way to convert 
a diesel engine to drive on biogas. In an industry that praises 
operators who have a single-digit profit margin he has reduced his 
fuel bills by £1m annually. Biogas (and natural/ propane gas) comes 
in at half the price of diesel (currently around 46p), and is even 
cleaner. He has even created his own infrastructure so his trucks can 
refuel along the motorway routes they travel.

A biogas reactor in Denmark. Power plants

such as these are beginning to appear all

over the world

This approach has huge potential. In the UK we currently give bus 
companies fuel-tax subsidies to the tune of £2bn a year. Yet because 
these companies operate around fixed points they could - probably 
more than any other sector - start to convert to biogas immediately. 
They are already doing this in Mauritius. The only public transport 
on the island is its bus service, which transports around 200,000 
people each day. Earlier last year the country embarked on a scheme 
to convert its entire fleet of 525 buses to run off biogas, thus 
tackling its waste, emissions and energy problems in one go.

Wales's first biomass district heating scheme was launched on 30th 
June 2006. A 500kW wood chip boiler, installed by Dulas Wood Energy, 
provides heat to Ysgol Vyrnwy School, Community Centre and 30 houses. 
Wood chip is sourced from within a 20 mile radius of the school and 
the scheme is operated through a partnership between Powys County 
Council, Dulas, Severn Trent Water and the residents.

At the National Botanical Garden of Wales, the Great Glasshouse, the 
offices, shops and catering facilities currently burn factory waste 
chippings and shavings that would probably end up in a landfill site 
otherwise. By about 2010 they hope to use coppiced willow and poplar, 
grown on an adjacent field.

Kingsmead Primary School in Cheshire has a biomass boiler, producing 
60 per cent of the school's heating needs. Initially fuelled on wood 
pellets from a local factory, the boiler now runs on waste factory 
wood chips sourced in Manchester. In combination with photovoltaic 
panels and solar water heating, the school has a total energy 
consumption of about one third of that which is typical for a school 
of this type and size.

Barnsley metropolitan borough council is replacing its old 
coal-burning power stations and finding a use for local forestry 
waste by converting to the use of woodchip burners. Though the 
project is ongoing, it has already cut its own CO2 emissions by 40 
per cent relative to 1990 levels. Not only do locals now no longer 
have to put up with the pollution that came with coal - they also 
have lower fuel bills. Whilst coal costs 1.8 pence per kW hour, 
biomass in the form of wood chips costs only 1.1 pence per kW hour. 
Residents at the first biomass scheme to be up and running in 
Barnsley found their heating bills cut by half due to the new 
combination of cheap energy, council-installed insulation, and 
individual energy meters, giving every householder a financial 
incentive to reduce electricity consumption.

Finally, the UK's first dung-fired power station opened at 
Holsworthy, Devon, in July 2002. The £7.7 million facility processes 
up to 150,000 tonnes of slurry each year from 30 local farms.

What all these many schemes show is that our energy and climate 
crises may be global, but they are best tackled at a local level, 
with the involvement and support of the community concerned. When 
people realise that diligent waste disposal coupled with prudent 
energy useage can free them of dependence on distant and fragile 
energy supplies while also massively reducing their impact on climate 
change, they are more likely than ever to wish to get involved.

The biofuels approach of Predient Bush and the like tries to solve 
one problem only to create many more. The many biogas models adopted 
by local communities worldwide, meanwhile, work with what we have far 
too much of - waste - and turn it into something in increasingly 
short supply - energy. In so doing they answer two problems with one 
simple and elegant solution.

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