Environmentalists are often sceptical when it comes to foreign countries and companies offering technologies to solve problems. The bill is usually exorbitant – or the catch is that spares are very expensive. Besides, they are often not suited to Indian conditions. In the 1970s and 1980s, for example, when India was first getting into flue-gas scrubbers – electrostatic precipitators -- for thermal power plants, US equipment wasn't meant to operate in the heat and therefore broke down repeatedly.

The sprinkling of environmentalists present for a recent road show in Mumbai by the British High Commission on solid waste management solutions from the UK could be forgiven for being sceptical. Britain hasn't exactly excelled when it comes to preserving the environment – as compared with Germany, Scandinavian countries or the Netherlands – and has been something of a laggard in reducing greenhouse gas emissions. Indeed, in the bad old days of the 1970s, Sweden was most worried that smoke stacks from Britain's dirty and decrepit thermal power stations were causing acid rain and polluting its pristine freshwater lakes.

One of the companies which demonstrated its prowess in Mumbai was WormTech, which runs a site in South Wales to degrade garbage by feeding it to the worms. One would have thought that Indian cities, and Mumbai in particular, had more experience in this regard, and the more worm-friendly temperatures here would surely make the exercise more efficient. Being an agricultural country too, India would have more use for vermicastings, which is the highly-nutritive waste generated by worms after recycling garbage and other biodegradable material. In Pune and Mumbai, householders are showing us how to recycle waste through vermiculture in terraces and even in pots on balconies, all of which reduce the need for kerbside collection and compactors, which WormTech relies on.

However, the one suitable technology which was showcased by the British was the recycling of fly ash – a bi-product of thermal power stations and a nuisance all through India – into cement. Georg Dirk, who owns the eponymous company, has put his technology into practice in Nashik. He calls fly ash a “commodity” rather than waste; India generates 100 million tonnes of it per year. The scale is obviously far bigger than in the UK: last year, Britain produced only about 4 million tonnes and is expected to produce only half that much by 2010, when India generates around 130 million tonnes.

Dirk noted that India's total power capacity will rise from 137 gigawatts of electricity (GWe) in 2002-03 to 1344 GWe by 2052-53. Nearly half will come from thermal power (and 15% from hydrocarbons, 10% from gas, 11% from hydro, 7% from renewables and 20% from nuclear). Thus the potential to recycle fly ash and convert a troublesome bi-product into a useful material is immense. Of the 100 million tonnes of this waste produced every year, 87 million tonnes end up on ash mounds or in lagoons covering 26,000 acres of arable land. Only 13% is recycled and lagoon re-cultivation is only in its experimental stage. In Santaldih, West Bengal, for example, the fly ash mounds pose a threat to cattle.

By 2012, thermal power plants in three countries - China, India and the US – are expected to emit an extra 2.7 billion tonnes of carbon dioxide, the main greenhouse gas, as demand for energy rises. Under the Kyoto Protocol, industrial countries are supposed to have reduced their emissions by some 483 million tonnes. Thus this is a problem literally of global dimensions.

But, as environmentalists firmly believe, every problem presents opportunities. India also produces 124 million tonnes of cement as the world's second largest producer and it does not take much perspicacity to realise that this is one country (with China) where the construction industry is booming. It takes 750 kilocalories (kcal) of energy to manufacture each tonne of cement – being one of the most prodigal consumers of electricity.

By converting ash into cement, Dirk shows that every tonne of this product saves a third of a tonne of cement and a third of a tonne of carbon dioxide emissions. Theoretically, he points out, 40 million tonnes of fly ash could be re-used every year. What is more, under the Kyoto protocol, which recognises carbon trading, India could sell emission credits (equivalent to the greenhouse gas saved by using this waste) and make substantial sums of money.

Under the Kyoto protocol, which recognises carbon trading, India could sell emission credits and make substantial sums of money.
At Nashik, Dirk makes Pozzolan Portland Cement, a fifth of which comprises fly ash. It signed a contract with the Maharashtra State Electricity Board (MSEB) to install a fly ash recycling plant in the thermal power station there. Dirk invested Rs 30 crore for this purpose and what is more, paid for the ash. MSEB provided land at a nominal rate and supplied the ash to silos provided by the company. The contract was signed in 2000 and the product has received ISO certification.

Producing 12 million tonnes of concrete a year, Dirk has 246 customers in India and is exporting to the Gulf. In the next stage, when it expands production, there are customers in the Gulf who want more than 10,000 tonnes a month. As much as 68% of the cement in the country uses fly ash, which costs only half as much as conventional cement. His product has been used in dams in this country, which is the ultimate test for durability and reliability, and in Mumbai fly-overs too. Interestingly, it is being sought for the construction of the 160-storey Burgh Dubai 800-metre-high tower, the world's tallest building: Dirk will supply 6,000 tonnes every month till 2008.