Sustainable or "green" businesses are a fast-growing sector of the global economy. As awareness of the world's ecological problems grows, more and more companies are turning their efforts to solving them. According to a 2010 study by Ethical Markets, private investment in green businesses reached approximately £1 trillion between 2007 and 2010, with the rate of investment increasing constantly. Here are just a few of the wide range of green businesses to invest in.
Home solar panels
With government incentives encouraging homeowners to generate some of their own energy by installing solar panels, and even to sell surplus electricity back to the grid, the number of homes with their own solar generators looks set to increase, whether because of new installations on existing homes or the inclusion of solar panels on new buildings.
As global fuel prices rise and rise, and as carbon emissions threaten to destabilise our climate more and more, renewable energy resources such as wind and water power become more and more important. The design and development of wind turbines is a growth field, with both major energy companies and specialist wind companies dedicated to producing more efficient, less expensive new devices.
Related: Top wind farm sites in the UK
Geothermal power derives from the relatively stable high temperatures found below ground. It can be used either for heating or to generate electricity. At present, geothermal energy isn't much used in the United Kingdom, although the Renewable Energy Association believes it could supply up to 20% of the nation's power needs. At the moment, lack of government subsidy means that geothermal energy is under-explored in the UK, but this could change at any time.
Hydrogen fuel cells
Another alternative to fossil fuels is the hydrogen fuel cell, a proposed power supply for vehicles and other devices. Although the technology for hydrogen cells is still in its infancy, many companies are working to develop this new source of clean power. As with wind farms, investors can choose to put their money into existing energy companies with hydrogen cell research programmes or dedicated research groups.
Related: Cars of the future on today's market
The development of non-polluting fuels is one way of reducing carbon emissions. Another is by improving energy efficiency to cut down on the amount of fuel used. Some energy-efficient technologies, such as compact fluorescent lightbulbs, are already spreading throughout society. Few companies specialise in energy-efficient technologies, but there are some, as well as efficiency consultancies which help corporations reduce their energy use.
Related: 10 Ways to improve energy efficiency
While some scientists work on replacing the fuel sources that produce harmful carbon emissions, others dedicate their research to reducing emissions from existing fuels by improving engine efficiency or exhaust filtering. Government legislation is the primary driver of pollution control technology. With more stringent restrictions almost certain to be put into place, the pollution control sector looks like it will be busy for some time to come.
Related: Major causes of air pollution
One area of research that contributes to cutting down on fuel expenditure, and by extension pollution, is the development of new materials. Carbon nanofibres, for instance, are an important part of new designs for fuel-efficient vehicles because of their high strength and low weight. With a wide range of applications, these new materials will play a role in the green technologies of the future.
The growth of landfill is another major environmental problem; just like air pollution, it has spawned a new set of industries attempting to deal with it. Some waste recycling is handled by the government rather than by private firms, but some companies are moving into this sector. One area which has expanded in recent years is fibre recycling. Used mattresses and carpet, which would once have been placed in landfills, are broken down so that their fibres can be recycled for other purposes.
Manufactured from petroleum and non-biodegradable, polystyrene packaging has been a major target of the environmental movement for years. In fact, the technology to recycle polystyrene packaging does exists, but high costs have made it rare until relatively recently. As this technology spreads, polystyrene recycling shows the potential to be an area of notable growth as well as a boon to environmentalists.
Related: How to recycle packaging
Consumer products made from recycled materials not only encourage recycling but spread the message that recycled goods don't have to be of inferior quality. As with many other green products, recycled consumer goods come both from specialist companies and from larger manufacturers. Even giants like Nike have seen the advantage of going green and begun to invest in recycling.
In the quest to create environmentally sustainable businesses, companies are looking not only to the new technologies of the future but the farming methods of the past. The organic food sector has grown dramatically over the last decade, although investment opportunities remain comparatively limited. Still, some businesses, both producers and retailers, offer investors a way to support this growing sector of the market.
For investors who don't have the time to research potential investments and assess their environmental impact, more and more brokers are offering "green funds" -- managed packages of investments that specifically select environmentally-conscious businesses or businesses that work to improve the environment.