You may be looking at the often forgotten clean technology sector, but you may have to be patient before it generates good returns.
The introduction of the carbon tax means the focus will be on companies that operate in the green sector, either delivering energy in an environmentally sustainable way, reducing waste or minimising the impact of other companies' pollution.
The carbon tax sets a fixed price for carbon units, as they are called, for the next three years. That price is $23 in the first year, rising to $25.40 in 2014-15.
That impost should make cleantech companies more viable competitors to fossil-fuel energy producers such as coal and oil.
But green investing is not a straightforward proposition. Many companies in the sector do not pay a dividend, so you are relying on the growth in the share price.
Also, the political turmoil over the carbon tax has not subsided, so the goalposts could shift again if the Coalition wins the next election.
As some cleantech companies are very new, they are yet to demonstrate commercial viability. That is often due to a lack of capital, a problem for many emerging businesses.
The editor and publisher of Eco Investor, Victor Bivell, says the sector has been hurt by the policy flip-flops of the past few years.
''There was a lot of momentum in the clean energy sector a few years ago but that has weakened,'' he says.
''However, there are still plenty of cleantech businesses that have great technology.''
We've highlighted five to watch.
The electric-scooter company recently signed a contract for 6000 scooters with Shanghai's PowerEagle International. China is the world's biggest two-wheeled market and the deal would see Vmoto produce about 150,000 units by 2015. PowerEagle will use its distribution network to sell the scooters in China.
CERAMIC FUEL CELLS (CFU)
This is one of the more established businesses in the cleantech sector. It produces power-generating products for home and office, built around its fuel-cell technology. In its ASX update in March, the company said it had orders for 619 units. Payments received in the March quarter totalled $2.7 million, which was 85 per cent above the December quarter. Some of its BlueGen units were sold to clients in Britain and Germany, and the company has launched a marketing effort in the Netherlands. Domestically, it has installed 25 of its units in Newcastle, NSW, as part of the ''Smart Grid, Smart City'' project and 30 units are in similar projects in Victoria.
Co2 GROUP (COZ)
The company has about 22,300 hectares of trees planted for its carbon sink (reforestation) projects for other companies.
Management announced a record net profit result of $1.6 million for its past half year. Revenue for the company was also up significantly. While the company did not pay a dividend last time, the board says it's reviewing its policy in that area.
It also has a range of other environmental services such as forestry mapping and management, mine-site rehabilitation and carbon accounting.
Co2 is expanding its operations in New Zealand and looking at other overseas markets.
CARNEGIE WAVE ENERGY (CWE)
The company (and its share price) recently received a big boost after the Prime Minister, Julia Gillard, confirmed the government's support for an exclusive agreement for Carnegie's Perth Wave Energy Project to power the Department of Defence's HMAS Stirling naval base. The company's wave-energy system includes an array of submerged pumps, which are tethered to seabed pump units. The motion of passing waves drives the pumps, which pressurise water, which is then delivered to the shore via pipes. That water then drives hydroelectric turbines. The managing director, Dr Michael Ottaviano, strongly supports carbon pricing.
The company has a high-yield algae-growth manufacturing system, which produces what it describes as sustainable and renewable oil for fuel. Algae has long been viewed as a possible replacement for fossil fuels. Algae production also avoids the ''fuel versus food'' debate, which can affect soybean and other biofuel foodstocks. Broker Patersons notes all companies in the algae sector face challenges in terms of the selection of algae species, optimum sunlight and water use. An Algae.Tec demonstration plant has been commissioned in Nowra on the NSW south coast and airline operator Lufthansa is conducting a test of algae oil.