20 proven ways to save the earth

Tackling climate change may be daunting but it is entirely feasible using existing technology

Charles Clover

1 Solar power
Spain is leading the way with solar power. The PS10 solar tower is already in operation near Seville, producing electricity with the aid of more than 600 large movable mirrors called heliostats. The country’s largest solar-power station, which will store heat for up to 15 hours in molten salt, is under construction in Cadiz. It will be operational in 2011. Heat-generated steam will drive a turbine that will power 25,000 homes.
2 Carbon capture and storage
Coal and waste materials are burnt in permanently-running power stations that provide electricity, heat and sometimes hydrogen. The carbon dioxide this creates is captured and sent, safely, to be disposed of in disused oil wells and aquifers. Carbon capture and storage has been practised in the North Sea by the Norwegian company Statoil since 1996. EU leaders have promised around 12 pilot projects attached to coal-fired power stations by 2020.

3 Smart meters
Home electricity is likely to be managed increa-singly by smart meters to cut wastage. The Italians are leading the way. Some 85% of households have one; there are more in Italy than in the US.
4 Wind power
The government’s Climate Change Committee estimates that wind power could provide 30% of Britain’s energy by 2020. Offshore wind power is the key to that and the UK is already the world leader in installed offshore wind. The next development is likely to be wind farms on floating platforms anchored in deeper water. The first floating turbines were inaugurated 10 kilometres off the Norwegian coast in June 2009.
5 Nuclear power
Thanks to its reliability, nuclear power is already enjoying a renaissance with 53 reactors under construction in 13 countries, notably China, South Korea, India and Russia. A series of applications to build reactors, offering safety improvements on existing designs, is being made in the UK; the government may introduce a carbon tax to cover the nuclear industry’s unpredictable costs. A repository to contain Britain’s existing legacy of nuclear waste, however, remains 25 years off.
6 Solar panels that heat water have long been used in sunnier parts of the world and are becoming more economic in UK.
7 Personal Rapid Transit
By the 2030s, many more vehicles will be powered by mains electricity or fuel cells run on hydrogen produced by renewable or nuclear energy. Personal Rapid Transit, based on existing technology, will eventually bring driver-less trains to our cities. Prototypes have been tested at Heathrow’s Terminal 5.
8 Carbon trading
New financial mechanisms, funded by carbon trading, are likely to be set in place in Copenhagen in December to tackle the destruction of the tropical forests such as the Amazon.
9 Wave power
Britain has the potential to dominate the global wave-power market, with 25% of wave technologies being developed here. Two different snake-like devices that move up and down with the waves offer the best prospects. Pilot wave farms are in operation off Portugal and Scotland. Wave power is 15 years behind wind power in being commercialised so it is unlikely to make a significant contribution to the national grid before the mid-2020s.
10 Eco aircraft that resemble “flying wings” have been designed by the Royal Aeronautical Society and shown to be up to 25% more efficient (picture 4, above). Boeing has been looking at the propfan, which promises 35% fuel efficiencies over current jet engines.
11 Tidal power
Existing technology, such as the La Rance tidal power plant in Brittany or the proposed Severn barrage, is expensive — but although the barrage is environmentally damaging, it could, in theory, supply 5% of the national grid.
12 Solar roofs that generate electricity should become more attractive to home- owners next year due to a new tariff that reimburses them for surplus energy they produce.
13 Solar electricity-generating cells
Where roof space is limited, transparent cells that can be fitted to windows have been invented by Konarka, a Massachusetts company.
14 Reversible heat pumps
Many homes in the countryside that have enough land are already using these pumps, which use the ground or local aquifers as heat stores; heat is dumped in summer and recovered from them in winter. These offer substantial savings on using gas.
15 Second-generation biofuels such as algae are known to yield up to 100 times the energy per hectare as corn, soy or sugar cane crops. Some 12% of annual global jet fuel is likely to be derived from algae, or pond scum, by 2030, according to the Carbon Trust.
16 LED bulbs give up to 95% savings on traditional lightbulbs. Far better ones can be expected. Philips Research have developed a non-mechanical means of electrically adjusting the size and shape of a beam of light.
17 Combined heat and power
In Denmark, high-density urban homes take hot water from specialised municipal power stations. There are many more opportunities to use more waste heat produced in IT and power generation.
18 Air travel can increasingly be replaced by better video conferencing.
19 Breakthroughs in existing technologies could change everything. Better batteries are a number-one priority if electric cars are to go from 40 miles between charges to 400. Lithium-air batteries offer the best hope of storing energy in cars.
20 Solar reflectors could generate solar power in space and beam it back to collectors on Earth in the form of microwaves.