The prospect of power cuts all over Tokyo this summer has forced Japan to think creatively about how to curb its massive appetite for electricity.

The crisis at the reactors operated by Tokyo Electric Power Company (TEPCO) in Fukushima has cut TEPCO鈥檚 generating capacity by about a third, to 31聽gigawatts. Rolling power cuts are already hitting Tokyo suburbs and beyond as Asia鈥檚 biggest utility firm struggles to meet demand.

For now, 鈥渟elf restraint鈥� 鈥� dimmed lights in shops and fewer trains running 鈥� has helped, as has the warmer weather. Fewer power cuts have occurred than were originally planned, and central Tokyo has been spared altogether. Last Friday, power demand hit 34聽gigawatts, within TEPCO鈥檚 present capacity of 37.5聽GW. At the same time last year, demand was more than 40聽GW. But the city soon faces its biggest test.

In summer, millions of air conditioners will kick in. TEPCO thinks it has a grace of only about two months, perhaps three, before commerce-sapping power cuts will be required all over Tokyo.

If this summer is as hot as last year鈥檚, power demand could reach 60聽gigawatts. TEPCO predicts it will be able to generate only 45聽GW of electricity, perhaps 50聽GW if it can get fossil-fuelled and geothermal stations out of mothballs quickly enough. That鈥檚 a shortfall of at least 10聽GW, meaning lights out for Tokyo and the area鈥檚 vital manufacturing powerhouses and businesses.

Not squeaking by

鈥淚 can imagine a scenario of just squeaking by through a combination of massive conservation, a mild summer and no further losses on the generation side. But I can more easily imagine other scenarios where one or all of these three don鈥檛 deliver,鈥� said at Lawrence Berkeley National Laboratory, California, author of the International Energy Agency鈥檚 . 鈥淭okyo won鈥檛 be a happy place if that happens.鈥�

The task is colossal. The last time Tokyo faced power cuts like these was in 2003, when TEPCO had 17 of its nuclear reactors down over safety fears. A massive effort to scrimp on electric power then managed a reduction of only 4.5聽per cent. That certainly won鈥檛 be enough to meet the 20 to 25聽per cent extra power TEPCO has to find between now and July to meet peak summer demand.

The government is budgeting 1聽trillion yen ($12 billion) to boost energy-efficiency measures, such as bolstering an existing 鈥渂uy eco-electronics鈥� scheme that cuts the price of energy-efficient home appliances. Tokyo shops now stock a slew of expensive new appliances that claim savings on up to 75 per cent on electricity use.

An increase in solar power, which currently has a capacity in Tokyo of around 780,000聽kilowatts, should also help ease the pain. It will be helped by a new measure that will pay 67 per cent more than at present for surplus solar power produced by businesses and schools. The initiative was already in the pipeline before the Fukushima crisis.

Cell mates

Fuel-cell technology will also play its part. Part of that 1聽trillion yen will give further subsidies for fuel cells, says Japan鈥檚 commerce ministry, which is behind many of the new initiatives. Firms like Panasonic and Toshiba sell their fuel cells, designed for home use and which produce both heat and power, for between 2.2 and 3.1聽million yen ($26,000 to $36,000). The government will pay for half of each purchase, while other incentives bring the price for consumers down to about 1 million yen ($12,000). Panasonic has said it aims to bring the price down even further in the future.

The government also announced this week that it will fast-track the introduction of smart meters that started in Tokyo last year through TEPCO.

Meier thinks personal technology could be the key to getting people change their power-consumption behaviour. 鈥淭his electricity-saving campaign needs to be built upon innovations in social media and smartphones. Everybody should be able to observe TEPCO鈥檚 grid status on their smartphone,鈥� he said.

He hopes Tokyo residents start changing their energy habits soon. If not, the city could yet find this summer dark and exceedingly sticky.

Life might take a hammering on the sun鈥檚 earthly anvil, the Sahara desert, but the two most abundant resources the desert has to offer 鈥� sunlight and sand 鈥� could help solar power to 鈥渂reed鈥� and thrive there.

The is a joint initiative by universities in Japan and Algeria that aims to build enough solar power stations by 2050 to supply 50 per cent of the energy used by humanity.

The idea is to begin by building a small number of silicon manufacturing plants in the Sahara, each turning the desert sand into the high-quality silicon needed to build solar panels. Once those panels are operating, some of the energy they generate will be used to build more silicon plants, each churning out more solar panels and generating more energy that can be used to build even more plants, and so on.

at the University of Tokyo leads the Japanese end of the project. He admits that making silicon panels from the rough sands of the Sahara or other deserts has not been attempted before, but says it is a logical choice.

鈥淔rom the viewpoints of quality, quantity and chemistry, Sahara sand is hard to beat for use as silicon for solar cells,鈥� he says.

Rivals for power

The Algerian-Japanese effort is by no means alone in targeting the Sahara for solar power. The , set up last year to promote 鈥渃lean power from deserts鈥�, also aims to generate solar power in the region.

Desertec has a more modest goal 鈥� it is dedicated to supplying only 15 per cent of Europe鈥檚 electricity by 2050. Nor does Desertec plan to use Sahara sand for its solar panels.

Desertec hails the new breeder project as 鈥渁 positive contribution towards climate protection鈥�. However, a spokesman said he was puzzled over the choice of energy delivery by the new scheme.

Koinuma wants to use 鈥渉igh-temperature鈥� superconductors to distribute the power as direct current 鈥� more efficient than a conventional alternating current. Despite their name, high-temperature superconductors typically operate at around -240聽掳C, and the long power lines will require a formidable cooling system.

鈥淭here is not really a need for superconductors. By using high-voltage direct current transmission lines it is possible to transport clean power from the deserts over long distances to centres of consumption,鈥� says the Desertec spokesman 鈥� adding that the technology is already used in dozens of projects worldwide.

鈥淭ransmission losses are fairly low 鈥� around 3 per cent per 1000 kilometres. Unlike superconductors, there is no need for cooling, while power transmission costs are just 1垄 to 2垄 per kilowatt-hour.鈥�

Koinuma disagrees. He sees the potential for linking the Sahara-powered stations to a special network of supercooled high-voltage DC grids for transporting electricity 500 kilometres or more.

鈥淓ven if we need to cool the grid line with liquid nitrogen, the system could be cost-competitive,鈥� he claims.

The coastal waters around Japan contain an estimated 7.4聽trillion cubic metres of methane, which equates to around 100 years鈥� worth of natural gas at today鈥檚 rate of usage. But it is only recently that an economically feasible way to extract the stuff has been developed.

The gas is locked beneath the ocean bed in methane hydrates, a sorbet-like substance consisting of methane trapped in ice. In 2002, a team of geologists from Japan and Canada investigated whether it was possible to release the gas using hot water to melt the ice. The demonstration was successful, but used too much energy to be practical.

Further experiments by the team in 2008 found a more economical approach. Holes were drilled into the methane deposits, decreasing the pressure on the ice and so raising its melting temperature. This allows the methane to separate out from the ice-like material and flow up to the wellhead.

It is this approach which will now be further tested in Japan鈥檚 coastal waters by a consortium led by the government and the . According to a government statement, the main area of study is the coastal region stretching 400聽kilometres from Tokyo to the western tip of Honshu Island 鈥� a region thought to hold enough reserves to supply Japan with natural gas for nearly 14聽years.

This latest attempt to bring down summer temperatures that have been hovering in the 40s Celsius involves pumping up the water that seeps into the metro system and spraying it from the kerbside onto the road surface. A water-retentive coating stops the water from draining away, and evaporation does the rest.

At the test site, directly outside Japan鈥檚 parliament building in central Tokyo, a solar and wind-powered pump forces the subway flood water into high-pressure sprinklers that spray it over a 350-metre stretch of road. Recently, the researchers managed to cool the road surface 鈥� which often reaches up to 60 掳C during the summer 鈥� by 10 掳C, and the air above the road by 1 掳C.

Japan longs to return to the cooler summers that were the norm decades ago. Outpacing global warming by a factor of four, average temperatures in Tokyo alone have risen 3 掳C in the past 100 years.

The experiments were designed to reverse the cause of the country鈥檚 urban woes: the heat island effect, in which temperatures in cities rise higher than those in the surrounding countryside. In Tokyo, the main culprit is the rapid loss of trees and other vegetation to development.

聯Average temperatures in Tokyo have outpaced global warming by a factor of four聰

Other human activities driving the heat island effect include heavy use of vehicles and of air conditioning units, which set up a vicious cycle by churning out more heat as they cool buildings. To tackle this latter problem, the government has suggested a scheme called 鈥淐ool Biz鈥�, encouraging the suited ranks of salarymen to abandon their jackets and ties and set air conditioning thermostats higher. Tokyo also hopes to counter urban warming with heat-busting greenery on all new high-rises.