Eccentric Energy: The sun can be a friend… or foe!

France facing nuclear meltdown?

With France experiencing record temperatures of over 45°C in its current heatwave, the nation’s rivers have been steadily overheating and reducing in volume.

This is a significant concern for French nuclear power plants, which supply around 75% of the country’s electricity and need river water to cool their 58 reactors. A nuclear plant in Civaux (western France) cooled by water from the River Vienne that’s supplemented by two dams. Even so, the local authority criticises the company for putting local farming, leisure activities and tourism at risk through its use of the river’s water.

According to Reuters, the French environment ministry recently announced the goal of reducing water use by 10% in five years and by 25% in 15 years. Encouraging wastewater recycling and using less water overall were two of the recommendations for achieving these targets – apparently the result of lengthy discussions with local authorities and utilities.

Ice cream vans to play zero-emissions tune?

When the summer comes, so do the ice cream vans. However, a recent article in “The Guardian” reported that some councils in London have banned the mobile, diesel-powered confectionery dispensers because of concerns about air pollution.

While these vehicles use their engines on the move, of course, they also use them when parked to power their onboard freezers and soft-serve ice cream machines. Critics point to the resulting emission of harmful carbon and nitrogen dioxide, especially in the light of the UK’s net-zero emissions 2050 target – as justification for the bans.

However, Nissan has a news-scoop to help counter these restrictions, having retrofitted its all-electric e-NV200 model to include a battery-powered ice cream maker, fridge and freezer. This prototype uses the vehicle’s standard 40kWh lithium-ion battery to drive the motor, plus a new 700Wh-capacity ROAM portable power pack to run the equipment.

Scottish ice cream producer Mackie’s of Scotland is helping Nissan to refine the vehicle before it continues development.

Who needs the sun when night generation’s possible?

One of the few drawbacks of solar power is that its source – the sun! – is only available in either hemisphere for around half of each day. So, wouldn’t it be great if we could generate power at night too?

Essentially, solar panels are photodiodes; they convert the sun’s light particles (photons) into electricity by exciting the electrons in a semiconducting material (e.g. silicon). The website ScienceAlert reports that Stanford University is trying to take advantage of the "negative illumination effect" – the flow of outgoing radiation created as heat escapes from Earth into space.

The experiment uses a sky-facing infrared semiconductor to convert this flow into an electrical current. While the 64 nanowatts per square metre of power produced is only miniscule, it does prove the concept. And with the right materials and conditions, it may be possible to produce a million times more power (4 watts per square metre).

However, this would still fall short of the capacity of today's solar panels: up to 200 watts per square metre. All of which means that the sun won’t be setting on renewable power for the foreseeable future.