Guest Blog: npower’s Wayne Mitchell on solar power

Solar really taking off Solar has taken a prominent role in the news this week, with the UK’s largest-ever solar farm coming online in Hampshire and Britain forecast to become […]

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By george marshall

Solar really taking off

Solar has taken a prominent role in the news this week, with the UK’s largest-ever solar farm coming online in Hampshire and Britain forecast to become the word’s third largest utility-scale (ie for 4MW-plus installations) solar market.

But by far the most exciting solar-related story has been about the Swiss-built Solar Impulse 2 plane embarking on its round-the-world flight.

After starting from Abu Dhabi on Monday, it then flew from Oman to the Indian city of Ahmedabad, setting a world record for the longest-ever flight in a solar plane. The 1,468km journey apparently took 13 hours and 20 minutes.

Exotic destinations around the world

Next stop is Varanasi, on the other side of India, before flying on to Mandalay in Myanmar then China. Solar Impulse 2 will then cross the Pacific via Hawaii to America, before completing its 35,000km journey by returning to Abu Dhabi in July. Sounds like a nice trip!

But while the destinations may sound exotic, the plane itself is distinctly no frills, with a cramped cockpit that measures just 3.8 cubic meters (around the size of a public phone box) with no heating or oxygen.

That’s because it’s designed to be as lightweight as possible. Despite the plane’s 72 metre wingspan – larger than that of a Boeing 747 – its carbon fibre composition means it weighs just 2,300 kilograms, about the same as a car.

Continuous renewable power supply

The high-tech part is the 17,250 solar cells built into the wing that power the plane’s four electric motors and charge lithium batteries which then provide power at night.

The plane’s motors are also super efficient, losing only about 3% of their energy through heat, which is impressive compared to conventional engines with energy waste of up to 70%.

So while it’s unlikely we’ll see commercial aircraft running on solar any time soon, Solar Impulse 2’s innovation and refinement of existing technologies can only be a positive step towards more widespread low or no-emissions transport.

Transport breakthroughs

Already we have seen:

  • Tindo, the world’s first solar-powered bus introduced in Adelaide, Australia more than seven years ago.
  • The Turanor Planetsolar boat circumnavigate the globe in 2012, becoming the first solar electric vehicle to do so.
  • The Vili Solar train near Budapest, Hungary become operational in 2013, able to carry an entire cabin full of passengers powered entirely by its own solar panels.
  • Solarcopter, the world’s first solar-powered quadcopter built by students at Queen Mary’s University in London in 2013.
  • The International Space Station, perhaps the most impressive solar powered vehicle ever constructed and powered entirely by its 33,000 solar cells.

Several UK local authorities, including Birmingham City Council, are currently assessing the potential of solar charging stations at bus-stops for electric buses.

So solar’s role in emissions-free transport could become more widespread than ever imagined in a relatively short time period. This is exactly the aim of Solar Impulse 2 pilots Bertrand Piccard and André Borschberg, who say they want their flight to prove that “renewable energy can achieve the impossible”.