Printed solar panels

[Ursa major]

Printed solar panels a shining light for saving energy

An Australian breakthrough in wafer-thin, lightweight solar panels that can be stuck on to any surface is set to deliver Australia a new source of local manufacturing, the researcher whose team developed it says. Newcastle University physics professor Paul Dastoor said his team had completed a fully functional demonstration project and has several more in the works. The technology is a couple of years away from full commercialisation and Professor Dastoor said he is now "gearing up to build the first factory to produce printed solar here in Australia".

While its production cost of $10 a square metre is very low, and the panels weigh next to nothing compared with rooftop solar, which tips the scales at about 15 kilograms a square metre, printed solar is far less efficient and durable than established technologies. Printed solar panels last for only two years and deliver just 2 per cent of the efficiency of rooftop panels, which are built to last about 20 years.

Professor Dastoor said his team had calculated that, to be competitive, his printed solar technology needed to deliver a three-year lifespan and operate at 3 per cent the efficiency of existing technology, which he said would be achieved "within the next two years".

 

[Justin Swanton]

A rooftop solar panel has an efficiency of about 20%, so 2% of that is 0.3%.

A typical domestic solar panel has an area of 1,6m2. If 20% efficient it generates about 320W per hour. On an ideal day it will get the equivalent of 5 hours good sunlight and generate 1,6kW per day. That's enough to power a little more than 6 x 60W light bulbs. A 3-bedroom house in the UK uses about 8.5 - 10kW per day. So presuming every day is ideal for sunlight it would need 6 panels. But of course you need to take cloudy and rainy days into account, and the winter months. So double or triple that to, say 15 panels. That's 24m2. A typical house in the UK covers a area of 76m2 which means in theory it can be powered by solar panels alone. The downside of all this though are the batteries. Since there will be days or even weeks when sunlight is not optimal the house will rely on battery storage. Problem is that batteries don't hold their charge for very long, hence the need for many more batteries than seems necessary at first glance in order to have enough residual charge for the home after long periods with little or no recharging. This pushes the price tag way up.

Once you get to lightweight panels it all goes sideways. Even at 3% efficiency you will need an area of 800m2 to power a home. That's an area measuring more than 28 x 28 metres. Just not feasible in an urban context.

 

[mosaix]

A rooftop solar panel has an efficiency of about 20%, so 2% of that is 0.3%.

A typical domestic solar panel has an area of 1,6m2. If 20% efficient it generates about 320W per hour. On an ideal day it will get the equivalent of 5 hours good sunlight and generate 1,6kW per day. That's enough to power a little more than 6 x 60W light bulbs. A 3-bedroom house in the UK uses about 8.5 - 10kW per day. So presuming every day is ideal for sunlight it would need 6 panels. But of course you need to take cloudy and rainy days into account, and the winter months. So double or triple that to, say 15 panels. That's 24m2. A typical house in the UK covers a area of 76m2 which means in theory it can be powered by solar panels alone. The downside of all this though are the batteries. Since there will be days or even weeks when sunlight is not optimal the house will rely on battery storage. Problem is that batteries don't hold their charge for very long, hence the need for many more batteries than seems necessary at first glance in order to have enough residual charge for the home after long periods with little or no recharging. This pushes the price tag way up.

Once you get to lightweight panels it all goes sideways. Even at 3% efficiency you will need an area of 800m2 to power a home. That's an area measuring more than 28 x 28 metres. Just not feasible in an urban context.

Agree with all that, Justin.

But, as with all new technology, it has to start somewhere.

 

[Ursa major]

A 3-bedroom house in the UK

The research was being carried out in Newcastle, New South Wales (i.e. Australia).

It's a bit sunnier down there than here (not to mention that I expect they're looking to export it).

 

[Justin Swanton]

Agree with all that, Justin.

But, as with all new technology, it has to start somewhere.

Sure, but my experience is that a new technology advances in leaps and bounds only for a short time after its initial appearance, and then tapers off. So from the first horseless carriage to the Model T was 25 years. Since then the price-for-performance has hardly improved. The only contemporary car comparable to a Model T for what it can do compared to how much it costs is the Tata Nano, and doesn't substantially differ. A bit faster, less hardy and with the same lack of modcons. Ditto for the aeroplane: first flight in 1903. First closed cabin commercial flights in 1919. First commercial subsonic jet in 1952, and that's where we are 70 years later.

This applies to solar panels. When first invented in the late 19th century their efficiency was about 1%. In 1954 a new design gave them an efficiency of 6%. In 1960 it was 14%. From then until now (60 years) the increase has been less than 6% for affordable panels. There are panels that manage up to 45% but they are very expensive and well out of the reach of the average householder.

Technology has limits, most of which were reached a long time ago.