Solar Tree Bears Fruit

Hugh Pickens writes "A prototype solar tree that recently went on display on a busy street in Vienna, Austria has passed a key test by providing light during the night-time even when the sun had been blocked by clouds for four days in a row. The branches of the solar tree were decorated with 10 solar lamps, each one powered by 36 solar cells. The tree included rechargeable batteries and electronic systems to measure the amount of light in the atmosphere and trigger the solar lamps to go on. 'Not just trees but other objects could be decorated with solar cells and so keep streets well lit at night time,' said Christina Werner from Cultural Project Management. Google uses a similar concept to light their parking lots with 3,000 solar panels that provide up to 10 percent of the Googleplex's power demand. We discussed Google's solar initiative last year."

Comments

Re:The question is...

[NorbrookC]

How much non-renewable energy does it take to produce each solar tree

If that were the only energy concern, then you'd have a point. It probably does take more energy in the beginning to produce it. However, the better (and more relevant) measure is total energy consumpption over its lifespan. That is, compare the manufacturing energy + energy use from grid + maintenance (replacement bulbs, etc.) over its projected lifepan to a standard lighting system. If it turns out that the overall energy used is less than that of a standard one, you come out ahead. You could also do cost analysis, but any pilot system has a much higher cost than production systems.

Looks promising

[dysfunct]

A better picture of that tree can be found here.

As a citizen of Austria, I find it quite astonishing that this thing was able to provide light for a couple of days, although I have to admit that compared to now October still had plenty of daylight. I don't know whether or not they have been removed from the streets, but it would be pretty interesting to see for how long they can go in December/January, when it's quite dark throughout the entire month.

Apart from the energy savings, though, I wouldn't necessarily want to see them implemented throughout the city. Most of the 1st district's lighting is quite dim, giving the whole city with its many historic buildings a bit of a romantic flair, which - in my opinion - would be lost with all those bright lights everywhere.

Re:good idea but...

[blackest_k]

Its not too bad not suitable for every street admittedly.

  its look is like an anemone quite alien an almost Martian chronicles feel to it. googles bus shelter designs are not as interesting to look at.

cost to make them may be quite high, however with 10% of European electricity production going into street lighting in europe the potential reduction in carbon emissions is significant.

  Retro fitting just the LED lamps to existing street lighting could be power saving in itself. The solar panels wouldn't need to provide power year round since existing lamps have a power supply they could switch too.

I'm sure more sympathetic designs could be made, its the potential of this project which makes it interesting.

The real questions are how much power is required and how much light do these tree's produce.

Re:The question is...

[StopKoolaidPoliticsT]

We (the continental US, but this applies to most places on Earth) receive 5.5 useful sunlight hours per day, on average. On average, maybe, but it doesn't make NY or Washington get as much sun as Texas. You'll get a better ROI the farther south you live and the less cloudy the atmosphere is.

Modern solar panels have an effective lifespan of at least 20 years. Is that taking into account hail storms and other forms of damage that happen in non-ideal conditions? I've seen hail leave dents in cars, I'd imagine that would be pretty devastating to a solar panel array. I'd imagine they'd also be pretty useless when they're covered with snow during the winter.

The cheapest commercially-manufactured home solar panels currently cost $3 per Watt. Is that just the panel cost? If so, that doesn't include power inverters, batteries to store the power (I use most of my power at night when I'm home, not during the day when the panels are producing energy), replacement and disposal of the batteries, maintenance of the system, replacement of damaged panels, etc. All of that will need to be factored into the cost per watt too.

Re:The question is...

[h4rm0ny]

Well, looking at the photo, it's certainly prettier to look at than most street lamps. Just a bit of a futuristic, more organic look. I like it. And it certainly gets more publicity than bolting some panels on top of an existing lamp. Besides, this is a prototype, so maybe you'll get your wish and the actual approach taken by city councils will be to adapt existing lights.

We should never give up our appreciation for elegance.

Re:The question is...

[h4rm0ny]

I haven't seen "real" (ie, damage-causing) hail since 1980 or 1981, and when it does happen, it tends to happen over a small area. I'd call that a low enough probability event to ignore. As for the more general "accidental damage" category - Well, does your house have windows? Do you need to replace them all every few years due to baseballs or hail or meteorite damage?

Didn't anyone see that indestructible monitor a few days ago with the crystal screen? Okay, it's not actually indestructible but it's a transparent material that is strong enough to resist hammers, nails and cheap crossbow bolts whilst being cheap enough to use as the front for a monitor. The technology to make tough solar panels probably exists.

So we might be down one more argument against solar panels and we already have some good arguments for them - the fact that Earth will run out of fossil fuels and the general consensus that existing energy production methods are destroying our environment.