Posts Tagged 'electricity'

Earth Hour before and after photos

Back in 2007 I took some good quality before and after photos of the very first Earth Hour event in Sydney. Unlike other photos published that year (and since) by the news media, mine are a ‘truer’ representation of the before and after effect.

The before photo was actually taken several days before Earth Hour because I knew that most building managers would have already shut down most lighting prior to Earth Hour on the actual day. Also, I used the same settings for both photos so they don’t exaggerate or mis-represent what was actually achieved. On the other hand, photographers sitting around on the evening of Earth Hour taking ‘real time’ before and after photos didn’t get to see the full effect at all.

The photos were originally picked up by WWF off Adam Searle’s blog post. I was happy to release them to promote the cause, but was a little disappointed when I saw them re-printed in the Sydney Morning Herald Earth Hour supplement in 2008 and credited to some agency. I really hope they didn’t get sold on (I still haven’t had a response from WWF to clarify this).

Anyway, happy to see they are still being put to use… now featuring in the opening credits of this year’s official Earth Hour video (see below).

Earth Hour 2007 (Sydney) - Before

Earth Hour 2007 (Sydney) - After

If you would like to reproduce these photos to promote or discuss Earth Hour or related issues, please:

1. Contact me and get my permission first (unless you are going to make money off them I’m happy for the images to be used free of charge).

2. Download them from this site (high-resolution versions can be obtained by clicking above).

3. Include an acknowledgement such as ‘Copyright Ryan McCarthy’, ‘Photos by Ryan McCarthy’, a link to this website, or similar.

Thanks… and don’t forget Earth Hour this year: 8.30pm, Saturday 27th March, Worldwide!

A brief introduction to photovoltaics

Photovoltaic cells generate electricity from sunlight, typically by means of a p-n junction semiconductor material. Their ability to generate energy from a free fuel, using no moving parts, creating no noise or on-site emissions, with minimal maintenance in a highly predictable and reliable fashion, is unparalleled. Application of the technology is modularised and deployment can take place where energy is most valuable: at the point of use. In a world of widespread energy inequality, dominated by unbalanced and typically centralised energy systems, photovoltaics’ time has come.

Knowledge of photovoltaic technology has progressed rapidly over the last half-century. Although the photovoltaic effect was discovered in the 1800’s, the silicon solar cell was first developed in a useful form by the Bell Telephone Laboratories in 1954. This wafer-based silicon cell has become the mainstay of the solar industry since that time and has certainly led the charge to production levels of a giga-watt per annum scale (reached in 2004). The global bottleneck in supply of high purity solar grade silicon experienced in recent years highlighted the point that this technology is not likely to lead the charge to a world with a terra-watt of installed photovoltaic capacity.

Photovoltaics is, however, not without its limits. Just as the amount of oil left in the earth’s crust is limited, there is only a finite amount of energy available from sunlight. Thankfully, unlike oil and other fossil fuels, this amount of energy is highly predictable, enormous on a global scale and quite obviously, constantly replenished.

This is an edited excerpt from Opportunities for Vehicle Integrated Photovoltaics.

If you are interested in buying an in-depth book on the topic I suggest Applied Photovoltaics from Amazon.

Energy Efficiency Tips:

- Get expert advice with a Home Energy Audit or Business Energy Audit.

- Use a Power Meter, Wireless Energy Monitor or Thermal Imaging Camera to understand your usage.

- Upgrade to high quality LED Lighting.

- Use these innovative Energy Saving Devices.