When I say I'm working on changing the way humans use energy, I may as well say I'm working to change every technology that exists. Everything we buy and use can be streamlined to consume less energy, and frankly many things we produce simply shouldn't get produced at all. To some extent, your average person's carbon footprint is a direct result of the technology based world that engineers have created. This goes for everything from lighting to automobiles to plastic bags to medicine. It's all technology, it all uses energy and resources (at some point of the process), and every aspect of it needs to be re-examined both by consumers and by producers.

Concentrated Photovoltaics
Solar is a part of the sustainable future. I worked on GreenVolts concentrated photovoltaic (CPV) solar arrays for the last few years. CPV is an interesting field in solar that is effectively still waiting for mass commercialization. It involves concentrating sunlight onto a special type of solar cell which is highly efficient at high concentrations of light. This means less solar cell used (the solar cell itself is a non-infinite resource) and more power created per area than traditional flat panel. The main thing still holding back CPV is the higher cost, though as CPV technologies improve this drawback may be reduced or removed. GreenVolts has a contract with PG&E to deliver a 3MW power plant and is taking part in several pilot projects in 2011.