Last year I waded through Jeremy Rifkin’s The Hydrogen Economy and wrote a blog post that explained what’s promising about hydrogen as a fuel, and its two major drawbacks. I used two charts, reproduced here, to explain how it works and what’s holding it back.
The chart above shows the energy economy we have today. Red boxes are non-renewable, polluting and environmentally damaging energy sources and green ones are clean and renewable. Whether we use hydrocarbon fuels or electricity to light, heat and cool our homes, it’s likely that non-renewable, damaging sources are producing it. Our cars likewise burn fossil fuels, and although hybrid cars are certainly an improvement, they still depend on fossil fuels to create (‘reform’) the hydrogen that the fuel cells convert into electricity.
The chart below shows the energy economy in twenty years, if we can solve the two major dilemmas of the hydrogen economy.
What are the two catches? First, the current cost of electricity produced from non-renewable sources is very expensive, and the process is cumbersome and not yet terribly efficient. Even more problematic is the $100 billion cost of building the infrastructure to generate, distribute and store the electricity and hydrogen, obsolescing a comparable amount of existing energy infrastructure, and probably causing some consternation to and resistance from the owners of that infrastructure.
Yesterday the University of New South Wales predicted that by 2010 a new generation of photovoltaic ‘harvesters’ based on titanium dioxide ceramics will both collect solar energy and use that energy to produce compressed hydrogen from water. A 10m square array, such as that depicted at right, mounted on just half the households in a sun-rich country like Australia, could produce the entire country’s energy.
This would allow an even more distributed, decentralized model than that depicted above: With each household able to produce its own energy, the local energy co-op might be nothing more than a virtual market, and the need for local service stations selling or even producing compressed hydrogen would be obviated. We’d all change from consuming to producing energy.
The university has even higher hopes for the titanium dioxide technology behind this advance: They believe it will allow innovations in other areas such as “water purification, anti-viral and bacteriacidal coatings on hospital clothing and surfaces, self-cleaning glasses, and anti-pollution surfaces on buildings and roads”.
Anyone know anything about titanium? I know it’s a metal, but is it plentiful and easy and clean to extract? Is it recyclable? Durable? Toxic in landfill sites? I sense a bit of grandstanding and breast-beating by UNSW here. Is there another catch they’re not telling us about?