Practical Eco

Humanure?

Now here's a subject you probably don't think about a lot - humane waste. Poo. Back Home Magazine's recent issue features a comprehensive article on composting toilets. And It got me wondering - exactly why DO we waste so much fresh water just to get rid of the product of our digestion? There are sensible and cheap ways of dealing with it that can yield a safe compost for your garden. I was surprised, however, to read that one person will produce only about 5 gallons of finished compost per year, so it's probably just a top-up to what you might need in a decent garden.

I'm definitely going to set up a compost toilet next year in my new house. And when water shortages arrive, I'll be well ahead of the game.

Full Back Home Magazine article (pdf)

Researchers develop technique to use dirty silicon for cheaper solar energy

A research team at UC Berkeley has come up with a simple way for solar photovoltaic (PV) cells to be made from cheaper and more readily available low-grade silicon.

As PV becomes more popular the price of pure silicon has been driven up. By switching to cheaper and more common low-grade silicon manufacturers could develop less costly solar panels.

There's still work to be done but this research suggests a potential step change in solar PV cost effectiveness in the near future. Even if it means lower efficiencies I imagine there will be a place in the world for low cost and somewhat less efficient panels. Where sun is plentiful, for instance, and where there are no constraints on size.

Full story