Wind Turbines

I've always liked the idea of wind power generation. One day I'd like to have a turbine on the roof of my house contributing to my household energy requirements.

There are a couple of major issues with current, propeller type wind turbines. Most turbines put the blades in front (upwind) of the support pole. This requires that the blades are very stiff, so they don't flex and hit the pole. This adds to weight and therefore cost, while also reducing efficiency as there is more mass for the wind to move.

Well, why not put the blades behind (downwind from) the pole, you ask? Seems obvious, because you can have lighter and more flexible blades. Unfortunately there are issues due to the turbulence created by the pole. There is a kind of "dead spot" behind the pole which causes the blades to lose pressure and flex towards the pole. This can set up a rhythmic flexing and can destroy the blades depending on wind speed/strength and rotation frequency.

Here is an alternate design that uses a vertical axis and doesn't have any of these issues. I'm not sure how feasible it is, but hopefully it can result in more efficient wind power generation.

As always, more information is available from Wikipedia here.

Shrink wrapped software and Feature Prioritisation

Just read an interesting article written by Joel Spolsky. You can read it here.

It covers two important concepts in Software Development.

1. Developing shrink-wrapped sofware vs customised software. I've developed both kinds of software at various times.

I find that writing customised software really isn't a good business model. The process tends to go like this:
- Sales guy talks to the client
- Asks for a quote with some very vague, hand-wavy "requirements"
- BA/Architect comes up with an estimate based on gut feel
- Estimate is turned into a dollar figure, discounts are applied to ensure the deal is won
- Contract is signed

Later on, down the track, the consulting company decides what functionality can be crammed into the budget, negotiates with the customer and they come to some agreement.

The end result is that the customer doesn't really get what they want and the consulting company make a very small profit (or sometimes, large losses!) and that's it. No more chance to benefit from that work at all.

At least if you develop some software that can be resold (even with customisation) you've got an opportunity to leverage that work into future earnings.

2. Priorities
The other interesting concept discussed is prioritisation. I think this is so important, but lots of people just don't get it. If you set priorities and then develop components based on their importance, everybody wins!