Showing posts from August, 2014

Pi Wars

I'm thinking about entering Pi Wars in December. It's a Raspberry Pi based robot competition. So far, I've scrounged a few bits and pieces, and put together a really basic remote control system using a Playstation 3 controller, an L293 H-Bridge driver board and an Arduino. The Raspberry Pi can do PWM and USB/Bluetooth, so it can take the place of both the laptop and the Arduino, when I get that far. There are a few bugs, as I mention in the video, related to input handling. Basically if I play with it too much, the motor gets stuck (usually at maximum speed) and I appear to stop getting events from the joystick char device. But for now, here's a short video.


And now for something completely different. Someone asked the question the other day - what's the CO2 cost of the concrete in a Wind Turbine? You need 1000 tonnes of concrete to install a wind turbine You create a total of 410 kg of CO2 per m3 of concrete Concrete has a density of 2.4 tonnes per m3 => One wind turbine requires 416 m3 of concrete => You can attribute 170 tonnes of CO2 to the wind turbine's concrete base Assume a turbine base lives for 20 years. Assume the turbine generates 2MW watts max Assume an average utilisation of 30% => in 20 years, the turbine will generate 105.2 GWh => concrete production adds around 1.6 tonnes per GWh (Or 1.6 grams per KWh) to wind power. If you make electricity using an fossil fuel power station, you create: Coal: 910 g/KWh Gas: 390 g/KWh (The UK average across all fuel types, including renewable and nuclear) is 470 g/KWh. So, the effect of the concrete on CO2 emissions is negligible, compared to traditio