From IT Project Management to Renewable Energy
MSc REBE
Burning coal in central London
Jan 26th
The smoky coal fires of London were banished in the fifties and all that remains of that smog filled, grimy time are the blackened buildings of parts of Bloomsbury which haven’t been cleaned. Sunny days with blue skies are now common, but open fires very rare indeed.
Much to my surprise, coal burning is still possible. The Clean Air Act of 1993 makes it illegal to emit smoke in a designated Smoke Control Area, such as the London boroughs. You’re only allowed to use authorised fuels which include gas, electricity and anthracite – ie. coal.
Anthracite coal
Anthracite is very hard, shiny coal and is over 90% carbon. If you burn it, even at temperatures below its ignition point, it doesn’t emit smoke. It’s not the greatest of fuels – heavy, hard to light, expensive and with a calorific content about half that of gas – but it is legal.
The Clean Air Act doesn’t concern itself with CO2 emissions, and because of its high carbon content anthracite has one of the highest emission rates of any solid fuel. When you consider the carbon cost of mining, cleaning and transporting it, its obvious that using it in London would be a very bad idea indeed. Make sure your flat is well insulated, and look to other types of heating first.
Walking to the Wind
Dec 16th
Last week we started the first practical module and in December, in Wales, the choice is between Biomass in a nice warm boiler room or Wind and walking on hills. The Welsh weather gods were in a kindly mood, and rewarded the hardy with crisp, clear days, perfect for a morning spent on the hillside at Mynydd Gorddu.
Typical Welsh countryside at Mynydd Gorddu wind farm – green hills, clear blue sky, sheep and turbines
There are 19 Nordtank* machines in the wind farm, 12 at 550kW and another 7 at 600kW. They’re the same machines, but the larger ones have short blade extenders at their hubs to increase the swept area slightly. When we were there, on a clear day with only a light breeze, they were still generating 2.3MW, powering a few hundred homes, or about a thousand kettles, all boiling at once.
*The link is probably for this 600kW machine, but I’m not 100% sure.
Archimedes Screw Turbine
Nov 27th
What a fantastic piece of technology is the archimedes screw turbine. It’s simple, works in situations where other hydro power turbines aren’t much use, has a very low environmental impact and is even safe for fishes.
The archimedes screw is a type of water pump which has been known since ancient times, and may well have been used to water the hanging gardens of Babylon. It was certainly familiar to Roman engineers.
Archimedes Screw (c)Siberwolf at Wikipedia 2009 (click image to see original and licence)
To pump water from the bottom to the top, the pump needs to be twisted, either by hand, perhaps a windmill or someone running on the casing, as an ancient treadmill.
A few years ago, a genius engineer unknown to google or wikipedia, figured out that if you turn it upside down and let the water drive the turbine, you could stick a generator on top and make electricity, being careful not to let the generator get wet.
The big advantage of these turbines over others used for small hydro schemes is that they work well when there is a low head of water so can be used over an existing weir, or in outflow pipes. That configuration means they don’t need much pipework either, making the civil engineering component of the scheme much smaller. Debris in the river just passes through (at least up to a point), so there’s no need for trash screens
A 48kW scheme installed on the river Dart in Devon in 2008 consistently produces 35-48kW, enough to power visitor facilities, a conference centre and two bungalows in the River Dart Country Park.
Another in Osbaston, Wales provides 150kW, and powers 152 homes. The environment agency cite it as an example of good sustainable practice in their guidelines for small hydro schemes.
Osbaston Hydro Scheme and Fish Pass
Most importantly, it doesn’t bother the fish. Because its open to the air, and large, the fish just swim up it. The water is going at the same speed as it would be over a weir, and so it makes little difference to them. The one in the photo above is actually a fish pass as well as a hydro scheme.
Environmentally friendly, low maintenance and robust – it’s an ideal technology
Changes
Nov 26th
After 25 years in corporate IT, I’ve decided to take a year off to do an MSc in Renewable Energy. On here, I’ll be blogging about renewables, being a student and trying to start a new career.
The course is at the Centre for Alternative Technology in Machynlleth, Wales. An old slate quarry has been turned into a research and education centre for all sorts of low-impact technologies – energy, waste, water, buildings. Power comes from wind turbines on the hills, solar panels on the roofs and hydro-turbines drawing from the enormous amount of water which cascades down the slate hillsides. The buildings are well-insulated and make use of experimental techniques – our lectures are held in a theater built of straw bales. It’s a beautiful, tranquil place full of trees, water and interesting people. Sometimes, a little too much water.
Centre for Alternative Technology, Machynlleth, September 2009
I’m up there once a month for an intensive week of lectures and practicals, then spend the rest of the time back home in London trying to figure out what I just learned, and writing essays and technical reports.
