Tuesday, October 15, 2013

Who'd have guessed? Increasing renewables really does decrease carbon emissions

Renewable energy, especially solar and wind are growing and supplying an ever greater percentage of the electricity in many countries. Common sense would tell you that as solar and wind increase and coal and gas generation goes down the amount of carbon pollution and other toxic gasses emitted from fossil fuel plants will decrease. Like anything in the climate and clean energy though, there are "skeptics" who don't agree with this, but data are better than opinions and the NREL lab at the Department on Energy in the US have crunched the numbers to find out.

The area of contention is that the intermittent nature of (some) renewables means fossil fuel plants need to fire up and then down more often (cycling). When you fire up a plant it tends to emit more, at that moment, than if it was running steadily. Kind of how like starting a car uses a burst of fuel. So what is the overall impact of this?

NREL found that:
"The negative impact of cycling on overall plant emissions is relatively small. The increase in plant emissions from cycling to accommodate variable renewables are more than offset by the overall reduction in CO2, NOx, and SO2."
"Emission Impacts of Cycling Are Relatively Small Compared to Emission Reductions Due to Renewables"
 NREL found that moving to 1/3 renewables from solar and wind would cause carbon emissions to drop by 1/3. Toxic gasses would also decrease. This is because although there might be a small increase in some emissions associated with cycling a plant on and off these are tiny compared to the decrease in emissions due to less fossil fuels being burnt, because 1/3 of the power is now coming from renewables. The claims of some "skeptics" is like claiming you should leave your car idling for an hour instead of turning it off and then on again an hour later because turning you car on uses more fuel that idling would at that second.

Here's the impact for 1/3 renewables:

So there you have it, increasing renewables decreases carbon emissions (as well as other toxic gasses that coal plants especially produce a lot of). Common sense right?

Tuesday, October 8, 2013

TTKD October meeting: The Story of Stuff

Click on the image to see it full size:

October 2013 TTKD Meeting
The Story of Stuff
Thursday October 17
7.15pm for a 7.30pm start
Kenmore Library Meeting Room

Australian heat records keep tumbling

Another heat record has tumbled as Australia's year long heat wave continues. Australia has (again) broken the record for warmest 12 months on record after previously breaking it only last month.

The heat in September was something else, at +2.75 °C above the long-term (1961–1990) September average. Naturally this was the warmest Sept on record, what's more amazing is that in the last hundreds years of temperature records, no month has ever been more above the long term average. On in meteorology speak Sept 2013 "sets a record for Australia’s largest positive anomaly for any monthly mean temperature."

Friday, September 27, 2013

Australia has hottest 12 months on record

If you felt it's been hot where you live recently, you're right. Recently the Bureau of Meterology (BOM) announced that the last year has been Australia's hottest 12 month period on record.

This information is containing in a short report you can find here and summarised here. Along with the warmest 12 months, a host of other records have also been broken in individual towns and cities and right across the nation. Because Australia is so big it takes a massive buildup of heat to break countrywide records, some of the most important I've taken from the report and shown below.

"The last 12 months saw a large number of temperature records set across Australia, including:
  • Australia’s hottest summer day on record (7 January) 
  • Australia’s warmest winter day on record (31 August) 
  • Australia’s warmest month on record (January) 
  • Australia’s warmest summer on record 
  • Australia’s warmest January to August period on record 
  • Australia’s warmest 12 month period on record"
Here's a map from the Bureau showing how the whole country has been warmer than normal this past year.

Overall the last year has seen temperatures 1.11 ̊C above average. While that may not sound like all that much, across a whole country, for a whole year, this gives us weather that's noticeably hotter.

Since the first half of the 20th century (1900-1950) temperatures across Australia have risen by ~0.75  ̊C and between now and 2050 are likely to rise by another 2 ̊C or more. This mean's that by 2050 the temperatures we have had over this past year (including the record breaking summer heat) would by then be a much colder than average year. A normal year would be a least a degree hotter than the past 12 months and a record breaking year could see temperature anomalies 3 or 4 times greater than experienced over the past year. Something to think about as Australia goes about dismantling all its policies to combat global warming.

Wednesday, September 18, 2013

TTKD Sept 13 Meeting: Fossil Fuels and Alternatives

Fossil Fuels and Alternatives 
Thursday September 19 
7.15pm for a 7.30pm start 
Kenmore Library Meeting Room 

Lloyd Hamilton will present information on fossil fuels, and Will Booth will present information from 350.org on the impact of these fuels and alternatives.

As usual the meeting will be followed by supper and conversation. Please feel free to bring along a plate to share (preferably locally produced or homemade!). No need to RSVP.