One challenge with renewable forms of energy like wind and solar power is that the power output from such facilities is intermittent. One way to address the problem is to store power from times when it is being produced in excess for use at times when the quantity demanded is high.
This article describes a number of such energy storage options, including ‘Green Power Islands’ along with systems based on pumping water, compressing air, and storing heat in molten salt.
Potentially big news: “Proposed new [EPA] emissions standards would limit carbon dioxide produced by new power plants, which would probably prohibit construction of any coal-fired facilities“
Some good news from Ontario:
Ontario is permanently shutting down two more dirty coal-fired units at Nanticoke Generating Station, ensuring cleaner air and a healthier future for families.
As of December 31, Ontario will have shut down 10 of 19 coal units and cut the use of coal by nearly 90 per cent since 2003.
By the end of 2014, Ontario will be the first jurisdiction in the world to replace dirty coal-fired generation with more sustainable alternatives such as wind, solar and bioenergy — the equivalent of taking seven million cars off the road. This is the single largest climate change initiative being undertaken in North America and will lead to savings of $4.4 billion a year in health care, environmental and financial costs.
Anyone who thinks it would be cheap and easy to bury the carbon dioxide pollution arising from coal-fired power plants would benefit from reading a passage from Daniel Yergin’s The Quest: Energy, Security, and the Remaking of the Modern World about the scale of that undertaking:
And the scale here would be very, very large. It would really be like creating a parallel universe, a new energy industry, but one that works in reverse. Instead of extracting resources from the ground, transporting, and transforming them, and then burning them, the “Big Carbon” industry would nab the spent resource of CO2 before it gets into the atmosphere, and transform and transport it, and eventually put it back into the ground. This would truly be a round-trip.
Indeed, this new CCS industry would be similar in scale to that of existing energy industries. If just 60 percent of the CO2 produced by today’s coal-fired power plants in the United States were captured and compressed into a liquid, transported, and injected into the storage site, the daily volume of liquids so handled would be about equal to the 19 million barrels of oil that the United States consumes every day. It is sobering to realize that 150 years and trillions of dollars were required to build that existing system for oil. (p. 402, hardcover)
Personally, I wonder whether it is really worth going through such a song and dance in order to keep coal viable as a source of energy. After all, it would still be producing large volumes of toxic air and water pollution, it would still require the destruction of mountains to dig up the raw matter to burn, and it would still ultimately be an exhaustible resource.
This study from MIT looks useful for those trying to understand the implications of coal use in a warming world:
An interdisciplinary MIT faculty group examined the role of coal in a world where constraints on carbon dioxide emissions are adopted to mitigate global climate change. This follows “The Future of Nuclear Power” which focused on carbon dioxide emissions-free electricity generation from nuclear energy and was published in 2003. This report, the future of coal in a carbon-constrained world, evaluates the technologies and costs associated with the generation of electricity from coal along with those associated with the capture and sequestration of the carbon dioxide produced coal-based power generation. Growing electricity demand in the U.S. and in the world will require increases in all generation options (renewables, coal, and nuclear) in addition to increased efficiency and conservation in its use. Coal will continue to play a significant role in power generation and as such carbon dioxide management from it will become increasingly important. This study, addressed to government, industry and academic leaders, discusses the interrelated technical, economic, environmental and political challenges facing increased coal-based power generation while managing carbon dioxide emissions from this sector.
Among other things, the report highlights the gigantic scale and cost that would accompany the use of carbon capture and storage (CCS) to try to mitigate emissions from coal-fired facilities. That said, they argue that coal use is inevitable because coal is “cheap and abundant” and argue that CCS is the only plausible way to square continued coal use with falling global greenhouse gas pollution.
Load balancing is one of the challenges associated with deploying renewable energy. Different energy sources like wind and sunlight are available to variable degrees at different times, and output might not correspond to energy demand. That is true both day-to-day and across the year. For instance, right now the dams in the Columbia river basin have an excessive amount of water due to melting snow and ice. As a result, output from wind farms is not needed and going unused:
BPA managers say near-flood conditions in the Columbia riverâ€”and strict laws protecting the riverâ€™s endangered salmonâ€”give the agency no choice but to disconnect the windmills as it grapples with a large power surplus. Not making electricity is not an option on the river, the BPA argues, because only a limited amount of water can be kept out of turbines and spilled over federal dams. Too much spill dissolves too much nitrogen in the river, which can kill migrating salmon.
Dealing with the intermittence of energy output from renewable sources probably requires a suite of approaches: energy storage using pumped hydroelectric and multi-lagoon tidal facilities, management of demand to correspond to periods where renewable output is high, using different types of renewable energy to balance one another, linking different regional grids, and more.
Tom Blackwell has taken some interesting and rather beautiful photos inside an abandoned coal-fired power plant.
Today, Dr. Kapil Khatter wrote a good letter to The Ottawa Citizen about the many problems associated with coal-fired electricity:
The Ontario Conservatives have pledged to eliminate coal-fired power by 2014. But the coal plants need to be closed well before that. The province has more than enough coal-free power to close the plants immediately. And coal is a disaster from start to finish.
Mining the fuel devastates landscapes. When it is burned, it releases a host of poisons, including lead and mercury (neurotoxins), chromium and arsenic (carcinogens), and components of acid rain (sulphur dioxide and nitrogen oxides). Perhaps most worrying is its contribution to climate change: Ontario’s coal facilities emit the greenhouse gas equivalent of several million automobiles. If global warming is the world’s most pressing environmental threat, banning coal is job No. 1.
The Canadian Association of Physicians for the Environment believes coal can be eliminated through a combination of conservation and renewable energy sources. And that the time to do it is now.
Dr. Khatter is on the board of the Canadian Association of Physicians for the Environment.