This quarter at BGI our one varying elective is a class on energy systems. I assumed it would be a study on renewable energy and certainly it is, but what I’m learning most so far is what a tiny fraction of global energy is provided by renewables now, and how little that’s expected to change.
So where’s the juice? Well, our most abundant energy supply is indeed The Sun. It’s collection, conversion, storage and distribution that stump us. For other energy sources, location, extraction, transportation and use also come into play. Solar energy is what gives us tidal energy and wind energy. Old solar energy is what gives us fossil fuels.
In looking at fossil fuels, many assessments of sources focus on a Reserve/Production ratio which gives a sense of how much of the source is left. Our book (Energy Studies by Shepherd & Shepherd), published in 2003, sums up that we have about 40 years of oil left, planet-wide. What we do have lots of, to my surprise, is coal. Coal is likely to last us another 200 years, and is widely available geographically. Over the last 30 years many countries (like the UK) have shifted from coal to natural gas because of pollution issues. Coal is what generates acid rain and international disputes because the rain rarely falls where the pollution is generated. Coal plant technology has improved over that time: smokestacks now include limestone “scrubbers” that interact with Sulfur Oxide and keep it out of the air, but it’s still one of our most polluting energy sources (depending on how you want to stack it up against nuclear waste). Thus the emerging “clean coal” industry, trying to figure out how we can hang on to this abundant energy supply w/o poisoning ourselves or compromising so much of our planet’s surface getting at it.
Most electricity is generated from coal-fired plants, which generate anywhere from 200 MhW to 500 MhW. In the US 2004 about half our power was generated that way. The other half was natural gas and nuclear about equally, then hydro at about half of those. “Other Renewables”, listed as “Wood, black liquor, other wood waste, biogenic municipal solid waste, landfill gas, sludge waste, agriculture byproducts, other biomass, geothermal, solar thermal, photovoltaic energy and wind” accounted for just 2% of the total US electricity generation. That’s a bit of an eye-opener for someone who lives in Eco-topia, aka The Pacific Northwest. My local utility, Puget Sound Energy (PSE) gets 42% of its energy from Hydro, and is about to go after Wind in a big way. I suppose I shouldn’t be that surprised, I’ve watched Kilowatt Ours – a documentary about the coal industry and electricity use in the southeast US.
That movie and our textbook emphasize another oft-under-mentioned energy source: conservation. We live in an infrastructure that was built on an assumption of energy abundance, as capital investments depreciate there are many improvements to be made, but the kicker is we’re waiting for the depreciation to do it. I’m personally due – we’re about to replace our 10+ yr old clothes washer. Friends said they were able to drop from 16 gallons of water/load to about 2.5, and drying is shorter now because the clothes aren’t as wet when they come out of the washer. PSE includes conservation in their energy planning.
As an investor, wind gets a lot of air, but I’m getting skeptical. A guest speaker at BGI asserted that most of the good wind sites are now taken, though a Canadian student begged to differ, there are some good sites on Vancouver Island that need to overcome political resistance. Like the highly contested Cape Wind project off the coast of Massachusetts. I’ve also heard rumors that all the commercial wind turbines expected to be produced in the next 5-7 years are spoken for, and it will take time to build new plant capacity. My biggest concern about wind came up when I learned that consultants usually do multiple years of wind studies on a site before deciding where to put turbines. How fixed are wind patterns in an era of climate change? I’ve seen one new innovation that seemed to have potential – a company working to actually store wind power. Currently the biggest recognized drawback to wind is availability – you get power when you get it, not necessarily when you want it. Folks talk about “backing” wind power with something more on-demand like hydro. You can’t go “all wind”, you need the on-demand power source to fill the gaps and meet demand. If this company figures out how to store it, that will be a big boost for the industry, assuming I’m wrong about climate change and wind patterns. I’m the only one who seems to worry about it, but I was also the only one in high school physics who decided that if moving electricity creates a magnetic field, and changing magnetic fields can generate a current, maybe we should think harder about electric blankets.