According to the EPA, power plants may rival transportation as the leading cause of air pollution in the United States. Due to the debate over which toxin is more toxic and which carries the highest medical and cleanup expense, there are too many caveats for certainty. But, recent EPA numbers for power plants indicate that they are responsible for 64% of all sulfur dioxide, 40% of all man-made carbon dioxide, and 26% of all nitrogen dioxides emissions. Then there are energy-related water pollution, nuclear and other toxic waste, and their impacts on birds, wildlife, aquatic life, plant life and human life. More radioactive particles are released from a single coal fired plant than all of the nuclear reactors combined. Power plants are also the leading cause of mercury pollution in our soil and water. Forty states are listed as having mercury-contaminated lakes and streams; most have issued fish consumption warnings and advise pregnant women to avoid fresh water fish altogether. Utility smokestacks release methyl mercury (mercury in a gas form) that can drift 1,000 miles before it settles out onto the earth. This puts virtually everyone in the US in the strike zone. Perhaps we will all become "mad" enough from ingesting mercury to do something about it!
According to Brookhaven Labs, a federal lab doing research on the environment, hydroelectric power may be no cleaner than burning fossil fuels. Momentarily disregard displaced people, many of them indigenous, and the massive amount of land and bio-systems lost from dam building (which creates habitat for mosquitoes and Jet Skis). New research at Brookhaven reveals that for at least the first thirty years, drowned, decomposing vegetation produces methane that is twenty times more effective as a greenhouse gas than carbon dioxide. So for the first thirty years hydroelectric generation is quite possibly as dirty as burning fossil fuels for the same energy output. The federal government is debating if hydro should be dropped from the renewable energy listing. On a very small micro scale many hydro installations can have little environmental impact while decentralizing generation.
What about natural gas? It is touted as the clean burning fuel; sure, by comparison to even nastier combustion alternatives. But it still creates carbon dioxide when burned, and that's the good news. The real problem with natural gas is the 50% of it that is not burned, but leaked out at the refinery and through the staggering number of miles of pipeline across the US. Like methane, natural gas is many times more damaging as a greenhouse gas than carbon dioxide. You can choose to not support the poisoning of our planet and life forms by reducing your consumption and using renewable energy.
For the fourth year in a row large-scale wind is the cheapest form of energy on the planet, even cheaper than the "too cheap to meter" nuclear energy. We are seeing large wind farms popping up all over the place, especially in Europe. The largest wind farm in the world is planned for Texas. Like solar power, wind resources in the US can supply the entire nation with clean energy. The two combined can make a powerful team of around the clock supply. Do wind generators kill birds? You bet, so do power plants, cars, people and buildings. To put it in perspective, skyscrapers in downtown Toronto kill more birds than all of the wind generators in North America combined. The American Wind Energy Association and their counterparts in Europe are embarking on a major bird kill study with the goals of documenting the number and species and determining methods of mitigation. Many of the solutions to our global energy crises may simply be "blowin' in the wind."
I mentioned earlier that micro hydroelectric power can be viable. What I call micro hydro is less than one megawatt, which is enough to power about 1,800 homes. Most of these systems are owned and operated by families and farms, too small for the utilities to bother with. There are a lot of them in the Sierras on mountain streams unreachable by spawning fish and without dams that flood large areas of land. Most mountainous watersheds can be ideal candidates for these conservative projects. Where I come from in Potter Valley there are three family owned hydro installations. I installed the first one about 15 years ago on a farm that is situated a hundred yards downstream from a sizeable PGandE hydro plant. The economics of the small installation were great, with a $1 million investment and a $250,000 annual return. Soon thereafter two more families installed similar sized units; they are all about 500 kW each, supplying enough energy for 900 homes at peak output. My own home unit is on a small seasonal runoff that I can straddle with my legs and that only flows in the rainy season. It produces triple the energy my home uses. I take some of the water out for 300 feet and put it back in the stream after I extract the energy from it, well above and far from any spawning fish.
Wave energy is beginning to come of age especially over the last five years, and like most things if done in a proper manner, can have little negative impact. In some cases it can have positive impacts by calming offshore waves creating sheltered harbors, marine habitat and minimizing beach erosion and structure damage. There are basically three marine zones that are being designed forÑshoreline, near shore, and offshore, in order of energy potential. The most common shoreline device is the Oscillating Water Column. The bottom of a tall tower is open to the sea; as waves swell up into the tower it compresses the air and spins a turbine. It is designed to spin in one direction regardless of the air direction. Another type, called TAPCHAN, is comprised of a gradually narrowing channel with the wide end facing the sea and oncoming waves. These waves begin to increase in size as they are forced into the narrows until they reach a reservoir in the back where the wave crests and breaks over the reservoir, filling it. As the water drains out it drives a low head turbine to generate power. There is also a device called a Pendulor. Like its name implies, there is a pendulum/float that drives hydraulic pumps coupled to generators producing power from the wave energy. Near shore devices are a cross section of Oscillating Water Columns and some of the offshore devices in less than 60 feet of water. Some schemes incorporate wind generators as well. At least one system captures the energy in tidal currents, not in the amplitude of the waves as in most. The currents drive large, very slow moving turbines that allow fish and silt to pass through without impediment.
Offshore devices harness the more powerful waves found in deeper waters of greater than 130 feet. A popular model is called the McCabe Wave Pump. There are three cylinders hinged together and pointing into the waves. As waves roll by each section pivots independently of the others and drives generators. There are several variations on this concept. One is the Archimedes Wave Swing. It has a large float in a vertical cage that is anchored to the bottom of the sea. As waves pass by the float is moved up and down to produce energy.
The farther offshore we go the more power is available from the sea. However, the tradeoff is increased costs of logistics, installation and power transmission. One of the more intriguing applications for these devices is to use ocean energy to drive pumps for reverse osmosis to desalinate water for drinking. Much work still needs to be done on all of these technologies to refine them and make them more robust. Most of the earlier attempts only proved how powerful, hostile and unforgiving our seas can be.
The oil crisis of the 70s fueled a renewed interest in bioenergy, and in particular, biofuels like ethyl and methyl alcohols. In the 90s improved bioenergy technologies began to meet market needs such as cogeneration of heat and electricity, and manage the urgent problem of municipal and industrial wastes. However, the most significant recent opportunity is to meet the climate change challenge. Bioenergy is extremely attractive in this regard because if done properly, it is a greenhouse gas neutral energy source. As usual, the words "if done properly" keep popping up. Bioengineers must be held to high scrutiny to prove their greenhouse gas neutrality, if not reductive benefit, on a full life cycle basis. Verification will be critical. When done properly, the original plant will remove more carbon dioxide in its life time than it will release during combustion.
Organic waste has the potential to cause significant pollution through atmospheric methane, polluted groundwater and the spread of disease. Anaerobic digestion can provide a range of benefits besides renewable energy, such as waste treatment; reduced pollution, odors and disease; recycling nutrients back into the soil; preserving top soil while sanitizing compost and reducing the spread of soil bound pathogens and weeds. We are better off burning methane from landfill sites to make power than simply letting it escape into the atmosphere. Many of our landfills will produce significant amounts of methane for 30 years or more.
Hydrogen can be used as a clean burning fuel for both transportation and power generation. Because it's part of the water molecule its supply is virtually limitless. Hydrogen burns clean and hot. It has the future potential of becoming the world's primary fuel. Cars and buses have already been developed that run on hydrogen powered fuel cells, which are virtually pollution free, emitting water vapor from their tailpipes. They don't release carbon dioxide or other heat trapping gasses that heavily contribute to global warming. Fuel cells big enough for electrical power generation are also being built. Until now, the process for extracting hydrogen involved the electrolysis of water, which is an expensive procedure using vast amounts of energy. Recently scientists from UC Berkeley and the Department of Energy have made a breakthrough that will make possible the commercial production of hydrogen gas. They discovered that they could cause algae to produce hydrogen gas by imposing nutrient stress on the algae. First they grow algae, then "fatten" it under normal photosynthetic conditions. Then they withhold sulfur, which is critical for the completion of normal photosynthesis. In the absence of sulfur the algae stops emitting oxygen and storing energy as carbohydrates, protein and fats. Instead the algae cells begin using "an alternative metabolic pathway" due to the absence of oxygen. The plant begins using the energy of sunlight to produce hydrogen gas instead of oxygen. The algae would eventually die if the nutrient stress were maintained for more than a few days. They fatten it again with sulfur and sunlight, which allows for repetition of the process and continued harvesting of hydrogen gas. At this point production performance still needs improving. Eventually this process will be used for the commercial production of huge quantities of hydrogen gas in tanks, ponds, lakes and possibly the open ocean.
Solar energy is the cleanest of all energy conversions and limitless in supply. There are many suppliers of photovoltaic systems throughout the state that can provide you with the guidance and equipment to either get off the grid or tie to it and use it for storage to reduce your bill. The California Energy Commission (CEC) currently has a grant program that will pay up to half of the cost of a photovoltaic or wind energy system. With the rapidly increasing utility bills, this can make for a very attractive investment, especially if it is for a business.
Now, back to choices. Every reader and everyone you know should be using renewable energy. Several states have now deregulated as California did a couple of years back, and you have the choice to buy power on the open market. You can choose to buy renewables at a small and reasonable premium. Make sure that what you buy is Green-e certified. Vote for renewables with your utility payment. Or, you can install your own renewable energy power plant. To get an idea of costs, look at your utility bill where it indicates your "Daily kWh". To calculate approximate cost multiply this number by $3,000 for a system with batteries, or about $1,400/ kWh without batteries for a grid line-tie, less incentives (incentives exist in CA, NY, IL, WI, MN, ID). Net-metering is now in about 30 states; the utility is required to trade watts for watts at the same value. In California go to the CEC site and look at www.energy.ca.gov/greengrid or call 800-555-7794.
Here in California, businesses can realize a payback on a utility intertied photovoltaic system in as little as eight years, or an annual return on investment of 12%. This is with the benefit of the CEC Buydown, Federal Investment Tax credit and Accelerated Depreciation. This return may well happen in half the time, as the rest of the state catches up with the rates people are seeing in San Diego. Personally I love seeing the gas and energy prices going up. It is time we start paying the true costs of power. Until this happens, renewables, without the subsidies received by nuclear energy and fossil fuels, will find it hard to compete
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Jeff Oldham is a designer and consultant of sustainable building practices and renewable energy for commercial and industrial applications. He has lived off-grid in Mendocino County for the past 22 years. The preceding is an excerpt from a speech he gave at the Bioneers Conference, October 2000.
Copyright Mendocino Environmental Center 2001
Permission granted to excerpt or use this article if source is cited