Tuesday, March 30, 2010

Stimulus and Infrastructure Impact

Anaerobic digesters are remarkably flexible machines. They can process most types of manure, a wide variety of food wastes, almost any green vegetation--in short, anything that will rot. In the process, digesters make energy and fiber while reducing emissions. Since a digester provides several different tools for several different issues, an installation is very likely to be running many years in the future--even a future very different from today.

Last week, Washington's State Energy Program awarded a second round of energy grants and loans through the Commerce Department; a Farm Power affiliate called Rainier Biogas received a $1.4 million grant/loan combo. Rainier Biogas was set up to build a digester in the shadow of Mount Rainier near Enumclaw, a small town about an hour southeast of Seattle. Enumclaw hosts one of the surviving half-dozen clusters of dairy farms in the Puget Sound region; although it is too far from the interstate for intensive building, the century-old farming community is threatened by the typical slide towards a post-agricultural pseudo-economy. Rainier Biogas will help the remaining dairy farmers on the Enumclaw Plateau better manage their manure while becoming self-sufficient in cow bedding from the digester's fiber product. Keeping the farms in the area will retain $30 million in annual local production, a boon for a community that can otherwise look only to tourism and boom-blight exurban building trends.

Not everyone approves of the government picking energy as a stimulus winner; the day of the announcement, the right-leaning Washington Policy Center singled out Rainier Biogas as a particularly wasteful way to create jobs. While both state and federal governments have a spotty record on supporting biofuels projects that actually succeed, manure digesters have consistently provided effective economic impact. It comes down to value judgments that someone must make: energy infrastructure is simply better for the economy than another housing development, and supporting existing agriculture is just more efficient policy than building industry (or worse, service business) where none existed before.

Rainier Biogas: expanding local energy, nutrient, and fiber output on the beautiful Enumclaw Plateau from 2011 for decades into the future.

Saturday, March 27, 2010


I read The Oil Drum blog somewhat regularly; as one might expect, the site focuses on energy in general and petroleum in particular, but I checked out a posting about soil the other day. One of the comments struck a chord:

"The absolute worst case scenario, from a nutrient standpoint, is what we are doing today.

Producing any grain (corn, soybeans, wheat, etc) and shipping that food away from where it was grown is the largest depleter of P & K [phosphorus and potassium] from the land. By exporting food out of where it was grown your are exporting your most concentrated nutrients the plants have stored. The process essentially is mining the soil.

You want to be exporting only C,H,O,and N off the land. They are all replaced via gases in the atmosphere. A century ago most of the food was recycled where it was grown via animal or human consumption and waste. Not so today. Exporting food from the "interior" to the major cities on the coasts moves P & K away from productive land, essentially into water systems"

The main nutrients plants need are nitrogen, phosphorus, and potassium--NPK. Most nitrogen fertilizer is made from natural gas, while legumes such as peas, alfalfa, and soybeans can also fix nitrogen naturally. Unfortunately, we don't have the same plant-based alternate sources of phosphorus and potassium--everything we use is either mined from phosphate and potash deposits or recycled organic matter.

Anaerobic digesters offer an opportunity to improve the recycling of nutrients--not only does manure become easier to handle, but food waste can be mixed in and its nutrients returned easily to farmland. It's definitely an improvement over practices other food-waste treatment practices such as composting and water treatment facilities. As long as most compost ends up as landscaping material, the nutrients might as well be gone, and wastewater treatment typically treats nutrients as a problem to be minimized rather than a resource to be recovered.

A movie called "Dirt" has recently gotten quite a bit of attention; I haven't seen it yet, and I suspect it doesn't dwell on specific nutrient issues, but hopefully it has been raising awareness over the importance of caring for the soil. A future with well-balanced agriculture needs plenty of awareness--and good stocks of phosphorus and potassium.

Saturday, March 6, 2010

A trillion dollar energy overhaul

During the past few months, the federal government has given about two billion dollars to completed renewable energy projects and provided construction grants (through the Department of Energy or state energy programs) for several billion dollars more. These are impressive totals, and there is more to come. Unfortunately, the stimulus package is only making a tiny down payment on the enormous cost of overhauling our energy system.

Americans use energy in two primary forms: liquid fuels and electricity. Expensive conversion equipment allows raw energy sources such as petroleum and coal to be refined into these two forms of energy. For a variety of reasons, some of the conversion equipment we have installed over the past half-century is becoming obsolete and will have to be replaced soon--but at a staggering cost. I estimate the energy overhaul during the next two decades will cost about a trillion dollars.

Let's look at electricity first. The United States uses about 4,000,000 gigawatt-hours of electricity annually (while we're talking about trillions, when converted into electric-bill kilowatt-hours that number becomes four trillion kWh); coal-fired power plants have typically produced about half of that amount. The good news is that electricity usage dropped slightly each of the past two years, and the portion generated by coal dropped as well. The bad news is that we're going to have to start cutting back on coal-fired generation for three main reasons:
  1. older plants not only waste about 70% of the energy in the coal but they also lack pollution control and are simply wearing out
  2. while the United States has vast amounts of low-grade coal, we're running out of the best stuff (and the Appalachian mountains that are blasted away to get at it)
  3. burning coal does more to drive climate change than any other human activity
I expect that half our coal plants will still be running twenty years from now, but we still have to replace a huge amount of equipment. Let's assume that electricity demand remains stable (not at all assured, with recession pulling one direction and electrification--primarily of transportation and heating--pulling the other); we still have to build enough power plants to supply a trillion kWh a year. Since a year consists of 8760 hours, it would take new power plants rated at more than 120 million kW to produce this much electricity. Natural gas plants are the cheapest capacity currently on the market, but building plants capable of running most of the year on renewable fuel (like wood biomass or wind) costs around $5,000 per average kilowatt. Altogether, this partial overhaul of our electricity generation system will cost over $600 billion.

Now let's look at liquid fuels. The United States uses about 200 billion gallons of gasoline and diesel each year. All of this is refined from petroleum, and we import the majority of the petroleum. As with electricity, consumption of liquid fuels has dropped slightly during the past two years, but the bad news is similar: we are going to have to cut back on petroleum refining for three reasons:
  1. older refineries were designed to run on the high-quality, low-sulfur ("light sweet") crude oil that flowed from early wells; refitting them to run on the heavier oils more commonly pumped today will be so costly that some refineries will just be shut down
  2. the United States imports over half its oil, sometimes from places we'd rather not see benefit from our dollars
  3. transportation emissions are the second largest source of greenhouse gases (after generation of electricity).
Industry measures its production in forty-two gallon barrels per day; again, this production currently takes place at 150 refineries, billion-dollar installations with an average capacity of over 100,000 barrels per day. Liquid fuels can be produced from other carbon/hydrogen sources, ranging from natural gas to wood waste, using processes that can differ substantially from oil refining and require very specialized equipment.

Let's assume that fuel demand drops, but we still have replace almost half of the lower demand--six million barrels per day of transportation fuels and other petroleum-replacement products. The EIA graph above shows that equipment for refining crude oil is the cheaper than any alternatives--just one of the reasons why there is twenty times more oil refinery capacity than corn ethanol capacity, the next largest liquid fuel source.

The cost of equipment varies inversely with the cost of its feedstock; natural gas is quite expensive, while some biomass can be free or even better. I expect we'll even have some coal-to-liquids conversion, using the extra feedstock freed up by closing the less efficient half of the coal-fired electrical generators. The coal-to-liquids plant cost of $60,000 per barrel offers a good average between the other technologies; at this price, the partial overhaul of our liquid fuel system production system costs almost $400 billion.

So, a cool trillion dollars buys the United States an energy capacity similar to today's but cuts coal and oil consumption by half. It's not complete energy independence and many facilities still require purchased feedstocks. The most interesting question, though, is whether we can afford this trillion-dollar overhaul; the United States has burned through close to that amount of stimulus funding without having a serious impact on energy infrastructure. Is there much hope that we'll focus our efforts better in the future?