Summary of Sergio Pacca and Darpa Horvath 2002 Greenhouse Gas Emissions from Building and Operating Electric Power Plants in the Upper Colorado River Basin
ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 36, NO. 14 pp. 3194-3200
As you can see, Wind and PV plants use enormous amounts of materials dependent on oil for their mining, forging, and delivery, yet deliver very little energy:
MT = MegaTon = 1,000,000 Metric tons. 1 MT = 2,204.62262 pounds
NOTE: the cost in 1992 dollars doesn’t include labor, installation, or maintenance costs.
Photovoltaic Plant 100-W panels of dimensions 1.316 x 0.66 m with array units of 3 x 10 panels, each having its own concrete foundation, for a surface area of 3.9 x 6.6 m, sited at 30° latitude, at a 30-deg tilt (approximately 1.2 m of additional width is needed to account for shading by the array due to the sun’s angle). There is 0.9 m between each of these array units for personnel access. Each adjacent unit covers a land area of 37.44 m2 and has a capacity rating of 3 kW. Some 1,372,500 of these 3 kW units are required.
Wind Farm location: Southern Utah, at 7,000 feet. average windspeed 6.5 m/s turbine: 600 kW in 4480 turbines
Hydropower: As the U.S. Bureau of Reclamation has suggested, “upgrading hydroelectric generator and turbine units at existing power plants is one of the most immediate, cost-effective, and environmentally acceptable means for developing additional electrical power”.
There is a large area of research devoted to figuring out how much material, energy, and cost is required to build various types of power plants. To estimate the overall greenhouse gas (GHG) emissions over the life cycle of a plant, Pacca and Horvath used Life Cycle Assessment (LCA), a method that calculates materials extraction, manufacturing and production, operations, and the disposal of the materials at the end of the life of the power plant.
As you can imagine, this isn’t easy. There are two main LCA models — Pacca and Horvath chose the EIOLCA approach, which uses a large commodity matrix that tries to identify the entire chain of suppliers of the raw materials, and then this matrix is multiplied by another one containing emissions and energy use per dollar.
Because dollars fluctuate in value, a better method would be to calculate the energy used at every step of the chain, but still, these dollar amounts give a rough idea of the embedded energy.
The study compares the Glen Canyon dam with four other types of power plants, all figures are scaled to each plant producing 5.55 TWh of energy per year.
This kind of study could help decide which direction a future energy Manhattan project should. This study rules out a Photovoltaic power plant, which is not possible now — it requires 4118 MW of power, but the total world production of PV modules up to 1997 was only 125 MW, less than 3% of what’s required for just this one plant. The PV plant also displaces an enormous ecosystem, about 20 square miles.
This study does not cover nuclear power plants. Another study states “nuclear fission energy requires small inputs of natural resources compared to most other fossil and non-fossil energy technologies. When we consider net electricity generation (e.g., net electricity after subtracting consumption by internal plant loads and by uranium enrichment plants), the life-cycle resource inputs for non-fossil power sources are dominated by construction materials, most notably steel and concrete. The construction of existing 1970-vintage U.S. nuclear power plants required 40 metric tons (MT) of steel and 190 cubic meters (m3) of concrete per average megawatt of electricity (MW(e)) generating capacity. For comparison, a typical wind energy system operating with 6.5 meters-per-second average wind speed requires construction inputs of 460 MT of steel and 870 m3 of concrete per average MW(e). Coal uses 98 MT of steel and 160 m3 of concrete per average MW(e); & natural-gas combined cycle plants use 3.3 MT steel and 27 m3 concrete” (Peterson, P. F. Will the United States Need a Second Geologic Repository? The Bridge 2003, 33 (3), 26–32).