I believe we should go forward into Vermont’s energy future slowly, thoughtfully and with all the facts about the technologies we will be employing. We are engaging the issue of energy from within its specifics and lack an important, broader view. Let’s look at a few energy examples that will help put into perspective aspects of the everyday energy we use.
Generation of new electricity is Vermont’s most well-advertised energy focus, but saving heat is by far the most effective way to “add” energy.
Our Vermont homes use 5 to 10 times as much energy in heat as electricity. If insulated to reduce the amount of energy used to heat by just one hardwood cord’s worth, a house would save the equivalent energy it uses in electricity all year, about 9,000 kilowatt hours. With no additional insulation, that savings will be made each year thereafter. In Vermont we heat most often with oil. Saving heat saves oil. Saving heat energy is the cheapest energy you can “buy” something you can take to the bank.
Much is made of using renewable energy to power our future. Modern economies rely on steady, stable, high-quality power. Today, as expensive as they are, solar-derived renewables, wind and photovoltaics – those sources most mentioned for Vermont – provide only low grade, sporadic and unevenly delivered energy to the grid. That energy has to be balanced by a source that can be varied rapidly enough to keep pace with the rate of change of the renewable source to clean it up. Neither coal nor nuclear power are among them, and wind power or PVs will not cause the closure of either one.
In Vermont wind and PV energy will likely be “followed” by hydro. Hydro emits no carbon dioxide, so if it is used, no CO2 emissions are avoided, and the global-warming justification for wind’s use is irrelevant. Also, it is likely that following a variable source with hydro will waste hydro power.
It is important to know that nowhere in the world have wind turbines proved to save CO2 on large, already efficient grids like ours. If we select wind, it should be for reasons other than CO2 savings.
The physical “footprint” of our energy generation plants is an important consideration. High-quality energy-producing nuclear and gas plants are small for the amounts of energy they generate. How much space will renewables take up? Sunlight, wind, waves, etc. are “diffuse” energy sources. Devices to capture important amounts of that energy will cover large areas. The discussion about hundreds of miles of turbines on Vermont ridge lines to deliver a small amount energy is an example of this, and the energy they generate is not of the high quality we need. A wind station will have to have a “follower” plant installed with it or assigned to it before we have a match for a nuclear, coal, gas, hydro or biogas plant.
There are other obvious impacts we haven’t heard about yet. It’s popular just now to put large photovoltaic arrays in our agricultural fields. Field-mounted PV arrays shade the ground inhibiting evaporation and CO2 sequestration by the shaded plants. PVs also get hot. They radiate heat into the atmosphere. Asphalt has similar properties. Putting PVs in Vermont fields is similar to paving areas of those fields with asphalt and getting a little electricity back.
Natural gas (methane)? Pound for pound natural gas produces four times the energy of wood and two to four times that of coal. Fossil fuel plants (coal produces almost half our electricity) are only 33 percent efficient. Natural gas plants are 60 percent efficient, and gas-driven combined heat and power plants are close to 90 percent efficient.
Natural gas could produce the same energy, pound for pound, as coal or wood with a fraction of the CO2 emissions in the case where coal or wood are replaced by gas-driven combined plants.
It’s worth recognizing here that the wind and sun are not free. The sun’s energy is not lying around, unused, waiting for us to put it to our use. Rather, it is being used 100 percent to run the planet as we know it. How could it be otherwise? Taking it for our use deprives what’s using it now, as the field-mounted PV example shows, and renewable energy’s enormous physical footprint often competes with food production and impacts our environment in a number of ways, some of which are subtle and poorly understood. Renewables have a value where energy (usually electricity) is essential and getting it there prohibitively expensive, that is, worth all its costs, costs we must understand as we select our energy generation technologies.
Vermont recently has been voted one of the top five most beautiful places in the world. We are at a crossroads regarding energy generation, and the choices we make will have wide-ranging impacts that currently are poorly appreciated. I believe our energy choices will be made well and wisely if we have all the information not only about the technologies themselves but of the wider range of their effects on Vermont.
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