Thursday, July 25, 2013

Vermont a more "dazzling" nuclear power producer than a solar producer: Guest post by Guy Page

Vermont is a more "dazzling" nuclear power producer than a solar producer
By Guy Page

Vermont produces about one nuclear kilowatt per capita, compared to 34 watts solar

The Dazzling Solar Story

Rooftop Solar  Middlebury College VT
According to a new study by Environment America, Vermont is now a member of the “Dazzling Dozen,” the 12 states with the highest per-capita use of solar power. The Vermont Public Interest Research Group July 23 used the study to call for even more subsidized PV power generation. News about the study, including the Vermont Energy Partnership’s perspective, may be seen in the July 24 Burlington Free Press.

The big, untold story is that Vermont produces more nuclear power as a percentage of overall production than any other state in the country.  In fact, as detailed below, we produce eight times as much nuclear power as we do all non-hydro renewables, including solar power. In order to reduce carbon emissions and to have reliable, cost competitive power it will be important to keep and expand nuclear power while we also expand the use of renewables like solar. This is not only the view of the Vermont Energy Partnership; it is the view of U.S. Energy Secretary Dr. Ernest Moniz and President Obama.

Now-- the calculations

According to the U.S. Census, Vermont’s 2012 population is 626,000.

According to the US Energy Information Administration, nuclear power accounted for about three-fourths of the electricity generated within Vermont in 2011, a higher share than any other State.

Electrical output is best measured in megawatt-hours (MWh). According to the current US EIA state energy profile, Vermont produces a total of 516,000 MWh; of this, 356,000 MWh (69%) is nuclear power, all of it from Vermont Yankee, of course. By comparison, all non-hydro renewable generation together totals 42,000 MWh (8%), most of it wind.

Therefore, using MWh as a yardstick: 0.56 MWh (568,690 watt/hours) per Vermonter from Vermont Yankee alone; from all non-hydro renewables combined, .07 (67,092 watt/hours) per Vermonter.

Rather than using MWh as yardstick, however, the solar study you cite uses capacity figures. Vermont Yankee has a rated capacity of 620 megawatts. That is 620,000,000 watts. Vermont Yankee therefore has a per capita capacity of about 1000 watts – roughly a kilowatt, or about 29 times the 34 watt per capita capacity of Vermont solar power cited in the study. It is important to note that in Vermont, solar power operates at about 10-15% capacity, while most nuclear power plants are 24/7/365 “base load” plants operating at about 90% capacity.

Comparing Power Sources

1000 watts per capita for Vermont Yankee compared to 34 watts for solar power. .56 MWh per capita for Vermont Yankee, compared to .07 MWh for all non-hydro renewables – that is a truly “dazzling” comparison. It is fair to note, however, that solar and nuclear power share enviable similarities. Both are considered “carbon-free” by the U.S. EIA. Numerous studies show that their “lifecycle” carbon dioxide output per kilowatt is virtually identical. Another positive similarity: both can be produced in Vermont, thus reaping benefits of jobs and state revenue.

The Partnership evaluates every potential power source through the prism of "safe, clean, affordable, reliable." Solar admirably fits the first two criteria. As to reliability: it can help the grid as a hot summer day power "peak" provider, although I'm not sold that this benefit justifies the expense. But affordable in its current, fixed-price, "if you can make it the utilities have to buy it" standard-offer form? No.

Solar in Context

Incentives are justified by the likely economic and environmental benefit. Therefore incentives for solar hot water heaters, which "replace" oil or electric powered units at a relatively low cost, would seem to make sense. However, Vermont must do better than promulgate as "energy policy" the practice of forcing ratepayers to pay guaranteed high rates for an increasing number of 2.2 MW, 10 year solar power contracts. Standard offer supporters say the price of solar power production will eventually fall. Vermont would do better to wait, or at best move cautiously, until this hope becomes a reality. If the goal is to be carbon-free, accessing more existing, low-carbon base load power sources (notably nuclear and hydro) would be a suitable policy goal.  

In Germany, Spain, and even in the Northeast Kingdom, Vermont town of Hardwick, ratepayers are complaining that they are being forced to subsidize the guaranteed high rates of solar power production. When the government gets into the business of picking energy production winners and losers, even for the best of reasons, affordability all too often becomes the first loser.

And finally, solar power boosters have no sound answer to the problem of intermittency. The modern-day power grid can't sustain more than 20% (give or take) intermittent power without risk of blackout, brownout, fires and damage. Even now, Green Mountain Power, Vermont’s largest utility, is unable to sell all of its Lowell Wind power due to "curtailment" by ISO-New England. The planned fix - a synchronous condenser - is likely to improve, but not completely solve, this vexing problem. The technology for intermittent into baseload just isn't "there" yet, but we are acting as if it is, or soon will be. This is not prudent.

Guy Page
In short, solar power has its place, and that place may grow more prominent in the future. But current state policy underestimates the inherent economic and transmission shortcomings of solar power.

This guest post is written by Guy Page, Communications director of Vermont Energy Partnership (VTEP) . Page is a frequent guest blogger on this blog. His most recent post announced a new VTEP report: Review of the Vermont Energy Plan: VTEP Review.


trag said...

I found one curiosity I was hoping you could clear up.

If VY has a generating capacity of 620,000,000 W how does it generate only 356,000,000,000 WHr per year? Is the electricity from Vermont Yankee consumed by Vermont only a portion of the plant's total output?

The numbers above would imply less than 1000 hours of operation per year. Even if Vermont Yankee is only achieving a modest ~80% (7000 hours) capacity factor, if run at full power it should generate about 4,340,000,000,000 WHrs or 4.34 TWHr or 4,340,000 MWHr per year.

Is 85% of VY's output going to other states?

Meredith Angwin said...

Comparing solar and nuclear energy production in Vermont.

1) Since solar and nuclear use the same number of hours in a year and the same population of Vermont, these numbers do not change the comparison ratio.

2) A good number to use for capacity factor of Vermont Yankee is 90%.

3) VY is 620 MW.

4) The capacity factor of the White River Junction solar installation, as reported by Willem Post, is 14%.

5) According to the "dazzling" report quoted above, Vermont has 21 MW solar capacity.

4) Thus, the average capacity of Vermont Yankee is 90% of 620 MW = 558 MW

5) And the average capacity of the Vermont solar installations is 14% of 21 MW = 3 MW

6) So VY generates 558/3 = 186 times as much power as the combination of all the Vermont solar installations. These include residential and commercial installations as well as utility ones.

7) The 14% capacity factor is for utility installations which will be higher than for residential and commercial ones because they often use servo motors to track the sun and are kept clean and free from shading.