Today, I am pleased to host this guest blog written by Willem Post.
Willem Post, Bob Hargraves, Howard Shaffer, Peter Roth, Steve Fox and I are all members of the local group, Coalition for Energy Solutions. Willem has both an MS in Mechanical Engineering and an MBA. He has many years of experience in financial estimation and oversight of large energy projects. Willem has written several reports on energy subjects. The Coalition For Energy Solutions Research and Reports page includes links to these reports. This is his first guest post for Yes Vermont Yankee.
A recent article on the New York Times Greenwire describes the Blythe Solar Power Project, BSPP. BSPP is a 968 MW thermal solar plant on 7,025 acres, or 11 square miles, of Bureau of Land Management, BLM, land in the California desert. The plant consists of (4) 242 MW units. Expected total energy delivered to the grid is 2,200 GWh. The capital cost will be $6 billion. It will take at least 6 years to complete. (A more complete description can be found in the project application documents.)
The BSPP will utilize solar parabolic troughs to generate electricity. Arrays of parabolic mirrors collect heat energy from the sun and refocus the radiation on a receiver tube located at the focal point of the parabola. A synthetic hydrocarbon is used as a heat transfer fluid (HTF). The HTF attains high temperatures (750 degrees F) as it is piped through the receiver tubes. The HTF is then piped through a series of heat exchangers where it releases stored heat to generate high- pressure steam. The steam is fed to a traditional steam turbine generator where electricity is produced. The plant is started in the morning and shut down in the evening.
The annual production from the plant will be = 968 MW x 8,760 hrs/y x CF 0.26 = 2,200 GWh. The power varies daily and seasonally with the strength of the sun and is available only during the sunshine hours of the day.
For reference: Vermont uses about 6,000 GWh/yr
The NYTimes article states this power is enough for roughly 800,000 households. As a California household uses about 6,000 kWh/yr, about 4,800,000,000 kWh/yr would be required by these households.
The NYTimes statement is grossly inaccurate, unless the writer meant that the power is enough only during the sunshine hours of the day. This is a sizable difference of 2,600,000,000 kWh. For a NYTimes writer to report on thermal power and not understand the real world and the numbers is truly incredible.
Other power sources, such as pumped storage hydro, nuclear, wind, stored biogas (CO2 emitting) and fossil (CO2 emitting) will be needed to supply the 2,600,000,000 kWh during low-sun and sunless hours.
Note: Wind power also varies daily and seasonally with the strength of the wind, and is not available at all when wind strength is too little or too much.
As such variable power becomes a greater percentage of the power mix, one approach is to have a greater capacity of CO2-emitting spinning reserves. These are usually fossil power plants that are running without sending power to the grid, but they can be called on to instantly increase their outputs when required. Spinning reserves allow the grid to maintain its required steady voltage. If there is too much voltage variation, all sorts of electrical equipment will automatically shut down.
Environmental Effects of the Project
The land will be leveled by bulldozers to accommodate the arrays. Even though it is desert, no fauna and flora lives there?
The 11 square miles of surface will create a heat island in the desert, hotter than an equivalent desert surface that is partially covered with vegetation, as in New Mexico. Some of that heat will be radiated outwards and some of that will be reflected back. A new, hotter eco-balance will be created in that area. Building a large number of such plants will add to global warming. It runs counter to having white roofs on buildings to reduce the heat island effect and global warming.
Legislative Requirements and Tax Credits
The force that drives this project is California's renewables mandate for utilities and the 30% federal tax credit; about $2 billion in this case.
If a developer cannot use the tax credit, he can opt to get a check for $2 billion from the federal government. In other words, a check from all of us.
Thermal Solar Compared with Nuclear Power
A standard 1,000 MW nuclear plant for about the same cost as the above thermal solar plant would produce = 1,000,000 kW x 8,760 hrs/yr x CF 0.90 = 7,884,000,000 kWh/yr, 3.58 times the power of thermal solar plant.
This power is steady and 24/7/365, i.e., it is available during all hours of the day, CO2-free, and will serve ALL the power needs of 1,314,000 California households for a year.
New nuclear plants are designed to have useful service lives of about 60 years. A spreadsheet comparison of the lifetime costs of PV solar and nuclear plants would need to include the replacement of all PV panels and disposal of the old PV panels at a multi-billion dollar capital cost around the 25th year of the comparison.
The 1,000 MW nuclear plant would require about 100 acres. This is only 1.5% of the land area required for the 1,000 MW PV solar plant.
Given the above, it is to be expected that the smart and knowledgeable power industry experts in at least 30 major nations, such as the US, the UK, France, Germany, Sweden, Japan, China (building about 50% of the nuclear plants being built), India, etc., have convinced their governments to continue to opt for nuclear power as a major component of their future power mix.
To do otherwise is a folly.
A German Renewable Power Demonstration
Several German power industry experts created, for demonstration purposes, a “renewables utility company” that uses several field-mounted, sun-tracking PV solar plants in southern Germany, several wind farms in northern Germany, several biogas-fueled combined cycle gas turbine plants with biogas storage tanks and several pumped storage hydro plants, all controlled from a central point to maintain a nearly constant output to the grid, as would any traditional utility company.
The experts maintain that as it was shown to be technically feasable for a small combination of renewable power plants, it will be for increasingly larger combinations as well.
This works in Germany because its national grid is designed as their cars and trains. For this to work in the US, its national grid, with about 1,000,000 MW of power plants connected to it, will need to be rebuilt at a cost in the order of $200-$300 billion during the next 10-15 years. Going “variable and renewable” has its costs.
As an alternative, that level of funding could be used to replace 33,000-50,000 MW of the older US nuclear plants; no significant changes to the grid would be required.