Overview of the Algae System
The algae system captures CO2 emissions for conversion to algae. Algae sales pay for the algae system, including:
- Carbon dioxide capture from electrical power plants,
- Synthesis of ammonia,
- Transport of the carbon dioxide and possibly ammonia to the algae photobioreactors and
- The photobioreactors themselves.
Other costs such as phosphorus, potassium, water purification, farm labor, etc. are also included.
The goal is to have enough profit from the algae sales to pay for the reengineering of fossil fuel power plants and, if possible, a reduction in the cost of electricity compared to sequestration.
Our analysis comprises a model with 3 scenarios, one for each of 3 sources of ammonia for nitrogen fixation:
- Wind ammonia
- Coal ammonia
- Solar ammonia
In these scenarios:
- Wind ammonia is transported from North Dakota to the desert Southwest for photosynthesis.
- Coal ammonia co-sourced with CO2, transported to the desert Southwest for photosynthesis.
- Solar ammonia is co-located with photosynthesis in the equatorial Pacific doldrums.
Our preliminary results favor the coal ammonia scenario. Tradeoffs:
- Wind and Solar produce less CO2 than Coal ammonia.
- Coal and Solar are better able to compete with soybeans than is Wind ammonia.
- Wind and Coal involve less technical risk than Solar ammonia.
- Coal is less complex than Wind ammonia.
- Solar has less environmental impact than Wind and Coal ammonia.
- Solar is better able to compete with soybeans than is Coal ammonia.
- The large market for soybeans mitigates the higher CO2 production for Coal ammonia.
- Coal's lower technical risk mitigates its higher environmental impact and cost than Solar ammonia.
The way to read the system is to click on the first item: FutureGen Prime Elex Cost With CO2 and NH3 Sales ($/kWh)
This presents you with that page in the system.
The system presents as a number of such pages. Each page can be thought of as a spreadsheet cell. As in a spreadsheet cell, each page represents a quantity. The title of the page is the name of the variable being calculated. The formula being evaluated on each page is called its "Model":
- FutureGen Without Sequestration Elex Cost ($/kWh) - Net Revenue Available For CO2 Payments ($/kWh)
Following that formula is the comment:
- The Bottom Line
- "FutureGen Prime" is an IGCC-based, enhanced efficiency, near-zero emission version of the FutureGen technology. It requires an initial investment of approximately $9.5962353908757/W to capture the residual emissions from FutureGen, as well as shipment of all unmarketable emissions back to be buried in their coal mines of origin. Over an industrial learning curve, this investment drops to an overall average of $4.8916515154283/W. In addition, rather than using air as the oxidizer, air is separated into its constituent gases by liquefaction. Since it uses IGCC, hydrogen is available for ammonia synthesis. Both CO2 and NH3 are produced in the ratio required for algaculture.
The economic impact of CO2 photosynthesis on electric costs is reflected in the ultimate cost per kWh of electricity generated by fossil fuel plants. Here that cost is designated by the variable FutureGen Prime Elex Cost With CO2 and NH3 Sales ($/kWh) = 0.093114465230852. (If that is a negative number it means the fossil fuel plant can give away electricity and still make money.)
In the table of variable names and values that follow, the primary control parameters are as follows:
- (ShortTerm=0 or LongTerm=1)
- (NaturalGasSystem=0 or CoalSystem=1)
- Default Amortization Interval Bond Rate (%/year)=.05
EquatorialOcean (0) is a speculative system that takes advantage of the high insolation of the equator and thermal buffering of the ocean. Although such a system *appears* highly profitable -- leading to a negative value for FutureGen Prime Elex Cost With CO2 and NH3 Sales ($/kWh) -- it is inadequately modeled.
The cost basis for the algae system is given in the AreaCost section of the spreadsheet, as costs are levelized and normalized to cost flow per insolated area of photobioreactor surface.
The market basis for the algae system is given in the Net section of the spreadsheet and the protein price per unit mass. See The Foresight project Global Food and Farming Futures final report for the long-term price outlook for protein.
Total system quantities (such as total land area required, total profit, etc.) are given in the Global section of the spreadsheet.
Employment figures are given in the Employment section of the spreadsheet.
Price supports to secure investment in the system are given in the PriceSupports section of the spreadsheet.
Environmental impact of the reengineered coal baseload power generation is given in the FutureGen section of the spreadsheet. These estimates are normalized per baseload power.
As thermal issues are a frequent failure mode of algae projects there is a dedicated Thermal section of the spreadsheet.
SCENARIO CURRENTLY SELECTED
|Scenario (name)||Coal ammonia|
Futuregen Inputs and Outputs
|Algae price support per dry mass ($/kg)||0.329472|
|CO2 FOB price support per mass ($/kg)||0.13796224624719|
|Efficiency incentive on CO2 FOB Price Support||1|
|CO2 Delivered price support per mass ($/kg)||0.14163662124719|
|NH3 FOB price support per mass ($/kg)||.25|
|NH3 Delivered Price support per mass ($/kg)||0.67258791970617|