Products

Biogas: SDP Cogen for Anaerobic Digesters

SDP Cogen for Anaerobic Digesters

SDP’s Cogen units, used in conjunction with anaerobic digesters (AD), serve two important purposes. First, the system provides a societal benefit by converting unwanted waste to a valuable gaseous fuel consisting of approximately 55% methane and 45% carbon dioxide. In the case of dairy applications the AD/Cogen plant also rids the environment of a greenhouse gas pollutant that is twenty times more harmful than carbon dioxide. Second, the biogas fuel is used to generate clean, cost effective power in a system that is qualified to operate under California’s strict air quality requirements for NOx, CO and VOC’s.

AD’s operate on the principle that bacteria, in the absence of air (anaerobic), can convert organic matter to methane and carbon dioxide. The process works best when the waste slurry is heated. For dairy manure the desired temperature is approximately 100F while crop waste requires a temperature near 135F. Heat to the AD is provided by the Cogen engine’s jacket with no additional fuel consumption.

SDP’s Biogas Cogen unit features a family of MAN natural gas-fired reciprocating engines that have been specifically engineered and modified for lower heat content fuel. They have compiled decades of efficient, reliable operation, (mainly in Europe) using these biogas fuels. The Biogas Cogen units have been further improved by SDP to increase the time between routine maintenance and to maximize the amount of heat made available to the AD from the engine’s jacket to maintain digester effectiveness and reliability.

Biogas in California Dairies: Biogas power plants have much to offer

  • Displace retail power
  • Sell excess to utility via PPA
  • Federal Production Tax Credit
  • Carbon credits from CCX
  • Process heat and/or cooling
  • Reduce Odor
  • High quality bedding
  • Reduce pathogens and weed seeds

SDP Biogas Plant Development: SDP Has the Skills and Credentials

  • Experienced cogeneration contractor
  • Service division and construction divisiont
  • Partner with premier digester and fuel treatment suppliers worldwide
  • Technology neutral
  • Offer dairies a complete turnkey solution

Digester Choices

Covered Lagoon

  • Solids content 0.5 – 2%
  • Best with flush manure systems
  • Usually not heated, output seasonal
  • Intolerant of feedstock additives
  • Proven reliability
  • Low cost
  • Low biogas and energy yield

Complete Mix

  • Solids content 3-10%
  • Best with slurry manures or feedstocks
  • Heated: Mesophilic 35-40C, Thermophilic 50+C
  • Mixing by impeller
  • Good for mixed feedstock
  • Higher cost
  • Highest biogas yield and quality

Covered Lagoon Digester: RCM Digester

  • New Horizons Dairy, Elmwood, Illinois, 2000
  • Cow Digester

Complete Mix Digester: Krieg and Fischer

  • Germany, 2005
  • Cattle manure,corn sileage, grass sileage
  • Concrete tank 2,615m3
  • 526 kWe

SDP Complete Mix Digester Power System

Value Proposition

Minimize Costs

  • Select best digester
  • Turnkey installation
  • State/USDA rebates
  • Tax credits
  • Carbon credits

Maximize Benefits

  • Select equipment for highest output and up-time
  • Use engine heat for process
  • Use feedstock additives
  • Negotiate PPA
  • Use as much power on site as possible
  • Tipping fees
  • Digester solids for bedding

SDP Site Visit

Confirm Dairy’s Operation

  • 3000 cows minimum
  • Additional feedstock (if complete mix digester)
  • Retail electric rates from utility
  • Retail gas cost
  • Hot water demand

Sign LOI

  • SDP conducts feasibility study at no cost to dairy
  • Turn-key proposal
  • Option to install COGEN separately

Biogas System Net Costs for 3000 Cow 500kW System

Digestor cost $600 per cow=
COGEN Cost per Cow**=
**SDP will Install and Own
Total:

Less: Incentives to Farmer:
Carbon Credits ($10 per cow)
Digester rebate (10%)
1/3 COGEN Rebate
Tax Incentives (18% of total system)

Net Costs:
$1,800,000
$0,000,000

$1,800.000


($ 30,000)
($180,000)
($100,000)
($414,000)

$1,076,000

Economic Return to Farmer

Farmer pays $1.076m net after taxes for SDP to install a digester to process manure from 3000 cows (plus animal fat/lard), provide 50,000 therms from COGEN to heat digester, produce 100,000 therms/yr extra gas besides COGEN use for farmer to sell to utility, produce 500kW of discounted electricity and 200,000 therms of discounted gas.

Extra Gas Revenue/yr (0.60/therm)=
Electricity discount ($0.05/kW)=
Gas Discount ($0.25/therm)=
By-pass Boiler Inefficiency (25%)=


Pay-back Period ($1.076m/$350,000)=
$ 60,000
$200,000
$ 50,000
$ 40,000
$350,000

3.1 years

Why Choose SDP?

  • SDP’s main business is Cogeneration
  • We care about the environment and reducing emissions using alternative fuels, e.g. biogas
  • We have construction expertise and COGEN service capability in house
  • We build the COGEN skids ourselves
  • We are technology neutral– clients’ needs drive the project
  • One stop shopping
  • Total biogas solution
  • Best performance, lowest cost

Contact Information

For further information regarding the Biogas plant offer please contact:

Hank Leibowitz
SDP Energy Biogas Manager
925/498-2502 or 925/324-3089
hleibowitz@sdpenergy.com

For information regarding the COGEN unit please contact:

Chris Stowell
President, SDP Energy
949/474-9660
cstowell@sdpenergy.com
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