Joe Zakovec, City of Janesville, presented information on local fleet experiences for our Natural Gas for Transportation Roundtable in Janesville, WI.

1. JANESVILLE’S ROAD TO CNG
Presented by:
Joe Zakovec

2. BIOGAS TO ENERGY SYSTEM
Digester upgrades
High Strength Waste unloading place
Gas Storage System
Gas conditioning and compressor system
(4) 65 kW microturbines with integral heat recovery
(1) 200 kW microturbine with heat exchanger
Bio CNG Option

3. HIGH STRENGTH WASTE

4. GAS STORAGE SYSTEM
•Capacity is 107,000 cubic feet of gas
•Allows for maximizing on peak power production
•Delays or prevents flaring of gas

5. GAS CONDITIONING SYSTEM
•Began operation November 2010
•Removes moisture, particulates, and siloxane from digester gas
•Compresses gas to pressure required by the turbines

6. (4) 65 KW MICROTURBINES
•Recovered thermal energy heats water that is used to heat the digesters
•Electricity is sold to Alliant Energy
•Low maintenance due to one moving part

7. 200 KW MICROTURBINE AND HEAT EXCHANGER
•Microturbine started up in January 2012
•Heat exchanger was added in December 2013

8. CO2 REMOVAL SYSTEM
•Required to make digester gas suitable for vehicle fuel
•Concentrates methane from 60% to 90% by removing Carbon Dioxide and other gases

9. CNG STORAGE AND FUELING STATION
•100 gallons gasoline equivalent storage spheres
•Includes further drying and compression of the gas before the entering the storage spheres
•Fast-fill system

10. CNG VEHICLE
•Handles the same as a conventional vehicle
•Uses the same engine with a few modifications
•Can switch from gasoline to CNG on the move

11. CNG LAWNMOWER

12. METHANE PRODUCED
0
20,000
40,000
60,000
80,000
100,000
120,000
140,000
160,000
180,000
200,000
CUB I C FEET / DAY
Last 6 months daily average

13. CNG PRODUCED AND USED
0
50
100
150
200
250
Gal l ons
Last 6 months

14. COST TO PRODUCE BIO-CNG
Cost to produce Bio-CNG $0.88/gallon
Current cost of Gasoline $3.15/gallon
On vehicles that use the roads the City pays $0.247/gallon in road tax.
Savings is $2.02/gallon
Exploring options to add more CNG vehicles to fleet.

15. THANK YOU!
Joe Zakovec
zakovecj@ci.janesville.wi.us