Tibbar Energy USVI is working to develop a biomass facility, which will produce biogas through the process of anaerobic digestion. The feedstock, called Giant King Grass, will be grown on a 1000 plus acres on St. Croix. The biogas from the process will then be used to generate 7MW of renewable electricity. Example of our process below:
How is the biogas generated and used to create electricity?
Naturally occurring bacteria breakdown organic material (such as agricultural energy crops like Giant King Grass) in the absence of oxygen resulting in the creation of methane and carbon dioxide, which make up the composition of biogas. This process is called anaerobic digestion and occurs in large enclosed tanks. The biogas is collected from the anaerobic digestion tanks and processed through a generator to produce renewable electricity.
Has this type of biomass project been done before?
Biomass projects utilizing energy crops in anaerobic digestion to create renewable electricity have been used successfully in tens of thousands of locations across Europe. Tibbar Energy has formed a strategic alliance with a Danish biogas company, Renew Energy, who has vast experience in designing and operating these types of systems in Europe. (Click here for a list of Renew's biomass projects)
What is Giant King Grass?
Giant King Grass is an energy crop grown for biomass projects. Its high crop and biogas yield makes Giant King Grass an ideal feedstock for a biomass project. Tibbar Energy has an exclusive agreement with Viaspace for Giant King Grass in the U.S. Virgin Islands. (Click here for Press Release)
Characteristics of Giant King Grass
- Perennial grass
- Not genetically modified
- Not an invasive species (lateral movement of less than 1 meter in 2 years)
- Modest fertilizer use required
- No pesticide required
Benefits of GKG to the Land
- 80% of the root structure is less than 12" inches.
- The GKG plant will help the soils hold more water vs. run off to the ocean
- Giant King Grass will prevent erosion control to the soils through its dense canopy
The total energy of raindrops is roughly 100 HP on an acre during a rainfall of 0.1 inch per hour. Vegetation intercepts rainfall and reduces its energy status. Drops that reach the ground are quickly take up in the leaf litter.
Root systems of vegetation has enormous capacity to mechanically bind the soil particles. Vegetation improves the structure of the soil by the addition of organic matter. Further, the root exudates and addition of organic matter from dead roots help in the process of binding soil particles. This increases the water holding capacity and infiltration of the soil. The humus layer itself acts as a sponge and absorbs a lot of moisture and allows it to enter the soil slowly. In the absence of such a layer, the run-off is greatly increased.
The vegetation also obstructs the easy flow of water in slopes. The friction developed by the vegetation tends to dissipate the flowing energy and spread out the run-off laterally. Further, it collects soil particles from the running water. Run-off water is usually dissipated harmlessly through various root decay channel or animal burrows. The roots bind the soil and prevent it from being washed.
Question: Is the GKG plant sterile?
Answer: While GKG does produce seedheads, as the plant is a breeding cross of Pennisetum Purpureum (Napier Grass) and Pennisetum Americanum (Millet). The seeds produced are sterile as the plant is only propagated via vegetative stems or rhizomes. This sterility is similar to crossing horse and donkey and getting a mule that cant re-produce. Since the genetic information (DNA) of GKG is mixed, the plant cannot revert back to Napier grass or millet.
Question: Is the plant invasive?
Answer: USDA has already determined that GKG is not an invasive species. The lack of viable seed and its inability to withstand tillage or frequent mowing were two important factors USDA used to determine the potential for this plant to become problematic in the environment. The plants rate of spread vegetatively is at best 2-3 feet per year, exclusively through rhizome development. The planting of segments of canes collected from GKG is the traditional method of propagation. These canes must be undergo a moist partial fermentation under very controlled conditions to allow for root development from the cane's nodes. If the cut canes are exposed to intense sunlight and allowed any drying, the metabolic processes are stopped and the cane segment dies. To insure full containment, all production fields of GKG will have a mowed buffer strip around the perimeter further preventing any rhizome movement. Unlike invasive species, GKG can quickly be killed with various grass and non-selective herbicide.
Question: How will the plants help the soil from erosion?
Answer: Grass plants and their long parallel leaf structures result in a funneling of raindrops toward the center of the plant. As the canopy develops, these grass leaves intercept the raindrops, and slowly funnel the collected water to the center of the plant where the water flows down the stem at very low velocity to the soil surface. The very dense fibrous roots system of a grass plant is the best structure for interacting with soil and holding the soil in place during intense rainfall events. Unlike trees with deep taproots, the shallow root structure is ideal for preventing gully formation.
Question: Is clump grass less effective with soil erosion?
Answer: In general, bunch grasses are less effective than solid stand grasses at preventing erosion. In the case of GKG, the very tall canopy plus the widening of the bunches over time will greatly protect the soil surface from direct impact of drain drops. Additionally, the constant dropping of lower grass leaves as the GKG reaches harvest high will provide a "trash" layer to protect the soil surface during the timeframe between harvest and normal grass canopy which is estimated to be on average 2 weeks during the first 3-4 years of production. The continued slow increase in bunch width will slowly result in nearly all of the soil surface being cover by the plant. This density will likely create management problems for GKG harvest and we anticipate the need to cultivate narrow rows through the field every 4-5 years. The cultivation process (12-15" wide) will quickly kill the canes in these paths. This process will be done in a manner that preserves as much residue on the soil surface to prevent erosion during short-term low canopy of the surrounding GKG.
How will the Giant King Grass be irrigated?
The Giant King Grass will be grown on commercial farms on St. Croix, which will be concentrated in higher rainfall gradient areas of the island.
How would a hurricane affect Giant King Grass cultivation?
Excess Giant King Grass is stored in large silage bags as a contingency. A 3 month supply of Giant King Grass will be stored in these large silage bags, which would allow Giant King Grass to re-establish itself in the event of a hurricane.
Is Giant King Grass currently growing on St. Croix?
Yes. It was planted on September 28th on St. Croix's south shore as a pilot and continues to grow very well (as shown in the pictures below).
In addition, Tibbar has planted a 20 acre Giant King Grass nursery at Estate Grange. This nursery will be used to propagate Giant King Grass on over 1,000 acres of farmland.
What government agencies/public interest groups is Tibbar working with?
Tibbar is working closely with the following agencies/groups on various aspect of the project: USVI Department of Planning and Natural Resources, Department of Labor, Waste Management Authority, Water and Power Authority (WAPA), Department of Agriculture, Public Works Commission,
Public Services Commission, Virgin Islands Energy Office, Farmers Cooperative and St. Croix Environmental Association (SEA).
How will Tibbar Energy’s agricultural plans affect the cattle on South Shore?
Tibbar Energy is working closely with the University of Virgin Islands’ Agriculture Department to help the 120 Senepol cattle herd to continue to thrive on St. Croix as Tibbar Energy begins farming operations on South Shore.
How does this project benefit the U.S. Virgin Islands?
This sustainable renewable energy project offers a myriad of direct economic benefits to the U.S. Virgin Islands:
- Provides 7MW of clean, renewable cheaper and continuous prime power to the community
- Creates over 40 high quality permanent jobs for the next 25 years to operate the energy generation and agricultural operations
- Serves as a catalyst for an agricultural renaissance on St. Croix through co-ops, agricultural scholarships, and free fertilizer
- Brands the USVI as a sustainable island directly benefiting tourism
How does Tibbar effect community recycling?
Anaerobic Digestion is currently being used across the United States and Europe as a sustainable recycling alternative over landfilling of organics such as food waste and cooking oils. Tibbar Energy will work with VIWMA to develop options to integrate the organics into our green renewable process with no tipping fee to VIWMA versus sending the waste to the landfill.
(Example of Food Waste separated for pick up)
(Green tank above is an example of cooking oil recycling tank)
(Example of sewer pipe plugged from kitchen grease)
By placing "FOG" (Fat, Oil, Grease) tanks at the SOLID WASTE collection area, as a community we can remove this stream from the landfill. This material does not belong in the kitchen sink. If it goes down the drain it solidifies farther down the pipes as it cools off. Then drains and/or sewers can block, which is costly to clean.
What are the advantages of biomass renewable energy over solar and wind energy?
The biomass project requires an extensive agricultural and anaerobic digestion/energy generation operation that will create over 40 full time jobs over 25 years. Solar and wind do not create permanent jobs.
Wind and solar projects only provide intermittent power based on meteorological conditions. Tibbar's biomass project will generate continuous prime power and provide diversification in U.S. Virgin Island's renewable energy portfolio.