How does it work?
Within the bulb lies the generator. This generator functions by a propellor that lies on the opposite side of the bulb. Water enters/exits the turbine without a change in direction. The turbine now powered by moving water rotates a connected wire. Magnets around the wire continuously push and pull the electrons to opposite sides within the wire; this movement of electrons generates electricity. Due to possible overheating, they need proper cooling to function properly.
Pros
The bulb turbine's main advantage is that it's versatile since it only needs constant, running water. It also doesn't need as much infrastructure compared to Francis, Pelton, Pump, and other types of Kaplan turbines.
Cons
It is the least energy-efficient type of water turbine, only at 92% efficiency, and can cap at producing only 80 MW of electricity.
Backstory
Roberto lived in a log cabin for 1 month for a camping trip at the Mississippi River. He noticed some houses had less access to electricity than others and was inspired to resolve their heating and lighting issues. He realized that a bulb turbine’s generated power using the Mississippi River's natural water stream could get stored in batteries and given to isolated rural communities. Considering the river runs all day and night, hydroelectric power seemed the best option for providing a constant source of energy to power them; the bulb turbine is the cheapest type of turbine to generate electricity without any maintenance or much infrastructure.
Sustainability
Sustainability means using renewable natural resources to produce a better product. Water is a renewable source of energy. Sustainable design in the context of our design means using renewable natural resources and at the same time preserving ecological balance while developing infrastructure. Hydroelectric power, since it's renewable and requires infrastructure that lasts a long period of time, future generations are able to use our designs and reduce pollution. The climate for future generations may become more stable and predictable, unlike ours.
Other Renewable Sources
Wind turbines and solar panels provide conditional electricity; they don't work all the time. Water is the most available and convenient source of power for this community. The money needed to operate the solar panels is more expensive than the turbine - $30,000 for installing solar panels versus $15,000 for building the turbine. Solar panels last for 25-30 years, while the bulb turbine lasts for 40 years. Wind turbines require too much land and cost too much - $1.3 million per MW of power, which is very expensive for a small community to afford as the average house only uses around 30kW of electricity each day.
Environmental Analysis
Turbines tend to alter the natural habitats of freshwater species in the areas they are located. Additionally, they change the concentration of nutrients in the water, its temperature, and the river's flow patterns and flow rate. The water quality decreases as a result. Fish migration patterns are obstructed, and according to recent studies, current fish death by turbines is at 5% to 10% for the best turbines existing (e.g., Kaplan turbines). Zebra mussels are dying as well due to the inability to breathe caused by such turbiens. A hydropower plant may use fish ladders to rectify the problem. Companies are also looking into fish-friendly turbines using the principles presented to the left.
Technical Analysis
- Small blades for the turbine increase the velocity of water.
- One nozzle increases and maintains a steady velocity of the water - the size of the turbine and nozzle is reduced/constrained as a result.
- Not an ideal system at a steady state, the velocity of the Mississippi River doesn’t equal the velocity of the turbine due to frictional losses and an inconsistent volumetric flow rate.
- Electrical resistance is present, and the work done by the water will be less than the theoretical volumetric flow rate.
Mass Balances (assuming steady state)
Nozzle and Turbine
- dMcv/dt = Mass flow rate (initial) - Mass flow rate (exit)
- 0 = Mi - Me
- Mi = Me
- Me = density * area * velocity
- Me = 1000 kg/m^3 * pi(0.020955m)^2 * 4.96 m/s
- Me = 6.842 kg/s
- Velocity (initial) = Mi/(density * area)
- Vi = 6.842 kg/s / (1000 kg/m^3 * pi(0.02413m)^2
- Vi = 3.74 m/s
Energy Balance (assuming steady state):
- dEcv/dt = Qcv - Wcv + Mass flow rate[(h1-h2) + 1/2(v1^2 - v2^2) + g(z1-z2)]
- 0 = 0 - Wcv + M[1/2(v1^2 - v2^2)]
- Wcv = M[1/2(v1^2 - v2^2)]
- Wcv = 3.945 Watts
- (3.945/M * 2) - v1^2 = -v2^2
- v2^2 = v1^2 - (7.89 Wcv/M)
- v2^2 = (4.96 m/s)^2 - (7.89 W/6.842 kg/s)
- v2 = 4.842 m/s
- Exit area: = Me / (density * velocity2)
- A2 = 6.842 kg/s / (1000 kg/m^3 * 4.842 m/s)
- A2 = 1.413 * 10^-3 m^2 (shape is a square)
- Length = (1.413 * 10^-3 m^2)^0.5 = 0.0376 m
- Length = 1.476 inches
Economic Analysis
The price of stainless steel is expensive. Given our current dimensions, we estimate the cost of a large-scale version of our system would be approximately $6,944.40
Cost Analysis Dimensions
- Frustum Cone- Surface Area is 1/2( Circumference 1 + Circumference 2) * L
- Radius 1- 2.475 in, Radius 2- 1.65 in
- Area of our model - 68.12 in^2 Large scale model - 1634 in^2 Ratio of 1:24
- Elbow Pipe- Surface Area = ((r*pi*angle)/180) degrees *Length
- Length- 4.95 in , Radius- 3.3 in , Angle- 90 degrees
- Area of our model- 80.61 in^2 , Large scale model- 1934.64 in^2
- Pipe Surface Area = 2*pi*r*L
- r = 1.85 in , L = 3 in
- Surface Area of our model - 34.87 in^2 , Large-Scale model area- 836.88 in^2
- Turbine Surface-Area = (Radius A * Radius B * pi) number of turbines
- Radius A- 1 in , Radius B - .5 in , 5 Turbines
- Surface Area of our model - 836.88 in^2, Large Scale Model- 2262 in^2
- Total Surface Area of our model 1.929 ft^2, Large Scale Model- 46.3 ft^2
The power generated by a larger-scale system would be approximately 40 kiloWatts. Our scale-up factor was 24. After the turbine is built, maintenance costs are minimal to none.
Credits:
Created with an image by progressman - "Female hands holding wooden bowl with sea bath salt"