# Hydroelectric Power: How Much Water for a 30m Head?

• Kevin2341
In summary, the problem involves determining the amount of water needed to charge a battery with 100% efficiency at a hydroelectric plant with a 30m head. The equation used is w=1000QgH j\s, where Q is the discharge rate @ m^3\s, 1000Q kg\s, H = net water head in m (30m), and g is 9.8 m\s^2. The attempt at a solution involves converting the energy stored in the battery (2,160,000 joules) into watts and using the potential energy of 1 kg of water at 30m (294 joules) to find the required amount of water. However, the obtained units (Q kg
Kevin2341

## Homework Statement

Assuming 100% efficient energy conversion, how much water
stored behind a hydroelectric plant with a head of 30m would
be required to charge the battery?

## Homework Equations

?
MAYBE:
w=1000QgH j\s, where Q is the discharge rate @ m^3\s, 1000Q kg\s, H = net water head in m (30m), g is 9.8 m\s^2

## The Attempt at a Solution

I don't even know where to begin with this question. My last question was a simple unit conversation question about how much energy was stored in a 12v 50Ah rated car battery, which I got 2,160,000 joules for my answer. I don't even know how to begin to tackle this question because the formula I gave was one I found on the internet that looked like it might apply.

What I'm thinking with that question however, is that perhaps I can use my figure from the total energy of the battery equaling:
2,160,000W = 1000*Q*9.8m\s^2*30m j (I borrowed the seconds unit from the j\s to turn my 2160000 joules into watts on the left hand side.)

2,160kW = 294Q kg\s m^2\s^2 j
7346.938 = Q kg m^2/s^3 j

The numbers look way off to me, and also the units have some serious funkiness going on with them which leads me to think this method isn't correct.

Any help?

1. How much energy is required to charge a dead 50Ahr battery (assumedly 12V)?
2. Potential energy of 1 kg of water 30m high is how many Joules? So how many of those Joules = 12V*50A*3600sec?

## 1. How does hydroelectric power work?

Hydroelectric power harnesses the energy of moving water to generate electricity. Water is channeled through a dam, which creates pressure and turns turbines. The turbines are connected to generators, which convert the mechanical energy into electrical energy.

## 2. What is the 30m head in hydroelectric power?

The 30m head refers to the vertical distance between the water intake and the turbine in a hydroelectric power plant. This distance is important because it determines the pressure and flow rate of the water, which affects the efficiency of the power generation process.

## 3. How much water is needed for a 30m head in hydroelectric power?

The amount of water needed for a 30m head in hydroelectric power depends on the flow rate of the water and the size of the turbines. Generally, a higher flow rate and larger turbines require more water to generate a significant amount of electricity.

## 4. What are the advantages of using hydroelectric power?

Hydroelectric power is a renewable and clean source of energy. It does not produce greenhouse gas emissions, and the water used in the process can be recycled. Additionally, hydroelectric power plants have a long lifespan and can provide a stable source of electricity.

## 5. Are there any limitations to using hydroelectric power?

One limitation of hydroelectric power is that it is dependent on the availability of water. This means that droughts and other changes in water levels can affect the efficiency and reliability of the power generation process. Additionally, building a hydroelectric power plant can have significant environmental impacts, such as altering the natural flow of rivers and disrupting ecosystems.

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