Last updated on November 22nd, 2019
Hydroelectric power has been a great resource of energy for years. What are the true pros and cons of hydroelectric power?
Pros and Cons of Hydroelectric Power
Hydroelectric dams are a great resource for electric power. There are some drawbacks to hydroelectric power as an intermittent energy resource.
What is hydroelectric power?
Hydroelectric power facilities are a form of power-producing plants that rely on the use of dams to produce consumable energy. Hydroelectric power has a long-standing history as being one of the most reliable and understandable forms of generation.
Usually, hydroelectric power plants are placed in line with dams. The theory is that dams hold significant pressure of water behind them from a reservoir or river. The water can be released into a penstock that will use gravity to flow through a turbine that will generate the consumable power.
It’s interesting because hydroelectric power plants and coal power plants produce electricity in a similar fashion.
Both hydroelectric power plants and coal power plants use a propeller-based turbine to generate power. With coal-based power plants, they use steam from the coal to turn the blades whereas hydroelectric facilities use water.
This is why hydroelectric dams are one of the purest forms of renewable energy. They simply use water (already river flowing water) to generate power. Hydroelectric power does not rely on a consumable feedstock to run the facility like biomass.
Hydroelectric Power Technologies
There are a number of different hydroelectric power technologies some of which are more proven than others. Here is a brief overview of some of the other hydroelectric power technologies.
1. Conventional Hydroelectric Dams
Conventional hydroelectric power dams are the most known technology. The power is built up from pressure from the dam. Then, the water flows down a penstock to the turbine to generate electricity.
2. Pumped Storage
The demand is not consistent with electricity. Peak demand is often at night time when the sun goes down and people consume power at the comforts of their home. Pumped storage is a form of energy storage that enables the use of water to act as a storage facility and can dispatch electricity in times of need.
Run-of-the-river facilities rely on a consistent supply of water coming from a lake, pond or reservoir upstream. The water comes from ‘upstairs’ and flows down the stairs in the penstock to run straight through the turbine.
4. Tide Energy / Wave Energy / Tidal Power
Tidal energy solely relies on the rise and fall of the tide in the ocean. Permitting is very tough for this form of hydroelectric power and is not readily available in every location around the globe. You can read more about Tidal Wave energy in our featured post.
What are some interesting facts about general hydroelectric power to help you understand the advantages and disadvantages of this renewable energy technology?
Let’s dive into the pros and cons of hydroelectric power.
Pros of Hydroelectric Power
When evaluating the pros and cons of hydroelectric power, I like to consider the pros side of the equation first. Here are the advantages and interesting facts about hydroelectric power.
1. Long-lasting asset class
Hydroelectric dams can last over 100 years. Hydro energy is extremely reliable and have a long operating history to stand behind.
2. Simple, understandable technology
The best part of hydroelectric power is the limited complexity. It really doesn’t need to be explained in careful detail. The technology can virtually be used around the globe so long as there is water. It is as simple as when the water flows through the penstock, the facility is running.
3. Low-cost installation and low operating cost
The install cost of hydroelectric facilities is very low when paired with a dam. To operate a hydroelectric facility, you do not have much in the way of operating expenses. You will typically have an operations and maintenance contract with a provider to oversee the power plant.
In addition, you will have some consumable power on-site for operating the facility along with property taxes. Beyond that, hydropower has a limited operating expense burden.
4. Flexibility of use
Hydro energy is very flexible to ‘turn on’ and ‘turn off.’ It is a renewable energy resource that can be shut down during low river flows with a limited operating expense, which won’t burden the overall performance of the facilities over a span of months.
Once flows are at peak levels, the hydroelectric power facilities can be ramped up very quickly to take advantage of the peak points. Large-scale hydroelectric facilities are usually front of the meter rather than behind the meter.
This being said, they have extremely high capacity factors. The plants generally are able to operate at their full capacity. Here is a video on what capacity factor means.
Cons of Hydroelectric Power
Just like anything in this world, there are always considerations for disadvantages relative to the advantages.
I’ll let you be the judge if the advantages outweigh the disadvantages. Here are the disadvantages of hydroelectric power.
1. Water loss
One consideration that is a very important one with hydroelectric dams is water loss. During the water turbine process, a portion of water is lost from evaporation.
Water is a very scarce resource for people on earth. Water is a renewable resource. Here are a few reasons why water is renewable.
However, we only have a finite amount of supply of good drinking water and any lost water is damaging. We as people of earth must conserve as much water as possible.
2. Land damage and blockage of reservoirs
The permitting process for hydroelectric power facilities is long for a reason… The development of dams typically damages the low-points in reservoirs.
These reservoirs are typically in biologically rich areas or in riverine valleys. After the water flows through the turbine, the sediment can scour the river beds.
3. Risk of large-scale failure
Traditional hydroelectric dams have large pools of water behind them. With natural disasters on the rise and getting worse as time goes on, these catastrophic events can literally demolish a dam completely.
Tidal power also faces a similar risk with typhoons and hurricanes. Run-of-the-river facilities run less risk since the facilities can be geographically located in climates without hurricanes.
Conclusion on Hydroelectric Dams
There are plenty of pros and cons of hydroelectric power. Hydroelectric dams are one of the best forms of renewable energy. Unfortunately, due to the long history of the technology, most of all dams are spoken for in regards to hydroelectric power. Most hydroelectric development has slowed.
This is due to the long permitting processes and most development locations have been already called for. Hopefully, development can be reinvigorated through the exploration of newer technologies like tidal energy.
Existing operating hydroelectric facilities are very attractive for investors due to the flexibility when paired with other asset classes. From a portfolio construction standpoint, they make a lot of sense for yield-based investors since the cash flow from the facilities is straightforward, proven and relatively predictable.
What are your thoughts on the pros and cons of hydroelectric power? Please let us know in the comments below. We’d love to hear from you.
Understand other renewable energy technologies? Check out our renewable energy section for more information about the facts of renewable power.