Renewable energy is finally making its way across the United States.
Everywhere in the country, homeowners are investing in renewable energy technology that reduces overall fossil fuel consumption and paves the way towards a brighter, cleaner future for everyone.
However, between the various types of renewable energy sources out there, it can be difficult for homeowners to choose the one that suits the circumstances best.
In particular, in areas that have both running water and ample sunlight, making the choice between solar power compared to hydropower can be a challenge. However, there are ways to compare solar power efficiency with the efficiency of dams in such a way as to make the decision easier.
Solar Power Compared to Hydropower Efficiency
In terms of energy production, hydropower is the most efficient way to generate electricity. Modern industrial-grade hydroelectric turbines convert up to 90 percent of available energy into electricity, whereas solar panels usually feature solar power efficiency ratings of between 14 and 20 percent. For comparison, fossil fuel plants are fortunate to reach beyond 50 percent efficiency.
However, base efficiency rates may not be the best way to gauge which renewable energy source is best for your property. Another way to rate overall system efficiency is by comparing the cost-per-kilowatt-hour of each power source.
- Modern solar energy panels costs around $0.06 cents per kilowatt-hour according to the United States Department of Energy.
- Hydroelectric power costs considerably more, generally in the range of $0.85 cents per kilowatt-hour. More than half of this figure comes from operational costs.
However, there are benefits to hydroelectric power that solar panels cannot match. For example, rainy days do not affect the efficiency of dams – if anything, the addition of rainfall water makes them even more productive.
Infrastructure and Installation Cost Comparison
When most people think of hydroelectric power, the first image that comes to mind is a huge concrete dam. While the most famous hydroelectric power plants are huge constructions that take years of work to finish and hundreds of employees to maintain and operate, microhydropower systems are increasingly common fixtures on residential properties with running water.
In this case, hydroelectric power generation is generally measured in the tens of kilowatt-hours – slightly more than the average solar array. While it’s generally easy to estimate the cost of a solar array, hydroelectric power generators depend heavily on local circumstances and can vary wildly in price depending on a two main factors:
- The vertical distance between the turbine and the forebay, called the head.
- The average quantity of water traveling between the two locations, called the flow.
To calculate a hydroelectric power system’s output in watts, you must multiply the head (in feet) by the flow (in gallons per minute) divide by 10. This equation assumes 53 percent efficiency, which is typical for a small residential hydroelectric generator.
Determining the flow of water on your property is not as hard as it sounds. In most cases, you can get this information from the most recent U.S. Geological Survey report for your county. You may also ask the U.S. Army Corps of Engineers for data, or local flood control authorities.
If this data doesn’t exist, you can also measure flow yourself. Any of the six most popular methods should give you a reasonably accurate measurement of your water source’s flow.
In general, installing a low-output residential-quality hydroelectric generator can cost anywhere from $1,500 to $10,000. Installing higher-output systems may surge north of $20,000. For comparison, solar panel systems almost never cost less than $10,000, so it’s important to compare calculations and determine which option is best for your particular plot of land.
The one area where solar power outperforms hydropower is in maintenance costs. For the most part, solar power has none – solar panels have no moving parts and generally do not require attention for decades at a time.
Hydroelectric generators, on the other hand, are highly vulnerable to a broad range of issues. Water carries debris hydroelectric systems must address in order to reliably produce power, and there are fish and wildlife concerns to keep in consideration.
To keep your microhydropower turbine working properly, you need to screen its water intake, regularly verify its pipeline, occasionally repair the turbine, and possibly deal with control malfunctions. All of these challenges can be overcome, but they depend on the unique circumstances of your particular water source and may increase the cost of your hydroelectric project.
As a last remark on the difference between solar power compared to hydropower, you will likely have to obtain approval from local authorities to divert public waters running through your property. Depending on the legislation of your particular county, this may be a simple one-day task or an extended bureaucratic challenge.