The overall evaluation of an energy source is based not only on how clean it is; it also has to be reliable, accessible, and affordable.

Not all of these factors can be categorized neatly.

For example, petroleum tends to be relatively affordable in the United States, but that is in part because the government subsidizes fossil fuel industries.

Similarly, while wind energy, solar energy, and hydropower tend to be relatively expensive, their cost has been steadily declining for years as their use increases.

The main difference between Hydropower and Solar Power is that Hydropower is a type of power that uses water to generate energy, whereas Solar Power uses sunlight to generate energy.

These two Energies are also different in their generation and use them to produce Electricity.

Let's have a look between the two.

• Cost difference

• Production

• Reliability

• Environmental Impact

• Use in small portable devices

• Suitability

• Life span

• Effect of climate

• Pollution

Solar Energy vs Hydro Energy Cost Differences

In Solar Power, The large upfront cost is one of the biggest drawbacks of solar panel systems.

As of April 2021, the average cost of solar in the US is about $2.85 per watt.

So, a 6 kW solar panel system would run you around $17,100, on average, before the federal tax credit is applied.

The actual cost of a solar system will vary by state, and by the incentives that you qualify for.

Luckily, there are solar financing options available.

In many cases, you can qualify for a zero-down solar loan, which allows you to still save money on your electric bill and reap the benefits of owning a solar system.

In Hydro Power, Building any type of power plant is expensive - hydroelectric power plants can cost as much as $580 per kilowatt to be built, and they usually range from 10MW to 30MWs (where one MW is equal to 1,000 kilowatts).

This means that the upfront cost of building a hydropower plant can be millions of dollars.

Compared to the falling prices of solar installations, for example, hydropower is a more challenging renewable project to finance.

In terms of production costs, hydropower holds a strong advantage over solar power.

The U.S.

Department of Energy calls hydropower the most common and least expensive form of renewable energy in the United States.

Hydroelectricity represents 6 percent of all U.S.

energy production and accounts for 70 percent of all renewable energy generated in the United States.

Solar installations tend to cost much more.

For example, 1 megawatt-hour of electricity costs $90.3 in 2011 dollars to generate using hydropower, or $144.30 to generate using solar collectors, according to the U.S.

Energy Information Administration.


During the production of hydropower, turbines are used that convert the kinetic energy of moving water into hydropower.

A hydraulic turbine converts the energy of flowing water into mechanical energy.

A hydroelectric generator converts this mechanical energy into electricity.

The operation of a generator is based on the principles discovered by Faraday.

He found that when a magnet is moved past a conductor, it causes electricity to flow.

In a large generator, electromagnets are made by circulating direct current through loops of wire wound around stacks of magnetic steel laminations.

These are called field poles and are mounted on the perimeter of the rotor.

The rotor is attached to the turbine shaft and rotates at a fixed speed.

When the rotor turns, it causes the field poles (the electromagnets) to move past the conductors mounted in the stator.

This, in turn, causes electricity to flow and a voltage to develop at the generator output terminals

Solar power is obtained by using solar plates that capture the energy from sunlight and convert it into solar power.

Solar radiation may be converted directly into electricity by solar cells (photovoltaic cells).

In such cells, a small electric voltage is generated when light strikes the junction between a metal and a semiconductor (such as silicon) or the junction between two different semiconductors.

The power generated by a single photovoltaic cell is typically only about two watts.

By connecting large numbers of individual cells, however, as in solar-panel arrays, hundreds or even thousands of kilowatts of electric power can be generated in a solar electric plant or a large household array.

The energy efficiency of most present-day photovoltaic cells is only about 15 to 20 percent, and, since the intensity of solar radiation is low, to begin with, large and costly assemblies of such cells are required to produce even moderate amounts of power.


The world is endowed with abundant free solar energy.

Using the country's deserts and farmland and taking advantage of 300 to 330 sunny days a year, the World could easily generate 50,000 trillion kilowatt-hours of solar energy.

Solar power is one of the fastest-growing renewable energy technologies and within a relatively short period of five years, we have seen a steep fall (more than 60%) in solar PV capital cost and tariff.

Against the background of increasing costs of conventional power, concerns regarding availability and reliability of power from the grid, and long-term commercial feasibility of solar power, commercial and industrial consumers are installing rooftop solar technology to meet their captive needs.

Investing in Solar Power is also helping companies meet their corporate social responsibility initiative along with long-term commercial gains.

The world is poised to become a global force in the Solar Power industry, and emerging regulatory regimes and high peak prices make this opportunity real and attractive.

Solar power could present a rapidly scalable solution for both on-grid and off-grid applications, some of the advantages of Solar Power are the ease of access to power, a renewable energy source, reduction in electricity bills, etc.

Hydropower is a more reliable source of energy than Solar Power because it has a steady supply of power, while Solar Power is an intermittent energy source with periods when the energy supply is interrupted, such as at night and on overcast days.

For a large-scale Solar Power project to work, it needs a supplemental energy supply to serve as a backup source and to help when demand is high and supply low.

Environmental Impact

The sun provides a tremendous resource for generating clean and sustainable electricity without toxic pollution or global warming emissions.

The potential environmental impacts associated with solar power-land use and habitat loss, water use, and the use of hazardous materials in manufacturing-can vary greatly depending on the technology, which includes two broad categories: photovoltaic (PV) solar cells or concentrating solar thermal plants (CSP).

The scale of the system-ranging from small, distributed rooftop PV arrays to large utility-scale PV and CSP projects-also plays a significant role in the level of environmental impact.

Hydropower is the least expensive source of renewable energy in the world, including solar power.

Hydropower creates greater environmental impacts than solar energy, however.

In particular, hydropower requires the damming of the rivers and streams that serve as sources of water, affecting animal, fish, and plant habitats.

Solar power, on the other hand, has a limited environmental impact; largely comprising the energy costs of manufacturing the Solar Power systems.

Use in small Portable devices

Hydropower is not a viable power source for small, portable devices the way Solar Power is.

Solar power can serve as a primary power source for a watch, flashlight, or calculator because the sun is more easily accessible for mobile devices than water sources; photovoltaic panels that conduct the sun's energy can be quite small.

Hydropower's use of turbines and a water source makes it an ill match for small, mobile devices that demand flexibility.


In solar Power, The architecture of your home can have a significant impact on how and where solar panels are installed.

First and foremost, your roof must be structurally sound and able to support the weight of the panels, especially during periods of high wind.

Your roofing materials should be in good shape as well since solar panels are generally in place for many years and must be removed and replaced when new roofing is installed.

For every 1 kW of capacity, approximately 100 sq.


of surface space is needed.

So for a typical 5 kW installation, approx.

500 sq.


of space is needed.

In the United Kingdom, solar panels are generally most effective when facing south, but east and west can work just as well depending on what time of day your family draws the most power.

As always, a trained solar integrator can help you examine your energy consumption patterns and determine the best design to fit your lifestyle.

Any features that can block the path between and sun and your solar panels (shade), such as adjacent trees or structures like chimneys, must also be considered.

The roof surface should be suitable for a long time.

While your solar panels can help extend the life of your roof's surface, they can also impede repair and replacement.

In Hydro Power, it is not available to all areas because of the unavailability of resources that why it's going to be a tough choice.

Life Span

In Solar Power, The key components susceptible to failure are the solar panels and inverter.

However, high-quality products tend to have long lifecycles which are reflected in the long warranties available, particularly for solar panels.

A solar panel is relatively a simple device with no moving parts.

Solar panels typically have a 25-year output warranty and depending on the quality of the panel can be expected to last beyond this.

Also, solar panels which are exposed to wind, fluctuating temperatures, and weather do deteriorate and each year produces a little less electricity.

Cheaper panels, with less UV, stabilized backing sheets, cheaper sealants and framing can deteriorate faster and more rapidly.

Solar Panel warranties generally predict an average of 0.6% loss of power each year after the 1st year and thus, at the end of the 25 year output warranty period the solar panel may have lost up to 16.4% of its initial power rating.

This means is where a high-efficiency solar panel would produce 315 watts; the same panel in 25 years might only produce 261-269 Watts.

In reality, for less productive quality panels, they may start at 250-260 watts (Solar Panel output after 25 years operation) and then degrade to 200 watts per panel after 25 years.

Inverters are complex electronic devices, having to adjust output power every second; inverters are more susceptible to failure although quality brands, which are designed using the highest quality components, are likely to exceed typical 5 year warranty periods.

Many manufacturers now offer warranty extensions of 10 years or more.

Although the cables, safety devices, and mounting systems are less influential, the use of poor-quality materials can lead to premature system failures.

In cases of non-branded plugs and cables, complete system failures have occurred.

Therefore, it could be argued that to get a decade of low maintenance solar electricity buys quality solar panels, quality solar inverters.

Hydro Power has a very long operational life.

The oldest operating hydropower systems are over 100 years old, including some utility-scale systems.

Hydro turbines by their nature are relatively low-stressed pieces of machinery and operate under very steady loading conditions with no sudden load changes.

This lends itself to a long life provided they are regularly maintained (mainly lubricating the bearings).

The civil engineering infrastructure should last almost indefinitely provided it is maintained.

The drive systems (gearboxes or belts) will require periodic oil changes/replacement along with bearings in all of the rotating machinery.

Most hydro hardware manufacturers quote design lives of 25 years, though this is normally because they have to set a figure, and in many cases, the same manufacturers have many turbines out in the field that are over 50 years old and still operating reliably and efficiently.

Effects of Climate Change

In Solar Power Ambitious climate change mitigation plans call for a significant increase in the use of renewable, which could, however, make the supply system more vulnerable to climate variability and changes.

Results indicate that the alteration of solar PV supply by the end of this century compared with the estimations made under current climate conditions should be in the range (-14%;+2%), with the largest decreases in Northern countries.

Temporal stability of power generation does not appear as strongly affected in future climate scenarios either, even showing a slightly positive trend in Southern countries.

In Hydro Power, climate change may lead to a decrease in discharge and water availability and thereafter a decrease in hydroelectric power generation without further constructions considering only the current facilities.


Solar energy systems/power plants do not produce air pollution or greenhouse gases.

Using solar energy can have a positive, indirect effect on the environment when solar energy replaces or reduces the use of other energy sources that have larger effects on the environment.

However, some toxic materials and chemicals are used to make photovoltaic (PV) cells that convert sunlight into electricity.

Some solar thermal systems use potentially hazardous fluids to transfer heat.

Leaks of these materials could be harmful to the environment.


environmental laws regulate the use and disposal of these types of materials.

In Hydro Power, Thermal pollution is the change in the water temperatures of lakes, rivers, and oceans caused by man-made structures.

These temperature changes may adversely affect aquatic ecosystems especially by contributing to the decline of wildlife populations and habitat destruction.

Any practice that affects the equilibrium of an aquatic environment may alter the temperature of that environment and subsequently cause thermal pollution.

There may be some positive effects, though, to thermal pollution, including the extension of fishing seasons and the rebounding of some wildlife populations.

Thermal pollution may come in the form of warm or cold water being dumped into a lake, river, or ocean.

Increased sediment buildup in a body of water affects its turbidity or cloudiness and may decrease its depth, both of which may cause a rise in water temperature.

Increased sun exposure may also raise water temperature.

Dams may change a river habitat into a lake habitat by creating a reservoir (man-made lake) behind the dam.

The reservoir water temperature is often colder than the original stream or river.

The sources and causes of thermal pollution are varied, which makes it difficult to calculate the extent of the problem.

Because the thermal pollution caused by Hydropower Plants (HPPs) may not directly affect human health, it is neglected in general.

Therefore, sources and results of thermal pollution in HPPs are ignored in general.

Solar Power Vs Hydro Power Conclusion

Both hydropower and Solar Power are energy sources that do not consume limited resources but instead take advantage of renewable ones -- water for hydropower and the sun for Solar Power -- using them to generate energy without eliminating them from other uses.

Neither hydropower nor Solar Power creates significant pollution or waste so both are great for the environment.

Page tags: solar power, hydro power