Solar panels are best known for producing clean, renewable electricity. Water conservation, meanwhile, is usually associated with shorter showers, efficient irrigation, and reducing household water waste. But these two environmental goals have more in common than you might think.

Solar energy can help conserve water, and water conservation can reduce energy consumption. When combined thoughtfully, these approaches can help communities save resources, lower operating costs, and reduce their environmental impact.

This relationship is known as the water-energy nexus, and it is especially important in dry regions where both electricity and freshwater are valuable resources.

How Solar Panels Help Conserve Water

1. Solar Energy Requires Relatively Little Water

Many conventional power plants use water for cooling or steam production. Depending on the technology, some of that water is consumed through evaporation or other processes.

Photovoltaic solar panels work differently. They convert sunlight directly into electricity without requiring water for cooling during normal operation.

Solar panels still require water during manufacturing and may need occasional cleaning, but their overall water-consumption footprint during electricity generation is generally much lower than that of conventional thermoelectric power plants.

As solar energy replaces more water-intensive forms of electricity generation, it can help reduce the amount of freshwater consumed to meet our energy needs.

2. Solar Panels Can Reduce Water Evaporation

One particularly promising application involves installing solar panels over irrigation canals and certain reservoirs.

Water exposed to sunlight can evaporate, especially in hot, dry climates. Panels installed above suitable water infrastructure provide shade, potentially reducing evaporation while generating electricity.

This approach offers two benefits from the same installation: producing renewable energy and helping preserve water supplies.

The idea is particularly relevant in the American West, where drought, population growth, and competing demands place considerable pressure on available water resources.

3. Solar Power Can Operate Water Systems

Moving and treating water requires energy. Municipal water systems use electricity to pump water through pipes, operate treatment facilities, and distribute it to homes and businesses.

Solar panels can supply some of the electricity these systems need.

Solar-powered irrigation pumps can also help farmers deliver water to crops, while renewable electricity can support water recycling, wastewater treatment, and desalination.

These applications do not automatically reduce water consumption. For example, a solar-powered irrigation system could use more water if it makes irrigation cheaper or easier without appropriate controls. However, when paired with efficient equipment and responsible water management, solar energy can support more sustainable water use.

How Water Conservation Helps Solar Energy

The relationship works in the opposite direction, too. Conserving water can reduce the amount of energy required to collect, treat, heat, and transport it.

1. Using Less Water Can Save Energy

Consider the journey water takes before reaching a household. Depending on the location, it may need to be pumped from a reservoir, treated at a water facility, transported through a distribution network, and heated for household use.

Each of these steps can consume energy.

Fixing leaks, installing efficient fixtures, using water-saving appliances, and improving irrigation practices can reduce demand on water infrastructure. That can also reduce its energy requirements.

When solar power supplies the electricity for these systems, water and energy conservation can reinforce each other.

2. Cleaning Solar Panels Requires Careful Water Management

Solar panels work best when sunlight reaches their surfaces. Dust, pollen, and other debris can reduce their output, particularly in dry and dusty environments.

However, cleaning panels too frequently can waste water, especially when the buildup is minor and has little effect on performance.

A better approach is to consider local conditions, monitor energy production, and clean panels when necessary. Rain may provide sufficient cleaning in some locations, while others may require periodic maintenance.

The goal is to maintain good electricity production without using more water than necessary.

3. Solar Panels and Rainwater Harvesting Can Work Together

Installing solar panels on a roof does not necessarily prevent that roof from collecting rainwater.

With suitable system design, gutters and downspouts can direct roof runoff into rain barrels or storage tanks. The collected water may then be used for appropriate nonpotable purposes, such as landscape irrigation.

Anyone considering this approach should account for local regulations, roof materials, panel-cleaning products, and water quality. Collected rainwater should not automatically be assumed safe to drink.

Combining rooftop solar with rainwater harvesting can help households make better use of both sunlight and precipitation.

Solar Panels Over Irrigation Canals: A Promising Example

One of the clearest examples of the connection between solar energy and water conservation is the proposal to cover irrigation canals with solar panels.

A 2021 study published in Nature Sustainability examined the potential benefits of covering California’s extensive canal network with solar installations.

The researchers estimated that covering the state’s approximately 6,350 miles of canals could save an average of about 39,000 cubic meters of water per kilometer of canal annually. That is roughly 10 million gallons per mile per year, based on the study’s modeled estimates.

These figures represent a projected opportunity rather than measured statewide savings from a completed installation.

The potential benefits extend beyond water conservation:

• Reduced evaporation: Shading the water can limit losses to the atmosphere.
• Renewable electricity: The panels generate power without requiring additional solar-farm land.
• Efficient land use: Existing infrastructure can serve a second purpose.
• Potential temperature benefits: Water beneath the panels may help moderate panel temperatures under some conditions.

There are practical challenges, including construction costs, maintenance access, structural requirements, and the need to protect the canals themselves. Nevertheless, the concept illustrates how one infrastructure investment can address two resource challenges.

Why This Matters in Utah and the American West

Water conservation is particularly important in arid and semiarid regions. Utah and neighboring states must balance residential growth, agriculture, industry, environmental needs, and variable water supplies.

Solar energy and water conservation offer several opportunities to address these pressures together.

Communities could install solar panels at water-treatment facilities, improve the efficiency of pumping systems, upgrade irrigation infrastructure, and explore solar canopies over suitable reservoirs or canals.

Homeowners can contribute as well by combining renewable electricity with efficient appliances, repairing leaks, and choosing landscaping appropriate for the local climate.

No single measure will solve the West’s water challenges. Solar energy does not create additional freshwater, and energy savings do not necessarily translate into water savings. The results depend on how systems are designed and managed.

However, considering energy and water together can help communities make more informed decisions about infrastructure, costs, and long-term sustainability.

The Water-Energy Nexus: Two Resources, One Opportunity

Solar energy and water conservation are often discussed as separate environmental goals. In reality, they are closely connected.

Producing electricity with photovoltaic solar panels generally requires less water than generating electricity in conventional thermoelectric power plants. Conserving water can also reduce the energy needed to pump, treat, and distribute it.

When these strategies are combined with efficient equipment and responsible resource management, the benefits can extend beyond either technology alone.

The larger lesson is simple: conserving energy and conserving water are often two parts of the same solution.

As communities look for practical ways to reduce environmental impacts and make better use of limited resources, the connection between solar energy and water conservation deserves greater attention.

By thinking about both resources together, we can find opportunities to produce cleaner electricity, reduce unnecessary water use, and build more sustainable communities for the future.