Benefits of Solar for Water Treatment Plants & Sanitation Facilities

Water treatment plants have become increasingly important to communities throughout the United States. As water insecurity rises, cities will rely on these facilities to keep their populations healthy.

However, water treatment and sanitation plants consume a significant amount of energy — about 4% of the U.S.’s total supply. This makes solar energy an exciting opportunity in this industry. It provides an efficient, sustainable power source to keep this critical infrastructure operating at a lower cost. 

This article explores the benefits of solar for water treatment plants in the context of these challenges. Read on to learn how municipalities can leverage this technology to prepare for the future while cutting operational costs.

Transitioning to a solar-powered wastewater treatment facility can prepare utilities to address three significant challenges they face today.

A water treatment plant requires energy to convert dirty water into a reusable resource. Between aeration, sludge treatment, pumping systems, and odor control processes, energy accounts for about 30% of these facilities’ ongoing costs.

This has become problematic as energy prices continue to rise. For example, electricity rates for California businesses have risen nearly twice as fast as the annual inflation rate over the past decade.   It’s a trend the California Public Utilities Commission expects to continue for the foreseeable future.

Given their energy-intensive processes, wastewater plants are particularly vulnerable to these price increases. This has made cutting energy costs a top priority for many water treatment facilities nationwide.

Energy prices aren’t the only thing that’s increasing. Wastewater facilities are also subject to increasing environmental regulations from organizations like the Environmental Protection Agency (EPA). Many are also trying to reduce carbon emissions and comply with various state-specific environmental standards.

Though beneficial to society, these regulations have placed strict limits on operational standards. They’ve reduced the strategies available to leaders in the ongoing quest for efficiency. So, while costs have risen, the pathways for dealing with efficiency and ecological standards have shrunk. That’s why the interest in getting a wastewater plant running on solar power is increasing.

Many U.S. wastewater facilities are also struggling with aging infrastructure. This not only increases operation and maintenance costs but also increases the likelihood of downtime, leaks, and quality control issues. The most recent estimates suggest about 15% of U.S. wastewater treatment facilities have reached or exceeded their design capacity. That’s why this situation has been called the “infrastructure crisis people don’t want to talk about.”

Solar helps wastewater plants overcome some of the most common challenges they face today. Here’s a look at how plants across the country have integrated solar into their operations.

Adding commercial onsite solar to a water treatment plant typically means installing ground-mounted and rooftop panels. These capture energy from the sun and transform it into a form of power the facility can use.

The installation process requires careful planning. Plants must identify the optimal locations for panels, assess structural integrity, and connect their new solar energy system to the existing utility grid. Most facilities rely on partnerships with solar companies to develop and execute these plans.

It’s also important to consider solar energy storage systems, such as batteries, during the integration phase. These store solar power for later use. Without them, a plant can only leverage the benefits of solar energy when the sun is out.

After installation, a treatment facility can use its new energy source to cut costs and reduce its reliance on the grid. That can sometimes mean using solar to directly power energy-intensive equipment like aerators and pumps.

The next factor to consider is how your plant would pay for its new solar energy system. One option is covering the cost of equipment and installation upfront. But that would require a significant initial investment — money most government-run organizations lack.

That’s why power-purchasing agreements (PPAs) are ideal for a water treatment plant. Popularized through commercial solar energy, these agreements make it possible to benefit from solar with almost no initial investment.

Companies that offer PPAs install solar panels at minimal upfront cost. In exchange, your facility agrees to purchase the energy those panels generate at a set price for a pre-determined number of years. The per-kilowatt-hour cost should still be substantially lower than what you pay for electricity today — saving your facility money while helping it meet goals around clean energy.

When it comes to integrating solar, the question isn’t just whether panels would be suitable for your treatment facility — it’s how you can justify the price and focus. If it falls on you to make the case, you can start by highlighting the following three benefits of solar for water treatment plants.

Solar panels help wastewater facilities save money. They do so by unlocking a new, free source of energy — reducing the amount of power that must be pulled from the utility grid.

Your organization’s savings math will vary based on whether it buys panels outright or enters a PPA. If you buy outright, your initial costs will be high. But your energy bills will drop significantly, recuperating what you paid over time.

If you enter a PPA, your initial costs will be low, but your energy bill will not decrease as much as it would with an outright purchase.  Some estimates say solar energy PPAs cut wastewater treatment plant costs between $25,000 and $50,000 annually. That means saving between $500,000 and $1 million throughout the panels’ lifespan — and potentially significantly more.To calculate your facility’s potential savings, consider what it pays today per kilowatt/hour. Then, get a quote on what you’d pay through a solar PPA. Take the difference and multiply it by the amount of energy your facility uses annually. This will give you a dollar figure you can use to make the case for solar at your wastewater plant.

Saving money is just one reason to add solar power to your facilities. Wastewater facilities also choose this option to reduce their environmental impact. Some estimates say adding solar to a water treatment center can reduce greenhouse gas emissions anywhere from 13 to 30%.This can do more than help a treatment facility comply with environmental mandates from regulatory agencies. It can also garner goodwill across the community, as the majority of Americans now care about climate change.

Finally, the benefits of solar for water treatment plants extend to increased resilience. Solar provides a backup source of power that the plant can draw from during outages. That can be the difference between continuing operations or everything coming to a stop during the next blackout.

This kind of reliability is becoming increasingly important throughout the United States — and California, particularly. Wildfires are becoming more common and causing major power outages. State utility companies are strategically shutting down electricity services to reduce wildfire risk.

In this environment, critical infrastructure like wastewater plants needs a backup energy source more than ever. Solar is the easiest, most cost-effective way to get there.

Reading about the benefits of a solar-powered water system is one thing; seeing a real wastewater utility reap the benefits is another. So, let’s look at REC Solar’s recent work with the Central Contra Costa Sanitary District (Central San).

Central San approached REC Solar with the goal of optimizing energy production and reducing greenhouse gas emissions. REC Solar designed, engineered, procured and constructed the 2.16 MW ground mount solar array on a repurposed portion of a 48-acre buffer property near Central San’s Martinez wastewater treatment plant.

The solar array now generates energy that is fed directly into the PG&E grid. This offsets various electrical meters across the utility’s operations in several counties.

Central San financed the project through a 25-year PPA. This shifted the project from a costly capital expense into a predictable monthly payment with zero price escalation. Over the 25-year agreement, the new solar array should save Central San nearly $6 million in electricity costs.

Solar has the potential to transform wastewater treatment plants throughout the country. When combined with PPAs, it offers minimal upfront costs to reap several valuable benefits, including:

These benefits of solar for water treatment plants should only become more pronounced over the coming years.  Plus, technology will continue to make solar energy systems more efficient. 

That’s what makes now an ideal time to begin exploring the potential of solar energy in wastewater treatment plants. If you need any support in that process, REC Solar is here to help. We’re commercial solar experts who can help your organization take the next step toward its energy goals. Get in touch when you’re ready to learn more.