How To Drain Solar Panels?

  • To the hose bib at the bottom of the tank, connect a hose. Place the hose’s other end below the tank’s bottom, in a location where it can drain without hurting anything. Flush for 2 minutes or until clear after opening the hose bib.
  • Turn off the 3/4″ valve that supplies the tank with cold water. Allow air into the tank by opening a hot water tap somewhere in the house. Allow the hose bib to remain open until the tank has entirely drained.
  • To stir up extra dirt, open the 3/4″ cold water supply valve for a few minutes. Allow the water to drain by closing the cold water supply valve. This should be done until the water is clean.
  • To begin filling the tank, turn off the hose bib and open the 3/4″ cold water supply valve.
  • Connect a hose to the hose bib on the pipe that returns water to the tank from the solar panels (the one without a pump on it). Flush for 2 minutes or until clear after opening the hose bib.

What happens if the solar panels are rained on?

Your solar energy system will be unaffected by rain. Moisture won’t harm solar panels because they’re waterproof. Rain, in fact, is beneficial since it washes away some of the dirt and debris that builds up on the panels over time.

In theory

  • Sun heats water flowing in a circuit through the collector in the simplest panels (the panel on your roof).
  • The water that exits the collector is hotter than the water that enters it, and it transfers that heat to your hot water tank.
  • The water does not actually enter and fill your tank. Instead, it goes into one pipe on one side of the tank and out of another on the other, passing through a coil of copper pipes inside the tank (the heat exchanger) and losing heat along the way.
  • You can draw hot water from the tank at any moment without disrupting the operation of the panel. Because the panel won’t produce heat all of the time, your tank will require additional heatingusually a gas boiler or an electric immersion heater.
  • The heat exchanger’s cold water returns to the panel to absorb more heat.
  • The water is kept moving through the circuit between the collector and the water tank by an electric pump (supplied by your regular electricity supply or by a solar-electric (photovoltaic) cell on the roof).

In practice

Of course, it’s a little trickier than that! What if it’s winter and the sun isn’t providing any usable heat? You don’t want your solar system to pump cold water into your house, but you still require hot water. What if it’s bitterly cold? You’ll need to keep your solar system from freezing up, so run hot water from your house through it every now and then. As a result, a typical solar system will have two interconnected water circuits, similar to this one.

Open loop solar water heating system

Water heated in collector panels is returned to the cylinder and subsequently to taps and appliances for household use in an open loop (direct) system. On chilly nights, a system such as a temperature-controlled pump that circulates hot water through the panel to prevent freezing must be added into the circuit.

Is it okay to clean solar panels with a hose?

You may not need to do much to clean your panels depending on the degree of the debris. This is why we advise you to assess the panels first. Examine them to see how much trash, grime, and substance build-up has accumulated on the panels (are there any sticky substances, such as bird droppings?).

For Minimal Dust Build-Up: Use a Hose

If the messiness of your panel is primarily due to dust and grime build-up, you’ll probably only need a simple hose-down to clean it up. If your garden hose can reach your panels, that should suffice. Simply saturate them with water and you’re ready to go. You can set them out in the sun to dry.

Just make sure you don’t use high-pressure jets or a pressure washer to spray the panels. This could scrape or damage the panels, resulting in decreased performance and efficiency.

For More Extensive Mess: Scrub Them Down

If the debris on your panels is more than simply dust and dirt, and includes sticky stuff like bird droppings or sticky plant materials, you should scrub them thoroughly.

You don’t want to be too harsh on the panels again. Choose a gentle scrubber, squeegee, or brush to avoid scratching or damaging the panels. Also, choose a gentle soap that contains no chemicals that could hurt or degrade the panels.

  • Scrub the panels gently with soapy water and the scrubber to remove any debris or buildup.

And there you have it; it’s a rather simple procedure that requires little more than a scrubber capable of reaching across your panels. However, keep in mind that solar panels grow extremely hot on hot summer days. You could wish to tidy first thing in the morning or last thing at night.

Another Option: Have them Serviced

If you don’t feel like doing the work yourself, you can hire an expert to service the panels. If you bought solar panels straight from a manufacturer, visit the manufacturer’s website to see if there are any service providers in your area.

Many providers offer servicing plans in conjunction with the purchase of the panel. Regular maintenance and upkeep may be included in these programs (depending on the supplier). They could also include routine inspections to verify that the panels are operating as efficiently as possible.

We, on the other hand, would not choose this option if it were up to us. These services could end up being quite costly. You’re basically spending money in order to save money on your electricity bill afterwards. You’re obliterating your own cost-cutting efforts! And, because cleaning solar panels isn’t a particularly difficult process to begin with, we wouldn’t advocate hiring someone to do it in most cases.

Keep in mind that you’re simply comparing the cost of maintaining the panels to the cost of generating more energy with cleaner panels. These expenses will almost never be offset.

Twigs, Leaves and Dirt:

Debris on your solar panels can scrape them, reducing the amount of electricity produced. Keep the trees around your house pruned so that no branches or debris fall on your roof. For best effectiveness, clean your solar panels once a year using a garden hose and a soft cloth.

Hail Storms:

Hailstorms are no exception to the rule that bad weather is bad for roofs. If you live in a location with extreme weather, your solar expert should be able to advise you on the best solar setup for you.

Sunrun’s System Service Warranty Has You Covered

At the very least, most professional solar panel systems come with a 20-year warranty. However, many rooftop solar systems continue to generate electricity after the warranty period, which can last anywhere from 25 to 30 years.

That’s why, with chosen solar plans, we cover the lifespan of your system and provide a comprehensive 25-year service warranty.

Daily monitoring, free maintenance, repairs, and complete insurance are all included! You can only get these options if you have a specific solar plan. Now is the time to compare our solar plans and services. Our solar experts are here to assist you and answer any queries you may have.

Do solar panels need the use of a water tank?

If you opt to install solar thermal in your home, you’ll need a hot water tank to hold the hot water generated by your collector. The difficulty is that these systems can’t be plumbed into the older hot water tanks that were traditionally used with boilers.

Is solar energy reliant on water?

Solar PV cells generate power without the usage of water. Water is used in the fabrication of solar PV components, as it is in all industrial processes.

Water is used to cool concentrated solar thermal plants (CSP), as it is for other thermal electric plants. The amount of water used is determined by the plant’s design, location, and cooling system.

CSP systems with cooling towers that use wet-recirculating technology use between 600 and 650 gallons of water every megawatt-hour of electricity generated. Water extraction is higher in CSP facilities with once-through cooling technology, but total water usage is lower (because water is not lost as steam). CSP plants can save up to 90% of their water by using dry-cooling technology. However, these water reductions come at a price: greater expenses and poorer efficiency. Furthermore, at temperatures above 100 degrees Fahrenheit, dry-cooling technology is substantially less effective.

Many of the regions in the United States that have the highest potential for solar energy also tend to be those with the driest climates, so careful consideration of these water tradeoffs is essential. (See How It Works: Water for Power Plant Cooling for more information.)

Solar panels save how much water?

An infographic has been circulating recently that claims to depict the proportionate amounts of water consumed by four main electrical power sources: coal, nuclear, natural gas, and solar. According to the picture, solar is the clear victor in terms of water conservation, as it generates power with no water at all. Is the claim, however, correct? That’s not the case.

The “Climate Reality Project” created the graphic, which is circulating on social media. At first glance, it appears to be rather basic. Coal-fired power plants consume 1,100 gallons of water per megawatt-hour of electricity generated. (A megawatt-hour is roughly equal to the amount of energy consumed by a typical California household over the course of six or seven weeks.) For the same amount of power, nuclear and natural-gas-fired power plants utilize 800 and 300 gallons of water, respectively. Solar, according to the Climate Reality Project, uses the least amount of water of all four energy sources, using 0 gallons per megawatt-hour.

The graphic’s designers spread the news on Facebook with bated breath, adding “You probably already know that solar power plants create electricity without emitting carbon dioxide, but did you know they also save a lot of water? ‘Share’ this page with your friends!” Is the graphic, however, correct? It depends on your definition of “accurate.”

What is a drain back system, and how does it work?

The advantages of a drain back solar water heating system vs a closed loop glycol solar water heating system are debatable. Both have their advantages and are capable of boiling hot water. However, we do not supply or recommend drain back systems with evacuated tube collectors in Canada or the Northern United States. In frigid climes, we believe a closed loop solar heating system is preferable to a drain back system for the following reasons.

What is a drain back system?

A drain back system heats with water rather than glycol. The water in the system is in an open loop, so when it reaches the shut-off temperature or becomes too cold, it drains back to a storage vessel via gravity. The system deals with both overheating and freezing in this way. When there is no solar gain in the evening, the system initiates a drain solenoid, which drains the water in the collectors to a smaller storage tank called the drain back tank, which is typically located in the basement or utility room. Water is not left in the collect in this system because it has been drained. A pump is engaged when the solar collector has enough energy to supply, and the water is pumped through the heating system. If the system overheats, it will drain itself, ensuring that no water is left in the collectors to overheat.

What is a closed loop system?

A closed loop, often known as a closed loop, is a loop that is closed at both ends “The “active” solar system is pressurized and employs a mixture of glycol and water. This necessitates the use of a pump station to initially fill the system (all our solar water heating kits come with the fill pump). The system is inflated to a pressure of 20-30 psi. An expansion tank with a rubber membrane is incorporated in a closed loop system, and it absorbs the expanding and contracting of the heating system as it heats up and cools. Hydronic in-floor heating, like any boiler system, is an example of a closed loop system. The heating fluid can be left outside without fear of freezing because glycol is utilized in the system. When a closed loop system overheats, the circuiting pump is turned off, and the system is forced into what is known as a closed loop “Stagnation” is a term used to describe a state of The heating fluid in the collector changes to steam in this stage, and the rubber membrane in the expansion tank absorbs the extra volume of steam in the system.


The drain back has the advantage of using water as the heat source. Because water has a slightly higher heat co-efficient of performance than glycol, it can generate slightly more heat energy than a glycol-based system. On the other hand, once installed, a closed loop system requires relatively little maintenance. The glycol/water is not impacted by oxygen and does not evaporate because it is in a separate loop. Because it is not affected by the forces of gravity that an open loop or drain back system must fight, a closed loop system has no vertical head pressure to contend with. As a result, the pump uses less energy, enhancing efficiency.


The temperature of a solar vacuum tube can reach 300 degrees Celsius. In a drain back system, where water is filled and drained in a system dependent on the heat in the collector, this creates an issue. If the collector is filled when the temperature is too high, the water will instantly turn to steam as it enters the collection. As a result, drain back is more common with flat panel collectors that do not reach the same high temperatures as vacuum tubes.

What is a solar water heating system with a drain back system?

Solar systems that drain back do not have an expansion tank or a propylene glycol system. The water is recycled in the heat exchange process using a separation mechanism, resulting in a closed cycle. The water is only heated in the collector when there is enough heat available.