Solar pool covers have one major advantage over virtually every other type of pool cover on the market. Solar covers can heat a pool an average of 12 degrees but it is not unheard of to get up to a 15-degree increase in heat from a solar cover alone.   

So, how fast does a solar cover heat a pool? The answer to that depends on a few factors.

The amount of daily sunshine plays a big part in how fast a solar cover can heat a pool. First, there needs to be sunlight for a good portion of the day. The way a solar cover works is that it heats the pool by allowing the sun’s rays to penetrate the barrier, but the air bubbles on the bottom of the cover do not allow the heat to evaporate into the atmosphere. This helps to heat the pool and it maintains the heat.  

To increase the heat in any pool, you need at least 2.5 hours of direct sunlight. That doesn’t seem that bad, but that is only raising the temperature one degree in accordance with the generally accepted speed at which solar covers heat a pool; which is 5 degrees every 12 hours.

The main function of a solar cover is not to heat your pool. Rather, it is one of the most effective ways to maintain the heat in your pool. Using a solar cover can reduce the heat loss in your pool, which can reduce your energy costs by up to 70%. However, the solar pool cover itself can only do so much when it comes to heating your pool.

Having a pool heater and a solar cover though will help heat your pool and keep it heated. The two entities work together extremely well, which is likely part of the reason people spend an average of $20 million on solar pool products each year.

The time of the year matters because it directly correlates with how much sunshine is available to you during the day. It is true that a solar cover alone will help extend your season both on the front end and on the back end of summer. If you live in warmer climates, such as the midwest, you might be able to extend your season from mid-April all the way until mid-October. 

However, you need to remember that in colder weather regardless of where you live, the speed which your solar cover can heat your pool will vary. Your pool is always going to be heated the fastest by a solar cover in the middle of summer.

Additionally, it is not practical to believe that you will get any increased heat benefit in winter. You will always need a heater to keep your pool warm in the winter. However, a solar pool cover will help maintain the heat. Although, it is recommended unless in very special situations to winterize your pool in the coldest months.

Of course if all the conditions are right, there is a general consensus of exactly how much the average solar cover can heat a pool. It is generally accepted that solar covers can heat the water by 5 degrees for every 12 hours of coverage. 

Keep in mind, though, that this is based on twelve hours of sunlight while the solar cover is on the pool. If you have a pool it is likely that you are going to want to use it, so getting 12 hours or more of direct sunlight even over the course of several days is difficult. After all, when you take the cover off, much of the accumulated heat escapes while you are using the pool.

Granted, reserving any amount of heat is helpful for lowering energy costs. At least you are not continually losing heat and making your heater work harder when you aren’t even using the pool. 

To close, when it comes to solar covers the added bonus of heating your pool along with all the other benefits it offers is something many pool owners take advantage of regardless of how long it takes. After all, every degree your pool is heated is a degree less your pool heater needs to work for saving you money. All those free degrees throughout the summer are bound to add up!