Solar Hot Water (Solar Thermal Panels) in Shetland

If you’re considering getting a solar thermal system, one of the first things that comes to mind is the possibility of the system functioning properly during the cold months. The short and simple answer to this question is yes, a solar thermal system works in the winter. However, the downside here is that it’ll be a lot less efficient when compared to how it operates during the warmer months or summer. As a result of this fact, you’ll likely need to rely more on your boiler, immersion heater or any other backup heating system during this period as your solar thermal system will fail to contribute as much as it does during the warmer months. So what exactly is the reason why solar thermal is less effective and less efficient in the winter period? Let’s have a look!

As you know, solar thermal system banks on the sun’s energy to heat the water for your home’s use. During the cold months or winter, the sunlight becomes a lot less available when compared to the warmer months, as a result, there’s less sunlight that’s available to be used for its solar energy. And even more so at the periods when the days are shorter or skies are clearly overcast.

Also having a great impact on a solar thermal system’s output is heavy snow. Flat plate collectors normally have the capacity to cope better during snowy conditions as the light that’s able to travel through the snow will heat up the absorber plate - thereby making the snow slide off more quickly. However, the case is contrary with evacuated tube collectors which possesses a form of vacuum insulation that’s crafted to minimize the loss of heat, meaning they can’t generate heat to melt and cause the snow to slide off in a similar way.

Like every other systems in your home, solar hot water systems will require periodic inspections as well as a regular maintenance in order to keep it running as efficiently as it should. Not only that, the various components will also require either repair or replacement from time to time. It’ll also be proactive to take the necessary precautions so as to prevent worrying issues like corrosion, scaling or freezing.

Is it a task you can handle on your own? Well, there are some inspections and maintenance activities you should be able to handle on your own, however, you’ll also require a qualified technician to carry out the more technical or complicated tasks. You should also take note that it may actually be more cost effective to have some systems replaced, shut off or removed completely than having it repaired. Here are some of the essential inspections that should be carried out on solar system components. They include:

✓ Collector soiling. Periodic cleaning of your collectors is important especially in dry and dusty climates.

✓ Plumbing, ductwork and wire connections. Check the pipe connections for fluid leaks. Examine duct connections and seals. Also make sure that all wire connections are tight.

✓ Roof penetrations. Flashing and sealant around the roof penetration should be checked to see that it’s in a good shape.

✓ Collector shading. Check for shading of the collectors on annual basis as this may greatly affect their performance.

✓ Support structures. Examine all bolts and nuts which connects the support structures to the collectors for tightness.

✓ Heat transfer fluids. Anti freeze solutions in liquid solar heating collectors will have to be replaced periodically. And this right here is a task that’s best handled by a licensed technician.

Obviously the performance of a solar thermal system will vary depending on the location of the home, the insulation of the property, and your own hot water requirements. Solar thermal panels are capable of providing all of your hot water requirements from April to September. They will still make a contribution to your hot water needs for the rest of the year, but in general you will need a backup system to further heat the water in the colder months.

If you’re thinking about installing a solar thermal system in your house, it’s always important to put into consideration numerous factors before you proceed. While some solar thermal systems are suitable for use at home, there are also some that are suitable for businesses or organizations which normally requires a big amount of hot water like hotels, restaurants, schools, hospitals and many more. You’ll also find some types available in the market that are suitable for communities to satisfy communal hot water demands.

It should, however, be noted that solar thermal systems do not have the capacity to produce all the hot water demand of a house. In the UK, an average household will need an annual water heating of between 3000kWh to 5000kWh. Whereas, a solar thermal system is only able to meet about 40 percent to 60 percent of this demand.

With that in mind, it’s also worth noting that during the summer months when the solar radiation is at its peak and hot water demand is relatively lower when compared to other seasons, a solar thermal system may be able to provide all of your household’s hot water needs. This implies that during this period you may not find the need to operate your boiler at all. However, during winter or colder months, when you have a higher hot water demands in contrary to a lower solar radiation, a solar thermal system will only be able to take care of about 20 percent of your household’s hot water needs. And that ultimately implies that during this period, you’ll need to rely more on a alternative or backup source of heat like gas, coal, electricity, oil or LPG.