Installing a solar hot water system can be one of the best things you can do for the environment, and also your hard earned cash. If I could only advise doing one thing to help you reduce your energy consumption, I would tell everyone to install a solar hot water system. For financial reasons, you are more likely to save money by installing a solar hot water system guaranteed. There is a lot more to consider when installing a solar energy system.
There are a few types of solar hot water systems on the market, and there is not a ‘one size fits all’ solution. Spend the time to educate yourself, so you can get the best system for your family’s requirements. The 2 most common systems are a split system, or a thermosiphon (also known as a roof mounted system).
Everyone’s requirements are different, and there are lots of differently designed systems, due to accommodating climate conditions, poor water quality and everyone’s individual usage.
If considering going off grid for your energy needs, installing a solar hot water system is a must because heating water with electricity is a huge calculation to add to your solar energy system.
Depending on your climate will depend on what type of system you will want to install. If you live in a warmer climate, a roof mounted system will be the most common, whereas in a milder climate you could get away with a roof mounted or a split system, and in a colder climate, a split system is a must. Then, you will have different types of collectors. There are 3 types of collectors- flat plate, evacuated tubes, and then there another type of evacuated tube which is out of this world. I will keep this article to the two most commercially available units.
Solar system hot water or energy works on its ability to have the right angle of the sun, which is a 45 degree angle- your latitude will depend on the angle your solar collectors will want to be mounted. Also, depending on the time of year you would like your system to perform at its peak, will depend on the angle. Most systems are installed to give an overall performance.
Flat plate collectors are normally installed in hotter climates, and the evacuated tubes are installed in colder climates. The evacuated tubes collect the sun's energy at different angles all day long, due to the round design which allows it to pick up the desired angles and give a better performance in colder climates.
Roof mounted, or thermosiphon systems, are installed in hotter climates as the tank is fine to be exposed to the warmer ambient air temperatures. A split system is installed in colder climates, as you capture the heat from the collector and store it in the split system tank. If possible, you would want the split system tank installed inside, out of the effects of the colder temperatures of your environment. The warmer your storage tank can be kept, the less you will rely on using electrical energy or gas to boost your hot water needs.
Your access to gas or electricity is what you will use to boost your hot water temperatures.
An electrically boosted system will have a heating element in the tank, and it is always a good idea to have control over when it comes on and off- or have it on a timer. If it works on a thermostat, it will want to keep the water temperature at set temperatures all the time, this will waste energy and cost you money. The set temperature can also waste energy as the hotter the set temperature, the more energy will be required to heat your water. It is a waste of energy to heat water up to 70-80 degrees, and then add cold water to reduce it back down to 40-50 degrees, which is what most of us find comfortable in the shower. For an experiment, check the temperature of your hot water next time you have a shower. If you like hotter water whilst washing the dishes, you will save energy by boiling the kettle or using the gas stove to generate hotter water. Most of us let the dishwasher wash up, which has a heating element in it anyway.
A gas boosted system will have a gas booster separate to the storage tank, when the water leaves the tank it will go through the booster. If the water from the tank is not at the desired temperature set on your gas booster thermostat, it will heat the water up to the desired temperature. For example, if the water in the tank is only 40 degrees, and you want it 45 degrees, the booster will heat it to that temperature. The higher the temperature from the tank, the less boosting is required, which will save you energy and in turn, it will save you money.
Currently, my personal system is a split system with a gas booster. We are installing a fire place with a wetback, which will heat the water from our fire place in the colder months. This will make our fireplace more energy efficient, as we will be using the heat created to heat our home and our hot water, therefore very rarely will we use the gas booster. It will come into play on the odd day that we have had little solar production and it’s just not cold enough to light a fire.
Thinking about designing your home to be self-reliant on energy will be the best way to save money in the long run. You will get creative on how to get a higher yield out of an energy source. An example is with the fire place- it heats our home, our hot water and it has an oven compartment in it which we use to cook in. All from the same amount of energy we once used just to heat the home, we are getting a higher yield from that source of energy.
Planning and education is the key.