Commercial Solar Hot Water Energy
Let the Sun Heat Your Water
For many businesses and commercial buildings heating water is a huge energy load and major expense. Installing a thermal solar water heating system will save your business significant money, help protect the environment and show your customers your company's dedication to the environment and community. Regardless of your goals, Sunergy Systems engineering staff can design a system to offset to meet your company's needs. A typical commercial solar water heating system west of the Cascades can offset 90% of your hot water demands in the summer, 75% in the fall and spring and 50% in the winter.
Not only is solar water heating a great way of staving off increasing energy costs, commercial systems are eligible for a 30% federal tax credit off of the total system cost, plus it will be eligible for a 5 year accelerated MACRS. E xperts agree that a solar water heater is far and away the easiest initial investment in renewable energy.
How it Works
The collectors turn the sun's energy into heat, which is transferred to the water in either your building's hot water tank, or a dedicated solar hot water tank, via piping loops from the collectors. This loop is filled with bio-degradable antifreeze solution, which stays inside the collectors and piping at all times. Whenever the sun shines on the collectors, the circulating pump comes on and the solar fluid circulates within the closed loop. The fluid gets hot inside the collectors and travels through the piping to a heat exchanger inside the solar heated water which transfers the heat from the antifreeze water inside the storage tank, which stores the heated water for your use. When the sun is not shining, the circulating pump simply turns off and the fluid stops circulating.
Works on cloudy days and even when it is freezing outside
Because solar hot water collectors use the full spectrum of the sun, they efficiently absorb even the diffused solar radiation present on cloudy days. They do not need direct sunlight to operate and are not nearly as impacted by shading issues like solar electric modules are.
Types of Solar Hot Water Collectors
There are two popular kinds of solar water collectors, the traditional flat plate and the recently more common evacuated tube systems. E ach technology has its strengths and weaknesses; this is why Sunergy Systems is one of the few solar contractors in the region that carries both technologies. Because we are not biased you will receive an honest appraisal of your site. Our engineering staff will design your system with the most cost effective solution and then our installation team (with over 750 installed systems of experience) will install it on your building.
Flat-plate collectors are by far the most popular kind of collector and work well in all climates. They have been around the longest and are efficient and competitively priced. They are very aesthetically pleasing and look just like a skylight. They also operate precisely within the temperature range needed to heat domestic water, but are not well suited for many commercial high temperature water applications.
How Flat-Plate Collectors work
The collector is a shallow rectangular box with a glazed top and insulated back and sides. An absorber plate inside gathers solar heat and transfers it to a network of copper tubing, through which the solar fluid flows. Like evacuated tubes, they do work well on cloudy days, but will have more heat losses during cold conditions.
Evacuated Tube Collectors
Evacuated tube systems are a proven technology and have been widely available in Europe and Asia over the last decade and are finally making their way into the US market. Up until the last couple of years they have been significantly more expensive than flat-plate collectors; however, with prices coming down and copper prices going up they are now cost competitive with flat-plates. Evacuated tube collectors are appropriate for both high temperature applications over 140 degrees F and easily perform in residential low temperature applications. Since they are more efficient than flat-plate collectors they require less surface area. For commercial high temperature water applications, evacuated tube systems are the better choice.
How Evacuated Tubes work
Each tube and fin of the collector is contained within a glass tube from which all the air has been evacuated. The purpose of the evacuated tube is to provide a perfect insulator from heat losses to the outside temperatures and prevents any air from carrying heat from the hot surface of the tube to the cooler surface of the glass. The temperature inside the tube can reach temperatures of 350 degrees while the outside of the tube is cool to the touch and they are barely affected by outside temperature and weather conditions.
To minimize radiant heat loss, the tube is covered with a selective surface. The special coating absorbs more than 92% of the arriving radiation, but radiates less than 8% back to the environment. Heat transfer from the absorber to the fluid circuit is performed by the heat pipe. A heat pipe is a closed system, carefully evacuated and charged with a small amount of water before it is sealed. The absorber imparts heat to this water, causing it to evaporate. The steam rises to the upper end of the heat pipe where it transfers heat to the fluid circuit via a metallic conduction bridge.
The Sunergy Systems Difference
Sunergy Systems is one of the few solar contractors in the region that carries both flat-plate and evacuated tube technologies. Because we are not biased you will receive an honest appraisal of your site. Our engineering staff will design your system with the most cost effective solution and then our installation team (with over 750 installed systems of experience) will install it on your building.