How They Work
Solar water heating systems are comprised of solar collectors and storage tanks. There are two types of solar water heating systems:
Active - have circulating controls and pumps which transfer the water from the collector to the storage tank
Passive – have no moving parts and work based on the principle of convection (cold water sinks and water rises)
Most solar water heaters require the use of a well-insulated storage tank. Solar storage tanks have an additional inlet and outlet connected to and from the collector. In the two-tank systems, the solar water heater pre-heats the water before it enters the conventional water heater. In the one-tank system, the back-up heater is used in conjunction with the solar storage in one tank.
Solar Hot Water
Advantages and benefits of using a solar hot water heater
Harnessing the sun’s power as a renewable source of energy is gaining in popularity globally. In the US alone, there are currently over 300,000 solar hot water heaters in operation and that number is growing all the time. Here are the primary reasons behind their ever-growing popularity:
-Adds value to your home
-Environmentally-friendly (make a difference by helping to reduce greenhouse gas emissions and your dependency on your electric or gas water heater)
-Extends the expected life of your residential hot water tank by dramatically reducing scaling
-Qualifies for the 30% Federal tax credit
-Solar energy is cost-effective and enables you to reduce your energy bills(using a solar hot water heater saves the homeowner up to 50% in hot water heating costs)
-Solar hot water heaters can be used in any climate
-The sun is an available and renewable energy source
Solar hot water heaters are efficient, reliable, and safe. Most importantly, they do not pollute the environment. Other key considerations include having direct control over the system. Additionally, and unlike conventional hot water heaters, you will always have hot water even when there is a power outage.
A Closer Look at the Solar Water Heating System
Today when someone says “solar” most people are immediately thinking of solar electricity – meaning solar panels that make electricity. But the oldest and most widely used solar technology is to heat water. Solar Water Heating (SWH), as it is commonly referred to, includes all the advantages of traditional water heaters but simply uses the sun to heat the water instead of propane or electricity or natural gas. Since the heat comes from the sun, your solar heats water without the energy cost associated with standard tank or even tankless heaters. What this means for Sacramento solar home owners is that there are immediate returns on monthly utility bills; plus there are federal tax credits and in some cases utility rebates for solar water heating.
Solar hot water technology, also technically referred to as Solar Domestic Hot Water (SDHW), utilizes collectors that have enclosed copper tubing, behind hard tempered glass and an insulated container that are designed to quickly heat a tank of 40 to 80 gallons of water to be used for your laundry, kitchen or bath. The concept basically uses a tank similar as the tank style water heater you already have, but the SDHW tank (or solar tank) is specially fitted to be connected to the solar collectors. The design can also be adapted to commercial and industrial use for larger quantities in facilities or apartments of commercial size. We can simply add more collectors and a large scale tank to meet the amount of hot water the facility uses. So whether for home or hotel, there is a solar hot water solution that fits your needs.
In addition to the solar collector, the other components to a solar hot water system are a water tank and a circulating pump. The solar tank is typically placed in the same location of the existing water heater of the home or building, but it can be relocated to another space if the proper access for the unit is available. As the sun hits the solar collector, a special food grade oil is super-heated while it is in the copper of the collector. The circulation pump moves the heated solution down to a coil of tubes that are submerged within the water in the SDHW tank. The heat in the submerged tubes is transferred into the water you are going to use. Then the oil, having transferred its heat to the water, goes back up to the solar collector to be reheated by the sun again. The food grade oil continues to make that circulation during the day, constantly heating the water to make sure it gets to the proper temperature for your laundry, kitchen, and bath use. This hot water in the insulated solar tank can then be used immediately or will be held in the insulated tank until you’re ready to use it. Solar tanks also have back-up heating elements to ensure your hot water will be available even during cloudy periods. During the days in which the solar is not producing as much energy as is needed to heat the water by solar alone, the backup heating element automatically detects this and makes sure the water is hot. The good news is that in our area, backup heating elements are typically only used several months of the year, which means that the solar heats the majority of your water all year long. The result is 60% annual savings or more for your solar versus a regular water heater.
Depending on budgetary concerns, needs, and location, there are various types of collectors and solar tanks that are available to choose from. Our trained Design Specialist for SDHW is an expert that will guide you through the options that are right for you.
For homeowners using Propane or Electric Water Heaters, the monthly savings on your water heater bill by using solar is significant. The Return On Investment (ROI) for solar water heating includes using the 30% Federal Tax Credit combined with the annual energy (propane or electricity) savings, plus in some cases utility rebates. The ROI for a home that converts a propane or electric water heater to a solar water heater is outstanding, it’s really a smart improvement that quickly pays for itself. The savings continue well beyond the payback period for a couple decades of trouble free performance.
For homeowners using a natural gas water heater, the low price of natural gas from PG&E typically makes the ROI for a solar water heating system quite a bit longer. PG&E gas customers qualify for generous rebates (about $2000 depending on the location) plus qualify for a 30% Federal Tax Credit. But since the price of natural gas is so low and a standard tank water heater does not use a large amount of gas, the investment for SDHW takes longer for the homeowner to see a return. However, the emissions coming out of the flu from a standard gas water heater add up significantly over the years. If you’re interested in doing something the reduces the amount of carbon your home emits, converting to a solar water heating system is a product that can have the biggest impact.
Because solar heated water is reliable, it is like an appliance that adds value to your home, and because it saves users so much money over the long run, it is undoubtedly a smart investment in the future. Considering that over the long run, energy prices go up, solar technology is a hedge against rising fuel costs of all types.
Simply put, solar water heating gives you the peace of mind that you will have a reliable water heating source that also saves you money, and increases the value of your home. Ask us about a free estimate for solar water heating to start using the sun’s amazing power to heat your water!
Tankless Water Heating: Considering tankless water heaters as an option? Sierra Pacific can install a tankless water heater for you as well. Visit our page for tankless here.
OnCommand Recirculation Pumps: Does it seem like you pour hundreds of gallons of water down the drain while you wait for the hot water to come out? A recirculation pump can be the perfect answer. Learn more about OnCommand recirculation pumps here.