Solar water heating systems combine several technologies for collecting the sun’s rays, heating the water, and then storing it until it’s ready for use. Since energy from the sun is free, the solar-savvy homeowner only has to pay for the services of HVAC specialists or solar specialists in and near Sacramento and for the water heating system itself.
After the purchase and installation, the functioning system is entirely free to use. A solar heater will work for most of the year, but can slow down in the winter when days are much shorter. If this natural slowing casts hardship on the household, gas or electric water heating can help bridge the gap during these months. If your climate doesn’t have a winter season to speak of, solar heaters might slow a bit on cloudy days. However, these systems store have the option to store surplus energy in rechargeable batteries, which compensates for days with less direct sunlight. Overall though, your solar water heating system should meet all of your solar needs.
How Solar Water Heating Systems Work
Your heating system will consist of two parts: a storage tank for water and solar collectors for the sun’s energy. There are two general types of water heating systems that use solar power, known as direct and indirect systems.
- A direct system will circulate water through solar collectors. The collectors are large panels that collect the energy of the sun.
- An indirect system will heat your household water by mixing it first in a reservoir with fluid that has already been heated by the collector. This heat transfer fluid is usually water but can also be a mixture of water and antifreeze mixed together. The antifreeze is propylene glycol which is non-toxic. Because of this process, indirect systems offer protection from freezing in the winter. However, indirect systems tend to be more expensive.
Active and Passive Systems
- Passive systems cost less because they use naturally occurring heat convection to circulate water through the system. These are great for places with no winter because they can be efficient for long periods without needing maintenance. If your region experiences freezing temperatures, however, the passive system may not be for you, as it can freeze or overheat in extreme weather.
- The active system uses a pump to circulate water rather than convection. Again, the relative complexity of this system in comparison to a passive one means that they can cost more.
Photovoltaic Solar Panels
Photovoltaic solar panels are used in photovoltaic systems (or PV systems) to collect the sun’s energy to convert to electrical energy. The direct current produced by the PV system can then be used for a variety of applications in addition to heating water. PV systems produce the highest energy yields, but you will need a converter to produce DC power. Several solar panels are often linked together to create a photovoltaic array to be able to collect enough solar energy for use in the household. A panel can produce 100 to 400 watts, depending on cloud cover.
Solar heating is more popular in Europe and Asia than it is in the United States. Israel is the first country to require new homes to install solar powered water heaters and today 85% of households use them, saving the country 3% in total energy costs. Considering the variety of systems available for household use, your local solar specialists would like to help you help Sacramento become a similarly green-powered area.