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Solar Heating
in general
Space heating with solar energy uses the same basic principles as solar water heating. It is best to involve Cedar Mountain Solar in the building process early so we can make suggestions and recommendations in building design and infrastructure planning that help the heating system use as little energy and deliver as much heat as possible.
We are happy to consult with architects, engineers, and contractors. We can use Energy-10, a computer simulator of the thermal performance of building envelopes using real local weather data, to evaluate the system requirements.
Solar heating is most appropriate for hydronic heating, wherein warm fluid is circulated through heating appliances thereby warming a room. Examples of hydronic heating systems include radiant floors, baseboards, and some air-handling units.
As different hydronic heating systems operate at different temperatures, solar collectors are used differently in different systems.
For example, radiant floor heating works well with fluid temperatures of up to 120 degrees F. Since solar collectors operate at or near that temperature, solar heated fluid can be fed directly into a radiant floor.
Baseboards, however, work best at higher temperatures, often 160-180 degrees F. In these cases, solar collectors are used as a pre-heater to a boiler. This approach reduces the fuel consumption of the boiler, as it is only required to make up the difference between collector temperature and ideal temperature. Some baseboards also function at lower temperatures, albeit at lower efficiencies.
Water tanks are used in some solar heating systems to provide thermal mass if the building construction lacks it. A well-insulated 2000 square foot heated area without mass floors, located in northern New Mexico, would typically require 300-400 gallons of water storage. This can consist of several smaller tanks plumbed together, or large un-pressurized tanks that are assembled on site.
SolarHeatingEconomics: top
Installation of a solar heating or domestic hot water system insulates the user from further increases in fossil fuel costs. When compared with heat derived from propane or electricity, solar heating systems have an aggressive return on investment. When replacing natural gas as an energy source, the return on investment is somewhat longer – for the time being. The wholesale cost of natural gas has tripled in the last three years. Production in the continental United States is already in decline by some reports, with more drilling rigs required each year to produce the same amount of fuel. , Due to these factors, we can expect the payback on solar installations to continually improve in the coming years.
When used in year-round applications such as pool heating or combined space and pool heating (using the same collectors to heat a home in winter and a pool in summer) a return on investment can be as short as 48 months. When a system is financed, it is possible for the energy savings to exceed the monthly payments, creating a net-profit situation. The installation of solar heating equipment can also increase the value of a home.
There are many different types of solar water heating systems. In Northern New Mexico, Cedar Mountain Solar designs and installs “closed-loop” active solar systems. In our experience, these systems provide the greatest degree of protection from damage to components by freezing, and they also work most efficiently from both heating and electrical perspectives.
A typical domestic hot water system ranges from $4,000 to $7,500. Cost depends on the existing infrastructure, the amount of water to be heated, and the type of collector installation. Collectors can be mounted on a flat or pitched roof, ground mounted on concrete pilings or footings, or wall-mounted vertically in some cases. The type of water-heating technology existing before the solar retrofit can affect the system cost as well, as some require replacement while others can fit easily into a new system design.
A solar space heating system has a much wider range of associated costs. These depend on all the factors above as well as on the size of the space to be heated, thermal characteristics of that space, and heating behavior of its occupants. Cedar Mountain Solar has supplied solar heating systems from $8,900 to over $70,000.
It should also be noted that another economic ideal is achieved through utilization of solar heating. In our current economic and energy models, the money we spend money on energy leaves New Mexico. Our utility is investor owned, and the leading owners are Hartford insurance firms, Wall Street investment firms, and other out-of-state entities. This means that the profit generated by energy sales does not remain in the community to be spent with local businesses and stimulate further economic development. By purchasing your energy from a locally owned company, you benefit the local economy for the long term.
System Environmental Benefits:
It is estimated by the EPA that installation of an 80-gallon solar water heating system in New Mexico can offset an average of 9,269 pounds of CO2 emissions, 26 pounds of Nox, and 26 pounds of SO2 per year, in addition to reducing particulate emissions and carbon monoxide release. These compounds are “greenhouse gases” associated with global warming, and they are also factors in acid rain, respiratory illness, higher asthma incidence, and host of other health issues.
The emissions reduced are equivalent to those produced by driving an average passenger car 11,586 miles per year. The amount of carbon dioxide NOT released as a result of using a solar water heater is equal to the CO2 absorption capacity of one acre of trees per year.
In short, using a modest-sized solar water heating system is comparable in ways to planting an acre of trees each year or to taking a passenger car at least partly off the road. These statistics may seem like drops in a bottomless bucket, but we must start somewhere. We have also observed a correlation between producing your own energy and feeling responsible for its use. Often after system installation, homeowners are much more conscientious about how they use energy, and they find more efficient and effective ways to manage consumption.