Open Loop Geothermal Heating and Cooling Systems
Open loop geothermal heating and cooling systems use either a surface or underground water source as a heat source in the winter and a heat sink in the summer.
Conventional air source heat pumps and air conditioners must use air as the heat source or sink. The outside air temperature is high in the summer and low in the winter, which is counter-productive to cooling and heating respectively.
This is why geothermal systems operate so much more efficiently than air source systems. Depending on location the temperature of ground water is typically 45 to 55 degrees Fahrenheit and stays stable throughout the year making it a great heat sink in the summer and a good heat source in the winter. Additionally, water has a heat capacity 4 times that of air, so not as much volume is needed to provide the heating or cooling needed as with an air source system.
Open loop systems tend to be slightly more economical than closed loop geothermal systems because they typically require less drilling, excavating, and pipe work, especially if an existing well is used for the open loop. Open loop systems also operate a little more efficiently than closed loop systems. Open loop systems do require periodic cleaning and maintenance that costs more than the maintenance on a closed loop system, but usually open loops are more economical overall even with the maintenance factored in.
Sources of Water for Open Loop Systems
Typical water sources include wells, ponds, lakes, rivers, etc. In many areas use of surface water is prohibited or requires an extensive and costly permitting process, so wells tend to be the most common water source.
As a rule of thumb most systems require around 2.0 gpm per ton (12,000 Btu/hr) of heating or cooling required, whichever is higher. This requirement can vary from 1.5 to 3.0 gpm per ton depending on water temperature, heat pump efficiency, and design conditions. It is important that there is enough water available annually at the site to achieve the required flow rates and to take into account any anticipated changes to either the system size or the water supply.
Some jurisdictions have a limit on ground water usage that may be prohibitive to installing an open loop geothermal system, but in cases where the limit is only marginally exceeded a pressure tank can be installed to boost flow rates during times of peak flow. Many heat pumps have multiple stages or are modulating, so the peak flow rate is only required when the system is operating at 100%, which only happens occasionally in a staged system.
Water quality is also an important factor when evaluating a source for an open loop system. Water that is very alkaline or full of minerals can cause heavy scaling on the heat exchanger, leading to increasingly poor performance over time. Some scaling is expected for most systems and can be removed every 1 to 3 years using an acid wash. This periodic maintenance has to be performed by a qualified technician because specialized pumps and strong acid are involved. If the water PH is less than 7.5 and contains less than 100 ppm calcium descaling can be performed less often or not at all.
In addition to a water source there also needs to be a place to discharge the water. Typically this is accomplished by drilling an additional well for discharge only. In some instances the water can be discharged into a lake, pond, or river or even used as irrigation water. The possibilities will depend on the water regulations for the area.
When dealing with local or regional water regulatory agencies it can be helpful to remind them that open loop geothermal systems are non-consumptive, meaning they don’t deplete the water supply used if the supply and discharge come from the same source. They do, however, change the temperature of the water which could be of concern for fragile ecosystems that may inhabit the water source. This is not a concern for underground water sources, but may come into play for surface water sources.
Reliability
Geothermal heating and cooling systems tend to be more reliable than conventional heat pumps and air conditioners. This is because the heat pump itself is located indoors and is exposed only to water of a known and consistent quality. Traditional systems are always at least partially exposed to the outside elements, so compressors go out more regularly and the heat exchanger coils are subject to harmful corrosion. Most equipment carries at least a 10 year warranty. In an open loop system the water loop is just as reliable as your domestic water well. The only things that can go wrong are the pump breaking down (easily replaceable) or the well drying up.
Equipment Manufacturers and Performance Rating
Open loop geothermal systems use the same heat pumps as closed loop geothermal systems and can be adapted to both residential and commercial applications. A selection of heat pump manufacturers offering both residential and commercial products is shown below:
• ClimateMaster
• Florida Heat Pump
• GeoComfort
• Econar
• Water Furnace
Geothermal heat pumps are subject to standardized testing to determine heating and cooling performance. For cooling heat pumps receive an EER (energy efficiency ratio) in the units BTUs Out/Watts In. For heating the COP (coefficient of performance) is specified and is a unitless value (Watts Out/Watts In). To receive an EnergyStar rating (required for federal incentives) a heat pump must meet requirements set by the EPA and DOE. To view the requirements currently in place and new requirements for 2011 click here.
Costs and Financial Incentives
Although a geothermal heating system costs more initially than a traditional system there are many incentives available to subsidize the initial cost of installing a geothermal heating and cooling system. The federal government offers a 30% tax credit with no maximum for residential heat pumps installed after 2008. Just make sure the heat pump you decide on meets the minimum qualifications for the EnergyStar program.
There are also state and/or local incentive programs that may be available in your area. To find out which rebates or incentives you qualify for visit: http://www.dsireusa.org/ and click on your state.
With the combination of incentives and lower monthly heating and cooling costs most systems pay for themselves in 3-7 years.
Taking the Next Step
Geothermal systems can be retrofitted to existing buildings or integrated into new construction. Each system is unique in many ways and requires attention to design details that can only be provided by an experienced designer.
A geothermal system can use an open well water loop, an open surface water loop, a closed vertical, horizontal or slinky loop, or a closed loop submerged in a pond. Inside the house the system can heat and cool using forced air, radiant heating, or a combination of the two. It can also provide some or all of the domestic water heating required for a building. Each building and site have their own requirements and considerations that must be taken into account when designing a geothermal system.
If you’re ready to see what a geothermal heating system could do for your home or business visit Energy-1 for experienced advice from initial concept development and design through installation and post-installation sevices.
Tuesday, January 4, 2011
Tuesday, February 9, 2010
Fuel Cell Applications
A fuel cell is a device used to create electricity using Ultra Pure Hydrogen producing water and heat as byproducts. Due to the difficulty of storage and transportation of hydrogen the market demand has been shifted to adapt to natural gas as a fuel source. The down side of using fossil fuels is the CO2 byproduct, however compared to competing technologies (ie: traditional generators), fuel cells emit dramatically less green house gases. Fuel cells also have the advantage of having no moving parts in the fuel cell stack, so there is less maintenance required and greater reliability. Lastly, fuel cells are more efficient than traditional generators, meaning it costs remarkably less to make more electricity giving the user a quicker payback on initial investment. The best generators powered by internal combustion engines produce electricity with a staggering 20% peak efficiency. Fuel cells produce electricity at 60% efficiency which is 3 times more productive than the top of the line generator. When combining heat and power technology fuel cells can be up to 90% efficient.
Combined Heat and Power (CHP)
The most promising fuel cell technology for residential and small commercial applications is combined heat and power or CHP. A CHP Fuel Cell captures the heat that fuel cells create and uses it to heat your home, water, swimming pool, etc. So not only can you supply your electricity, you can also supply heat using the same piece of equipment. Residential fuel cells for CHP applications typically have electrical outputs of around 5kW and can produce enough heat to cover the demand of a large residence.
CHP Fuel Cells operate as long as there is a need for heat, so large homes in cooler climates are the most well-suited applications. Other prime candidates include homes with heated pools or hot tubs, where the heat generated can be used to heat the water. Fuel cells can also be used to make sure you always have power to critical electronics or refrigeration needs that you may have. This is of great concern in areas where grid power is unreliable and inconsistent.
How Do Fuel Cells Work?
In short there are three phases. In the first phase of a fuel cell Natural Gas is converted into an Ultra Pure Hydrogen with a carbon dioxide byproduct.
The second phase converts the hydrogen into usable energy. The hydrogen is split using a catalyst into protons and electrons. The hydrogen protons travel through the PEM membrane and join oxygen molecules on the other side to create water.
The electrons cannot travel through the membrane and are forced to travel around the membrane through an electric circuit. These electrons traveling through the circuit create DC electricity.
The final phase converts the DC electricity into a 110 AC power thru a process using an inverter. Inverters are also used in solar electric and wind applications.
Using a fuel cell that operates on natural gas will yield an electricity cost of about $.06 per kWh while power from the utility company costs about $.12 per kWh. The savings coupled with the Government tax credits help to offset the initial cost of purchasing a fuel cell.
They are proven in commercial applications, but what about residential?
In the United States fuel cells in the 1 to 10 kW range are an emerging market. Currently there are few options available to the general consumer, but rapid development is underway. It looks like the first fuel cells to become more widely available in the US are PEM fuel cells. PEM fuel cells operate on natural gas with electrical conversion efficiencies in the 30 to 40% range. Their total efficiencies with heat recovery can be up to about 90%. There seem to be three major companies that are leading the way in the US for residential fuel cells. Clear Edge and Plug Power both have fuel cells operating in the field, but availability seems to be limited.
http://www.clearedgepower.com/
http://www.bloomenergy.com/
http://www.plugpower.com/
Closely following the PEM cells will be solid oxide fuel cells. This type of cell has more fuel flexibility and can be configured to run on LPG (propane) as well as natural gas. SOFCs can have up to around 60% electrical conversion efficiency, but the total efficiency is still about 90% when used in a CHP configuration.
For updates on residential fuel cell applications stay tuned to the blog. If you have questions about fuel cells or other alternative energy solutions for your home or business don't hesitate to contact Energy-1.
A fuel cell is a device used to create electricity using Ultra Pure Hydrogen producing water and heat as byproducts. Due to the difficulty of storage and transportation of hydrogen the market demand has been shifted to adapt to natural gas as a fuel source. The down side of using fossil fuels is the CO2 byproduct, however compared to competing technologies (ie: traditional generators), fuel cells emit dramatically less green house gases. Fuel cells also have the advantage of having no moving parts in the fuel cell stack, so there is less maintenance required and greater reliability. Lastly, fuel cells are more efficient than traditional generators, meaning it costs remarkably less to make more electricity giving the user a quicker payback on initial investment. The best generators powered by internal combustion engines produce electricity with a staggering 20% peak efficiency. Fuel cells produce electricity at 60% efficiency which is 3 times more productive than the top of the line generator. When combining heat and power technology fuel cells can be up to 90% efficient.
Combined Heat and Power (CHP)
The most promising fuel cell technology for residential and small commercial applications is combined heat and power or CHP. A CHP Fuel Cell captures the heat that fuel cells create and uses it to heat your home, water, swimming pool, etc. So not only can you supply your electricity, you can also supply heat using the same piece of equipment. Residential fuel cells for CHP applications typically have electrical outputs of around 5kW and can produce enough heat to cover the demand of a large residence.
CHP Fuel Cells operate as long as there is a need for heat, so large homes in cooler climates are the most well-suited applications. Other prime candidates include homes with heated pools or hot tubs, where the heat generated can be used to heat the water. Fuel cells can also be used to make sure you always have power to critical electronics or refrigeration needs that you may have. This is of great concern in areas where grid power is unreliable and inconsistent.
How Do Fuel Cells Work?
In short there are three phases. In the first phase of a fuel cell Natural Gas is converted into an Ultra Pure Hydrogen with a carbon dioxide byproduct.
The second phase converts the hydrogen into usable energy. The hydrogen is split using a catalyst into protons and electrons. The hydrogen protons travel through the PEM membrane and join oxygen molecules on the other side to create water.
The electrons cannot travel through the membrane and are forced to travel around the membrane through an electric circuit. These electrons traveling through the circuit create DC electricity.
The final phase converts the DC electricity into a 110 AC power thru a process using an inverter. Inverters are also used in solar electric and wind applications.
Using a fuel cell that operates on natural gas will yield an electricity cost of about $.06 per kWh while power from the utility company costs about $.12 per kWh. The savings coupled with the Government tax credits help to offset the initial cost of purchasing a fuel cell.
They are proven in commercial applications, but what about residential?
In the United States fuel cells in the 1 to 10 kW range are an emerging market. Currently there are few options available to the general consumer, but rapid development is underway. It looks like the first fuel cells to become more widely available in the US are PEM fuel cells. PEM fuel cells operate on natural gas with electrical conversion efficiencies in the 30 to 40% range. Their total efficiencies with heat recovery can be up to about 90%. There seem to be three major companies that are leading the way in the US for residential fuel cells. Clear Edge and Plug Power both have fuel cells operating in the field, but availability seems to be limited.
http://www.clearedgepower.com/
http://www.bloomenergy.com/
http://www.plugpower.com/
Closely following the PEM cells will be solid oxide fuel cells. This type of cell has more fuel flexibility and can be configured to run on LPG (propane) as well as natural gas. SOFCs can have up to around 60% electrical conversion efficiency, but the total efficiency is still about 90% when used in a CHP configuration.
For updates on residential fuel cell applications stay tuned to the blog. If you have questions about fuel cells or other alternative energy solutions for your home or business don't hesitate to contact Energy-1.
Friday, January 8, 2010
Ground Source Heat Pumps
What is a ground source heat pump?
Ground source heat pumps (GSHPs) are electrically powered systems that tap the stored energy of the greatest solar collector in existence: the earth. These systems use the earth's relatively constant temperature to provide heating, cooling, and hot water for homes and commercial buildings.
How do ground source heat pumps work?
Ground source heat pumps can be categorized as having closed or open loops, and those loops can be installed in three ways: horizontally, vertically, or in a pond/lake. The type chosen depends on the available land areas and the soil and rock type at the installation site. These factors will help determine the most economical choice for installation of the ground loop.
For closed loop systems, water or antifreeze solution is circulated through plastic pipes buried beneath the earth's surface. During the winter, the fluid collects heat from the earth and carries it through the system and into the building. During the summer, the system reverses itself to cool the building by pulling heat from the building, carrying it through the system and placing it in the ground. This process creates free hot water in the summer and delivers substantial hot water savings in the winter.
Ground source heat pumps (GSHPs) are electrically powered systems that tap the stored energy of the greatest solar collector in existence: the earth. These systems use the earth's relatively constant temperature to provide heating, cooling, and hot water for homes and commercial buildings.
How do ground source heat pumps work?
Ground source heat pumps can be categorized as having closed or open loops, and those loops can be installed in three ways: horizontally, vertically, or in a pond/lake. The type chosen depends on the available land areas and the soil and rock type at the installation site. These factors will help determine the most economical choice for installation of the ground loop.
For closed loop systems, water or antifreeze solution is circulated through plastic pipes buried beneath the earth's surface. During the winter, the fluid collects heat from the earth and carries it through the system and into the building. During the summer, the system reverses itself to cool the building by pulling heat from the building, carrying it through the system and placing it in the ground. This process creates free hot water in the summer and delivers substantial hot water savings in the winter.
GSHPs are a cost effective, energy efficient, and environmentally friendly way of heating and cooling buildings. Both the DOE and the EPA have endorsed the technology. GSHPs reliably deliver quality air-conditioning and heating, on demand, in every season. GSHPs are appropriate for new construction as well as retrofits of older buildings. Their flexible design requirements make them a good choice for schools, high-rises, government buildings, apartments, and restaurants--almost any commercial property. Lower operating and maintenance costs, durability, and energy conservation make Ground Source Heat Pumps the smart choice for commercial applications.
Ground Source Heat Pumps offer great benefits:
Simultaneously heat & cool different parts of the same building
Very quiet--users do not know when the system is operating
Can be set up in multiple zones, with each zone having an individual room control
Greater freedoms in building design due to 50-80% less mechanical room space
No outside equipment to hide, eliminating vandalism and roof top units
Pipes have 50-year life expectancy
All electric, which eliminates multiple utility services
Expel boiler and chiller maintenance
Ground heat exchanger is maintenance free and will last 40+ years
GSHPs offer great savings:
Very competitive on initial costs and lower lifecycle costs than most HVAC systems.
Savings of 25-50% on energy consumption in new construction
Lower peak demand, lowering your operating costs
Water heated with waste heat from air conditioning at no cost in the summer and at substantial savings in the winter
Some utilities offer rebates or incentives to their customers who purchase GSHPs.
Ground Source Heat Pumps offer great benefits:
Simultaneously heat & cool different parts of the same building
Very quiet--users do not know when the system is operating
Can be set up in multiple zones, with each zone having an individual room control
Greater freedoms in building design due to 50-80% less mechanical room space
No outside equipment to hide, eliminating vandalism and roof top units
Pipes have 50-year life expectancy
All electric, which eliminates multiple utility services
Expel boiler and chiller maintenance
Ground heat exchanger is maintenance free and will last 40+ years
GSHPs offer great savings:
Very competitive on initial costs and lower lifecycle costs than most HVAC systems.
Savings of 25-50% on energy consumption in new construction
Lower peak demand, lowering your operating costs
Water heated with waste heat from air conditioning at no cost in the summer and at substantial savings in the winter
Some utilities offer rebates or incentives to their customers who purchase GSHPs.
The above information was derived from the IGSHPA (International Ground Source Heat Pump Association). In the next few weeks we will discuss the different methods of GSHP and a few examples of Hybrid systems (combining GSHP with other mechanical systems). For additional information regarding GSHPs please contact Energy 1.
Tuesday, December 22, 2009
Photovoltaics (Solar Panels)
Solar Panels or Photovoltaics have the ability to harness the suns immense energy and convert it into electricity. This is most commonly achieved by using cells manufactured using one of several types of silicon. These cells are arranged in panels which are then in turn arranged together in groups referred to as strings or arrays. These arrays are placed together to gain the optimal balance between space and sizing for a desired output. The largest photovoltaic plant in the world can generate up to 60 megawatts of electricity, or enough to electricity to supply the demand of 40,000 homes. Yet the smallest systems power your standard hand held calculator. The possibilities are truly endless.
Many have found that solar panels can be the ideal option for providing power to homes or businesses. A system can be sized to provide all of your electrical requirements or desired portion. Generating your own energy can also provide the security of knowing you will not be without power when the grid goes down, and it is less wasteful and harmful to the environment than using energy from the utility company. An additional benefit is once the initial investment is paid back your electricity is produced at no cost. Many people chose to add solar panels as a statement rather than an investment. Whatever your interest may be photovoltaics may be your solution. So what are some things to consider when pondering using photovoltaics? Let’s look at the installation of a system on a residence to get an idea of the process.
First, there are several options regarding the type of system you may choose to install. The three main types are grid-tied (connected to your local utility), independent or a grid-tie with battery backup.
Grid-tied systems make up the majority of installations. These systems feed energy to the home first, and whatever the house doesn’t use goes back into the electrical grid. When the panels are not producing energy the home is powered by electricity from the utility company. For this system to work, the utility company that supplies the house must provide net metering. Net metering means that the power meter for the house literally runs backwards when it’s being supplied by the solar panels. This allows the owner of the house to save on the monthly power bill. This type of system also uses the least equipment, so it results in the quickest payoff of your investment.
An independent system is completely local with no connection to the grid. This type of system requires storage of the energy generated by the panels for use when the sun is not shining. This is usually done using batteries. Batteries are an expensive addition to the system, so candidates for an independent system are usually those that are in mountainous or remote areas that are far away from utility lines. The high cost of connecting such homes to grid power makes the cost of batteries very reasonable in comparison.
Lastly, it’s possible to have a grid-connected system that also has battery storage to provide electricity in the event of a power outage. Such a system would be a luxury for most home-owners and would not be worth the extra cost financially speaking, but for some the added security of knowing you will never be without power is worth it.
The next decision to make is to choose the optimal panel and desired mounting location. Panels that double as roof tiles are available for a truly integrated look, but the more economical option for retrofit applications would be separate panels that you can mount on the roof or at a remote location a little ways away from the house. For a sloped rooftop installation you will want to use the portion of the roof that faces south for the best efficiency from the panels (if you’re in the northern hemisphere that is). The optimum angle for the solar panels varies with the latitude of the location, but oftentimes it would require additional mounting hardware to achieve this angle. In some cases the best option is to mount the panels directly on the roof. Many sloped roofs are close enough to the optimum angle that not much efficiency is lost by mounting the panels at the same angle. If the roof is flat, however, it is better to use frames that provide for the optimum angle of tilt. For the best efficiency and most power output a solar tracking mount can adjust the panel to the optimum angle of tilt and rotation (for a dual-axis tracker) or just the best angle of tilt (single-axis tracker). Remote installations can use either a fixed mount or a tracker as well.
With the type of system and type of panel chosen it’s time to move on to the other required equipment. The electrical current that a PV panel generates is DC (direct current). Most modern household appliances and electrical accessories are designed to run on AC (alternating current) power. To switch the power from DC to AC an inverter is needed. Depending on the system, other components include batteries, AC and DC switches, a charge controller, and various other miscellaneous parts.
Although photovoltaics can seem rather expensive to purchase and install, incentives are available that can help to subsidize the initial costs resulting in reasonably short payoffs in many cases. Most installations will require a knowledgeable engineer to perform a site analysis, feasibility study, and design of the system as well as a licensed electrician to install the system. An improper installation can cut your panels ability to produce electricity. The shadow of an exhaust pipe can lower your output by as much as 50% on a roof mounted system. Energy-1 can provide all of the above and answer any other questions you may have about photovoltaics or any other renewable energy solution for your home or business.
Photovoltaics can be a great way to provide your house with electricity, but what about heating and cooling? Check back in a week or so for the basics of geothermal heating and cooling.
Thursday, December 3, 2009
HOW SOLAR THERMAL PANELS WORK
Solar Thermal
Over the coming weeks I’ll be discussing a number of renewable energy technologies that can be applied to your home or business in order to save on energy costs and reduce the carbon footprint of your building. The topic for next two weeks will be solar power. When most people think of solar power they think of photovoltaic panels that turn energy from the sun directly into electricity. We’ll be going over that next week. What we’re looking at today is solar thermal energy.
What is Solar Thermal Energy?
Solar thermal energy refers to the process of using the sun’s energy to heat something up. The heat can be used to provide hot water for residential or commercial use, space heating using radiant floors or panels, or converted to electrical power via a turbine. The focus of this entry will be solar thermal for hot water and space heating because these topics are of the most interest to a building owner looking to incorporate some renewable energy.
What goes into a solar hot water system?
A solar hot water system uses a solar collector that heats a fluid which is either used directly (if the fluid is water) or is used in a heat exchanger to heat water. Water can generally only be used in warm climates where freezing is not a worry. In these situations a flat plate collector is used. The flat plate collector is basically an insulated box with a clear glass or plastic top that has a dark colored copper or aluminum absorber plate connected to a series of pipes that water flows through. The sun heats up the absorber plate which heats up the water pipes and the water itself, while the box prevents heat from escaping to the environment. A flat plate system with water as the fluid can be used to heat a pool or to provide domestic hot water for the home.
In cooler climates a solar thermal system can still be very effective, but a different fluid is needed to prevent freezing. Generally a mixture of glycol and water is used. This fluid can be used in flat plate collectors, or evacuated tube collectors. Evacuated tube collectors have one larger tube with a smaller tube inside of it in which there is a fluid. The space between the tubes is vacuum-sealed to provide near-perfect insulation, so the radiant energy heats the fluid and the heat cannot escape. The heated fluid rises to a manifold at the top of the tubes through which the glycol mixture is being pumped. The heat from the fluid inside the tubes is transferred to the glycol mixture. The glycol then goes through another heat exchanger that heats pure water.
The water that is heated can be used directly for domestic or commercial use, or it can be used to heat your home using radiant floor heating, radiant panels, or a forced air system. Regardless of the use, a system usually incorporates a pump, one or more heat exchangers, and a tank to store hot water. Specification of the components and layout of the system should be performed by a qualified Mechanical, Electrical, and Plumbing Engineer.
Images courtesy of the U.S. DOE: http://www1.eere.energy.gov/solar/sh_basics_collectors.html
How long will it take to pay for itself?
Generally solar thermal collectors are cheaper to buy and install than photovoltaic panels, but a detailed technical and economical analysis is needed to determine how long it will take for energy savings to exceed installation costs. Some things to take into account are:
· The solar resources available which depends on latitude, local climate, cloud cover, and shading.
· The efficiency of the solar collector which depends on the collector itself, the fluid to be used, orientation, and placement.
· Cost of equipment purchase and installation.
· Incentives that may be available through federal, state, and local governments as well as utility companies.
What is Solar Thermal Energy?
Solar thermal energy refers to the process of using the sun’s energy to heat something up. The heat can be used to provide hot water for residential or commercial use, space heating using radiant floors or panels, or converted to electrical power via a turbine. The focus of this entry will be solar thermal for hot water and space heating because these topics are of the most interest to a building owner looking to incorporate some renewable energy.
What goes into a solar hot water system?
A solar hot water system uses a solar collector that heats a fluid which is either used directly (if the fluid is water) or is used in a heat exchanger to heat water. Water can generally only be used in warm climates where freezing is not a worry. In these situations a flat plate collector is used. The flat plate collector is basically an insulated box with a clear glass or plastic top that has a dark colored copper or aluminum absorber plate connected to a series of pipes that water flows through. The sun heats up the absorber plate which heats up the water pipes and the water itself, while the box prevents heat from escaping to the environment. A flat plate system with water as the fluid can be used to heat a pool or to provide domestic hot water for the home.
In cooler climates a solar thermal system can still be very effective, but a different fluid is needed to prevent freezing. Generally a mixture of glycol and water is used. This fluid can be used in flat plate collectors, or evacuated tube collectors. Evacuated tube collectors have one larger tube with a smaller tube inside of it in which there is a fluid. The space between the tubes is vacuum-sealed to provide near-perfect insulation, so the radiant energy heats the fluid and the heat cannot escape. The heated fluid rises to a manifold at the top of the tubes through which the glycol mixture is being pumped. The heat from the fluid inside the tubes is transferred to the glycol mixture. The glycol then goes through another heat exchanger that heats pure water.
The water that is heated can be used directly for domestic or commercial use, or it can be used to heat your home using radiant floor heating, radiant panels, or a forced air system. Regardless of the use, a system usually incorporates a pump, one or more heat exchangers, and a tank to store hot water. Specification of the components and layout of the system should be performed by a qualified Mechanical, Electrical, and Plumbing Engineer.
Images courtesy of the U.S. DOE: http://www1.eere.energy.gov/solar/sh_basics_collectors.html
How long will it take to pay for itself?
Generally solar thermal collectors are cheaper to buy and install than photovoltaic panels, but a detailed technical and economical analysis is needed to determine how long it will take for energy savings to exceed installation costs. Some things to take into account are:
· The solar resources available which depends on latitude, local climate, cloud cover, and shading.
· The efficiency of the solar collector which depends on the collector itself, the fluid to be used, orientation, and placement.
· Cost of equipment purchase and installation.
· Incentives that may be available through federal, state, and local governments as well as utility companies.
Energy 1 is a company that can provide a feasibility study that takes all of this into account and provides you with the information you need to know like savings on your monthly energy costs, payback period, installation costs, etc. They can also provide feasibility studies for photovoltaics, wind energy, micro-hydro, cogeneration, and geothermal energy.
If you aren’t concerned with detailed economic analysis and would like to “jump right in” you should still be aware of the incentives available to offset the cost of your project. Energy 1 can give you a comprehensive break down on Federal, State and Local tax grants and incentives. In most cases this can give a residential application a payback in less than 7 years.
How can I get a Solar Hot Water system for my building?
Need a hand installing your system? For an easy no-headache installation Energy 1 can do a feasibility study, provide the design, install the system, and provide routine maintenance on your installed system. Or call (406) 587-2917.
Need a hand installing your system? For an easy no-headache installation Energy 1 can do a feasibility study, provide the design, install the system, and provide routine maintenance on your installed system. Or call (406) 587-2917.
Monday, November 30, 2009
E1
Energy 1 is committed to the comprehensive development, integration and installation of renewable energy systems; employing the latest technologies in geothermal, solar electric, solar thermal, wind and mini hydro‐electric applications. Our team of engineers and specialty service providers allows for seamless delivery, from initial concept to installation to post commission performance tracking.
We believe our process ensures the most proficient solutions are attained, producing an end product that is cost effective, feasible and effectively integrated into the building and site.
Energy 1, based in Bozeman MT, was founded by a team of engineers to fulfill a niche that was clearly missing from companies offering sustainable energy solutions.
Energy 1 is a “full service” renewable energy solutions provider.
Our team has, collectively, over 50 years of experience designing, developing, installing and servicing renewable energy systems. Today, we are one of the few specialty firms that provide multi-tiered, fully integrated systems. Our core team allows for a seamless transition from concept to delivery, providing critical early involvement to ensure the most appropriate system is employed, and proficiently integrated into the building and site.
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