What is an Evacuated Tube Collector?

An Evacuated Tube Collector is a solar collector in which the absorber is contained in a sealed glass tube, thereby providing for relatively high temperature heat gain.


What is a Net Zero Energy Building?

A Net Zero Energy Building produces as much energy as it uses over the course of a year. Net Zero Energy Buildings are very energy efficient. The remaining low energy needs are typically met with on-site renewable energy. 

There is no such thing as a "zero energy building."

EVERY building uses energy.  

The important considerations are, 

1.  How efficient is the building?  

2.  How much energy does the building use?  

3.  How much "carbon free energy" or "pollution free power" is generated by the buildings' own onsite renewable energy system?

4.  What are the utility company's prices for the excess power generated and sent to the grid? 
(see: Net Energy Metering)

5.  How difficult is it to interconnect the renewable energy system of the building with the utility company's powerlines/electric grid?   

At the heart of Net Zero Energy Buildings is the idea that buildings can meet energy requirements from low-cost, locally available, nonpolluting, renewable sources. 

What is "Net Zero Energy?"

Net Zero Energy - when applied to a home or commercial building, simply means that they generate as much power and energy as they consume, when measured on a monthly or annual basis. 

Copper Indium Gallium diSelenide (CuInSe2) is a material that provides an extremely high absorption of light ( 99%) to be absorbed in the first micron of the material. Copper Indium Gallium diSelenide is projected to be the revolutionary material that some are saying, could put typical "central" power plants and some electric utilities, out of business, as it will be much cheaper for customers to generate their own onsite power with Thin Film Photovoltaics made from these materials.   

When additional small amounts of Gallium is added to Copper Indium diSelenide, this increases its' light-absorbing band gap, thereby making the solar panel more closely match the solar spectrum of the sun.  This, in turn, increases the voltage and the efficiency of the Thin Film Photovoltaics solar panel. 

Solar panels produced with Copper Indium Gallium diSelenide cells have reached efficiencies of more than 20% - which is much higher than the other Thin Film Photovoltaics. 

Copper Indium Gallium diSelenide solar panels create more electricity from the same amount of sunlight than other Thin Film Photovoltaics panels.  This translates into a higher conversion efficiency. 

The conversion efficiency of Copper Indium Gallium diSelenide PV technologies is very stable over time, meaning its power output remains stable over many years, while the power output of many other PV materials can rapidly decline with time. 

What are "Building Integrated Photovoltaics?"

Building Integrated Photovoltaics (BIPV) are solar energy systems that are integrated into a part of the building, that serve as the building's exterior or the building's skin. 

Commercial buildings and facilities (including houses) that integrate their own solar power systems into the building's exteriors, are referred to as "power buildings."

The technology that makes this possible is "Thin Film Photovoltaics."

What are Thin Film Photovoltaics?

Without a doubt, the most exciting technology in the solar power industry is "Thin Film Photovoltaics."  Thin Film Photovoltaics technology represents the next big thing in renewable energy and solar power as it integrates nanotechnologies into the production of solar photovoltaics. 

According to the Department of Energy, the recent technological advances in thin film photovoltaics make this a very exciting time to be in the solar energy industry.  These advances have led to many new developments in the components and manufacturing of thin film photovoltaics. This has made thin film photovoltaics cheaper to manufacture as they are also now easier to install since they are extremely versatile, flexible, bendable, and much lighter.

Thin film photovoltaics  have led many to believe that as much as 50% of our nation's future power will be generated by "power buildings" that integrate "building integrated photovoltaics" or "BIPV" into the building's skin or exterior surfaces, that convert sunlight into "pollution free power" for use in the building.  This also designates these buildings (and homes) as "Net Zero Energy Buildings" and make the option for going grid-free, or not connecting to the grid, a real possibility.

According to the Department of Energy, the market potential for printed electronics will grow into a $47 billion market by 2018.  Thin film photovoltaics represents a significant portion of this market - and based on this heavily researched solar technology, thin film photovoltaics now represents a $20 billion/year industry in the U.S.

The solar PV panels produced under the thin film photovoltaics umbrella have the potential to produce power significantly cheaper power than today’s typical silicon-based PV panels.  The panels are usually made in the form of a monolithic piece of glass, upon which various thin films are deposited, although a number of firms are working on depositing the materials on a substrate, such as stainless steel or plastic.

Types of Thin Film Photovoltaics – there are primarily three types of thin film photovoltaics and include:

1. Amorphous Silicon

2. Cadmium Telluride

3. Copper Indium Gallium Diselenide

Amorphous Silicon had the largest share of the thin film photovoltaics market through 2006. It has been researched for the longest period of time, may be the best understood material of the three and has been commercial for the longest. Cadmium Telluride has the remaining share and is growing. 

Thin Film Photovoltaics Advantages over Crystalline Silicon Photovoltaics

• Lower cost of production of the 

• Lower production facility cost per watt - CapEx

• Uses as little as 1/500 of the amount used in standard silicon cells

• Lower energy payback – amount of time until the product produces more energy than was utilized in its manufacture.

• Produces more power/watt

• Superior performance in hot and cloudy climates

• Integrates seemlessly in homes and buildings – see Building Integrated Photovoltaics 

• Produces the lowest cost power

What is Net Energy Metering?

Net energy metering is used to measure a customer's total electric consumption against that customer's total on-site electric generation.  When a customer's onsite generation of power exceeds the amount that they use, the customer's solar energy system (or other renewable energy system) exports the extra electricity to the grid.  When the power requirements of the customer exceeds their onsite generation of power, the customer imports the electricity they need from electric grid. The customer pays the electric company for any extra power they use over the amount they generate - OR -  the customer receives a credit or refund from the electric company if they exported more power to the grid, than what they consumed.  

Renewable Energy Is Necessary for Net Zero Energy Buildings

Much focus is placed on energy efficiency as the most cost-effective way to reduce energy use in commercial buildings. However, consumption can be reduced only so much. There is a point at which the cost of adding efficiency measures is higher than that of using renewable energy such as thin film photovoltaics and other solar energy systems. 

Aggressive energy efficiency strategies can reduce a building's energy consumption by 50% to 70%. Renewable energy technologies must be used to reach the goal of a net-zero energy building (NZEB).

Supply-Side Technologies

Various supply-side renewable energy technologies are available for Net Zero Energy Buildings. Supply-side technologies, often called energy producers, collect natural energy and transform it into a useful form. Examples of these technologies include PV, solar hot water, wind, hydroelectric, and biofuels.

Ranking of Energy Options

All renewable sources are favorable over conventional energy sources such as coal and natural gas; however, the U.S. Department of Energy recommends the following ranking for these options (the lower numbers are preferable):

This hierarchy is weighted toward renewable technologies within the building footprint and site. Rooftop PV and solar water heating are the most applicable supply-side technologies for Net Zero Energy Buildings. Other supply-side technologies such as parking lot-based wind or solar energy systems may be available.

The goal in developing the ranking was to encourage technologies that:

• Minimize overall environmental impact by encouraging energy-efficient building designs and reducing transportation and conversion losses

• Will be available over the lifetime of the building

• Are widely available and have high replication potential for future Net Zero Energy Buildings.

Unlike most companies, we are equipment supplier/vendor neutral. This means we help our clients select the best equipment for their specific application. This approach provides our customers with superior performance, decreased operating expenses and increased return on investment. 

For more information: call us at: 832-758-0027

Concentrating Solar Thermal Heating Systems

Solar thermal systems convert sunlight into heat. "Flat-plate" solar thermal collectors produce heat at relatively low temperatures (80 to 140°F [27 to 60°C]), and are generally used to heat air or a liquid for space and water heating or drying agricultural products. Concentrating solar collectors produce higher temperatures. They are most often used where higher temperature heat is desirable, there are large thermal loads, and/or where there are limitations in the area available for installing solar collectors, since they provide more energy per unit of collector surface area. They can also be applied in the production or refining of chemicals and fuels or to produce mechanical or electrical energy. The following is a discussion of concentrating systems for space or water heating. Such collectors can also be used to produce heat for absorption cooling.

There are a variety of types of concentrating solar thermal collectors. They achieve higher temperatures by using a concentrating reflector to direct sunlight from a large area to a smaller receiver and absorber area. A liquid is pumped through the absorber, where it is heated and then sent to a storage system or used directly for heating. Concentrating collectors work best in climates that have a high amount of direct solar radiation. They do not function as well on cloudy days, when available solar radiation is mostly diffuse. The amount of useful heat they produce is mainly a function of the intensity of solar radiation available, the size of the reflector, how well they concentrate solar energy onto the receiver, the characteristics of the absorber, and the control of the flow rate of the heat transfer fluid.

A concentrating collector system can have a fixed or stationary collector, or it can track the sun. In stationary systems the reflector and absorber are in a fixed position, usually oriented directly true south. Tracking devices shift the position of the reflector and the receiver to maximize the amount of sunlight concentrated on the receiver.

Tracking collectors are either single-axis or double-axis. Single-axis tracking devices move the collector on one axis: east to west or north to south. Dual-axis tracking devices track the sun on all axes. The entire collector, containing the reflector and receiver, generally moves as a unit in both types. Systems with dual-axis tracking concentrate solar energy the most and therefore produce the highest temperatures, but are the most complex and expensive.

The most common types of concentrating solar thermal heating collectors are based on the parabolic trough. Parabolic troughs are U-shaped, concentrators that focus sunlight onto a linear receiver tube located along the focal line of the trough. The receiver may be enclosed in a transparent glass tube to reduce heat loss from the absorber and maximize absorption of solar energy. They generally have single-axis tracking.

Another type of concentrating system that is possible to use in a heating application is the parabolic dish. This has a bowl shaped reflector that focuses the sun onto a relatively small receiver. For optimum performance they require dual axis tracking and the receiver moves with the reflector. This complicates their practical application for water and space heating. Most parabolic dish systems are very sophisticated systems used for electricity generation or very simple systems for cooking food on a small-scale. Other types of concentrating systems have an array of reflectors that individually track the sun and focus sunlight onto a central receiver located on a tower. Development of these systems has focused on electric power generation.

There are two basic types of parabolic trough solar heating collectors that have been commercially developed: cylindrical parabolic troughs and compound parabolic collectors.

A standard cylindrical parabolic trough has a fixed receiver/absorber positioned in the middle of the trough at or slightly above the radius across the edges of the reflector. The shape of the trough (rim angle) determines the focal point, and thus the position of the receiver. The reflector surface is usually polished aluminum, aluminized plastic, silvered glass, or stainless steal. The receiver usually has an absorber tube coated with a selective material that has a high absorption for the solar spectrum and low emittance for infrared radiation. The absorber tube may be enclosed in glass with a vacuum to reduce heat loss due to convection and radiation. Receiver temperatures can reach 750°F (400°C).

The trough can be oriented east to west or north to south. They are typically single-axis tracking. When the trough is oriented east to west, the collector moves north to south or south to north as the sun's altitude (height above the horizon) changes throughout the day. When the trough is oriented north to south, the collector moves east to west following the sun's movement across the sky, and returns at sunset to face the sunrise in the morning.

Systems with north-south orientation can be installed so that the collector is at an angle that optimizes performance for different seasons of the year, much like flat-plate solar collectors. For example, if maximum winter performance is preferred, the angle of the collector would be set at 15 degrees plus the site latitude; if summer performance is to be maximized, the angle would be set at 15 degrees less than the site's latitude. An angle equal to the site latitude is a compromise for year round performance.

Most applications of tracking parabolic troughs are relatively large systems to supply heat for domestic water and space heating in commercial and institutional buildings. Examples include the headquarters of the U.S. Department of Agriculture in Washington, DC and at correctional facilities in Phoenix, AZ, Adams County, CO, and Tehachapi, CA. Parabolic solar concentrators are also used for electric power generation at the Solar Electric Generating Systems (SEGS), located in the Mojave Desert at Harper Lake and Kramer Junction, California. The SEGS consist of nine hybrid solar thermal parabolic trough/natural gas turbine power plants. These power plants have a combined generation capacity of 354 MW (peak), and are the largest in the world.

Compound parabolic- or Winston-collectors, have two half-parabolic reflectors with a metal absorber pipe located at the bottom of the trough. The compound parabolic collector funnels solar radiation to the absorber pipe. If oriented from east to west, troughs with low concentration ratios can be stationary. They are able to collect some diffuse, as well as direct, solar radiation. These stationary collectors are efficient for medium temperature uses. These systems are much less common than the cylindrical trough type.

Solar Water Heating Systems

Solar water heating systems use the energy from the sun to heat either water or a heat-transfer fluid in collectors. There are passive systems and active systems. A typical solar water heating system will reduce the need for conventional water heating by at least two-thirds, depending on several factors. 

Sometimes the plumbing from a solar water heating system can connect to a house's existing water heater, which stays inactive as long as the water coming in is hot or hotter than the temperature setting on the indoor water heater. When it falls below this temperature, the home's water heater can kick in to make up the difference. High-temperature solar water heaters can provide energy-efficient hot water and hot water heat for large commercial and industrial facilities. 

Solar Water Heating Systems

Direct Systems

This system uses a pump to circulate potable water from the water storage tank through one or more collectors and back into the tank. The pump is regulated by an electronic controller, an appliance timer, or a photovoltaic panel. 

Indirect Systems

In this system, a heat exchanger heats a fluid that circulates in tubes through the water storage tank, transferring the heat from the fluid to the potable water. 

Thermosiphons

A thermosiphon solar water heating system has a tank mounted above the collector. As the collector heats the water, it rises to the storage tank, while heavier cold water sinks down to the collector. 

Draindown Systems

In cold climates, this system prevents water from freezing in the collector by using electric valves that automatically drain the water from the collector when the temperature drops to freezing. "Drainback systems," a variation of this approach, automatically drain the collector whenever the circulating pump stops. 

Swimming Pool Systems

Our Solar Heating and Cooling system is the cleanest, greenest, and lowest cost method to cool and warm your home or commercial office or other buildings.  Our Solar Heating and Cooling system will eliminate your energy costs for heating and cooling your home, office, school, or any other commercial facility for *free: Requires the purchase of our Solar Heating and Cooling system. Minimum size is 10 tons. You must be located in a qualified geographic location, which means our system must be located to receive direct sunlight.  For qualified customers, we will install the system with little to no money down and you pay for the system with the savings our system provides! 

Solar Absorption Cooling. Solar heat can be used to displace electricity used for cooling. Absorption chillers use a heat source, such as natural gas or hot water from solar collectors, to evaporate the already-pressurized refrigerant from an absorbent/refrigerant mixture. Condensation of vapors provides the same cooling effect as that provided by mechanical cooling systems. Although absorption chillers require electricity for pumping the refrigerant, the amount is very small compared to that consumed by a compressor in a conventional electric air conditioner or refrigerator. Solar Absorption Cooling systems are typically sized to carry the full air conditioning load during sunny periods. 

Solar Trigeneration
www.SolarTrigeneration.com

* FREE SOLAR POWER SYSTEMS!

Through an affiliated partner company, we are now installing *Free Solar Power Systems for qualified commercial businesses in California and Texas.

To qualify for our Free Solar Power Systems, businesses must:

• Have a good credit rating

• Agree to buy all of the power generated from the Free Solar Power Systems under a 20 year Power Purchase Agreement

We expect ALL of our customers will be very happy knowing that the clean, green, renewable power they are using is: 

• More reliable than the electricity from the power company.

• Saving the environment by reducing Greenhouse Gas Emissions and helping reverse Climate Change and Global Warming.

• Generated from their own reliable Solar Power System on their roofs.

• Saving Money!  At today's published electric rates at Southern California Edison, TXU, Reliant and Centerpoint, most of our customers will also enjoy a SAVINGS on their present electric bills by as much as 10% from what they are now paying for their electricity from the electric utility.

• Under warranty.

• At the end of the Power Purchase Agreement, the Free Solar Power Systems is then owned by our customers and the savings really start to add up as the power and electricity generated from their Free Solar Power Systems is now free!

To find out if your business qualifies for one of our Free Solar Power Systems, call (832) 758 - 0027 today!

Our "Solar Trigeneration™" Power and Energy Systems
Generate Carbon Free Energy and Pollution Free Power
Which is Sustainable, Clean, Renewable and Affordable

Solar Energy Systems provides cooler, cleaner, greener power and energy project development services. We specialize in renewable energy technologies and renewable fuels including; B100 Biodiesel, Biomethane, E100 Ethanol and Synthesis Gas.

Our Solar Energy Systems are an environmentally-friendly and economically-superior choice to expensive natural gas and electricity. Additionally, our renewable energy technologies generate "green tags" or a Renewable Energy Credit.  

We provide Solar Power and Energy systems that we refer to as "ecogeneration" solutions that produce cooler, cleaner, greener power and energy for our customers and our environment. Unlike most companies, we are equipment supplier/vendor neutral. This means we help our clients select the best equipment for their specific application. This approach provides our customers with superior performance, decreased operating expenses and increased return on investment. 

• Engineering and Economic Feasibility Studies 

• Project Design, Engineering & Permitting

• Project Construction

• Project Funding & Financing Options

• Shared/Guaranteed Savings program with no capital requirements. 

• Project Commissioning 

• Operations & Maintenance 

• Green Tag/Renewable Energy Credit Application, and Marketing

For more information: call us at: 832-758-0027

Net Zero Energy Buildings
www.NetZeroEnergyBuildings.com

The Audubon Nature Center Installs Solar Trigeneration  System
Making this one of the World's First "Net Zero Energy Buildings"
at Their New Facility in Los Angeles, California

NO CONNECTION TO THE ELECTRIC UTILITY!

The Solar Trigeneration  Provides All of their Facility's (5000 sq.ft.)
Cooling, Heating and Power Requirements, Even After the Sun Sets
And WITHOUT ANY CONNECTION to the Electric Utility
with out Solar Trigeneration System!

The Sun Powers the Audubon Nature Center's Solar Trigeneration  
System at Debs Park in Los Angeles. The Audubon Nature Center's 
building is one of the world's first "Net Zero Energy Buildings." 
The Solar Trigeneration System Consists of a 10 Ton “Solar Absorption Cooling"  
System Matched with a Solar Electric Power System

By:  Monty Goodell, M.B.A.
www.SolarTrigeneration.com
Los Angeles, California

There is now a better, more efficient, “pollution free power” solution for cooling, heating and powering homes and commercial buildings where solar energy is available. It's called Solar Trigeneration

Solar Trigeneration is defined as the simultaneous generation of cooling, heating and power with only the free solar energy from the sun providing the "fuel". Solar Trigeneration is now a reality at the Audubon Center at Debs Park several miles from downtown Los Angeles and is one of the world's first "Net Zero Energy Buildings."

The Audubon Nature Center is totally powered by the sun’s energy and the building operates entirely “grid-free” and without any electric connections to the electric grid, or natural gas connections – a truly sustainable power and energy solution. Best of all, the Audubon Center doesn’t rely on the over-burdened electric grid or even natural gas.  Therefore, the Audubon Nature Center NEVER receives an electric bill or natural gas bill.... ever!

The Audubon Nature Center's 5,000 square foot office and conference facility is powered by a Solar Trigeneration system that features a 25-kilowatt solar electric power system where the energy is stored in a bank of batteries. The Center is cooled by a 10-ton solar absorption cooling system powered by an array of very efficient solar heat pipe vacuum tube thermal collectors.  The collectors heat the water to temperatures of 200+ degree F stored in a 1,200 gallon insulated tank, another type of inexpensive battery. The Solar Trigeneration system at the Audubon not only provides the air-conditioning in the summer but also heats the building in the winter, and provides the hot water for the kitchen and bathrooms. 

Absorption chillers, and cooling with solar energy with an absorption chiller are not new technologies.  In fact, absorption chiller technology is over 70 years old.  The first refrigerators were powered by propane gas to run the absorption chillers that used ammonia as a refrigerant.  Electricity and the electric compression chiller gained popularity only because of the convenient “plug and play” appliance and relatively cheap electric rates.  Electricity is no longer economically, or environmentally “cheap.”

Cogeneration refers to the simultaneous production of heat and power. Cogeneration plants are much more efficient as compared with typical power plants.  Cogeneration is usually about 55% to 70% efficient in terms of overall system efficiency, or about 200% more efficient than typical power plants.  However, cogeneration power plants are fueled by natural gas, which is a limited resource, and whose price has exploded as a result of all the new cogeneration plants that have been built and fueled by natural gas. Even in early 2001, the price of natural gas was only $2.75 - $3.25 per mmbtu. However, with all of the new cogeneration power plants, limited supply of natural gas, and the huge demand placed on natural gas for fueling the new cogeneration plants, the price of natural gas is now around $7.50 - $8.50 per mmbtu.

Solar Trigeneration is an EcoGeneration solution.  EcoGeneration refers to a power and energy system that uses the “natural” energy or fuel that is available for a specific site or location. Such energy or fuel includes, solar, wind, BioMethane, geothermal, and ocean power, including ocean tidal and ocean thermal energy conversion. For example, in the desert areas of the Southwestern U.S. , there is an abundance of solar energy. Therefore, home-owners and business owners in this part of the country should seriously consider an EcoGeneration system (“ecogen system”) that optimizes the opportunities available through solar energy

Today, the cause of the summer peak electric demand, electric supply problems, and black-outs, are the result of the energy crisis in California , primarily attributed to the air conditioning load. Over 40 percent of the electricity generated every day goes is used for air conditioning.  At this time of year, the electric utilities are forced to turn on all of their power plants to generate the “peak” demands required by the customers, primarily for air-conditioning.  This means that all of the efficient power plants, the inefficient power plants, along with all of the “peaking” power plants have to run to generate the electricity needed. The high cost of meeting the peak demand is passed on to the consumers with rates of $.20+ per kWh during the summer months.   For fixed income seniors living in desert communities, they are already forced to conserve on energy, food, water, and other necessities of life. 

Greater Demands on California’s Limited Electric Supply, Lack of New Electric Power Supplies, and This Summer’s Heat Wave are Compounding the Problem Leading to the “Perfect Electric Storm”

Many people will remember the movie “The Perfect Storm” from several years ago, when several storms came together in the northeastern part of the U.S. to produce a deadly and catastrophic “perfect” storm. Today, a different type of “perfect storm” is brewing in California . The storm that’s looming on the horizon in California is a “perfect electric storm” wherein the supply of electricity from the electric utility company’s power plants are unable to keep-up with the demand – meaning a black-out, or loss of electricity, like the black-outs from previous years, and like the northeastern black-out from 2003.

The most likely time of year for a black-out in California , unfortunately, is the summer, when air-conditioners are running at the maximum, and placing the maximum load on California ’s electricity supply.  Should such a black-out occur in the desert areas of California, where daily high temperatures routinely reach 110 degrees and higher, and where a significant percentage of the population is comprised of retired and senior citizens, and should the black-out be prolonged, a number of deaths will be the likely outcome. People, and especially the elderly, simply cannot tolerate prolonged high temperatures

How Do We Prevent the “Perfect Electric Storm” from Occurring in California and Other Regions in the U.S.?

Another major concern is how do we prevent the “Perfect Electric Storm” from happening, like the Northeast Blackout several summers ago, especially for people living in the desert?  California ’s energy authorities are warning of a possible energy crisis during the hot summer months, due to the excessive and prolonged summer temperatures where demand increases by over 40 percent.  Compounding the problem is the rising demand for electricity due to population growth and the limited transmission capacity in some areas in the region.  According to the California Energy Commission, the State must build three natural gas-fired 500-megawatt peaking power plants, every year, just to keep up with the growing demands of electricity. Failure to keep up with demand means The problem is getting worse due to the population growth in the Inland Empire , Coachella Valley and Antelope Valley. The projected power gap for the coming summers of 2006, 2007, and 2008 is very bleak.

Governor Schwarzenegger’s “Million Solar Roofs” program and the passage of the 2005 Federal Energy Act will be the foundation to create a “Perfect Solar Storm” to trigger the Solar Economy throughout California. 

With the threat of California’s seniors and elderly dying from heat exhaustion due to power outages, black-outs, rolling black-outs and the rising costs of electricity and natural gas, combined with the continuing impact of global warming, the perfect solution is to create a Solar Revolution by cooling, heating and powering the desert with solar energy and technologies like Solar Cogeneration or Solar Trigeneration.

To find our more about the new Solar Trigeneration system at the Audubon Center in Los Angeles, or arrange for a tour of the Audubon Center, or discuss your Solar CHP, Solar Cogeneration or EcoGeneration requirements, call Monty Goodell at 832-758-0027

The Audubon Center's new Solar Trigeneration power and energy system
makes this building a "Net Zero Energy Building"

The Audubon's Roof showing the Solar Thermal Collectors, part of the 
Solar Trigeneration power and energy system

The heart of the Audubon's Solar Trigeneration power and energy system
provides "free heating, cooling and domestic hot water," a "net zero energy building."

The hot water from the Solar Thermal Collectors on the roof of the Audubon is pumped here for producing the building's heating, cooling and domestic hot water.
Hot water is stored in the tank on the left for overnight.

Solar Electric Power Systems (PV)

Solar electric power systems transform sunlight into electricity. Sunlight is an abundant resource. Every minute the sun bathes the Earth in as much energy as the world consumes in an entire year. Solar cells employ special materials called semiconductors that create electricity when exposed to light. Solar electric systems are quiet and easy to use, and they require no fuel other than sunlight. Because they contain no moving parts, they are durable, reliable, and easy to maintain. How It Works Solar cells, also known as photovoltaic (PV) cells, do the work of making electricity. Several types of solar electric technology are under development, but four—crystalline silicon (a form of refined beach sand), thin films, concentrators, and thermophotovoltaics—are illustrative of the range of technologies. Solar cells are connected to a variety of other components to make a solar electric power system. Crystalline Silicon Crystalline silicon solar cells are used in more than half of all solar electric devices. Like most semiconductor devices, they include a positive layer (on the bottom) and a negative layer (on the top) that create an electrical field inside the cell. When a photon of light strikes a semiconductor, it releases electrons (see animation). The free electrons flow through the solar cell's bottom layer to a connecting wire as direct current (DC) electricity. Some solar cells are made from polycrystalline silicon, which consists of several small silicon crystals. Polycrystalline silicon solar cells are cheaper to produce but somewhat less efficient than single-crystal silicon. A simple silicon solar cell can power a watch or calculator. However, it produces only a tiny amount of electricity. Connected together, solar cells form modules that can generate substantial amounts of power. Modules are the building blocks of solar electric systems, which can produce enough power for a house, a rural medical clinic, or an entire village. Large arrays of solar electric modules can power satellites or provide electricity for utilities. Solar Electric Power System Components In addition to modules, several components are needed to complete a solar electric power system. Many systems include batteries, battery chargers, a backup generator, and a controller so that people in solar-powered homes and buildings can turn on the lights at night or run televisions or appliances on cloudy days. Grid-connected systems don't require batteries or backup generators because they use the grid for backup power. Some remote system applications, such as those used to pump water, do not require a backup power source. Components of a typical standalone PV system using crystalline silicon technology. (Source: Solar Electric Power Association) Solar electric power systems can incorporate inverters or power control units to transform the DC electricity produced by the solar cells into alternating current (AC) to run AC appliances or sell to a utility grid. Complete systems usually include safety disconnects, fuses, and a grounding circuit as well. Thin Films Solar electric thin films are lighter, more resilient, and easier to manufacture than crystalline silicon modules. The best-developed thin-film technology uses amorphous silicon, in which the atoms are not arranged in any particular order as they would be in a crystal. An amorphous silicon film only one micron thick can absorb 90% of the usable solar energy falling on it. Other thin-film materials include cadmium telluride and copper indium diselenide. Substantial cost savings are possible with this technology because thin films require relatively little semiconductor materials. Thin films are produced as large, complete modules, not as individual cells that must be mounted in frames and wired together. They are manufactured by applying extremely thin layers of semiconductor material to a low-cost backing such as glass or plastic. Electrical contacts, antireflective coatings, and protective layers are also applied directly to the backing material. Thin films conform to the shape of the backing, a feature that allows them to be used in such innovative products as flexible solar electric roofing shingles. Concentrators Concentrators use optical lenses (similar to plastic magnifying glasses) or mirrors to concentrate the sunlight that falls on a solar cell. With a concentrator to magnify the light intensity, the solar cell produces more electricity. Today, most solar cells in concentrators are made from crystalline silicon. However, materials such as gallium arsenide and gallium indium phosphide are more efficient than silicon in solar electric concentrators and will likely see more use in the future. These materials are now used in communications satellites and other space applications. Concentrators produce more electricity using less of the expensive semiconductor material than other solar electric systems. A basic concentrator unit consists of a lens to focus the light, a solar cell assembly, a housing element, a secondary concentrator to reflect off-center light rays onto the cell, a mechanism to dissipate excess heat, and various contacts and adhesives. The basic unit can be combined into modules of varying sizes and shapes. Concentrators only work with direct sunlight and operate most effectively in sunny, dry climates. They must be used with tracking systems to keep them pointed toward the sun. Thermophotovoltaics Thermophotovoltaic (TPV) devices convert heat into electricity in much the same way that other PV devices convert light into electricity. The difference is that TPV technology uses semiconductors "tuned" to the longer-wavelength, invisible infrared radiation emitted by warm objects. This technology is cleaner, quieter, and simpler than conventional power generation using steam turbines and generators. TPV converters are relatively maintenance-free because they contain no moving parts. In addition to using solar energy, they can convert heat from any high-temperature heat source, including combustion of a fuel such as natural gas or propane, into electricity. TPV converters produce virtually no carbon monoxide and few emissions. They may be used in the future in gas furnaces that generate their own electricity for self-ignition (during power outages) and in portable generators and battery chargers. Advantages Solar electric systems offer many advantages. Standalone systems can eliminate the need to build expensive new power lines to remote locations. For rural and remote applications, solar electricity can cost less than any other means of producing electricity. Solar electric systems can also connect to existing power lines to boost electricity output during times of high demand such as on hot, sunny days when air conditioners are on. Solar electric systems are flexible. Solar electric modules can stand on the ground or be mounted on rooftops. They can also be built into glass skylights and walls. They can be made to look like roof shingles and can even come equipped with devices to turn their DC output into the same AC utilities deliver to wall sockets. These advances mean individual homeowners and businesses can relieve pressure on local utilities struggling to meet the increasing demand for electricity. More than 30 states offer grid-connected solar electric system owners the chance to save money on their energy bills by feeding any excess power their solar electric system produces into the utility grid—an arrangement called net metering. Solar power systems require minimal maintenance. They run quietly and efficiently without polluting. They are easy to combine with other types of electric generators such as wind, hydro, or natural gas turbines. They can charge batteries to make solar electricity continuously available. For utilities, large-scale solar electric power plants can help meet demand for new power generation, especially in distributed applications. A solar electric power plant is created from multiple arrays that are interconnected electronically. Solar electric plants are easier to site and are quicker to build than conventional power plants. They are also easy to expand incrementally—by adding more modules—as power demand increases. Solar electric power systems are good for the environment. When solar electric technologies displace fossil fuels for pumping water, lighting homes, or running appliances, they reduce the greenhouse gases and pollutants emitted into the atmosphere. The use of solar electric systems is particularly important in developing nations because it can help avert the expected increases in emissions of greenhouse gases caused by the growing demand for electricity in those countries. Solar electric technologies also benefit the U.S. economy by creating jobs in U.S. companies. Exporting solar electric technologies to developing nations expands U.S. markets while protecting the global environment. Disadvantages Although solar electric systems make financial sense in remote areas that lack access to power lines, they are usually more expensive than fossil fuels for grid-connected applications. This disadvantage is significant for utilities considering large-scale solar electric power plants. Although solar electricity costs considerably more than electricity generated by conventional plants, regulatory agencies often require utilities to supply electricity for the lowest cash cost. Utilities view solar electric power plants differently than they view conventional power plants. Solar electric modules produce electricity intermittently—only when the sun shines. Their output varies with the weather and disappears altogether at night. Integrating solar electricity into a utility system requires creative planning. Applications A combination of solar electric arrays and pool-heating solar collectors were used to provide power and heat to the Georgia Tech University Aquatic Center, site of the 1996 Olympic swimming competition. (Credit: Heliocol) Solar electricity has powered satellites since the dawn of the space program. It has run remote communications outposts high in the mountains and turned on the lights, kept medicines cold, and pumped water in rural areas for more than 30 years. Small solar cells are used to power wristwatches, calculators, and other electronic gadgets. More recently, solar electric systems have been used to provide supplemental power to homes and commercial buildings in cities. Solar electric technology has important roles to play in both the developing and developed worlds. From the farmer irrigating his crops in rural Mexico to an innovative lighting system for an Olympic sports arena, solar electric solutions abound. Electric utilities harness solar electricity for distributed applications—near substations or at the end of overloaded power lines, for example, to avoid or defer costly line upgrades. They use solar electricity during hot, sunny periods when the demand for air conditioning stretches conventional power generation to its limit. The Sacramento Municipal Utility District, for example, uses large solar electric arrays as part of its power generation mix. Utilities also rely on solar electricity to power remote, standalone monitoring systems. Consumers and builders are integrating solar electric modules into their homes and offices. Innovative solar electric technologies can replace conventional roofing and facade materials in new buildings. Solar electric roofing shingles, for example, are being used in some new residences. In grid-connected applications, solar electricity supplies some of a consumer's energy needs; the local utility provides the rest. Standalone solar electric systems power a variety of applications far from the reaches of the power grid. These applications include remote communications systems such as television and radio transmitters and receivers, telephone systems, and microwave repeaters. Standalone solar electric power is also used to prevent corrosion of metal pipes, tanks, bridges, and buildings. Many remote residences worldwide use solar electricity as their source of power. For instance, more than 100,000 vacation homes in Scandinavia rely solely on solar electric technology to run lights and appliances. Villages around the world are building solar electric systems to bring electricity to their homes and local industries, often for the first time. To make the maximum use of available resources, village power is typically produced by a hybrid power system that combines solar electricity with diesel backup generators and sometimes another renewable energy technology such wind power. Villages also use standalone solar electric systems for pumping water—an application shared by rural farmers and ranchers in the United States.

Our Solar Heating and Cooling System - Uses the "free" Power of the Sun to Heat and Cool your Commercial Business or Home for Free!

Cooling and heating your building (home, office, school, hospital, etc.) costs you up to 60%, or more, every month you receive your electric bill. You can eliminate the heating and cooling portion of your electric bill forever, and cool and heat your home with the sun's power with our Solar Heating and Cooling system!   

Our Solar Heating and Cooling system is the cleanest, greenest, and lowest cost method to cool and warm your home or commercial office or other buildings.  Our Solar Heating and Cooling system will eliminate your energy costs for heating and cooling your home, office, school, or any other commercial facility for *free: Requires the purchase of our Solar Heating and Cooling system. Minimum size is 10 tons. You must be located in a qualified geographic location, which means our system must be located to receive direct sunlight.  For qualified customers, we will install the system with little to no money down and you pay for the system with the savings our system provides! 

Solar Absorption Cooling. Solar heat can be used to displace electricity used for cooling. Absorption chillers use a heat source, such as natural gas or hot water from solar collectors, to evaporate the already-pressurized refrigerant from an absorbent/refrigerant mixture. Condensation of vapors provides the same cooling effect as that provided by mechanical cooling systems. Although absorption chillers require electricity for pumping the refrigerant, the amount is very small compared to that consumed by a compressor in a conventional electric air conditioner or refrigerator. Solar Absorption Cooling systems are typically sized to carry the full air conditioning load during sunny periods. 

Our company provides turn-key project solutions that include all or part of the following: 

• Engineering and Economic Feasibility Studies 

• Project Design, Engineering & Permitting

• Project Construction

• Project Funding & Financing Options

• Shared/Guaranteed Savings program with no capital requirements. 

• Project Commissioning 

• Operations & Maintenance 

For more information: call us at: 832-758-0027

Absorption chillers use heat instead of mechanical energy to provide cooling. A thermal compressor consists of an absorber, a generator, a pump, and a throttling device, and replaces the mechanical vapor compressor.

In the chiller, refrigerant vapor from the evaporator is absorbed by a solution mixture in the absorber. This solution is then pumped to the generator. There the refrigerant re-vaporizes using a waste steam heat source. The refrigerant-depleted solution then returns to the absorber via a throttling device. The two most common refrigerant/ absorbent mixtures used in absorption chillers are water/lithium bromide and ammonia/water.

Compared with mechanical chillers, absorption chillers have a low coefficient of performance (COP = chiller load/heat input). However, absorption chillers can substantially reduce operating costs because they are powered by low-grade waste heat. Vapor compression chillers, by contrast, must be motor- or engine-driven.

Low-pressure, steam-driven absorption chillers are available in capacities ranging from 100 to 1,500 tons. Absorption chillers come in two commercially available designs: single-effect and double-effect. Single-effect machines provide a thermal COP of 0.7 and require about 18 pounds of 15-pound-per-square-inch-gauge (psig) steam per ton-hour of cooling. Double-effect machines are about 40% more efficient, but require a higher grade of thermal input, using about 10 pounds of 100- to 150-psig steam per ton-hour.

A single-effect absorption machine means all condensing heat cools and condenses in the condenser. From there it is released to the cooling water. A double-effect machine adopts a higher heat efficiency of condensation and divides the generator into a high-temperature and a low-temperature generator.

Is It Right for You?

Absorption cooling may be worth considering if your site requires cooling, and if at least one of the following applies:

• You have a combined heat and power CHP) unit and cannot use all of the available heat, or if you are considering a new CHP plant

• Waste heat is available

• A low-cost source of fuels is available

• Your boiler efficiency is low due to a poor load factor

• Your site has an electrical load limit that will be expensive to upgrade

• Your site needs more cooling, but has an electrical load limitation that is expensive to overcome, and you have an adequate supply of heat.

In short, absorption cooling may fit when a source of free or low-cost heat is available, or if objections exist to using conventional refrigeration. Essentially, the low-cost heat source displaces higher-cost electricity in a conventional chiller.

In Practice

In a plant where low-pressure steam is currently being vented to the atmosphere, a mechanical chiller with a COP of 4.0 is used 4,000 hours a year to produce an average 300 tons of refrigeration. The plant's cost of electricity is $0.05 a kilowatt-hour. 

An absorption unit requiring 5,400 lbs/hr of 15-psig steam could replace the mechanical chiller, providing annual electrical cost savings of:

Annual Savings = 300 tons x (12,000 Btu/ton / 4.0) x 4,000 hrs/yr x $0.05/kWh x kWh/3,413 Btu = $52,740

Actions You Can Take

Determine the cost-effectiveness of displacing a portion of your cooling load with a waste steam absorption chiller by taking the following steps:

• Conduct a plant survey to identify sources and availability of waste steam

• Determine cooling load requirements and the cost of meeting those requirements with existing mechanical chillers or new installations

• Obtain installed cost quotes for a waste steam absorption chiller

• Conduct a life cycle cost analysis to determine if the waste steam absorption chiller meets your company's cost-effectiveness criteria.

Absorption Chiller Refrigeration Cycle

The basic cooling cycle is the same for the absorption and electric chillers. Both systems use a low-temperature liquid refrigerant that absorbs heat from the water to be cooled and converts to a vapor phase (in the evaporator section). The refrigerant vapors are then compressed to a higher pressure (by a compressor or a generator), converted back into a liquid by rejecting heat to the external surroundings (in the condenser section), and then expanded to a low- pressure mixture of liquid and vapor (in the expander section) that goes back to the evaporator section and the cycle is repeated.

The basic difference between the electric chillers and absorption chillers is that an electric chiller uses an electric motor for operating a compressor used for raising the pressure of refrigerant vapors and an absorption chiller uses heat for compressing refrigerant vapors to a high-pressure. The rejected heat from the power-generation equipment (e.g. turbines, microturbines, and engines) may be used with an absorption chiller to provide the cooling in a CHP system.

The basic absorption cycle employs two fluids, the absorbate or refrigerant, and the absorbent. The most commonly fluids are water as the refrigerant and lithium bromide as the absorbent. These fluids are separated and recombined in the absorption cycle. In the absorption cycle the low-pressure refrigerant vapor is absorbed into the absorbent releasing a large amount of heat. The liquid refrigerant/absorbent solution is pumped to a high-operating pressure generator using significantly less electricity than that for compressing the refrigerant for an electric chiller. Heat is added at the high-pressure generator from a gas burner, steam, hot water or hot gases. The added heat causes the refrigerant to desorb from the absorbent and vaporize. The vapors flow to a condenser, where heat is rejected and condense to a high-pressure liquid. The liquid is then throttled though an expansion valve to the lower pressure in the evaporator where it evaporates by absorbing heat and provides useful cooling. The remaining liquid absorbent, in the generator passes through a valve, where its pressure is reduced, and then is recombined with the low-pressure refrigerant vapors returning from the evaporator so the cycle can be repeated.

Absorption chillers are used to generate cold water (44°F) that is circulated to air handlers in the distribution system for air conditioning.

"Indirect-fired" absorption chillers use steam, hot water or hot gases steam from a boiler, turbine or engine generator, or fuel cell as their primary power input. Theses chillers can be well suited for integration into a CHP system for buildings by utilizing the rejected heat from the electric generation process, thereby providing high operating efficiencies through use of otherwise wasted energy.

"Direct-fired" systems contain natural gas burners; rejected heat from these chillers can be used to regenerate desiccant dehumidifiers or provide hot water.

Commercially absorption chillers can be single-effect or multiple-effect. The above schematic refers to a single-effect absorption chiller. Multiple-effect absorption chillers are more efficient and discussed below.

Multiple-Effect Absorption Chillers

In a single-effect absorption chiller, the heat released during the chemical process of absorbing refrigerant vapor into the liquid stream, rich in absorbent, is rejected to the environment. In a multiple-effect absorption chiller, some of this energy is used as the driving force to generate more refrigerant vapor. The more vapor generated per unit of heat or fuel input, the greater the cooling capacity and the higher the overall operating efficiency.

A double-effect chiller uses two generators paired with a single condenser, absorber, and evaporator. It requires a higher temperature heat input to operate and therefore they are limited in the type of electrical generation equipment they can be paired with when used in a CHP System.

Triple-effect chillers can achieve even higher efficiencies than the double-effect chillers. These chillers require still higher elevated operating temperatures that can limit choices in materials and refrigerant/absorbent pairs. Triple-effect chillers are under development by manufacturers working in cooperation with the U.S. Department of Energy.

The Heat Pump Solution

The geothermal heat pump doesn't create electricity—but it greatly reduces consumption of it. If you would like to reduce the cost of heating and cooling your home, you might want to consider installing a geothermal heat pump, an economical and energy-efficient technology for space heating and cooling and water heating. Nationwide, more than 350,000 of these systems are in operation in homes, schools, and businesses. And the geothermal heat pump industry expects to be installing 40,000 systems per year by 2000.

In winter, heat pump systems draw thermal energy from the ambient temperature of the shallow ground, which ranges between 50° and 70°F (10° to 21°C ) depending on latitude. In summer, the process is reversed to a cooling mode, using the ground as a sink for the heat contained within the building. The system does not convert electricity to heat; rather, it uses electricity to move thermal energy between the building and the ground and condition it to a higher or lower temperature according to the heating or cooling requirements. Consumption of electricity is reduced 30% to 60% compared to traditional heating and cooling systems, allowing a payback of system installation in 2 to 10 years. And these low-maintenance systems have long lives of 30 years or more. Some systems are also capable of producing domestic hot water at no cost in summer and at small cost in winter.

An analysis by the EPA found these systems to be among the most efficient space-conditioning technologies available—with the lowest environmental cost of all that were analyzed. But this might be the most compelling statistic: Surveys show that the number of satisfied geothermal heat pump customers stands at 95% or higher.

About Solar Heating and Cooling

It is possible to use solar thermal energy or solar electricity to operate or power an HVAC or heating and cooling system.  The following is a brief description of "active" solar cooling and refrigeration technologies. Active solar energy systems use a mechanical or electrical device to transfer solar energy absorbed in a solar collector to another component in the "system." It is possible to also cool a building or structure by using the natural processes of solar heat transfer (conduction, convection, and radiation). This is often referred to as "passive solar cooling," and is primarily an architectural technique. This brief focuses on active solar cooling systems. The American Solar Energy Society (ASES, see Source List below) is one source of information on passive solar cooling techniques.

Absorption Cooling and Refrigeration

Absorption cooling is the first and oldest form of air conditioning and refrigeration. An absorption air conditioner or refrigerator does not use an electric compressor to mechanically pressurize the refrigerant. Instead, the absorption device uses a heat source, such as natural gas or a large solar collector, to evaporate the already-pressurized refrigerant from an absorbent/refrigerant mixture. This takes place in a device called the vapor generator. Although absorption coolers require electricity for pumping the refrigerant, the amount is small compared to that consumed by a compressor in a conventional electric air conditioner or refrigerator. When used with solar thermal energy systems, absorption coolers must be adapted to operate at the normal working temperatures for solar collectors: 180° to 250°F (82° to 121°C). It is also possible to produce ice with a solar powered absorption device, which can be used for cooling or refrigeration.

For more information, call us at: 832 - 758 - 0027

* Some of the above information from the Department of Energy website with permission.

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