Oct 20 2009
Background
Solar Thermal Collector Panels
Materials
Vacuum Insulation
Energy Output
Orientation to the Sun
Comparison with Photovoltaic Panels
Thermal (Heat) Storage
Vacuum Insulation
Connections
Heat Exchanges
Comparison with Batteries
Hot Water
Heat Exchanger
Thermostatic Technology
Space Heating
Floors
Rooms
Thermal Chilling and Air Cooling
Evaporation Cooling
Thermal Electricity and Thermoelectric Generators
Patents
Microgrids
Background
Solar energy technology converts light energy into different forms of energy like heat and electricity. Azure ALI technology first converts the light energy into thermal energy, which is better known as heat. Azure uses thermoelectric technology to convert that heat into electricity. The electricity is used to power buildings and produce hydrogen, which can be stored and used to fuel cars. The heat is also used to heat water and rooms as well as drive thermal chilling technology for air conditioning.
Figure 1. Above is an image of a concept house showing the thermal chillier, thermal storage and hydrogen storage on the ground and solar collectors on the roof.
Solar Thermal Collector Panels
Solar thermal collectors convert sunlight into heat. They are a very simple technology in principle and work in the same way a metal roof gets hot in the sun. They are used for the heating of water in common solar hot water heaters. We use them to provide heat to our thermal storage and thermal appliances, like thermo electrics for electricity.
Figure 2. Above the registered design of the vacuum tube solar thermal collector system
Materials
We use metal foils made of Copper, Aluminum or Steel as the surface, which absorbs the sunlight. The foils have a film on the surface which prevents the reflection and radiation of the light and heat so that most of the energy in the sunlight is converted to heat and not radiated back out of the foil. Our supplier claims that 95% of the incident energy is trapped by the foils. The film on the foil is optimized to be most efficient at a particular temperature.
Vacuum Insulation
The metal foils can trap most of the light but air can still conduct the heat away unless the foil is protected. The best protection from the atmosphere is a vacuum. We can use a glass tube to surround the foil and remove all the air inside to create a vacuum.
We can also create a vacuum around the tubes that connects the solar collectors to the storage unit on the ground to create the most efficient solar thermal system possible.
Energy Output
95% of the energy in the sunlight will be converted into heat with some materials, as mentioned. This percentage changes with temperature to become less efficient with higher or lower temperature then at the optimized temperature
Orientation to the Sun
The optimum orientation is to point the panels north in the southern hemisphere and south in the northern hemisphere. The angle from the ground should be 33 degrees in Sydney. In reality the panels Azure use could point east or west or any angle in between. The difference with the direction is the amount of collector you will need.
Comparison with Photovoltaic Panels
The thermal collectors are much cheaper then Photovoltaic (PV) panels and more efficient. The PV panel converts sunlight directly into electricity and has an efficiency of 35% at best and average just below 20%. The 35% PV technology is not on the market; the best on the market is 23% efficient. Our thermal collectors are 95% efficient at converting sunlight into heat.
The lower cost of the thermal collectors means you can use sub-optimum roofs by just adding some more panels without adding much additional cost to the whole system. In PV the additional cost would be considerable.
Thermal (Heat) Storage
Using a thermal system enables Azure to store energy easily. Thermal energy can be stored in liquids like water or ethylene glycol, which is in a insulated tank.
Figure 3. Above is a thermal storage tank with thermo electric generators
Vacuum Insulation
Our thermal storage units will employ the same standard of vacuum insulation technology as used in the solar collectors.
Connections
Our connections to the thermal storage tank are highly resistant to heat conduction to the atmosphere. The high resistance and the vacuum insulation mean we will lose less the 1% of the heat stored per day.
Heat Exchanges
We may have 10 separate heat exchanges attached to your thermal storage tank. This will enable us to drive multiple appliances at once and control the heat flow rate into and out of each one.
Comparison with Batteries
Lead acid batteries are commonly used with PV solar systems. They are expensive costing as much as the PV panels for a few days worth of storage. They only last for 5 to 10 years and can be damaged easily by flattening them, depleting the energy to low.
Thermal storage will last decades and can’t be damaged be depleting the energy.
Hot Water
We will be able to provide hot water via a heat exchanger attached to the thermal storage unit.
Heat Exchanger
The heat exchanger will be capable of providing continuous heating of water at what ever rate may be required.
Thermostatic Technology
A thermostatic mixer will be used to fine-tune the temperature of the water leaving the heat exchanger. The mixer, which blends hot and cold water, will also limit the maximum temperature for safety reasons.
Space Heating
Space heating of rooms in winter can be achieved in two ways using our system. One is to use heat exchangers at the hot thermal storage unit to warm air which is pumped through the house. The other way is to use the hydrogen in a similar way to heating with natural gas.
Floors
Floors can be warmed by pumping a warm liquid though built in pipes. This technique is often used in cold climates but not so much in warmer climates.
Rooms
The most efficient way to warm a room would be through a ducted system sourcing it’s heat from the thermal storage unit. As mentioned a Hydrogen gas heater may be good in one room and create a open fire like experience.
Thermal Chilling and Air Cooling
The technology known as absorption chilling is quiet widely used in air conditioning refrigeration and freezers. A small camp fridge uses this technology. The camp fridge/freezer can run on burning gas, 12V dc and 240V ac energy. They all are heat sources that drive the absorption chillier. We will explain how they work next. The version running on gas is preferred for air conditioning in parts of Asia where the electricity is expensive or infrastructure not suitable.
Thermo-acoustic chilling is also being considered by Azure Energy. Thermo-acoustic chilling has no moving parts or chemicals.
Evaporation Cooling
When liquids evaporate they need energy. As a result of this they cool the remaining liquid. The most common example of this is sweating which in a way for people to cool down using the evaporation of the sweat.
In common refrigeration technology like a common electric refrigerator or air-conditioner they use a substance known as a refrigerant. When in the liquid state it will evaporate easily having a cooling effect in anything the liquid comes in contact with. The refrigerant in this type is compressed by an electrically driven compressor to form a liquid which is air cooled and then put though the cycle again. This uses a lot of electricity so we will not use it with out system, a small unit can need 30kW of electrical power to run which compares to 2kW for the rest of the house.
We will use the absorption chillier which can run on heat from the thermal storage unit. The absorption chillier cools via evaporation like the other types of air conditioner. The difference is the evaporation is caused be a low pressure vacuum in the chamber the refrigerant is in. The vacuum is created by using a substance to absorb the gas like a sponge would. The substance that absorbs the refrigerant gas is moved to another chamber where it is heated to cause the release of the gas. The absorber and gas are both air cooled. The air cooling condenses the gas to a liquid. The liquid is then pumped back to the first chamber to be used for evaporative cooling once more. The big advantage with this is that it is easy to deliver high power as heat avoiding the need for thermoelectric conversion step.
Thermal Electricity and Thermoelectric Generators
The ability to turn heat into electricity has been around officially since 1821. We use this very old technology in our system because we have improved it in recent years to be the most efficient method. Most electricity is generated by using mechanical turbines driven by superheated steam to turn an electromagnetic mechanical generator. The technology we use has no moving parts and is very simple. Where this thermoelectric technology is used at present is in places where reliability is the most important feature.
Patents
We have two key patents covering the improvements to the thermoelectric generator. They are all international PCT type applications. We have filed in USA, China, India, Brazil, Europe and Australia.
Microgrids
The term Micro grid is currently what we use to describe the combination of energy technologies we have bundled together to make our system. We could do a single home or building or multiple homes building in Micro grid arrangement. You could have one central unit that provided energy to one building or multiple buildings. You could also have multiple units linked together to provide a more sophisticated system.
Source: Azure Energy