Note: Descriptions are shown in the official language in which they were submitted.
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1
TITLE OF THE INVENTION:
Sun Tracking Panel for a Solar House and a Solar House equipped with the Sun
Tracking Panel
FIELD OF THE INVENTION
The present invention relates to the field of solar energy systems and, in
particularly
to the field of solar energy applications and systems for fulfilling the
energy needs of a
single-family house. The solar energy system and house structure as developed,
from an
innovative, cost-effective, solution for supplying a single-family house with
electricity, hot
1 o water and with space and heating. More specifically, the invention relates
to a sun
tracking panel for a solar house and a solar house that is equipped with such
a sun tracking
panel including energy collecting system, solar collector arrangement and
generated energy
management, distribution, and backup systems.
BACKGROUND OF THE INVENTION
One of the emerging environmental concerns, especially in the developed
countries, is
excessive emission of COa with desire for substantial COa emission reduction
before 2012.
2 o It is expected that a combination of different approaches will be required
in the next 12
years to meet the COZ emission reduction target as set in the Kyoto Agreement.
Significant
reduction of COa emissions can be achieved by direct application of solar
energy for the
generation of electricity and heat. The most promising and realistic solution
is
construction of the specially design houses and the development of the solar-
based energy
system that can be applicable for not only the grid-connected houses in the
residential
areas but also for off grid small communities.
Presently, using advanced solar technologies and proper house design it is
possible to
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2
develop a solution that provides more than 90% of the home's total energy
needs. The
environment friendly house design integrates an efficient solar energy system
with an
environmentally responsive house design. The purpose of the invention is to
develop solar
technologies that have the potential to provide cost-competitive energy source
for houses.
The claimed invention is a solution for a single-family house that applies
solar energy to
satisfy a single-house energy needs in terms of the electricity, heating and
hot water.
A number of solutions are offered to utilize the solar energy for the purpose
of
supporting the single family house energy needs. However, so far, none of them
fully
1 o covers the house energy needs, especially when the house is located in the
cold region
area. In most cases solar photovoltaic batteries or thermal systems are
installed on the
existing houses and located on the roofs, on the walls or as a standing alone.
These
systems are stationary (not tracking) and as a result their efficiency is very
low because of
reduced solar irradiation.
A wide variety of different solar energy utilizing houses designs could be
found in
the practice. In most cases these are typical houses adopted, or modified for
the purpose of
solar energy applications. Interesting examples described in the literature
are the Maine
Solar House, Van Geet Residence, and especially the Gemini solar house.
The Maine Solar House applies the solar energy to generate electricity and hot
water. The Maine Solar House is equipped with a roof mounted, stationary PV
array with
surface of 36 m2 and solar thermal modules with 45 m2 collecting area covering
the South
exposed portion of the roof. It also contains two water tanks (2 m3 each) for
heat storage,
2 5 have improved wall insulation and propane backup for heat, cooking and
drying clothes.
The disadvantages of the Maine Solar House solution are: reduced system
efficiency (not
tracking system), large occupied area, possibility of snow deposits formation
during winter
disturbing system operation and water leakages possibility during summer.
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The van Geet Residence one is a specifically designed house with many
different elements
implemented. The solution as presented is grid-independent home with I kW
photovoltaic
ground located PV system to provide power and with active solar system for
domestic hot
water and space heating system. The solar energy system is supplemented by a
wood-
burning stove, energy-efficient appliance and lighting. The van Geet Residence
is passive
solar house with the Trombe walls (glazed concrete blocks wall). Propane is
used as a
seamless backup when solar energy is not available and also is used for
cooking and
clothes drying. The van Geet Residence energy saving solution was recognized
with a
1 o first-place Technology Award by the American Society of Heating
Refrigerating and Air-
Conditioning Engineers (ASHRAE) in 2001 Winter Meeting in Atlanta and was also
.awarded by the U.S. DOE Office of Building Technology in 2000 for this sort
of the
structure.
1 s The main deficiencies of the van Geet Residence are: ground location of
the solar
system occupying an additional space, exposure to potential damages, covering
with snow
during winter and reduced efficiency as a stationary system.
Another very interesting example of solar house is the rotate-able Gemini
house. It
2 o was constructed in June 2001 in Austria and it turns with the sun to
increase the amount of
collected solar energy. It represents a completely new approach to improve the
solar
system collecting efficiency. As a result of sun tracking, it collects more
energy then
typical stationary systems. The big disadvantage is the complex and expensive
house
structure to facilitate the house rotation, which seems to be not practical.
The house design offered in U.S. Patent 5,259,363 [Peacock) describes a solar
roofing panel system for use in residential and commercial buildings applying
conventional metal roofing components. The system collects thermal energy and
delivers
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it to heat the house. It also, by application of the photavoltaic batteries,
provides electrical
energy. In the preferred embodiment the system employs an air-to-liquid
system.
The solution, described in U.S. Patent 4,517,958 [Worf], offers heating and
cooling
s system with exchangers that are mounted on both northern and southern
exposures, and
can accomplish a combination of functions either separately or at the same
time to meet
varying energy demand situations.
The solar house design with photovoltaic batteries, as given in U.S. Patent
l0 5,542,989 [Yukimi], offers the solution with a solar battery that is formed
of a plurality of
solar cells connected in series to form a solar cell row arranged parallel to
the crosspieces.
The solution offers solution for the roof that includes a plurality of
crosspieces arranged
parallel to each other, and solar battery roofing for the solar house is fixed
to the
crosspieces.
The solar house design according with U.S. Patent 4.317,443, (Masaru] offers
solution that has two walls. The outer wall made of heat absorbing and
transmitting
material and inner wall made of heat insulating material. There are two
chambers. The
area between the outer and inner wall defines an outer chamber and an inner
chamber is
2 o defined to be the area within the inner wall. By changing direction of
flow between the
chambers and rearrangement of the passageway heating and cooling effects are
generated.
U.S. Patent 4,928,444 [Mitsukazu) describe the solar house with a passive
solar
system that has a roof which enables changing of the angle of inclination
according to the
2 5 season to allow different sunshine utilization. A house structure has two
downwardly
inclined roof surfaces (south and north orientated). South and north side
openings extend
upwardly through the roof surfaces on opposite sides of the ridge and a shaft
is rotatable
along the top ridge. A roof board selectively closes one of the south and
north side
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openings.
The system presented in U.S. Patent 4,197,993 [Trombe] comprises inclined
thermal enclosure forming all or part of the roofing of the house, bound by an
inner roof
s element, essentially constituted by a collector material of very low thermal
mass that
absorbs solar radiation. An outer covering element also of very low thermal
mass, is made
of material transparent to solar radiation and behaves as an opaque material
to infrared
radiation of wavelength between 4 and 30 microns. The circulation of air
through the duct
formed between these enclosures is used for house air conditioning.
The solution of the house described in U.S. Patent 4,323,053 [McCullough] is
equipped with combined transparent front wall and heat trap, a radiation
absorbent
collector element positioned in the housing and arranged to accept incident
solar radiation
passing through the front wall. The combined front wall and heat trap are
integrally
1 s formed from one piece from glass. The house is also equipped with a means
for passing a
fluid to be heated through a heat collector.
The U.S. Patent 4,128,124 [Worthington] describes mufti-mode solar heating and
cooling system equipped with a solar collector/heat exchanger unit. The unit
is used for
2o air and /or liquid, has an air compartment through which air is circulated
and has a liquid
compartment through which liquid is circulated from a liquid storage tank.
Liquid from
the tank may be selectively circulated through the solar collector/heat
exchanger unit (or
cooling evaporator) for appropriate heating (or chilling) of the liquid, which
is employed
for treating the air circulating through the solar collector/heat exchanger
unit. Auxiliary
2 s heating and cooling coils are provided within the storage tank for standby
heating or
chilling of the conventional heating and cooling devices.
The design described in the U.S. Patent 4,237,865 [Lorenz] has a thermal panel
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mounted on the side of a building, in vertical position. A longitudinal
passage extends
within the panel and is equipped with lower and upper passageway into the
lower and
upper portions of the building to be heated. In some situations, the
photovoltaic arrays or
thermal panels are located next to the house using special supporting
structure, or towers,
s that are located on the ground.
In many cases these types of systems are sun tracking and quite often use
concentrators. A solar concentrator far producing electricity and heat is
described in the
U.S. Patent 6,080,927 [Johnson]. The solution as described, uses a self
steering heliostat
1 a to concentrate solar radiation onto an absorbing surface such as a solar
cell array,
meanwhile removing heat from the surface with fluid heat transfer means, then
making
effective use of that low-grade heat. The 3ohnson reference uses generated
electricity to
pump a fluid through a heat exchanger and excess of electricity may be
available fox local
storage or use. However, the solution with the heliastat requires additional
space outside
15 the house and needs a solid support structure (especially for a large
systems).
The solution as in U.S. Patent 4,187,834 [Hoinski] presents a solar heating
system
for space and hot water heating. The solar heat-absorbing panel is used. The
panel can be
positioned away from the building and follows the sun movement.
Most of solutions for the solar energy collection, as described in the patent
review,
offer systems that address only partial solution, in terms of house and energy
system
integration, the house structure optimization, collecting system efficiency
improvement or
adaptation for the harsh Canadian weather conditions. In most cases the solar
photovoltaic
arrays or thermal systems modules are installed on the existing houses and
located on the
roofs or on the walls.
In the conventional solar houses, the photovoltaic or thermal solar panels are
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mounted separately and are stationary. As a result, the production capacity of
the system is
underutilized and the maximum production is achieved only during short, mid-
day period
theirs efficiency is very low because of reduced isolation.
s The existing roof mounted stationary systems are experiencing many problems
like
snow build-up, water leakages, and mechanical damage (e.g. hail). The wall,
vertically
mounted, panels that are obviously stationary, are not efficient as a result
of the not
optimized incidence angle (tilt). When mounted as a sloped they require a
strong support
to prevent braking by wind.
None of the discussed systems, except may be for the Gemini house, is fully
integrated with the house structure to optimize the solar energy system
performance and
reduce the costs.
SUMMARY OF THE INVENTION
What is required is an improved sun tracking panel for a solar house. The
solar
house design and energy system as proposed in this patent offers a quite new
concept that
offers exceptional efficiency and performance, and specifically is
advantageous for
applications in the regions with cold, long winters and a harsh climate.
According to one aspect of the present invention there is provided a sun
tracking
panel for a solar house which includes a support structure having a
horizontally oriented
axcuate mounting face. Horizontal guide rails are attached to arcuate mounting
face of the
support structure. A solar panel support is mounted on the guide rails. A
solar panel is
2 5 supported by the solar panel support. A drive system is provided for
moving the solar panel
support along the guide rails, so that the solar panel tracks horizontal
movement of the sun.
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The sun tracking panel, as described above, enables the solar panel to track
movement of the sun across the horizon. Of couse, during the course of the
year the height
of the sun in the sky will vary. Even more beneficial results may, therefore,
be obtained
when the solar panel is mounted to the solar panel support for pivotal
movement about a
substantially horizontal pivot axis. A drive system is provided for pivoting
the solar panel
about the horizontal pivot axis to track vertical movement of the sun. The
ability to pivot the
solar panel about the horizontal pivot axis improves the ability of the solar
panel to track the
sun.
1 o Although the support structure can be placed anywhere on the properly of
the solar
house, it is preferred that the support structure be incorporated into the
solar house. It is also
preferred that the arcuate mounting face be semi-circular, to maximize travel
of the solar
panel.
Although there are a variety of heat gathering technologies that would be
suitable for use
with this sun tracking panel, it is preferred that the solar panel have a
series of photo voltaic
battery arrays and series of thermal solar collectors. These photo-voltaic
arrays and the
thermal collectors may be assembled together as a hybrid module with
transparent or semi-
transparent photo-voltaic modules positioned in front of the thermal solar
collectors.
There will hereinafter be described a new home design and solar energy
collecting
system utilizing the sun tracking panel which is targeting grid-connected
dwellings. The
solar house design has a highly efficient, mufti-mode energy supplying system,
based
mostly on the solar energy application and covers all energy needs of the
detached house.
It can be also applied in the remote, off grid areas with houses or small
communities. It
offers a solution for supplying the single-family house with electrical power
and thermal
energy necessary to generate hot water and to heat the house. The house is
designed
mainly for cold regions, with a significant number of sunny days (e.g. Central
Canada), but
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it can be applied in warm climate areas as well.
This solar house is equipped with an integrated solar energy system (ISES),
which
uses an efficient solar energy panel, composed of photovoltaic and thermal
collectors. The
solax panel tracks the sun and maximizes the amount of energy collected. The
solar panel
system is hybridized type with solar PV array and thermal modules mounted on
the same
frame. The transparent PV array is located in front of the thermal module
reducing the
required surface exposed to sun. The solar energy system is supplemented with
a backup
thermo-photovoltaic (TVP) furnace with infrared photovoltaic cells. Thus the
stove
1 o generates electricity and heat, and might be used during the nighttime or
during very
cloudy days. The TVP furnace operation is supported by natural gas or propane
combustion.
The ISES system is also characterized by significant heat storage capacity and
1 s optimized heat management system. The house structure permits a reduction
in the heat
losses during winter and limits solar house warming during the summer months.
The ISES
system operation is controlled by computer and responds automatically to any
changes in
the weather conditions.
2 o In regard to the electrical energy production capability, such a system is
expected
to be sufficiently powerful and efficient to deliver at least 90% of the.
house electrical
energy needs. Generated energy can be tied in to the existing transmission
grid at
customer locations without taxing the existing infrastructure. The grid-
connected system
is actively exchanging the energy between the house and the grid. It is
supplying the
2 s energy to the grid during daytime and recovers this energy during the
evening hours.
In regard to the thermal energy production, the system is equipped with a heat
storage accumulator that gathers the collected solar thermal energy during the
day and
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releases it during the night. The proposed solution is especially advantageous
in the
regions with specific weather conditions such as cold climate regions with
many sunny
days. In this regard the central Canada and United States are well suited and
very
attractive regions.
5
By applying the active and passive solar technologies with combination of the
advanced construction, improved thermal insulation and innovative energy
saving cost
competitive solutions are feasible. This new type house design opens doors for
homebuilders to create energy-efficient, cost-effective and environmentally
friendly
1 o housing.
The integration of the solar panel, with the house design structure gives
significant
benefits in terms of house construction, occupied space, equipment used,
resources (costs)
and operation. Implementation of the hybrid system (solar panel combined with
thermo-
photovoltaic furnace) and energy recovery and storage system, house heating
system and
back-up system is quite significant and gives additional benefits in terms of
the reliability
in power and heat supply. The option for selling the excess of the electrical
energy
production (day time) to the grid significantly improves the economics of the
system. The
invention relies on the house design modification and integration of several
different
2 o technologies including the solar-based technologies, the thermal
photovoltaic system
(TVP), energy conversion and advanced heat storage system. These new
technologies,
applied together with advanced home design improved insulation and better
ventilation
systems, and with innovative energy saving features like low-energy appliances
and lights,
will bring a new perspective to fulfill the humans energy needs without harm
to
2 5 environment.
The proposed combined system is sufficiently powerful to provide not only the
amount of energy required to cover the house needs but potentially to generate
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supplemental power that can be transferred from single-family home clusters to
large
businesses during the day, thus reducing the power production by conventional
power
plants.
s Implementation of the system as invented, will significantly reduce the
amount of
energy to be delivered from conventional power plants and related COZ
emissions
generation. According to this invention the proposed solar energy system can
be regarded
as a grid-connected photovoltaic power station and as a local thermal energy
generator. It
is expected that the application of the solar house with the integrated energy
system, as
1 o proposed in this invention, could be the greatest possible single strike
to resolve the C02
problem.
The main features of the solar house integrated energy system are:
1 s * Full and efficient utilization of the solar energy
* The house functions on energy from the sun and, only occasionally, from
natural
gas
* The solar house will produce a substantial amount of the electrical power
that can
be sold to the power grid
2 0 * The heat management system i.n optimal way collect, store and
redistribute the
thermal energy and minimizes heat losses (e.g. the heat losses with waste warm
water)
* The solar power and heat system can cooperate with the thermal photovoltaic
system and as such practically it might operate as independent of traditional
2 s utilities.
The Solar House
The house design and structure was developed in conjunction with the applied
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solar energy-collecting system (active and passive), heat storage and heat
management.
The new solar house design main feature is that it implements a large solar
tracking panel
in the house structure and is equipped with the semicircular gallery that make
glazed
enclosure for the sun-tracking hybrid solar panel. The gallery application
purpose is:
s formation of the thermal barrier, noise barner and shelter for the solax
panel against
adverse weather conditions. The ground floor front facade is made as a Trombe
wall.
That wall is overshadowed is summer and exposed to sun in winter.
Hybrid Solar Panel
l o A double-layer hybrid solar panel combines the transparent photovoltaic
modules
that absorbs on average only 10 to 15% of the solar energy, and thermal vacuum
collectors
adsorbing the rest. The to modules are separated with an air gap allowing free
air
movement. This solution prevents PV array to be heated and keep the
photovoltaic cell
efficiency high. The second layer of the solar panel consists of the thermal
modules (e.g.
15 vacuum tubes) that heat the circulating fluid to the required temperature
level without any
impact on the PV array performance. As a result of implementation of the sun
tracking
system the effectiveness of utilization of the installed collectors is 100%
throughout the
whole day. Installation of the solar panel in the air lock between the house
and glass
enclosure, brings additional benefits in terms of better house thermal
insulation during
2 o wintertime (air-lock closed) or protection against excessive house warming
during summer
time by overshadowing the house and ventilation (air-lock open) and as a noise
barrier.
Thenno-Photovoltaic Stove (TPV)
2 J The thermo-photovoltaic stove/generator is a recent invention that
utilizes an infrared
photovoltaic cell for generation of the electricity. The system is activated
by flame from
combustion of natural gas or propane (or any other fuel). Excess heat is used
to heat house
hot water and overall house heating.
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The integration of the different approaches to effectively utilize solar
energy
reduces the house energy requirements during the winter seasons and generates
the excess
of the electrical energy that might be used for other applications or sold to
, the grid
(income).
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the
s o following description in which reference is made to the appended drawings,
the drawings are
for the purpose of illustration only and are not intended to in any way limit
the scope of the
invention to the particular embodiment or embodiments shown, wherein:
FIGURE 1 is a block diagram of the integrated system with distinguished
components of the system.
FIGURE 2 is a pictorial representation (view and cross section) of the single-
family house design, equipped with a tracking solar panel and integrated
energy system.
FIGURE 3 is a presents some details of the design of the combined solar panel
FIGURE 4 is presents the solar house overshadowing principle
FIGURE 5 shows example of the thermal energy demand and production for the
2 o Alberta located house constructed according to the present invention.
FIGURE 6 shows example of the electrical energy needs and production potential
for the Alberta located house constructed according to the present invention
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
2 5 The preferred embodiment, a sun tracking panel for a solar house,
generally
identified by reference numeral 10, will now be described with reference to
FIGURES 1
through 6. The preferred embodiment will describe the integration of the sun
tracking panel
into the construction of a solar house with highly effective heat and
electrical energy
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generating systems.
Structure and Relationship of Parts:
The solar house design illustrated applies solar energy with a view to
satisfying a
s single-house energy needs in terms of the electricity, space heating and hot
water. It is
based on the modified house design and utilization of the sun trucking hybrid
solar panel,
where a supporting frame is implemented into the house structure and represent
an integral
part of the house design.
1 o Implementation of the hybrid solar module (PV array and thermal modules
assembled together) into the house structure offers many benefits. As a
result, the house
front wall becomes the support structure for the sun tracking combined panel.
The panel
moves in a semicircular glazed gallery that is mounted on the front wall of
the house.
1 s The Integrated Solar Energy System (ISES) according to this invention is
bayed on
a concept, which utilizes a hybrid type solar energy-collecting panel that is
tracking the
sun's movement.
As a result, the solar energy gain of the system is maximized because of
permanent
2 0 optimal panel orientation by the sun tracking system.
Integration significantly reduces the balance-of system costs.
Solar House Features
Integrated, solar tracking panel with photovoltaic array to provide electrical
power and thermal collector to provide heat for space heating and hot water
2~ supply
Solar panel module implemented directly into the house envelope
Sloped, semicircular, south oriented and glazed house facade for maximizing
the
solar energy collection
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Narrow galiery/gap used as a solar panel compartment
° Support/backup thermal photovoltaic generator (or fuel cell) operated
by
combustion of propane (or natural gas) to supply electricity (1.0 kW) and heat
(I 5
MJlh)
5 ° Integrated movable panel that is used also a shading device
Warm drain water heat recovery system
Floor heating system
Overshadowing and overhang system with a natural ventilation for cooling
° Trombe walls at the ground floor front wall
10 "Reversible" connection to the grid by a inverter with net metering
Solar House
According to this invention the solar house design and structure was developed
in
15 conjunction with the applied solar energy collecting system. The solar
house design as
shown in FIG. 1 consists of two segments: the rectangular north exposed
segment and
semicircular south exposed segment.
The rectangular, north segment of the house is constructed like typical single-
2 o family house but has improved thermal insulation and tightness.
The semicircular, south oriented solar segment of the house, at the ground
level
comprise a Trombe wall 102 with windows 103. That wall provides support
structure for
the solar panel 300 located on the second floor.
The second level of the south segment is covered with the glass enclosure 201
forming a glazed narrow gallery 200 surrounding the house. The glazed gallery
contains
movable hybrid solar panel 300 with all mechanisms required for its movement
and
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16
orientation. The solar panel 300 operates in the gallery that forms a gap
between the house
wall and the external glass enclosure.
The solar panel, when following the sun moves along rail 202 that is mounted
around the semicircular solar house segment. On the side of the wall, below
the main rail
202, there is another lower rail 203 used for supporting the tilt controlling
mechanism 308.
The glass enclosure 201 works like any greenhouse effect utilizing light
permeable
envelope and forms a temperature buffer zone. The glass selected for the
enclosure is a
1 o single-layer, high-transmittance type of glass. The enclosure protects the
solar energy
collecting system from adverse weather conditions (e.g. snow, wind, hail,
dust) and
secures its undisturbed operation. However, the gallery can be regarded also
as a double
purpose thermal barrier.
The gallery is equipped with air louvers, lower 205 and upper 206, that are
shut-off
during the winter season, keeping the gallery warm, and wide open during
summer-time,
for ventilation and cooling, The efficient cooling effect during the hot
season is achieved
by overshadowing the house with the solar tracking panel. Thus the house
design permits
reduction of the heat losses during the winter and prevents overheating of the
house during
2 o the summer months.
That space, with the louvers, is closed during winter and open during the
summer
letting passage for air circulation from the exterior of the house for purpose
of gallery
ventilation, when the temperature grows too high.
An internal wall, between the gallery and second floor room, contain internal
windows 207 that are occasionally overshadowed by the solar panel.
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]. 7
Additionally the solar gallery forms an overhang 210 for overshadowing the
Trombe wall 103 in the summer. In winter, the Trombe wall is fully exposed to
the sun to
increase the solar energy gain as shown in FIG. 2.
On the top of the house a skylight 220 was installed for using natural light
to
reduce the energy for I17 lighting.
Integrated Energy System
The block diagram of the integrated system for supplying electricity and
thermal
1 o energy for house space heating and hot water preparation is shown in FIG.
3.
The main components of the integrated energy system as shown in Figure 3 are:
The hybrid solar panel 300 with tracking system for the solar energy
collection
Thermal photovoltaic (TPV) or fuel cell generator 400 for producing electrical
and heat energy during the coldest, winter-time period when there is not
enough
energy from the solar system, and it is also regarded as a backup energy
system.
An alternative fox the TPV generator is a fuel cell.
Heat storage, heat exchange and hot water generating system 500
Electrical energy conversion system (inverter) 600
2 0 ~ House space heating system 700
For purpose of the efficient solar energy collection (electricity and heat
generation), a sun-
tracking hybrid solar panel 300 is used.
It is composed of transparent PV arrays and thermal solar modules. The
electric
energy collected by PV array 301 supplies the house appliances and systems,
and the
unbalanced amount of electrical energy is actively exchanged with grid by an
inverter 600.
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18
The heat from the thermal solar collectors 302 is removed from the solar panel
by
circulation and is transferred to the heat exchangerlstorage system 500.
The heat storagelexchange system 500 combines four functions. It recoveries
the
heat from the solar panel to heat exchanger, generates hot water, delivers
heat to the house
space heating system and recovers the heat from the warm waste water. The heat
exchange/storage system 500 has also another function for additional supply of
heat (if
necessary) from the TVP generator or fuel cell 400. The thermal photovoltaic
TVP system
400 is a separate unit with an ability to supply both electricity (15 to 20%)
and heat, by
1 o combusting natural gas (or propane) as a fuel. As a result the TVP unit
efficiency is close
to 95%. This system can be used when solar energy is not available (cloudy
days, night) or
when additional amount of heat is required to supplement the solar system. The
TVP unit
has also an option to transfer, via inverter 600, the unbalanced amount of
electrical energy
to the grid.
The inverter 400 is used for electrical energy conversion, and distribution of
the
energy load between all sources of electrical energy - solar PV, thermal TVP
and grid.
Important function of the inverter is the ability for instantaneous energy
exchange with the
grid of the unbalanced amounts of electrical energy, that makes possible that
every
2 o excessive, amount of energy that is extracted from the photovoltaic (or
thermal TVP) unit
is utilized. House owners can utilize that energy exchanged with grid .via net
metering
whenever it is needed or could be sold to the grid.
Hybrid Solar Pahel
2 s The solar panel is a large element, with the surface area of 15 to 30 mZ
that can be
tilted and moved along supporting rails around the house perimeter. In the
morning the
panel is facing the East and during the day slowly follows the Sun until the
Western side is
reached. The total (horizontal) rotation angle covered is about 160'. The
inclination angle
CA 02412028 2002-11-18
19
of the panel is controlled independently following the sun's seasonal angle
changes. The
range of changes of the inclination of the solar panel is sufficient to cover
seasonal sun's
angle changes (for Alberta 27° in Winter and about 67° in
Summer).
By the application of panels that can supply both electric and thermal kinds
of energy, the
energy yield per area unit can be substantially increased. Benefits of the
hybrid panels in
terms of costs and space are significant compared to the solar installations
with separate
PV and thermal modules.
The solar panel 300, as shown in FIG. 4, combines two solar elements - PV
arrays
301 and thermal modules 302 - into one hybrid panel. In effect the solar
energy flux, and
radiation-collecting area, is utilized to full potential (100% use). The photo-
voltaic,
transparent array 301 adsorbs only a small portion of the available solar
energy (10 to
15%) and the rest is transmitted and absorbed by the thermal module.
Arranging the PV and thermal modules in such a way that they are separated by
the
air gap, prevents the PV module to be heated by the thermal module, and allows
PV array
to operate at the optimal temperature conditions thus avoiding loss of
efficiency. In the air
gap the light shatters can be applied (if required) for an option of
separating of thermal
modules operation form PV modules operation.
Making the hybrid panel operating as a sun-tracking system, the solar energy
gain
from the panel is maximized by the solar module, which permanently operates at
the pick
performance. Theoretically, this is the only solution that allows the
extraction of all the
available energy from the solar radiation.
The solution as described increases the system performance to the maximum and
significantly improves the economics of its implementation. It is assumed that
properly
sized panel will cover about of 90% of the total energy needs (power and heat)
required by
CA 02412028 2002-11-18
the single-family house. It is also assumed that during the summer there will
be excessive
amount of energy generated that might be used for many different applications.
One such
application for electrical energy is charging short-range electrical car. The
excess of
thermal energy can be used for air conditioning systems or swimming pool
heating.
5
The panel includes two layers of for solar radiation absorption. The first
layer
consists of the transparent photo-voltaic battery 301 and the second the
thermal absorber
302 that can be made of the vacuum tube arrangement. In between the layers is
an open
volume allowing passage of portion of the solar radiation from the first layer
to the second
10 layer.
The arrangement and nature of the two layers keep the solar cell array
relatively
cool and as a result the photo-voltaic efficiency is kept high.
15 Panel assembly 300 combine both types of solar energy receivers, the photo-
voltaic
array and thermal absorbers assembled Like a sandwich. The first, transparent
photo-
voltaic layer adsorbs about 10-15% [Watt, 1999] of the solar radiation energy
and thermal
absorber absorbs the rest. Such arrangement prevents the overheating the photo-
voltaic
battery thus preventing electrical efficiency loss related to the PV module
overheating.
A frame 303, rail 304 with rollers 305 that can move freely along the rail
supports
the assembled panel. The panel is moved with motor 307 and its tilt is
controlled by the
hydraulic angle changing mechanism 308.
2 5 The panel is also capable of cooling the house (by overshadowing) when the
ventilation slots are open and therefore has a dual capability.
A lightweight, solar radiation-reflecting device (shutters) can be introduced
in the
CA 02412028 2002-11-18
21
gap between PV arrays and thermal modules to have an option to cut-off thermal
module
(if required) from operation of the PV array. This device is off during winter
period but
might be activated during very hot summer days when there is no need for heat.
The panel has means to change its position 307 and align (tilt) 308 to
direction of
the solar radiation, and for returning the panel to its initial, beginning of
day position:
The solar panel 300 moves in the space (gallery) formed by the glass enclosure
and
the wall of the house. That space, with the louvers 20S and 206, is closed
during winter
1 o and open during the summer letting passage for air circulation from the
exterior of the
house for purpose of gallery ventilation, when the temperature grows too high.
If the temperature goes too high the PV cells suffer efficiency reduction. The
reduction of efficiency is in the range from 0. 1 %J°C to
0.6%J°C.
Installation of the solar panel in the air-lock gallery between the house and
glass
enclosure, brings additional benefits in terms of better house thermal
insulation during the
winter (louvers closed) or protection against excessive house warming during
the summer
by overshadowing the house and ventilation (louvers open).
Creation of the hybrid panel gives significant synergistic benefits: These
benefits
include:
The same collecting area is used for the electricity and heat generation, so
the
collection area used is reduced almost two times (smaller surface required) as
compared with that occupied by two separate collectors
Tracking system increases annual energy gain by about 50% as compared with
the stationary system
Cost of the supporting structure common to both modules is significantly
CA 02412028 2002-11-18
22
reduced
The thermal collectors work as a cooling system for the photo-voltaic array
preventing overheating
The moving panel perform an other energy related role working as a shield
s during hot summer
days, thus reducing air-conditioning energy demand
Energy is generated at the point of end use and as a result transmission
losses
and distribution
costs are minimized
The integration of the solar panel, with the house design, gives significant
benefits in
terms of house construction, occupied space, equipment used and resources
(costs).
The unique combination of the hybrid solar system, thermal photo-voltaic
furnace,
with grid connected inverter and heat recovery/storage system creates a very
energy
efficient and reliable solution for supporting the house operation. The option
for selling the
excess of generated electrical energy to the grid, or use it for the other
purposes,
significantly improves the economics of the system.
2 o The main features of the solar house integrated energy system are:
Full and efficient utilization of the solar energy (sun-trucking system
maximizes
the energy gain)
The house relies mostly on energy from the sun a.-,id only occasionally form
2 5 natural gas
The solar house will produce a substantial amount of the electrical power that
can
be sold to the power-grid during
The house design and heat management and recovery system reduces heat losses
CA 02412028 2002-11-18
23
to a minimum (e.g. the heat losses in waste warm water)
The thermal photo-voltaic system generating both power and thermal energy
during power outages gives the unique comfort in terms of power availability
and
security.
The invention as described, which serves two functions (heating and
electricity
supply), may also offer important benefits when applied in remote areas or
areas with few
resources for development of adequate housing or other building
infrastructure.
1 o Although the present invention has been described with a certain degree of
particularity, it is understood that the present disclosure has been made by
way of example
and that changes in details of structure and system may be made without
departing from
the spirit of the invention.
EXAMPLE
Even in cold climate regions; like Central Canada, the amount of useful solar
energy reaching the ground (even in winter) is greater than the daily enerlry
requirements
of a properly designed house.
For example for the typical house located in Edmonton area the annual
insolation is
about 460 GJ. The energy demand, by typical medium size detached house is
about 170
GJ (electricity ~12%, hot water ~20% and space heating ~78%). By small
improvements
(better insulation and more tight construction, upgraded ventilation) the
energy demand
2 s can be easily further reduced down to about 90 GJ per year.
For purpose of illustration, in FIG. 5 (thermal energy) and FIG. 6 (electrical
energy) examples of the solar house energy generating potential and the energy
demand for
CA 02412028 2002-11-18
24
an Alberta located solar house constructed according to the invention for
different months
of year are shown.
This invention is integrating several different technologies including solar
technologies, therrno-photo-voltaic systems, and advanced heat storage and
energy
conversion. Basically, the energy is delivered from a solar photo-voltaic and
thermal
modules combined together as one hybrid solar panel.
During the day the sun-tracking energy collecting, panel moves along the semi-
1 o circular house perimeter in a narrow gallery (gap) between the house wall
and outer glazed
enclosure. The panel, when following the sun, changes its inclination (tilt)
in such a way
that it always stays perpendicularly orientated to the solar radiation, thus
working at the
maximum possible efficiency. The solar panel consists of the transparent photo-
voltaic
arrays combined with the solar thermal modules forming sandwich type solar
panel.
Portion of the incident solar radiation, about 10 - 15%, is absorbed by a
transparent photo-
voltaic array and used to generate electricity. The rest of the radiation is
transmitted to a
second layer, forming a thermal solar module, were it is absorbed to generate
heat.
Generated electrical energy is used to support electrical needs of a house
with an option to
2 o transfer the excess of electrical energy to the grid (via an inverter), or
could be used for
other purposes e.g. to charge the electrical car battery. The heat energy-
generated in the
thermal modules is used for hot water preparation and for space heating.
During cold
weather the thermal energy collected during the day will be stored in a heat
storage/exchanger system to secure the house heat supply required during the
night. The
heat storage/exchanger system is used not only as a heat accumulator but is
also used to
recover heat from warm wastewater (bathroom, appliances). The design of the
house,
construction, its shape and orientation are adapted in a way to maximize the
solar energy
gain and minimize heat losses.
CA 02412028 2002-11-18
During hot, summer weather, the moving panel will work as a solar shield
preventing extensive house overheating by overshadowing.
The solar energy system is supplemented with a gas operated (natural gas or
propane)
thermo-photo-voltaic (TVP) generator (TPV system as described in patents,
US5312521,
US5616186, US5651838, and US5865906 and US5942047) that has ability to
generate the
electrical energy and heat simultaneously. This system generally is designed
to operate
during winter, when both kinds of energy are required. The excess energy can
be
i o transferred to the grid (electrical energy) or stored in the heat storage
system (thermal
energy).
Because of the unsteady nature of the solar energy Generation it is preferred
that
the house energy system is connected to the utility grid. Using an inverter
with net
1 s metering can do this. It is assumed that on sunny days that the applied
system can generate
a surplus of energy.
The excess of the electrical energy will be either sold to the grid or used to
charge a
short-range electrical car. This will further reduce the X02 emissions.
The excess of thermal energy that will be generated during the summer can be
utilized for any purposes e.g. for swimming pool heating, for powering an air
cooling/conditioning system, or can be transformed into other useful forms of
energy. If
required special shutters will be activated and will block the thermal unit
from solar
2 5 radiation.
The house equipped with the integrated energy system as invented is will be
grid-
connected, however, it can also perform very well in the off grid applications
reducing
CA 02412028 2002-11-18
26
significantly the amount of house energy demand.
It is assumed, that in the grid-connected applications the house energy
consumption
can be reduced as much as 80-90%.
Location of the moving solar panel inside of narrow glazed gallery/enclosure
is
very important because the system is protected from harsh Canadian climate, is
not
impacted by snow and rain, and by operation inside of the enclosure reduces
heat losses of
the thermal collector. The enclosure also reduces house heat losses (buffer
zone). During
1 o the summer the gallery is ventilated and protects the house form
overheating.
The glazed gallery could be regarded as a greenhouse enclosure covering a
significant portion of the house and forming a buffer zone. Its role, except
for a protective
role for equipment, is to apply the greenhouse effect to warm the house during
the winter.
1 s During the summer that space will be well ventilated and greenhouse effect
heat will be
removed and dissipated to atmosphere.
The implementation of the solar tracking panel into the house structure offers
further advantages; such as lower costs, improved esthetics, better weather
protection and
2 o system reliability, and higher thermal efficiency.
Important feature of the proposed solution is that by sun-tracking the system
operates always at the maximum possible efficiency and has the total energy
production
higher about 50%, when compared with a stationary system. Another advantage is
that the
2 s integrated panel combines three functions, the generation of electrical
energy, production
of heat, and house shading/screening. That makes this solution very functional
and
attractive.
CA 02412028 2002-11-18
27
The houses equipped with the solar integrated. energy systems show great
promise
for both, grid-tied building-integrated applications and remote houses or
villages, and
might play a big role in resolving future energy problems.
The present invention accomplishes the following:
1 . It provides a house design that will:
I o - maximize the solar energy capture
- integrate the sun-tracking solar panel with the house structure
- implement glazed, greenhouse effect enclosure
- use (expose) an additional surface (Trombe wall) for the solar energy
capture during winter
- apply the sky-light for prolonged daylight application
2. It provides the glazed enclosure that will:
form a thermal barrier (e.g. reduces the heat losses during winter, and is
well ventilated during summer)
2 0 - create a weather protection shield (snow, hail, wind or rain) for the
solar
collector and its equipment, and let the equipment operate in the optimized
conditions
- form a noise barner
2 5 3. It provides highly efficient solar energy collecting system capable to
deliver
electrical energy, hot water and space heating
4. It provides hybrid sun tracking solar energy panel that is composed of
transparent
CA 02412028 2002-11-18
28
photo-voltaic (PV) arrays and thermal, vacuum tube/chamber type collectors.
Both, PV and thermal modules are mounted on the same supporting frame and can
be used independently.
5. It provides hybrid sun-tracking solar energy panel that allows operate the
PV array
at temperatures completely independent of the temperature of the thermal solar
module that in applied arrangement is used as a heat sink for PV arrays.
6. It provides a movable panel that woks as a solar shield and permanently
l o overshadows the house and prevents its excessive heating during summer
7. It provides an integrated energy system that:
- actively exchanges the unbalanced electrical energy with the grid
system by using net metering system
15 - is equipped with highly energy efficient backup source of energy
that is thermal-photovoltaic generator using natural gas, propane or diesel
oil, for simultaneous electrical and heat energy generation (it can be
replaced by a fuel cell if justified)
- can storage, in a heat accumulator, the excessive thermal energy for
2 o night house heating application
- recovers the waste heat from warm sewer water
8. It can apply excess of generated energy in summer for electrical car
charging
(electrical energy), and for empowering of the air conditioning
system/refrigerator, or to be
25 used for any other purpose (thermal energy).
In this patent document, the word "comprising" is used in its non-limiting
sense to
CA 02412028 2002-11-18
29
mean that items following the word are included, but items not specifically
mentioned are
not excluded. A reference to an element by the indefinite article "a" does not
exclude the
possibility that more than one of the element is present, unless the context
clearly requires
that there be one and only one of the elements.
It will be apparent to one skilled in the art that modifications may be made
to the
illustrated embodiment without departing from the spirit and scope of the
invention as
hereinafter defined in the Claims.
