U.S. patent application number 10/188688 was filed with the patent office on 2002-11-28 for electric vehicle roof.
This patent application is currently assigned to PowerLight Corporation. Invention is credited to Dinwoodie, Thomas L., Shugar, Daniel S..
Application Number | 20020174889 10/188688 |
Document ID | / |
Family ID | 26816899 |
Filed Date | 2002-11-28 |
United States Patent
Application |
20020174889 |
Kind Code |
A1 |
Shugar, Daniel S. ; et
al. |
November 28, 2002 |
Electric vehicle roof
Abstract
A PV roof assembly (6) includes a roof (12) mountable to an
electric vehicle (4), and a PV assembly (10) at the upper part of
the roof. The PV assembly may be mounted to a separate roof surface
(34) or the PV assembly may itself constitute all or part of the
roof. The vehicle may include a secondary PV assembly (96) coupled
to a display unit (92) to provide an independent indication of the
intensity of solar irradiation. The roof may have mounting element
recesses (68) to accommodate mounting elements (70) of the PV
assembly, the mounting elements configured so as not to shade the
PV panel (14). The roof may also be configured to accommodate a
global positioning device (80). The roof preferably includes a
peripheral gutter (88). The roof body preferably includes hand-hold
recesses (90) housing hand-hold elements (42) at positions to
provide a horizontal setback (92) from the lateral sides (93) of
the roof body.
Inventors: |
Shugar, Daniel S.; (San
Bruno, CA) ; Dinwoodie, Thomas L.; (Piedmont,
CA) |
Correspondence
Address: |
HAYNES BEFFEL & WOLFELD LLP
P O BOX 366
HALF MOON BAY
CA
94019
US
|
Assignee: |
PowerLight Corporation
Berkeley
CA
|
Family ID: |
26816899 |
Appl. No.: |
10/188688 |
Filed: |
July 2, 2002 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10188688 |
Jul 2, 2002 |
|
|
|
09785665 |
Feb 16, 2001 |
|
|
|
09785665 |
Feb 16, 2001 |
|
|
|
09494068 |
Jan 28, 2000 |
|
|
|
6313394 |
|
|
|
|
60118943 |
Feb 5, 1999 |
|
|
|
Current U.S.
Class: |
136/251 ;
136/244; 136/291 |
Current CPC
Class: |
Y02T 90/14 20130101;
H02S 10/40 20141201; B60L 2200/22 20130101; Y02T 90/12 20130101;
Y02T 90/16 20130101; Y02T 10/70 20130101; Y02T 10/72 20130101; B60L
8/003 20130101; B60L 2240/622 20130101; B62D 25/06 20130101; Y02T
10/7072 20130101; Y10S 136/291 20130101; Y02E 10/50 20130101 |
Class at
Publication: |
136/251 ;
136/244; 136/291 |
International
Class: |
H01L 031/00 |
Claims
What is claimed is:
1. An electric vehicle photovoltaic (PV) roof comprising: a vehicle
roof body comprising a generally flat PV assembly-supporting upper
surface, a peripheral edge circumscribing the upper surface, and a
peripheral gutter formed between the upper surface and the
peripheral edge; the gutter having a minimum chosen depth below the
upper surface.
2. The roof according to claim 1 wherein the chosen minimum depth
is at least about 6 mm.
3. The roof according to claim 1 wherein the gutter has a minimum
width of about 3 mm.
4. The roof according to claim 1 wherein the peripheral edge
comprises an upper edge spaced apart above the upper surface.
5. The roof according to claim 1 further comprising PV assembly
attachment devices configured for the attachment of a generally
flat PV assembly to the roof body.
6. An electric vehicle photovoltaic (PV) roof comprising: a vehicle
roof body comprising a generally flat PV assembly-supporting upper
surface, a peripheral edge circumscribing the upper surface, and a
peripheral gutter formed between the upper surface and the
peripheral edge; the gutter having a minimum chosen depth below the
upper surface; the peripheral edge comprising an upper edge spaced
apart above the upper surface; and PV assembly attachment devices
configured for the attachment of a generally flat PV assembly to
the roof body.
7. An electric vehicle roof comprising: a roof body comprising
front and rear edges and lateral side edges; hand-hold recesses
formed into the lateral sides at chosen position; and hand-hold
elements located within said hand-hold recesses at positions to
provide a minimum horizontal setback between the hand-hold elements
and the lateral sides.
8. The roof according to claim 7 wherein the minimum setback is 2.5
cm.
9. The roof according to claim 7 wherein the roof body has an upper
surface overlying the hand-hold elements.
10. An electric vehicle roof comprising: a roof body comprising an
upper surface, front and rear edges and lateral sides; hand-hold
recesses formed into the lateral sides at chosen position; and
hand-hold elements located within said hand-hold recesses at
positions to provide a horizontal setback of at least about 2.5 cm
between the hand-hold elements and the lateral sides; and the upper
surface overlying the hand-hold elements.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a division of U.S. patent application Ser. No.
09/785,665 filed Feb. 16, 2001, which is a continuation in part of
U.S. patent application Ser. No. 09/494,068 filed Jan. 28, 2000,
now U.S. Pat. No. 6,313,394, which claims the benefit of
Provisional Patent Application No. 60/118,943, filed Feb. 5,
1999.
BACKGROUND OF THE INVENTION
[0002] Smaller electrically powered vehicles, typically called
electric cars or electric carts, are widely used on golf courses
and for a variety of electric utility vehicle applications.
Although electric golf cars have become widely accepted, they
typically require recharging after about to 36 holes of golf.
Therefore, a typical 18 hole golf course requires about 80 cars to
serve the golfers each day and a building large enough to house all
the golf cars at night, during which they are commonly recharged.
The recharging process not only takes time, but recharging during
daytime hours can significantly increase the cost of electricity as
a result of increasing peak demand charges from the utility to the
customer.
SUMMARY OF THE INVENTION
[0003] The present invention relates to several aspects of an
electric vehicle with a photovoltaic (PV) roof assembly which
permits the batteries on an electric vehicle, typically referred to
as an electric car or electric cart, to be charged during operation
resulting in several benefits. These benefits include extending the
range of the electric car because the batteries are charged during
operation. The cost of using electricity from the utility to charge
the cars is reduced because the batteries are typically at least
partially charged by the solar charging during use. The battery
life of the car can be extended because the depth of discharge can
be reduced during normal use of the car. By increasing the length
of time required between charges, labor costs incurred in the
process of charging the batteries are reduced. Cars can be used
more efficiently, thus possibly reducing the number of cars
required by the facility. Finally, there are also benefits to the
environment resulting from the reduced use of electricity from the
electric utility and the potential need for fewer cars.
[0004] A first aspect of the invention is directed to an electric
vehicle of the type including a vehicle body carrying a motor, a
battery and a main PV assembly, the main PV assembly being coupled
to the battery so to charge to battery. This improved electric
vehicle includes a display unit mounted to the body, the display
unit being electrically isolated from the battery and the main PV
assembly. A secondary PV assembly is mounted to the body and is
electrically connected to the display unit so the display unit
provides an indication proportional to the intensity of the solar
irradiation on the secondary PV assembly.
[0005] Another aspect of the invention is directed to an electric
vehicle PV roof assembly including a vehicle roof comprising an
upper surface having a number of assembly mounting element
recesses. A PV assembly is secured to the upper surface of the roof
of using PV assembly mounting elements at the mounting element
recesses. The mounting elements are configured so that they do not
shade the PV assembly.
[0006] A further aspect of the invention is directed to an electric
vehicle PV roof assembly comprising a vehicle roof having an upper
surface with first and second surface portions. A PV assembly is
mounted to the first surface portion and a global positioning
device, such as the ground plane of a global positioning system or
a global positioning system antenna, is mounted to the second
surface portion. The vehicle roof may include an opening through
which the wires from the global positioning device can pass.
Further, the second surface portion of the upper surface may
include raised portions so to provide ventilation regions between
the PV assembly and the upper surface. The upper surface may also
include a depression positioned to accommodate wires exiting the PV
assembly.
[0007] A still further aspect of the invention is directed to an
electric vehicle PV roof including a PV roof body having a PV
assembly-supporting upper surface, a peripheral edge circumscribing
the upper surface, and a peripheral gutter formed between the upper
surface and the peripheral edge. The gutter has a chosen minimum
depth below the upper surface. The chosen minimum depth may be at
least about 6 mm and the width of the gutter may be at least about
3 mm.
[0008] Another aspect of the invention is directed to an electric
vehicle roof comprising a roof body with front and rear edges and
lateral side edges. Hand-hold recesses are formed into the lateral
sides at chosen positions. Hand-hold elements are mounted within
the hand-hold recesses at positions to provide a minimum gap
between the hand-hold elements and the lateral sides. The minimum
gap is preferably at least about 2.5 cm.
[0009] Other features and advantages of the invention will appear
from the following description in which the preferred embodiments
have been set forth in detail in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a side elevational view of a covered electric car
incorporating a PV roof assembly made according to the
invention;
[0011] FIG. 2 is a top, rear, right side isometric view of the PV
roof assembly of FIG. 1;
[0012] FIG. 2A is an enlarged cross-sectional view taken along line
2A-2A of FIG. 2 illustrating the closable trunk opening which opens
into the interior of the roof;
[0013] FIG. 2B is a cross-sectional view taken along line 2B-2B of
FIG. 2 passing through one of the hand holds in the roof;
[0014] FIG. 2C is an enlarged view illustrating a rain gutter
outlet along one of the back corners of the roof of FIG. 2;
[0015] FIG. 3 is a top, front, left side isometric view of the roof
of FIG. 2;
[0016] FIG. 4 is a bottom isometric view of the roof of FIG. 3;
[0017] FIG. 5 illustrates an alternative embodiment of the
invention in which the circumferential edge of the PV panel is
captured within a circumferentially extending recess formed in the
edge of the roof to help protect the edge of the PV panel;
[0018] FIG. 6 is a simplified overall view of a PV roof assembly
incorporating a misting system coupled to a controller;
[0019] FIG. 7 is a simplified cross-sectional view of a portion of
an alternative embodiment of the invention which the PV assembly
constitutes the roof;
[0020] FIG. 8 is a top, front, left side isometric view of an
alternative embodiment of the roof of FIG. 3;
[0021] FIG. 8A is an enlarged view of a portion of the roof of the
FIG. 8 illustrating a mounting element recesses;
[0022] FIG. 9 as a bottom, rear, right side view of the roof of
FIG. 8;
[0023] FIG. 10 is a cross-sectional view taken through the center
of the rear edge of the roof of FIG. 8 similar to that of FIG.
2a;
[0024] FIG. 11 is a cross-sectional view through a handhold of the
roof of FIG. 8 similar to that of FIG. 2B; and
[0025] FIG. 12 is a side elevational view of a covered electric
cart, similar to that of FIG. 1, incorporating a display unit
coupled to a secondary PV assembly.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
[0026] FIG. 1 illustrates a covered electric car 2 including an
electric car 4 covered by a PV roof assembly 6, the PV roof
assembly 6 supported by a roof support framework 8. Electric car 2
may be a conventional electric car such as that made by Club Car,
Inc., of Augusta, Ga. While PV roof assembly 6 will typically be
used with golf car type of electric cars, can be used with other
types of battery powered cars and vehicles which can be designed
for use with one, two or more occupants. PV roof assembly 6 could
also be used with, for example, hybrid vehicles which use both
electricity and a fuel (such as gasoline or natural gas for an
internal combustion engine) or with fuel cell-powered vehicles.
[0027] FIGS. 2, 2A-2C and 3 illustrate PV roof assembly 6. Assembly
6 includes a PV assembly 10 which is mountable to a roof 12. PV
assembly 10 includes a PV panel 14 having a circumferential edge 16
surrounded by a generally C-shaped edge protector 18. Edge
protector 18 is preferably made of rubber; it could also be made of
other protective materials such as metal or plastic It is preferred
that PV panel 14 be a monolithic PV panel. This eliminates many of
the problems associated with conventional vehicle charging systems.
That is, conventional solar charging systems often use several,
typically three, conventional solar panels interconnected to one
another to create a solar panel array. By using a single,
monolithic PV panel, interconnections between individual panels are
eliminated creating a system which can be stronger, less expensive
and more reliable than multi-panel systems. PV panel 14 includes an
array of individual PV cells 20 electrically coupled to one another
in a desired pattern to provide the desired voltage and current
output.
[0028] PV panel 14 is preferably a self-regulating voltage design.
That is, PV panel 14 is specially designed to match the voltage
characteristics of the electric car 4. This design maximizes
electric current charge at low (discharge) battery voltages and
self regulates (reduces) its charge at higher battery voltages. The
self-regulation feature results from using an appropriate ratio of
PV cells to individual battery cells. For crystalline and
poly-crystalline photovoltaics, the preferred self regulation range
is about 4.80 to 5.48 PV cells to battery cells, and more
preferably about 5.10 to 5.40 PV cells to battery cells. For hybrid
crystalline/thin-film photovoltaics, the preferred self regulation
range is about 4.20 to 5.20 PV cells to battery cells, and more
preferably about 4.40 to 5.00 PV cells to battery cells. For
thin-film photovoltaics the preferred self-regulation range is
about 4.10 to 5.50 PV cells to battery cells, and more preferably
about 4.20 to 5.40 PV cells to battery cells. Accordingly, the
self-regulation is achieved by the appropriate selection of the
ratio of PV cells to battery cells which produces an optimal
current for a given battery voltage condition.
[0029] As seen in FIGS. 2A and 2B, circumferential edge 16 of PV
panel 14 lies below the upper edge 22 of the circumferential lip 24
of roof 12. Therefore, in addition to edge protector 18, the
circumferential edge 16 is also protected because its position
relative to circumferential lip 24 is such that a golf ball G will
not fit into the space 26 between the two. More preferably, the
distance between corner C1 of lip 24 and corner C2 of edge 16 is
less than the diameter of a conventional golf ball G, that is about
4.3 cm, such that a direct strike of a golf ball G on edge 16 is
not possible; this may reduce or eliminate the need for edge
protector 18.
[0030] Roof 12 includes an upper wall 28 and a lower wall 30 which
defines a storage region 32 therebetween. Upper wall 28 has a
herringbone pattern of upwardly extending supports 34. Supports 34
include numerous high bond-strength double-stick tape patches 36
used to secure PV assembly to roof 12. Tape patches 36 are
preferable made of relatively thick, such as 0.47 mm (0.1875 inch)
thick, somewhat spongy material to provide not only secure adhesion
but also a certain amount of vibration isolation. Other techniques
for securing PV assembly 10 to roof 12, such as using an adhesive,
spring clips, shock mounts, threaded fasteners, clamps, etc., could
also be used. Laterally-extending kiss-offs (not shown) provide
separation between upper and lower walls 28, 30.
[0031] In addition to providing a mounting surface for PV panel 14,
supports 34 also help to provide cooling air to the underside of PV
panel 14. In addition, the herringbone pattern of supports 34 helps
to guide water to rain gutters 38, 39, see FIGS. 2A and 2B, formed
adjacent to lip 24 along the sides and ends of roof 12. Water
empties from roof 12 through one or both gutter drains 40 shown in
FIGS. 2 and 2C.
[0032] FIG. 2B illustrates a cross-sectional view taken through one
of two hand holds 42. FIG. 2A is a cross-sectional view taken
through the trunk opening 44 and trunk opening cover 46. Trunk
opening 44 provides access to storage region 32 so that various
accessories, such as a charge controller, a spray mist pump and
reservoir (described below), or other things can be mounted within
storage region 32 and yet permit access by, for example, one or
more of the owner, the user and a service technician.
[0033] FIG. 4 illustrates the underside of roof 12. Roof 12 is
designed to be used with more than one brand of electric car 4 and
is thus suitable for retrofit applications. To accommodate
different types of roof support frameworks 8 for different brands
of electric cars 4, different mounting recess, such as those
identified as 50, 51, are provided along lower wall 30. FIG. 2B
illustrates a cross-sectional view of a typical mounting recess 48
formed in roof 12. Other accommodations, such as brackets,
removable or not, may be made to permit assembly 6 to be used with
more than one type of electric car 4.
[0034] The positioning of edge 16 relative to lip 24 and the use of
edge protector 18 helps to protect circumferential edge 16 from
damage. FIG. 5 illustrates, in simplified form, an alternative
method for protecting circumferential edge 16 of PV panel 14 from
damage. In the embodiment of FIG. 5, circumferential lip 24A
includes a generally u-shaped recess 52 which houses
circumferential edge 16 to support and to help prevent damage to
the circumferential edge.
[0035] FIG. 6 illustrates, in a very simplified form, a PV roof
assembly 6B including misting pipes 53 (only one of which is shown)
coupled to a water reservoir 54 housed within storage region 32 of
roof 12B as parts of a misting system 55. Reservoir 54 could be,
for example, made of a flexible bladder or a rigid container, or
created by sealing off all or part of region 32. Misting pipes 53
include misting heads or nozzles 49 at appropriate locations along
the misting pipes. Misting system 55 also includes a pump 56
coupled to a controller 57. Controller 57 is also coupled to PV
panel 14B and batteries 58 to control the charging functions. A
control panel 59 is coupled to controller 57 to permit input to the
controller and access to various operational parameters, such as
battery charge level, charging rate, battery life, etc. Control
panel 59 preferably includes a graphical display capable of
displaying graphical and alphanumeric information to a user,
typically to the driver of car 2, so to inform the user of, for
example, energy production, pollution avoidance and battery state
of charge.
[0036] Misting system 55 permits PV roof assembly 6 to provide not
only solar charging of batteries 58, but also helps to provide a
more pleasant environment for the occupants during hot weather.
Misting nozzles 49 may be placed at different locations on the PV
roof assembly, the roof support framework and/or the car; for
example, misters could be positioned at each corner of the PV roof
assembly. Water reservoir 54 could be located on the car rather
than the PV roof assembly. The tubes or pipes coupling water
reservoir 54 to misting pipes 53, or other misters, could, for
example, pass through hollow members of roof support framework 8
and between PV panel and upper wall 12. Misting system 55 could be
completely manually controlled, automatically controlled or
semi-automatically controlled. Automatic control could be based on
one or more of ambient temperature and humidity, solar radiation
intensity, whether the car is moving or is stopped, whether the car
is occupied, etc. For example, the user could set system 55 to mist
continuously only while the seat is occupied and the ambient
temperature is above 30.degree. C. (86.degree. F.). Seat occupancy
maybe sensed by, for example, a pressure sensor, a proximity sensor
or an infrared detector, coupled to controller 57. The seat
occupancy sensor may also be used in the control of, for example,
radio volume or other passenger-sensitive aspects of car 2. System
55 could also include features to reduce excessive battery
discharge, such as automatically shutting the misting system off
after a prescribed period; this could also be used to prevent over
misting.
[0037] FIG. 7 illustrates in a simple schematic form, a section of
a PV roof assembly 6C which includes no separate roof 12 as in the
earlier embodiments. Rather, PV assembly 10C constitutes the roof.
In this case, PV assembly 10 includes an upper, protective, at
least semi-transparent, and preferable transparent, top layer 60, a
bottom layer 62 and a PV layer 64 secured between an in contact
with top and bottom layers 60, 62. PV layer 64 may be
semi-transparent and bottom layer 62 may be transparent or
semi-transparent so that roof assembly 6C can be semi-transparent.
By the term semitransparent it is meant to include layers which
allow at least some light to pass through, such as surfaces which
are partially transparent and partially opaque, partially
translucent and partially opaque, and partially translucent and
partially transparent.
[0038] FIGS. 8-11 disclose an alternative embodiment of the
invention incorporating several modifications to the above
embodiments with like reference numerals referring to like
features. FIG. 8 illustrates roof 12D from above. The upper surface
66 of roof 12D includes upper edge 22D into which three mounting
element recesses 68 are formed. Tabs 70, see FIG. 8A, extending
from PV panel 14D are positioned within recesses 68 for securing
the PV panel to roof 12D using screws 72. Double sided tape, not
shown, is placed along the upper surfaces 84 of the chevron-shaped
supports 34D to help secure PV panel 14D in place. The raised
nature of chevron-shaped supports 34D permits airflow within gaps
formed between the bottom of PV panel 14D and the upper surface 86
of upper wall 28D. This helps to cool PV panel 14D. FIG. 8 also
illustrates numerous standoff depressions 74 formed into supports
34D which extend to lower wall 30D. Also shown in FIG. 8 are
numerous blinded counterbores 76; appropriate ones of the
counterbores are drilled out according to the location of mounting
hardware for the particular electric cart with which the roof
assembly is used.
[0039] FIG. 8 also illustrates a flattened surface region 78 formed
in upper surfaces 66 along the upper edge 22D at the front end of
roof 12D. Surface region 78 is used to support a global positioning
device 80, shown schematically in FIG. 10, such as the ground plane
of a global positioning system or a global positioning antenna. One
or more holes, not shown, may be formed in roof assembly 12D to
permit wires from global positioning device 80 to pass
therethrough. Such holes will typically be adjacent surface region
78. FIG. 8 also illustrates a depression 82 in upper surface 86 to
accommodate wires exiting from PV panel 14D.
[0040] Upper surface portion 86 of upper wall 28D lies between
supports 34D and is circumscribed by a peripheral rain gutter 88. A
portion of peripheral gutter 88, that is rain gutter 39D, extends
between gutter drains 40D. Peripheral rain gutter 88 preferably has
a minimum death below surface 86 of at least about 6 mm. Gutter 88
preferably has a minimum width of about 3 mm. FIG. 10 also
illustrates the positioning of cover 46D along the underside of
roof 12D as opposed to the positioning shown in FIG. 2A. This
positioning helps to shield the contents of storage region 32 from
the elements.
[0041] FIG. 11 illustrates the location of handhold 42D within a
handhold recesses 90. Handhold 42D has a minimum horizontal setback
91 of at least about 2.5 cm from the lateral sides 93 of roof 12D.
The provision of horizontal setback 91 helps to prevent injury to a
rider's hand as the cart passes close to, for example, a building,
post, sign, or another cart. This is in contrast with conventional
electric carts which often expose a rider's hands to injury when
passing close to structures, objects or vehicles.
[0042] FIG. 12 illustrates the covered electric cart 2 of FIG. 1
with several additional features shown schematically. A display
unit 92 is mounted to the vehicle body 94 at any convenient place,
such as towards the front as shown in FIG. 12. Display unit 92 is
connected to a secondary PV assembly 96 mounted to electric cart 2,
typically on the roof assembly 6. Also shown schematically are a
motor 98 and a battery 100 as is conventional. Battery 100 is
coupled to PV panel 14 through an appropriate controller (not shown
in FIG. 12). Display unit 92 may be of a variety of types, such as
a light emitting diode display, a cathode ray tube display, an
analog meter, or a liquid crystal display. Display unit 92 provides
an indication proportional to the intensity of the solar
irradiation on the secondary PV assembly 96. Display unit 92 is
intentionally electrically isolated from battery 100 and main PV
assembly 10. Using display unit 92 and a secondary PV assembly 96
to obtain an indication proportional to the intensity of the solar
irradiation is simpler and less expensive than obtaining this
information through the controller.
[0043] Modifications and variations can be made to the disclosed
embodiments without departing from the subject of the invention as
defined in the following claims.
[0044] Any and all patents, patent applications and printed
publications referred to above are incorporated by reference.
* * * * *