Electric vehicle photovoltaic charging system

• US 6,313,394 B1
• Filed: 01/28/2000
• Issued: 11/06/2001
• Est. Priority Date: 02/05/1999
• Status: Expired due to Fees

• Current Assignee: Sunpower Corporation (Totalenergies Se)
• Original Assignee: PowerLight Corp. (Totalenergies Se)
• Inventors: Dinwoodie, Thomas L., Shugar, Daniel S.
• Primary Examiner(s): DIAMOND, ALAN D
• Application Number:
  US09/494,068
• Time in Patent Office: 648 Days
• Field of Search: 136/244, 136/249.MS, 136/251, 136/291, 180/2.2, 180/65.3, 180/65.1, 180/65.2, 296/37.7, 323/906
• US Class Current: 136/244
• CPC Class Codes: B60L 2200/22 Microcars, e.g. golf cars
• CPC Class Codes: B60L 8/003 Converting light into electric energy, e.g. by using photo-voltaic systems
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/90 Energy harvesting concepts as power supply for auxiliaries' energy consumption, e.g. photovoltaic sun-roof
• CPC Class Codes: Y10S 136/291 Applications
• CPC Class Codes: Y10S 323/906 Solar cell systems

Abstract

A PV roof assembly (6) includes a roof (12) mountable to an electric car (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 PV assembly may include a monolithic PV panel (14) with a plurality of PV cells (20). The roof may define a storage region (32) accessible through a closable access opening (44). The roof may include a circumferential lip (24) which extends around and above the PV assembly to help prevent damage to the PV panel. The roof may include a protective, at least semi-transparent top layer (60), an at least semi-transparent bottom layer (62) and a semi-transparent PV layer (64) secured between and in contact with the top and bottom layers to create a roof which is itself semi-transparent. The ratio of PV cells to the number of battery cells may be chosen to create a self-regulating design. A misting system (55) with roof-mounted misting outlets (53) can be used for enhanced comfort during hot weather. A graphical display may be used to provide the driver with, for example, energy production and battery charge level.

Claims

1. An electric vehicle photovoltaic (PV) charging system, the system usable with an electric vehicle, comprising:

a roof, mountable to an electric vehicle, comprising a support surface;

a PV assembly secured to the support surface;

the PV assembly comprising a PV panel having a circumferential edge and the roof comprising;

a circumferential lip extending around and above the PV assembly, whereby the circumferential lip helps to prevent damage to the PV panel;

the circumferential lip and the circumferential edge defining a gap therebetween; and

a rain gutter formed below the gap so that water flowing through the gap is collected in the rain gutter.

2. The assembly according to claim 1 further comprising an edge protector covering at least a portion of the circumferential edge.

3. An photovoltaic (PV) roof assembly usable with an electric vehicle having battery cells, comprising:

a roof mountable to an electric vehicle, the roof comprising an upper part;

a PV assembly at the upper part of the roof; and

the PV assembly comprising a plurality of PV cells, the ratio of the number of PV cells to the number of battery cells being between about;

4.80 to 5.48 PV cells to battery cells when the PV assembly comprises at least one of crystalline and poly-crystalline photovoltaics;

4.20 to 5.20 PV cells to battery cells when the PV assembly comprises hybrid crystalline/thin-film photovoltaics; and

4.10 to 5.50 PV cells to battery cells when the PV assembly comprises thin-film photovoltaics.

4. The PV roof assembly according to claim 3 wherein said ratios are about:

5.10 to 5.40PV cells to battery cells when the PV assembly comprises at least one of crystalline and poly-crystalline photovoltaics;

4.40 to 5.00 PV cells to battery cells when the PV assembly comprises hybrid crystalline/thin-film photovoltaics; and

4.20 and 5.40 PV cells to battery cells when the PV assembly comprises thin-film photovoltaics.

5. An electric car having battery cells comprising:

an electric vehicle;

a roof mountable to the electric vehicle, the roof comprising an upper part;

a PV assembly at the upper part of the roof,

the PV assembly comprising a monolithic PV panel with a plurality of PV cells connected in series;

the roof comprising;

a bottom spaced-apart from the upper part and defining a storage region therebetween;

an access opening opening into the storage region; and

a movable cover removably covering the access opening;

the PV panel having a circumferential edge;

the roof comprising a circumferential lip extending around and above the PV assembly, whereby the circumferential lip helps to prevent damage to the PV panel;

a misting system, comprising misting outlets from which mist can be discharged, mounted to the roof; and

the PV assembly comprising a plurality of PV cells, the ratio of the number of PV cells to the number of battery cells being between about;

4.80 to 5.48 PV cells to battery cells when the PV assembly comprises at least one of crystalline and poly-crystalline photovoltaics;

4.20 to 5.20 PV cells to battery cells when the PV assembly comprises hybrid crystalline/thin-film photovoltaics; and

4.10 to 5.50 PV cells to battery cells when the PV assembly comprises thin-film photovoltaics.

6. The assembly according to claim 5 wherein the PV panel constitutes at least a major portion of the roof, and wherein the PV panel comprises:

a protective, at least semi-transparent top layer;

a bottom layer; and

a PV layer secured between and in contact with the top and bottom layers.

7. The assembly according to claim 5 further comprising an edge protector covering at least a portion of the circumferential edge.