Eaton Advances Integrated Solar-Assisted Electric Vehicle Charging Station in Collaboration with Tennessee Valley Authority and EPRI
26 July 2010
Eaton Corporation is collaborating with the Electric Power Research Institute (EPRI) and the Tennessee Valley Authority (TVA) on a prototype integrated solar-assisted electric vehicle charging station to be erected at EPRI’s research laboratory in Knoxville, Tenn. Additional stations are planned for Oak Ridge National Laboratory, Nashville, Chattanooga and another site in Knoxville.
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| Simple block diagram of the SMART system. Source: EPRI. Click to enlarge. |
The prototype charging station used by EPRI and TVA, also known as a Smart Modal Area Recharge Terminal, or SMART station, will provide information on energy usage, the time when the equipment is used, the amount of solar-generated electricity produced and stored, and the potential impact of load clusters—when several vehicles are refueled at the same time—on distribution system reliability.
The collaboration will create a model charging facility that will charge electric vehicles quickly and reliably, and it will produce data to assist in implementing key components of a smart electrical grid. These components could include integrating renewables onto the grid, utilizing a battery storage system, assessing the impact on reliability of a distributed resource generation, testing advance metering infrastructure and analyzing electric vehicle supply equipment.
The base design includes the following attributes:
- 10 parking spaces each with electric vehicle supply equipment (EVSE) rated at 32 A, 240 V (7.68 kW capacity)
- Approximately 2 kW of solar photovoltaic (PV) panels provided per charge space (Its primary function is to offset vehicle energy usage.)
- Approximately 5 kWh of usable battery storage provided per charge space (Its primary function is to allow mitigation of peak system power demand.)
- All subsystems are linked by being grid-tied.
- Nose-to-nose parking layout with a center access aisle
- Subsystems modular at the two-space level
Eaton recently announced that it will collaborate with Takaoka Electric Manufacturing Company, Ltd. to develop and launch DC Quick Chargers, a key component in the charging of electric vehicle battery packs. The collaboration will enable Eaton to provide a complete line of charging stations across residential, commercial and industrial applications in North America.
Resources
Tennessee Valley Authority Smart Modal Area Recharge Terminal (SMART) Station Project: Volume 1 - Base Design Report
Good idea.
Posted by: HarveyD | 26 July 2010 at 08:27 AM
I don't see the point of these, unless you are off grid.
If you are on grid, just pump the power into the grid when you generate it, and suck it out when you need to recharge vehicles.
There is no need for battery storage, use the grid for this.
I continue to fail to see the synergy between EVs and solar power: if you want to generate electricity with PV cells, fine, go and do it, if you want to charge an EV, go and do it, but there is no need to link the two - it just complicates matters.
Posted by: mahonj | 26 July 2010 at 09:37 AM
"provide information on energy usage"
This could be useful for swappable battery packs. There is a complete history digitally stored and read out when the pack is swapped. It tells you all the power profiles and remaining useful life of the pack.
Posted by: SJC | 26 July 2010 at 10:43 AM
I agree with mahonj. Cleaner, low carbon electricity for the Grid (Mains) is one issue. Cleaner transportation with electric propulsion is related, yet a separate issue.
Connecting them in a project may help one imagine the possibilities and such development helps overcome resistance to grid-tied solar.
Posted by: jcwinnie | 26 July 2010 at 11:42 AM
These are interesting demonstration projects, it gets people to think of some possibilities. I could see solar panels on the home with advanced battery packs and inverter/chargers in the garage. People would really like driving around using the power of the sun.
Posted by: SJC | 26 July 2010 at 11:56 AM
My rooftop solar is rated at 5KW DC, 4KW AC. If I am losing that much in the conversion to AC, then it may be worth storing some power in fixed batteries (Axion or similar) to charge the BEV rather than feeding the grid and then taking from grid, while losing energy both ways.
Forgive me if this is not correct. I know little about electricity, AC, DC, Inverters, etc.
Posted by: JMartin | 26 July 2010 at 12:47 PM
Power in batteries to quick charge your EV is a possibility. The utilities may even encourage this in a G2G (call it Garage 2 Grid) to reduce the load and heating on their transformers. Inverters are usually about 90% efficient and large storage batteries are less efficient. Most would say just put the power on the grid during the day and charge from the grid at night.
Posted by: SJC | 26 July 2010 at 01:15 PM
It's a demo/gimmick. There is no reason to use PV when you have the grid.
I do not believe the loss is to-from the grid, but from the DC that the PV panels generate to the AC used by you and the grid.
I am not sure the inverter actually dissipates 1 KW out of 5, but PV providers do often compare their own DC KW to other's AC KW.
Posted by: ToppaTom | 26 July 2010 at 07:14 PM
There almost seems to be a disconnect between the article and the comment thread about gimmicky use of PV for recharge bays. I thought this was about setting up a framework (physical model) testing smart grid components to handle intermittent renewables and sudden (recharging) energy demand. In this case they are using PV and car recharging as these will stress the smart grid components. In that context it seems an entirely reasonable exercise.
If anyone has them, I would be interested in seeing actual figures for DC-AC-DC conversion losses and for comparing rates of recharge for AC(grid) to car and vs. direct battery to battery charge transfer.
Posted by: Thomas Lankester | 27 July 2010 at 06:53 AM
Google is your friend.
Posted by: SJC | 27 July 2010 at 10:08 AM