Very nice! Wish I could afford [a Tesla]...

A Chevy Volt can run a Field Day (or a house under minimum power) for about 8 hours before it has to start the engine to recharge the battery. These 3 year-old off-lease Volts go for only about $12k.

-----Original Message----- From: AMSAT-BB On Behalf Of jim k6ccc Subject: Re: [amsat-bb] Tesla Field Day mode

Bob - WB6APR said:

Tesla is releasing Field-Day mode (er, "party mode") in its models to allow the vehicle to continue with AC/Heating, Temperature control, airflow, selective lights and music for up to 48 hours or more while in Park. The feature will also allow users to power other electric devices using the electric car's battery.

Very nice! Wish I could afford one...

73

True, Zach....the difference is, the taxpayers don't pay for your setup !!

73, Ted K7TRK

-----Original Message----- From: AMSAT-BB [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Zach Metzinger Sent: Wednesday, February 20, 2019 11:57 AM To: amsat-bb@amsat.org Subject: Re: [amsat-bb] Tesla Field Day mode

On 2/20/19 1:28 PM, Robert Bruninga wrote:

...

Very nice! Wish I could afford [a Tesla]...

A Chevy Volt can run a Field Day (or a house under minimum power) for about 8 hours before it has to start the engine to recharge the battery. These 3 year-old off-lease Volts go for only about $12k.

Seems a bit overkill when a marine deep-cycle and a solar panel will run you about $500, no? ;-)

--- Zach N0ZGO _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb

On 02/20/19 16:41, Frank Karnauskas wrote:

I think Mr. Bruninga published an article in QST or CQ a few years ago about the advantages of using a vehicle instead of a separate gasoline powered generator for emergency uses?

It is, perhaps, a convenience to go this route. However, in terms of efficiency, small generators win every time.

Just think about all the systems your car is running (fluids being pumped around, electrical loads) and the fact that a gasoline engine at idle has terrible thermodynamic efficiency. Quoting a 2008 paper[1] by Remy:

With a typical engine efficiency of 40%, a belt efficiency of 98% and an alternator efficiency of 55%, this leads to an overall energy conversion efficiency of only 21%. Assuming a fuel cost of $4.00/gal, this leads to an on-board electrical power cost of $0.51/kWh, or roughly 4 times a typical household utility rate.

Now, that's just the alternator, discounting all of the other stuff bolted to the engine. Compare this to my back-of-the-napkin calculation of $0.70/kWh for the EU2200i at max rated load[2]. The car seems like a win, but it won't be due to the "other stuff" eating energy.

I can attest to the quietness of the EU2200i, as I own one. However, a solar panel is even quieter. :-)

--- Zach N0ZGO

[1] http://www.delcoremy.com/documents/high-efficiency-white-paper.aspx [2] https://powerequipment.honda.com/generators/models/eu2200i