View Single Post
Old 05-03-2011, 10:25 PM   #14 (permalink)
bwilson4web
Engineering first
 
bwilson4web's Avatar
 
Join Date: Mar 2009
Location: Huntsville, AL
Posts: 843

17 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

Blue Bob's - '19 Tesla Std Rng Plus
Thanks: 94
Thanked 247 Times in 157 Posts
Hi,

I've been running errands today and just had a chance to get back:
Quote:
Originally Posted by jamesqf View Post
A few thoughts, for what they're worth.

1) I didn't see any mention of disconnecting the house from the grid lines before hooking up the Prius. You do know that the current could be a hazard to repair crews?

2) Why not get a solar water heater instead of doing all the work to hook up the Prius' exhaust &c? Gives you free hot water 365 days a year.

3) Do you really need to run a plasma TV? A few good books and a couple of LED headlamps use a lot less energy.
1) I run extension cords from the Prius into the house and to the various loads. Until I have enough for whole house power, I'm not going to install a cut-over switch.

2) I've looked at solar hot water systems and rather than do a piece-meal solution, I'm planning a whole house solution. Meanwhile, the exhaust heat is 'low hanging fruit' and easy enough to implement.

3) We only had one TV, the plasma unit, that had a DVT receiver. The bedroom 19" unit is analog and only works when the cable system is operational which it wasn't during the outage. We did use an FM radio as backup to the TV but valley radio was only useful when they chose to simulcast with a TV station.

During a wide-area, power outage, we needed accurate, current information including the curfew, location of gas, food, and supplies, changes to traffic rules, and how to avoid impact areas. I love a good book but how do we get current disaster information?

Quote:
Originally Posted by dcb View Post
Bob, is there any guesstimate on additional costs in cogen? i.e. nat gas to electricity/heat, extra hours on the prius engine, etc?

How hard is it to get a prius to run off a nat gas hose (I want to teach my little generator how to do that).
I can't give the cost until I freeze the design but every time we go through a power outage, I learn valuable lessons. But here are my current thoughts:
  • Exhaust heat - route through a 'gutted', gas fired, hot water heater. Ebay suggests prices in the $300-500 range.
  • electrical power - I'm expecting to design a power-switch for two legs of MG2 and leaving the current sensor by-passed. With two legs removed, I can provide AC power limited only by how much I wish to draw from the traction battery and MG1 generator. Pulse-width modulation into a filter network should provide exceptionally clean power. The isolation transformer will be $250-350 and the rest of the bits should be about the same, call it $700.
  • engine compartment heat - I'm thinking rigging up the hood so it can hinge at the front and rise up at the windshield. Then a wedge-shaped insert can form an air-tight seal and a thermostat controlled fan force warm air into an insulated, flexible duct. It will also include a carbon monoxide and smoke detector to shut it down if anything 'bad' is detected. I figure hardware ~$50 and a foam-and-glass wedge another $50 and insulated duct $200. Add some electronics and sensor, we're looking at $300-400.

As for the fuel cost, I downloaded a spreadsheet of fuel costs. It looks like for one million BTUs:
  • $10.54 - natural gas
  • $23.73 - kerosene (untaxed, gasoline substitute)
Now I will lose some heat compared to a more efficient, heat-only system. However, it will leave the car fully warmed up each morning so my MPG costs should go down, significantly. Best of all, loss of electrical power will no long be an issue.

Now I have found some conversion systems but the EPA has been a 'horse's ass' about conversion systems. They insist that the vehicle be re-certified with the conversion system and that is a $250-500,000 expense. However, there are . . . alternative sources. So far, I've seen:
  • $500 - carburetor systems
  • $2,000 - fuel injector systems

Bob Wilson
__________________
2019 Tesla Model 3 Std. Range Plus - 215 mi EV
2017 BMW i3-REx - 106 mi EV, 88 mi mid-grade
Retired engineer, Huntsville, AL

Last edited by bwilson4web; 05-03-2011 at 10:40 PM..
  Reply With Quote