Forget 'Baby on board'

[Jim Becker]

Alan, how would a traditional fossil fuel generator be handled in this situation where you have solar as you describe with the draconian prohibition of using it during a utility power outage? In essence, a battery "generator" is what would fit in that same space.

[Alan Lightstone]

Alan, how would a traditional fossil fuel generator be handled in this situation where you have solar as you describe with the draconian prohibition of using it during a utility power outage? In essence, a battery "generator" is what would fit in that same space.

A propane generator (we have a tank here, but no natural gas available) would be able to power the house during a grid blackout (automatic or manual transfer switch). The solar panels, I believe, would again not be usable during the time the grid is out.

If at all usable, I would think they would have to supplement the generator output, otherwise that brownout scenario would occur. Not sure how equipment would handle that scenario. Certainly not technologically impossible, but I don't think fossil fuel generator companies (Generac, etc...) would have any interest in that.

[Larry Edgerton]

I'm guessing yours is not a diesel dually. I haven't looked at them lately, but not too long ago they were all around a hundred grand. New stereo is a good tip. It needs one anyway. That's about the only thing that's quit working in this 24 year old one with 387,000 miles. I was hoping it would last until they came out with a plug in version. I only put a few hundred miles a year on it these days. This one has been so reliable because it was the last year they made them with no smog control stuff on it. It doesn't even have an EGR system on it.

I put one on my step van, but that was easy. The one I used did not have a data link, it was wireless. I did have to tap into the tail light for power at the camera. And I had two acres of dash to install it on.

[Jim Becker]

A propane generator (we have a tank here, but no natural gas available) would be able to power the house during a grid blackout (automatic or manual transfer switch). The solar panels, I believe, would again not be usable during the time the grid is out.

If at all usable, I would think they would have to supplement the generator output, otherwise that brownout scenario would occur. Not sure how equipment would handle that scenario. Certainly not technologically impossible, but I don't think fossil fuel generator companies (Generac, etc...) would have any interest in that.

Generac actually has an excellent battery backup solution...I considered it for here (along with solar panels), but in the end, I decided we would not be at this property for long enough to make it worth the investment, at least for us. They use the same automated transfer switch as with the gas powered generators (which I did opt for, having an all electric house other than oil backup on the heat pump) so that potentially would be a solution you could use. During normal times, the solar panels could keep the battery array topped off and if the utility goes down and they shut off your panels, you still have power. It's just coming from a bunch of very heavy batteries rather than from a traditional generator.

[mike stenson]

Most grid tie solar inverters need a source of power to sync to. Even if you had a transfer switch to isolate your solar the panels won't produce any power. This is starting to change. The latest Enphase microinverters can produce power even if the grid is down.

Those must be newer than a year.

[Alan Lightstone]

Generac actually has an excellent battery backup solution...I considered it for here (along with solar panels), but in the end, I decided we would not be at this property for long enough to make it worth the investment, at least for us. They use the same automated transfer switch as with the gas powered generators (which I did opt for, having an all electric house other than oil backup on the heat pump) so that potentially would be a solution you could use. During normal times, the solar panels could keep the battery array topped off and if the utility goes down and they shut off your panels, you still have power. It's just coming from a bunch of very heavy batteries rather than from a traditional generator.

I extensively looking into getting Tesla Powerwalls a few years ago. Also looked at a few competitive products. I also look at them periodically.

To power our whole house would take 4 Powerwalls, which would run $46K. Now one thing you realize (or should realize) living in hurricane country is that you don't have to power your whole house if the grid goes down. You need 1 room with AC (hurricanes in summer the issue down here), some lights, and fridge/freezer. Really don't need to power the whole house. So I actually had my electrician reorganize my circuit breakers to have those loads on one panel, to make that easier. Planned on having 1 floor of the house have power in an emergency.

I also had an energy monitoring system installed on those breakers, to see just how much power they use during the day. Easy-peasy. Knew what I needed. Time to get the battery backup system.

At that point, for whatever reason that cost them a sale, my solar installers dropped the ball and didn't return my calls about getting the battery backup installed. A year later, the company called and asked if I had any interest in buying a battery backup. I told them too late, they lost the sale.

After looking into the economics of getting battery backup, it doesn't make any financial sense with my utility. Duke Energy only pays me back $.025/Kwh of electricity I send back to them as surplus, and now charges $15.6/kWh for usage. So if I used the batteries every night to power the house, and charged them with the solar panels every sunny day, it looks like the batteries will pay for themselves in about 15 years. But their lifetime is about 10 years. I've had a few solar companies confirm this. The honest ones here will tell you that they will never pay for themselves. A whole-house propane generator here would only cost around $15K.

Since I built the big homemade UPS for our medication fridge, the real risk (other than inconvenience) of a prolonged power outage here is just food in the fridge. Economically a drop in the bucket compared to the cost of a battery backup system. Now on the other hand, if a huge battery in an EV like the Cybertruck can provide that power, the economics change. And if every 3 days you need to run to the Supercharger for an hour to recharge the Cybertruck, not a big deal (during the last hurricane here the vast majority of the gas stations had no power. I checked 5 Superchargers - all were working fine.)

Now if I lived in a wildfire prone area, like some in California, that often have brownouts or blackouts, I'd likely give a different answer. Or if my utility paid me the same for surplus that they charge for usage.

[Steve Demuth]

Those must be newer than a year.

They've been available since 2021 from Enphase. If you have IQ8 inverters, those are grid-forming capable. Whether or not, and when, they will provide AC power absent grid input depends on how they're configured (which of course depends on what your utility will permit).

[Roger Feeley]

I’m curious, the navigation system learn routes from manual driving? When I’m driving home, I often use a particular highway and the gps in our Chrysler wants me to use what looks like the most direct exit. But I don’t like that exit because I only have a hundred feet to cross three lanes of traffic to make a turn. I use a different exit that’s much less stressful. I usually turn the gps off by that time but you see my point.

I remember when we got our first gps, I was running it while I drove to well known places to see how it would behave. At some point, I plugged in my neighbors address, literally 40 feet away. The route the gps came up with was over 10 miles. It wanted me to go to a major highway, go one exit and navigate back. My testing was very useful.

[Jim Becker]

I extensively looking into getting Tesla Powerwalls a few years ago. Also looked at a few competitive products. I also look at them periodically.

Tesla eventually "closed" their offer and started requiring their own solar roof or panels, if I'm not mistaken, in order to buy the PowerWall system. Originally, it was able to be used with other solar collectors, again, AFAIK, but I could be wrong about this. When I priced the Generac system, I found it pretty reasonable for the backup scenario I wanted which was on the upper end of things, although it was more than I could justify for how long we will live here as I previously noted. The good news is that solar solutions, including battery backups, are continually coming down in cost and there are a lot more options available on the market.

[Steve Demuth]

After looking into the economics of getting battery backup, it doesn't make any financial sense with my utility. Duke Energy only pays me back $.025/Kwh of electricity I send back to them as surplus, and now charges $15.6/kWh for usage. So if I used the batteries every night to power the house, and charged them with the solar panels every sunny day, it looks like the batteries will pay for themselves in about 15 years. But their lifetime is about 10 years. I've had a few solar companies confirm this. The honest ones here will tell you that they will never pay for themselves. A whole-house propane generator here would only cost around $15K.

You might look again. The price on batteries has dropped dramatically in the last 3 years. What would have cost you $46K 3 years ago can probably be had for closer to $20K today.

Also, doesn't the price differential between what you export, and what you consume from Duke make batteries more attractive, not less? If you can charge enough battery capacity most days to power your house during the 18 or so hours the panels aren't producing at scale, that's saving you the difference between the rates, minus efficiency losses in going to and from the battery, for each kwh the batteries provide. That's be in the vicinity of $0.10 per kwh in your case. Still not going to pay for itself in a short period, but at less that $8000 for a 13.5 kwh Powerwall 3, it'd be in the vicinity of paying for itself over the lifetime of the battery, and you get the backup as a bonus.

[Doug Garson]

I’m curious, the navigation system learn routes from manual driving? When I’m driving home, I often use a particular highway and the gps in our Chrysler wants me to use what looks like the most direct exit. But I don’t like that exit because I only have a hundred feet to cross three lanes of traffic to make a turn. I use a different exit that’s much less stressful. I usually turn the gps off by that time but you see my point.

I remember when we got our first gps, I was running it while I drove to well known places to see how it would behave. At some point, I plugged in my neighbors address, literally 40 feet away. The route the gps came up with was over 10 miles. It wanted me to go to a major highway, go one exit and navigate back. My testing was very useful.

You must be referring to much older GPS systems. Yes they all have glitches in their data base maps but the glitches are becoming much less common. I use Google Maps and sometimes Waze (also owned by Google), it does not use your manual driving to determine your route. It has an incredible database of maps covering a lot of territory including, (based on my experience), fairly remote areas of Costa Rica. My understanding is it calculates your route using real time traffic information including traffic delays, accidents and road construction sites. I've used it to navigate home and wondered why it was taking an odd route only to hear on the radio that there was a big accident on my normal route. My understanding is it uses cell data from thousands of cars pinging cell towers to determine that cars are not moving at usual speeds on a certain road and interprets that as a traffic jam. It also uses input from drivers reporting speed traps, cars stopped on the side of the road etc (at least Waze does this) to warn you of problems. I think the navigation side of the self driving issue is the least to worry about.

[Doug Garson]

PS: I have always wondered what a fully autonomous car would do if I am going straight through a busy intersection, while a big truck is going fast running the light, and there is a troop of Girl Scouts on the opposite sidewalk. Will it sacrifice my car full of Nuns, or the Girl Scouts? I know the manufacturers have thought of this, and I suspect they have addressed it somehow. I also suspect it will remain a dark secret.

Live long and prosper.

I wonder what the answers would be if that scenario was described on the driver's test and applicants were required to answer? I also wonder what % of drivers could think it thru and react in time to do what they say they would do.

[Rick Potter]

Roger's post (#38) made me curious, so when I left to get a burger, I went down my street about 100', since the car needs a bit of movement to know exactly where you are. I stopped, and entered the address of the house across the street from my house, then started out. About 50 feet down the street I was told to do a u=turn and go back. I did that, and it took me to the correct street address.

PS: Just got a notification telling me they have used data from thousands of trips to hone and improve the city street driving by nav. Sounds like a lot of people are trying the free month trial. I also got a notification that Tesla has reduced the price from $200 a month to $100, after only a couple of weeks into the trial subscriptions. Not sure about my car, but four others in the family will definitely be doing it.

[Bill Dufour]

I have heard that tesla now requires you to buy at least one powerwall if they add solar panels. People also take used car batteries that no longer hold a full charge and use those as solar backup batteries. A battery that is like 80% gone from original amp hours is considered a warranty item. It will last a long time inside a home with no big temperature swings, no vibration, no heavy load accelerations. Who has 700 Hp in their home shop?
A tesla battery breaks into something like six, 40 volt sections. If only five are good use those in the home system.
Frito Lay is using the Tesla semi trucks here. UPS no longer uses the BEV trucks. They lasted about five years. I understand the mega charger for the trucks are like 1,000 volts at 1,000 amps
BilL D

[Alan Lightstone]

Many years ago now, I had a Lexus LS that was perhaps the first car that could park itself. My daughter used it for her driving test, and when she had to parallel park and not hit the cones to pass the test, she had the car do it.

The instructor laughed hysterically, then said. OK. You pass. Now do it yourself.