Just a question for you guys with panels and an EV...

[smkettner]

Thanks to the idiotic company I used to install the pv system I am only going to be producing maybe 80 of what I use.

80%? Do you have any optional TOU rate plans?

[jimbo69ny]

Thanks to the idiotic company I used to install the pv system I am only going to be producing maybe 80 of what I use.

80%? Do you have any optional TOU rate plans?

Im not sure what TOU means. I live in Central NY. Our electric is already quite cheap. Currently its around $.12/kwh

[dgpcolorado]

How many miles do you drive? That is some serious conservation! You obviously have gas for space and water heating?

It takes a 17.9kW system (east/weast/south facing with lots of shade) to produce about 13.5 kWh annually for space/water heating, driving ~10k miles, and the rest of my electricity needs.

I drive about 7400 miles a year. And, yes, I heat with gas (used to be propane until gas lines got installed in this remote rural area). Water heater is on-demand (tankless) gas. I designed my house to be "sun tempered" so I get a lot of heat from the sun on sunny days in the fall and winter. And I dress warmly and keep the thermostat fairly low in winter: 62ºF mornings and evenings and 52ºF at night.

Before I put in the solar panels I scored a 9.9 (99th percentile) on energy use for my household size and climate zone on the Home Energy Yardstick. To get better than that I'd have to heat with a woodstove. I do the little things: I don't own a clothes dryer, instead I strung lines across my oversize utility room to line-dry clothes (in my previous house I used the basement for that). I started using fluorescent lights in the mid eighties and my three most used lights are now LED. And, of course, I don't use air conditioning. My biggest power use, besides the furnace blower and the LEAF, is my home theater setup, but it only runs a couple of hours a day, on average.

Last year my 2170 watts of solar panels produced 3327 kWh of electricity. That's about 9.1 kWh a day or about 4.2 hours x panel wattage. Colorado is a pretty good solar location. Despite the snow.

Before solar panels and the LEAF, I measured my electricity usage at about 4.8 kWh/day, on average. I take conservation pretty seriously but I don't live a third world lifestyle.

[GRA]

Thanks to the idiotic company I used to install the pv system I am only going to be producing maybe 80 of what I use.

80%? Do you have any optional TOU rate plans?

I'm not sure what TOU means. I live in Central NY. Our electric is already quite cheap. Currently its around $.12/kwh

ToU (or TOU) = Time of Use. Rates typically vary depending on time of day, day of the week and/or season, usually between peak and off peak, sometimes adding a super-off peak rate as well. ToU availability varies depending on the utility, and not all offer it.

EV charging is typically done overnight at lower off peak rates. With grid-intertied PV, depending on whether or not you have net metering or separate meters, you can often sell electricity to the utility at peak rates during the day when you're not home using it, and buy it from the utility at night at much lower rates when you are home.

[jimbo69ny]

Oh. I kinda thought thats what you meant.

One of the meters was upgraded to a "smart" meter but they left the other one the basic meter with the dial. I assume because the pv system on the smart meter was a larger system but I dont know. Like I said, it was all a mess.

[RegGuheert]

Im pretty happy with my set up.

How much more output do you expect to achieve based on that extra tilt? I presume the extra spacing help keep the wind loads limited significantly?

There are two PV systems and the panels on the right are solar hot water.

I agree with a high tilt for the solar hot water, since that prevents collecting WAY too much heat during the summertime. They look like about 60 degrees, which is about right.

OTOH, I'm not sure I would have used flat-panel water heaters in NY. When it is cold, I expect the efficiency will be very low.

Thanks to the idiotic company I used to install the pv system I am only going to be producing maybe 80 of what I use. Probably less actually. I used a local company called Solar Liberty in Ithaca NY and they were a bunch of idiots!

The PV systems are 3 kw and 5 kw I believe.

It appears from the picture that the entire available roof space is covered with PV. Is there space for more PV that I am not seeing?

One of the meters was upgraded to a "smart" meter but they left the other one the basic meter with the dial. I assume because the pv system on the smart meter was a larger system but I dont know. Like I said, it was all a mess.

This might be an issue. I'm going to guess that the upgraded meter contains ALL the PV, but if you have a duplex, assumedly you have two houses using power. If you are on a net-metering arrangement, then you might find that one house gets no benefit from the PV and the other house only benefits until you produce more than was used. In other words, you will be giving free electricity back to the power company if the 8 kW array produces more electricity over the course of the year than you use in the ONE house. This is because most net metering arrangements do not pay you net electricity rates beyond what you use.

But the devil is in the details. Perhaps you have more details about the arrangement with the power company?

[KillaWhat]

Ok, I know this has been touched on, but here goes anyway.

I'm currently about half way through installing a 4Kw PV system on the garage roof.

16 ET 255 Black on Black panels with 16 New style Enphase M250's

With no help or incentives here in PA, it's really expensive.

The problem I'm having is with the family and friends.

"What do you mean it won't provide power during a black-out? That's stupid!"

Etc.

Yes, I'm an engineer and I know about islanding, etc.

Having said all that....

I'm sure I could trick the M250 micro- inverters into producing using a small 240 vac pure sine wave inverter, and use the array to charge the Leaf.

I could then use the Leaf and the inverter to provide limited power for the house.

The Leaf would provide the needed load for the PV system, and I would disconnect from the street by shutting off my main breaker.

There would be some "critical races" like with the EVSE powering up, etc., but it should be doable.

Any thoughts?

[smkettner]

I think it will be harder than you expect to trick the inverters. I might be wrong....
If you had a string inverter you could use the DC power direct through a charge controller to charge some batteries. Then another inverter to power the home or charge the vehicle.

There are some string inverters that will supply limited AC power to a separate circuit if the grid is down.

[JasonA]

We should talk... I'm using what's called a "blackout breaker" to trip once the grid goes dark.. then my APC 10kw Smart-UPS backfeeds into the whole house via one of their isolation transformers.

It keeps the micros happy and I can even keep power feeding into the APC with the gen for ext periods if nec (earthquake, etc). I've already tested charging the Leaf and Rav.. no issues.

Best way is just with a big UPS

[jimbo69ny]

Tubes suck. People always think they are better in colder climates because they deliver a hotter temp but they collect more snow in the winter. Flat plates are more reliable in colder temps and thats a fact.


Yes there is more space, they couldve put panels in front of the solar pv panels. There is plenty of room. They also couldve put panels over the garage which has nothing above them.

There are two separate systems one for the left side of the house and one for the right.