Solar Power Stuffs - Questions and Answers

[vall]

I'm currently set up on net metering but this setup isn't what I THOUGHT I was buying. Currently I get all my daily electricity from the grid. The power my panels generate goes straight to the grid. Essentially it runs my meter backwards. So I'm not really using any of the power I generate myself. If the power grid goes down, my house defaults to the backup generator which runs the entire house on propane.

So here's what I REALLY wanted to do and a subsequent question... I really would like to use my own power to run my house. I realize I need a battery wall to store the power to do that. But what I'd like to know is if I can set my system up as such -

Use my own power FIRST. If I don't have enough stored or available, then pull energy from the grid. If my battery wall is full, then send excess electricity to the grid. So basically keep the net metering but allow me to use the energy I create first. That way if the grid goes down, I can still use the power my panels are creating even if the grid is down. Then, my house will not fail over to the generator unless the battery wall is depleted AND the grid is down.

The question is if this is possible...

Yes. My folks in California have a powerwall, and it does use your own power + net metering like you want. I think these answer your questions better than I could:
https://www.tesla.com/support/energy/powerwall/learn/how-powerwall-works
https://www.tesla.com/support/energy/powerwall/learn/combining-systems

 

[Sally PB]

You'd have to do a work sheet, see how much power you use and go from there. Also your useage is seasonal, your generation is seasonal, that will need to be taken into account too.

Our electric bill includes a bar graph showing the number of KWH used each month, going back 13 months, so you can see how this month compares with a year ago.

Some appliances are seasonal use, like the clothes dryer. I don't use it if I can dry clothes on the line. I use the stovetop a lot in August and September for canning. (Both are electric.)

What is the name of the thing you plug an appliance into to see exactly how much power they use? I think I might start there and see what we're using.

ROI... Not looking to "make the cost back," as much as be self sufficient.

We do have a gas generator for when the power goes out, so losing a freezer full of food is only a risk if a power outage happened when we weren't home. We are looking into a whole house propane backup generator. One of the neighbors has one, likes it a lot.

 

[Ascholten]

What is the name of the thing you plug an appliance into to see exactly how much power they use? I think I might start there and see what we're using.

You can get them at some box stores / e bay / amazon etc.
Kill A Watt is one brand name. I use a panel type that you manually wire because it has more resolution but for you this should work nicely:
Edit maybe not, i hate those stores, incompetent morons ignorant ...working there.

anyways
https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU

is about as easy as it gets, plug it into the wall, the device into it and you can see pretty much anything you need.

they run about 25 to 30 dollars.

Aaron

 

[TJAnonymous]

Our electric bill includes a bar graph showing the number of KWH used each month, going back 13 months, so you can see how this month compares with a year ago.

Some appliances are seasonal use, like the clothes dryer. I don't use it if I can dry clothes on the line. I use the stovetop a lot in August and September for canning. (Both are electric.)

What is the name of the thing you plug an appliance into to see exactly how much power they use? I think I might start there and see what we're using.

ROI... Not looking to "make the cost back," as much as be self sufficient.

We do have a gas generator for when the power goes out, so losing a freezer full of food is only a risk if a power outage happened when we weren't home. We are looking into a whole house propane backup generator. One of the neighbors has one, likes it a lot.

We rarely use the dryer except in the winter. Everything gets line dried. However we do run the A/C pretty much nonstop from June - September. We only recently turned it off in the past 2 weeks. So basically I was upside down on my usage versus production until now but my Enphase app doesn't match what the electric company shows. For example, the app says my panels only covered 55% of my total consumption in the month of September. However the electric company says my panels covered 100% of our consumption and provided a surplus off nearly 700 kWh.

 

[Ascholten]

Enphase really is just looking at what you made, it does not consider really where it went, it grid or use, just what you made

Aaron

 

[TJAnonymous]

Well... Power is out to half the town. No idea why....

Thankfully we have a backup.

 

[chickengr]

we have 350-360 sunny days per year. I am thinking to get 9-10 385W solar panels (24V system), inverter 4kW and probably 12 batteries 2V/500 Ah. I also have a 6 KV petrol generator.

I wanted a wind turbine as well (with less solar panels) but the guy who sells them advised me against. he suggested more panels instead. told me I can add it later. it will be windy all year around but I am afraid anything might happen in winter when it will be too windy and I will not be able to climb high if anything gets into wind turbine (a plastic bag, branch, etc.).

 

[Ascholten]

we have 350-360 sunny days per year. I am thinking to get 9-10 385W solar panels (24V system), inverter 4kW and probably 12 batteries 2V/500 Ah. I also have a 6 KV petrol generator.

I wanted a wind turbine as well (with less solar panels) but the guy who sells them advised me against. he suggested more panels instead. told me I can add it later. it will be windy all year around but I am afraid anything might happen in winter when it will be too windy and I will not be able to climb high if anything gets into wind turbine (a plastic bag, branch, etc.).

why 2v batteries? now you have to spend all the extra money for balancing systems for them? why not a few 12v or a few 24 with self riding BMS built in?

Aaron

 

[allenw]

Wiring a dozen 2v batteries in series for 24v sounds like a lot of work plus a lot of extra connections to cause problems.

I've seen it about as direct as you can that cleaning panels will increase out put. More then once I've cleaned a panel on a solar pump and either have it start running or increase output. You can ear the pump running in a shallow well.

 

[chickengr]

why 2v batteries? now you have to spend all the extra money for balancing systems for them? why not a few 12v or a few 24 with self riding BMS built in?

Aaron

I don't have much choice here. 4 12V (240 Ah) batteries cost the same as 12 2V (500 AH) batteries.