Can I charge with a solar array?

The electric part of my utility bill is between $200 and $300 a month here in the boonies.

It is estimated that Google requires a constant 300 million watts (300000 KW) to keep the internet happy.

 

And that's why you have a solar array my entire utility bill including gas and electric has been under $21 since May.

 

One of the reasons. I also plan to buy either a Leaf or a Tesla Roadster in the coming years. I am also getting ready (before the car) to put in between 8KW and 10KW of solar on a couple dual axis passive trackers. That would power the house completely on average. Huge surplus during sun, same draw during darkness.

10KW is the maximum allowable on a lot of the rebates, so that is where I stop. Going from $1.20/W to $6.00/W is hard to justify when I do not need the extra power.

That is the thing about the internet. Everyone expects anything to be available anytime from any device. If just one of my servers goes down, 20-40 domains go down with it. If my farm goes down, that hundreds and hundreds of domains. If one person anywhere in the world can't access a picture of their cat while my power is out, it is a failure.

My electricity bill is an order of magnitude cheaper than my internet bill...

 

Was this a grid-isolated system, or a grid-tied system? 6 figures for a 3 kW system sounds like a ripoff scam to me. Even if you were going for a grid-isolated system, 6 figures is still way too much. I recently had a 4.94 kW DC / 4.34 kW AC grid-tied system installed on our roof. Cost of the system before rebates/incentives was $30K. Out of pocket cost is $20K. Originally the system was going to be 2.47 kW DC, and the cost for that was $18K before incentives, etc. The price for our system was about middle of the road. I probably could've gotten it cheaper if I had shopped around more. We're already saving money from day one. It will take 15 to 20 years before the full cost of the system is paid back, but that's at current utility rates. Electric rates in CA are going up. PG&E has already announced plans to raise rates in the near future. As rates go up, my payback period shortens considerably. I'm supposed to save at least a grand a year to start with.

It's not rocket science, but you need to be careful. Any failure to seal things properly and the panel will easily fail, and depending upon the failure mode, can cause a fire on your roof. Your insurance company might refuse to pay off the claim if they found out that you built your own solar arrays and it caused the fire. In general, most if not all utilities will want you to use UL listed equipment before connecting to their grid.

Did you actually tell the power company that you were making your own panels, or that you were building the array yourself? There's a big difference there. Lots of people do their own solar arrays with commercially available panels. But I haven't heard of anyone building their own panels and being allowed to tie it to the grid.

My advice? Start by getting some more quotes from other solar installers and think about going grid-tied rather than grid isolated. Making your own solar array is a great science project. But it's not practical for a large system. And it won't be practical for charging a car. It'll be way easier and cheaper to just charge the car via the regular utility power than to try to build enough panels, buy enough batteries, and get a big enough inverter to feed the car.

Panel prices have been steadily decreasing in the over the last few years. Grid-tied systems combined with a solar lease is making it way more affordable these days. Our system is actually a solar lease. No money down and my electric bills have pretty much disappeared. I used to spend $200 to $400 a month on my electric bill. I'm paying $100 to the solar leasing company and and my electric bill has been about $15 a month (minimum connection charges mostly). It will go up this winter because of low production from the array, but when spring arrives, I'll be making credits again which should balance things out. I won't know until July just how much I've saved, but we're supposed to save at least a grand a year.

 

You realize that your PiP draws 3.2 kWh to recharge?

 

Our monthly consumption before the install of the array was between 650 kWh and about 1100 kWh. Our system was designed to eliminate about 60% of our usage. That gets us out of the highest 3 tiers and gives us the most bang for our buck. Trying to eliminate the two lower tiers tends to not be as cost effective as it is to eliminate the top 3 tiers.

 

i really have to wonder what people are doing in their homes to have such huge power requirements…are you guys like growing stuff in your house …? lol

 

Well, to start with, we've got 4 adults living in a 1200 square foot house. 1 works from home now, another one used to work from home for a while. And a third person was un-employed for a while. We've got a number of laptops that are on at various points, a linux box that was on all the time acting as a web server on the internet (I've since replaced it with a Mac Mini that draw way less power). Various TV's and DVR's. I do at least 2 large loads of laundry per week for my wife and I, plus whatever the housemates are doing. When we had the electric dryer it was even worse. It was also pretty bad when the kids lived at home and weren't as, ummm, responsible with their electric usage. Most of the lighting in the house is CFL or LED. I'm looking to replace the ancient furnace we've got since I'm sure the blower motor in it is pretty inefficient. That and gas fired furnaces are way more fuel efficient these days.

So, no, we're not growing anything in the house. We just love our tech toys and modern conveniences.

 

Maybe your neighbor (who is stealing your electricity) is growing something in his house

 

yeah, laundry twice a week would do that. the Linux box was a huge draw as well i'm sure – when i had a roommate who had a desktop tower and would regularly fail to put the machine into standby mode, we managed to actually break into tier 2 territory.
i guess i don't watch TV that much (maybe one movie a week?) and most my time is spent on a macbook pro/ipad/iphone, basically the most efficient tech toys on the market today. also, no incandescent light bulbs at all, and i'm pretty good with shutting things off behind me.
btw, i presume you're using power strips to eliminate parasitic draws from devices on standby?

 

My monthly usage before the PiP averaged 220 kWh between October 2011 and June 2012. During one of the hottest summers on record, keeping my 5-ton central air unit (a little over 5 kW running) set to 73°F bumped our usage up to 633 kWh per month. That's with two wireless routers that burn through a good 18 kWh a month on their own. If I'd switch them off at night I could save some more without much effort.

I haven't had the PiP but a week, so it's hard to say what impact it will have at this time.

 

If you count the roommate's use of the laundry, it's 4 loads a week. And when we're in faire mode (Dickens right now, Ren Faire in the summer), it easily rises to 8 loads a week. Thank god for a large front loader machine and a gas dryer.

Replacing the linux tower has certainly made the room it's in a lot quieter, and a lot less warm.

We don't use power strips to shut off parasitic loads, I'm afraid. Too much of a pain to do so, I'm afraid. The L2 EVSE is always on, too (no way to put that on a power strip).

 

i'd recommend getting something like this for power strips: Amazon.com: Belkin Conserve Switch Energy-Saving Surge Protector with Remote: Electronics because it has a remote control, it makes it much more convenient to shut on/off. the current price is way too high though – set up an alert on camelcamelcamel.com when it drops below ~$32 or so and grab a bunch when it hits.
and quit being afraid

 

30 kW? Why would you need a system that huge? No wonder they told you the payback period would be 50 years. Most household grid-tied systems are usually in the 4 kW to 10 kW range. The only time I see people going over the 10 kW size is because they have a really huge house with lots of people, or they're going off-grid.

 

If the cost of it is more than what I expect to save in electricity, then I know what my wife's answer is gonna be...

 

well, get a kill-a-watt and figure out how much you'd save

 

If you charge everyday from empty to full, figure about 3.2 to 3.5 kWh per charge, or about 100 kWh per month. For me, I tend to charge only during the week. We tend not to use the PiP much on the weekends, or don't go anywhere, so my usage is about 75 kWh per month. At the highest Tier, it was costing about 34 cents a kWh, or about $20 to $25 a month. Now that we're on solar, it's about 10 to 12 cents a kWh, or about $7 to $8 a month.

 

Or I could go into the panel with a clamp-on meter and directly measure things.

I've also got UPSes deployed to protect the DVRs and the Mac server. I know those have a definite parasitic drain, but it's the cost of protecting the DVR, the TVs, the home theater stereo, etc.

 

LADWP discounts EV charging during off peak hours. You can charge for as low as $0.025/kWh and they'll rebate up to $2,000 of the cost of installing a Level 2 charger.