Using Grid-Tied Solar To Power Your Home And Vehicle – Driving On Sunshine

FEB 5 2014 BY MICHAEL CHIACOS 56

Michael With His Chevy Volt

Michael With His Chevy Volt And Solar Panel System (photo via James Studarus)

While I’ve always commuted by bike, eaten low on the food chain, recycled and composted, reduced my use of plastics and used energy efficient lights and appliances, the two largest things I could do to cut my carbon footprint drastically evaded me until just a few months ago.

After buying a small house, I started saving to invest in solar panels. Because of my work at CEC (Community Environmental Council) to help prepare the Central Coast for a large number of electric vehicles, I had been eyeing the new electric cars starting to come to market. Then last year, the 1998 biodiesel Volkswagen that my girlfriend Sarah and I shared became less reliable — and after repairs and much debate we decided to lease a Chevy Volt. Soon after that, we had enough saved up to install a 2.88 kW solar system at our house – large enough to zero out our monthly electricity bill and charge our new electric car.

Specs On Michael and Sara's Setup

Specs On Michael and Sarah’s Setup

Our solar panel system

Before getting an electric car, our electricity bill ran around $40/month — small enough that while going solar was something we wanted to do from an environmental standpoint, the financial payback was on the longer side. Once we added a Chevy Volt to the household, however, the bill increased by around $50/month (replacing a $100/month fuel bill for our old biodiesel Volkswagen), and we were pushed into Southern California Edison’s more expensive Tier 3 electricity rates. Suddenly solar power jumped to the top of the home improvement list, especially considering we could switch to Time-of-Use rates and charge the car inexpensively at night while getting credited for valuable daytime peak solar power.

Our 2.88 kW solar system from California Solar Electric cost $7,500 after the state rebate and federal tax credit. The payback is six to seven years (though may be faster if we mostly charge the car at night) and with a 25-year warranty on the solar panels we’ll be able to power our house and an EV for free for decades. If electricity rates continue increasing at about 6% a year (the historical average), then the system should produce enough clean electricity to save us about $55,000 in electricity bills over 25 years. This home improvement has also increased the value of our property.

Our electric vehicle

Chevy Volt

The Chevy Volt Was The Optimal Vehicle For Michael’s Household

After looking at all of our options, we determined that the Chevy Volt would best meet our household’s needs as it combines the best of an electric car’s efficiency (getting 100 mpg equivalent with zero tailpipe emissions) with the long distance range of a hybrid. By charging overnight off a regular 120-volt outlet, the car can go 38 miles on electricity, which is usually plenty of charge to cover Sarah’s daily client meetings. On occasional trips to neighboring cities like Ojai or Ventura, we use public charging stations — effectively enabling us to travel 75 miles a day in electric mode. We often go a few weeks without using a drop of gas, but on longer trips such as to San Francisco the gasoline range extender kicks in, enabling the Volt to achieve around 40 mpg for over 300 miles of driving before refueling.

Since we leased our Volt, the dealer was able to pass through the $7,500 federal tax credit, which I didn’t have enough tax liability for. The $1,500 California rebate covered the down payment, first month, and registration. With these incentives, our $355/month lease payment is actually cheaper than leasing a Toyota Prius or other much less expensive car, and we save on gas as well. Our Volt is nicely appointed and quite luxurious, filled with great technology and fun to drive. Once I even saved the day by unlocking the car remotely from my smartphone app when Sarah had locked the keys in the car and was late for an appointment!

While we never previously considered leasing a car (or even buying a new car), we like moving the EV market forward with our purchase while knowing we won’t be spending money on repairs. This recent article in Consumer Reports outlines why they also think leasing an EV is the way to go. In the last year, EV prices have come down even further. Some pure electric vehicles like the Chevy Spark EV and Fiat 500e start at $199/month with $199 down. They also qualify for a larger $2,500 rebate, so some potential buyers could use this to pay for the down payment and first seven months of driving and use their gas savings to pay the monthly payment.

Home Smart Meter Details

Home Smart Meter Details

Putting the two technologies together

With the new time-of-use pricing from Southern California Edison, we can charge our car at night for 9 cents/kWh using inexpensive off-peak power. Meanwhile, our solar panels generate valuable daytime peak power, which is credited to our bill at up to 47 cents/kWh during the summer. In short, we are buying low and “selling” high. Our last bill, for August, was negative, at -$33.88!

According to our home smart meter, on the first day with our solar panels, February 21, production exactly matched consumption. (See graphic) Note the green super-off-peak generation from the car charging midnight to 5 am, then the solar red on-peak generation spinning the meter backwards during the day, and the small orange off-peak consumption in shoulder hours. Charging an electric vehicle (EV) at night is equivalent to paying less than $1/gallon in a 30 mpg gas car.

We were very excited to discover that having solar and an electric car were possible on an average middle class income and the feeling of Driving on Sunshine is priceless!

“Driving on Sunshine” is a series about people who are using grid-tied solar panels on their homes to power their electric vehicles.  More plug-in vehicles are entering the market at competitive prices, including low monthly leases starting at $199/month. In addition, more people are able to afford home solar systems thanks to solar leasing programs and group-purchasing options, such as CEC’s Solarize program.

Michael first published his story at Community Environmental Council’s “Power For Good” News Blog – which we encourage anyone who is green-minded to check out.

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56 Comments on "Using Grid-Tied Solar To Power Your Home And Vehicle – Driving On Sunshine"

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I would love to do something like this as a Doomsday Prep in that if something knocks out the gas supply I can make my own fuel. But if the electric company decides to jack up rates I can at least bring something to the table to tell them off. Also I like the idea of a self sustaining none polluting system. I think though five to ten years in the future everyone is going to be adding battery back ups to their systems to save power for the night time.

Realize that grid tied solar (inverters) are designed to only produce power when there is power on the grid.

Ie, power goes out, so do your solar panels. This is to prevent you from energizing the grid during a blackout when lineman are working.

Your only option for “doomsday” is to have a cutoff and a generator which can put a load on the system so the panels will generate (it’s actuality the inverter that shuts off, not the panels).

Don’t know how much power that would require.

Hi Kosh.
New SMA inverters now have a 120 volt 15 amp circuit and plug that is energized when the grid is down. It’s not much but will be most useful in a long lasting emergency for hygene, cooking, mobile communications, and some refrigeration.

Not designed to charge a car however on the low 8amp setting of some chargers it would work.

As long as the sun is up!
Cheers

Battery-back-up is generally not worth the cost. If you have a remote cabin not connected to the grid then batteries are good. But if you are on a reliable grid, batteries are just a big extra expense and added maintenance for something that you’ll rarely ever use. I have no problem with losing power maybe one day a year due to a storm.

If I where to buy a existing house with solar panels I might consider adding batteries to it. But in terms of adding batteries I think the costs for them are going to go down like solar panels soon so that is why I’m waiting to add solar panels now to my existing house in that they are most likely going to keep going down.

Yes, and no (batteries not worth the cost). To grid tie, you must show you got installed by a “certified installer”, which means your cost goes way up, typically double the raw materials cost. What you are paying for is to be a “certified producer of power”, that is, you will generate certified clean power back to the grid.

If you self install and use the grid only on an input basis, that is, backup only (or backup on backup, since this would only kick in if the sun does not shine long enough for the battery to lose charge), then you can apply the cost saving to batteries. The result is a fully independent system, no need to sell power back to the power company and repurchase at night, and means you are immune to the (inevitable) price hikes that the power companies want to pass on to solar users.

Maybe not….

Maybe it’s different in your state, but here in California I was able to install my own system as a homeowner. All I had to do was get it inspected by both the city and PG&E, but that would true for professional installers as well.

Yeah, no. As Kosh pointed out, you probably don’t need a ‘certified installer’. You do need the system approved & inspected by the building department but I didn’t need a certified installer for the two systems I have self-installed.

It is a common misconception that you can’t self install. The utilities and the solar installers both don’t want you to know that you can do it yourself due to their own vested interest and write their materials up in ways that will make it appear that you can’t do it yourself. I met a guy who did his own home EV conversion (something I would not dare attempt . . too complex for me) but he got tricked into thinking he could not do his own PV install.

TO add to what Spec9 said, keep in mind that grid tied solar with enphase micro inverters is SUPER easy. Darn near plug and play. The only electrical work was just standard (adding circuit breakers, running wire in conduit to a box under the panels).

The hard part was really just the 3′ by 7′ deep holes for the poles (I did pole mounted)…. but that’s ANOTHER story.

Michael,

Congratulations on your setup! I especially enjoyed the “Home Smart Meter Details” image. It really highlights the value your setup brings to yourself, the grid, and society at large. By adding to the grid during high demand, and utilizing energy during overproduction, you are helping to stabilize the grid.

It is exciting how many people are making the switch to EV+PV. Keep spreading the good word!

Well done and well written, congrats to the both of you! The main takeaway for me is your comment about the average middle class now being able to to do this. It truly is now possible for many/most Americans to do similar. It’s all about choices but the path is there and you’re helping lead the way.

Cheers

Peder
95,000 ev miles powered by sunshine!

“Once I even saved the day by unlocking the car remotely from my smartphone app when Sarah had locked the keys in the car and was late for an appointment!”
———
My Volt won’t let me lock the keys in the car. How did you manage this?

He must have had them in the back seat or something so that it didn’t know they were in there… In the front seat as you stated there’d be no trouble.

The volt is a good all around vehicle, the 120 volt charger docking station included with the vehicle is just fine for most people, and it charges efficiently.

SCE’s rates will undoubtedly increase along with San Diego, since they’re co-owners of that San Onofre Nuclear Boondoggle.

I actually had the car lock up with the keys in the front cup holder last week. Odd, it never did that before.

The cost of a solar watt with batteries and inverter etc is less than $1 (one Dollar). How did these boys manage to sell it to you for $7.5k? If you store your electricty in even lead acid batteries it will make you independent of the grid completely and you can sell anything exrtra to the ones next door.

LOL, No. You can get PV panels for like 70 cents a watt . . . but when you add inverters, wiring, permits, racks, junction boxes, conduit, disconnects, grounding lugs, grounding wire, breakers, etc. then all the parts bring it to around $2/watt. And if you add installation then it can be $4 to $5/watt.

I have a 3.5kw solar system that cost $9000 out the door. Less than $3 a KW. I bought it from and they did a great job and were fast. I got them from Pedersen Dean. Best purchase ever. I save over $200 a month

Gents, I am in Cairo Egypt and I can buy the watt for as little as $0.3 Putting them on your roof in the USA and buying cables etc is a simple thing. You should be able to do it yourselves. The new grid tide micro inverters make it even simpler. a wire from each micro inverter will go in a box and from that box a single wire will go to the mains and that is it. No need for a larger inverter. No need for batteries. Nothing. It is plug and play. You will be feeding the grid and will get money back. I can not see how they manage to sell you the watt for more than a dollor.

Put in 6kW system for $3.61/W (before incentives and tax breaks and whatnot), which is pretty darn good. Offsetting our Volt plus some. Love it. California utilities must hate solar and net metering, but I think EVs may save them in the end. Just that the EV ramp is trailing the solar ramp so their pain will get worse before it gets better.

Yeah, solar is going to raise the price of electricity from utilities. We can’t cut down the natural gas capacity needed, because solar can go out, but solar will take away the kWh that the utilities sell. Therefore all fixed costs – capital, labor, maintenance, etc – gets amortized over fewer fossil-fuel-kWh sold.

And this is why the Utilities should push EVs like crazy. That will increase electricity demand. Especially from those solar customers.

What I really want to see is home builders getting serious and offering energy efficiency/solar/thermal/etc. The costs for these systems would drop dramatically when rolled out on as mass scale. Alas, there is very little incentive and high structural inertia in that industry (pun intended).

Some markets are considering changing the building code so as to make it much easier to add solar panels to the roof later. This is similar to requirements to wire for a future 240V EVSE in new construction (I believe already on the books in Palo Alto, CA). It would dramatically reduce the cost of future upgrades without requiring the new building to have the panels/EVSE installed immediately.

I think both of these need to be rolled out nationwide ASAP. We already have tons of old building to retrofit, why continue to add homes that will need expensive future work?

Hmm. Not a bad idea. But I’m not sure what else you’d need to do. Modern code already probably requires nice big main panels. I guess you could require a reserved spot for a back-fed double-breaker. If you require an AC disconnect and conduit to the roof, that would be great but that might be asking for a bit too much. Then again, compared to the cost of a house, it would be a tiny amount.

Except this guy has a successful solar installation, and he is using the plain 120 volt charger docking station included with the car. He seems to have no need for any additional EVSE’s. Last I’ve heard, only a minority of Volt owners have any additional EVSE’s. Myself, I just happen to have one available when my Roadster is not charging, or I’m running IT on 110 volts just to heat the battery. Some municipalities have special requirements, but most of the california ones have the avg priced house at $1million. Most of us don’t live in such upscale areas. The NEC requires the following ‘upgrades’ compared to 100 years ago. 2 – 20 amp appliance circuits. 1 – 20 amp laundry circuit. 100 amp 120/240 volt electric service. (Some utilities are recommending 150 or 200 amp services since the cost of the equipment has gotten very close to free, and you’re basically paying for the slight additional labor required). Other things required by the NEC are ground-fault protected outlets (although they do not have to be included in the service entrance capacity calculation) Bathroom Outlet Cellar General Purpose Outlet Front and back door outlet. Garage Outlet. One requirement that has… Read more »

People move around a lot in the US.
That makes investment in solar etc more problematic.

No, it really doesn’t. The value of the solar system will be reflected in an increased home sale price.

Not really. If you buy the system, you just add the cost to the house when you sell. If you lease the system, the new owner can assume the lease, or you can pay off the lease and add the cost to the price of the house.

I said: ‘More problematic’ not: ‘Impossible’.

The trouble with home improvements including solar is that you often don’t get back as much as it cost you, not to mention the hassle.

So if you plan on spending a long time in a house you do things that you don’t bother with if you are likely to be there for a shorter time.

Not to mention that the true economics of solar to less than wealthy people are very different to that which enthusiasts claim.

They never, ever include the interest cost on a multi-thousand dollar investment, which actually eats up most of the savings.

Well, one thing I will say about the sales pitch of solar was that they do all these calcs and assumptions that are all ‘pro-solar’ but don’t include the negative ones. For instance, on my install, the “payback” assumes (openly stated) an increase in price in electricity. But they neglect to include the increase in property tax that you’ll get with your new system, so factoring that in… not nearly as advantageous!

In California, adding a solar PV system is exempt from a property tax increase.

In Florida, adding a PV system is exempt from a property tax increase for 10 years.

” the system should produce enough clean electricity to save us about $55,000 in electricity bills over 25 years”

This number sounds quite fuzzy. He said that he paid $50/month in electricity after getting the Volt. $50/month * 12months/year * 25 years = $15,000. Even if you add inflation to that, I don’t think you’ll get $55K. I presume that the $55K number comes from calculating the gasoline costs saved since gasoline car fuel is much more expensive than electricity car fuel.

Yeah, the 6% annual expected increases in utility rates was also a choice by Solar City, in its promotional estimate. Without that, the savings go down significantly. Power rates tend to go up that much for 3-5 years, when utilities invest the “capex” to add some generation, here or there. It’s not a perpetual thing.

SolarCity uses a 6% annual utility increase number?!?! That is some seriously deceptive numbers. Electricity prices are notoriously stable and generally do not rise faster than inflation. These solar lease things are a rip-off for consumers.

Ah . . . I stand corrected. The article says that the electric bill INCREASED by $50/month. Thus if you go with a $100/month bill, it is $100/month * 12 months/year * 25 years = $30K. And with inflation, it will go higher .. .

DaveMart is exactly right on with his comment that people move around a lot in the US. Our system today requires individuals to finance solar on their personal credit. As people move every few years, it’s a capital expense that few want to make. People move, buildings don’t.

We need to perfect the model of financing solar as part of the buildings rather than the people, The building with solar will provide a lower cost of utilities and fuel/electrons foar all the inhabitants over the buildings lifetime.
We still are not there yet.

I don’t really see the problem here. Adding a solar PV system will increase the value of the home and thus you will actually get back your solar investment FASTER if you move.

I’m sure there are some home buyers that would be a little afraid of the system but you show people you zero electricity bill and they’ll see the value of the system. And grid-tied PV systems are pretty much zero maintenance. They just run by themselves. For years. Yeah, it would be nice if you clean off the dust now & then but you don’t really even have to do that except maybe once every few years. We have Mars rovers that have been running for over 10 years on solar panels and no one is service those systems.

Those rovers are amazing…the one got stuck near the pole in a dust storm and couldn’t get enough charge…pronounced to be defunct a few years ago. But the other is still working and collecting data after all this time!

And of course they have the new, bigger one, Curiosity, that is roving around sampling soils, etc.

Right there are two sources of national pride and human ingenuity…why aren’t these things bigger news? Then, the fastest vehicle ever built is the New Horizons probe that is a little over 4 AU away from it’s flyby of Pluto (launched over 5 years ago) – it will be the first to take pictures of the planet up close.

Too bad it will get there too late to take pictures of the planet. Pluto hasn’t been a planet in years 😉

Well Done! This is what I want to do. Planning to use the high capacity panels over the entire roof of the detached 4 car garage, and above the 2nd story master suite at the other end of the property. Which would offer more power than the home and full EV would need, and would pay back every month to make the lease payment. While having a 1 week energy supply storage battery on site for power outages. Which means the house would actually run off the energy stored in the batteries charged by the sun.

There was a guy on the Volt forums, DC Fusor, who was untied. Had Rolls Royse batteries, I think? Few do this. Unless you take issue with incentives, your state has to substantially lack them for the economics to work better than simply net metering, etc. Given that battery storage is lossy, an ultimate enviromental arguement can also be made that displacing peak day-time load is both more efficient, and apt to replace conventional power.

Besides, what kind of battery storage gets you through a week’s needs? ~100+kwh??

All you really need is solar panels and a VIA Motors VTRUX with the inverter option. 🙂

It’s so good to see more people joining the EV/PV club. We got our PV system in 2002 and shortly after bought our first EV, a Toyota RAV4, one of the now rare SUVs that turned out to be an amazingly robust EV. Most of them are still running like brand new. EVs rarely have problems.

I’ve driven over 130,000 miles on sunlight the past twelve years. It’s a terrific feeling, and gets even better when I don’t ever give the oil, coal or natural gas companies any of my money. The economic argument for EV/PV is powerful!

Paul, I wish more people thought like you.

Hi guys, thanks for all the great comments on my story. @Bloggin, glad you are thinking of driving on sunshine as well. Adding batteries and truly running on sunshine is a great idea, however it adds extra cost and environmental impact, and doesn’t allow you to charge at night super off peak and sell back valuable peak power worth 2-5 times as much. If your utility offers time-of-use rates I’d encourage you to explore this. @Spec9 – the article states the Volt increased our bill by $50/month, so that plus the house meant it was usually around $90-$100/month before solar – thus making the math not fuzzy at all, with the 6% annual utility increases 🙂 @ DaveMart – I agree on people moving a lot, however solar adds value to your house, so makes it worth more when you sell it. This article in Forbes references a study that found you recoup all the cost of the solar when you sell http://www.forbes.com/sites/ashleaebeling/2011/08/01/how-much-do-solar-panels-boost-home-sale-prices/ @kdog – not sure how she locked the keys in the car. I’ve never done it either but she has twice 😉

Ah, my apologies. Yes, at $100/month for electricity that does raise the number much higher. I will still pick on the 6% annual increase figure though, that is ridiculously high. The real number is more like 2% to 2.6%, IMHO.

Maybe CA is different…. Rates went up 5% in 2012, 6.3% in 2013, and 5.9% in 2014 http://articles.latimes.com/2012/nov/29/business/la-fi-edison-rate-hike-20121130

This is from a solar company, so might be biased, but they state California’s average has been 6.7%/year since the 70s…. http://www.pierrosolar.com/why/cost/historical-utility-rate-increases

Regarding the keys. As someone that designs controls systems, we always say “You can’t make it idiot-proof because they keep making better idiots” 🙂 (not calling your wife an idiot, just a saying).

Congrats! That load profile is a total inverse of the grid, and that’s really cool to see.

To some extent – there is a big power load, particularly residential, in the evenings from the time the Sun sets until somewhere around 10pm or later, local time.

Excellent clarification.
In many areas the air con has to stay on well outside of the hours when the sun is up too, or you boil.
Even on a diurnal basis, solar has problems in dealing with load.
Of course on an annual basis, things are much, much worse.

Michael,
Thx for the article. We love owner written articles here as you can see from the comments.

I have a Volt and a system very similar to yours and I love it.

but as Spec says it doesn’t work if the grid goes down so I have other sources of emergency power. I have had my system now going on 5 years. I have Enphase micro inverters that bake under my panels in the hot Arizona sun. I finally had one fail recently but no problem as enphase just did the trouble shooting over the internet and determined the micro inverter had failed and is sending me a new one in the mail and I will replace it myself.

Thx for the article.

Just have to admire the beauty of the Volt. Amazing front end. such a looker.