Second Year Performance Review

Monthly Solar Production 2019

Time to run the numbers again: let’s check out the performance of our solar system during year two. In 2019 we produced 6,764 kWh of power, about 7% less than 2018. Spring and Fall were noticeably grayer in 2019, which likely accounts for the drop. We consumed 2,300 kWh of the power we generated on premises and fed the other 4,464 kWh of excess power production to the grid for others to use.

At the 2019 utility rate of 15.33 cents per kWh, we saved $1,036.92 on our utility bills in 2019. Combine that with 2018 savings and after two years we’ve recouped 14% of our investment.  At the current rate in 12 more years we’ll have saved as much as we spent on the system. But of course the utility rates will rise during that time so we’re probably looking at 10 years or possibly less, depending on the rates.

July was the biggest month in terms of power generated in 2019, compared to May in 2019 (as I said earlier, gray wet spring). March was also a big month last year, which makes sense given the bare trees (one of our strings is partially shaded by oak trees in the morning) and the cold weather, which noticeably boosts panel efficiency. March is also the month when the sun’s angle is optimal for our 45 degree panel orientation.

So far, so good. Here’s to a sunny spring this year.

Electric Cars and Home Solar

Bud Wheeler inspecting the front battery bank in his electric car.

When I was 10 my grandfather built an electric car out of an old 1970 Volkswagen Fastback, a modest little two-door that was a bit bigger than the Beetle. This was 1977, shortly after the Arab Oil Embargo, when many Americans were first starting to think seriously about just how valuable alternative energy could be. It could make the nation less vulnerable to oil price fluctuations or supply shortages, relieve us of the expensive and hazardous burden of “policing” the Middle East to protect our oil supply, and cleaning up our smog-filled air (climate change was not quite on the public’s radar yet).

Rear battery bank in Bud Wheeler's Electric Car.
The trunk was filled with another battery bank and electric relays. This is the area where the explosions occurred: sparks from the relays ignited explosive hydrogen gas produced by the batteries.

Grandpa loved working on cars and took it upon himself to build an electric. He used 6V golf cart batteries for power and built the whole thing out of various commercially-available parts. At night he plugged it into an outlet in the garage, then drove it to work in the morning. It had a range of 45 miles. The thing that always struck me was how quiet it was.

Bud Wheeler's Electric Car
Bud Wheeler made his electric car in 1977 from a shiny black 1970 Volkswagen Fastback.

It had some issues, including the occasional explosion in the trunk when hydrogen gas produced by the batteries would accumulate in the confined space and  ignite when one of the relays sparked. But it worked well and was a real testament to Grandpa’s ingenuity and resourcefulness.

Plain Dealer Profile of Bud Wheeler's Electric Car
Published in the Cleveland Plain Dealer on October 27, 1977.

And now, 42 years later, my wife and I bought a production electric car–the Nissan Leaf. It’s remarkable how far electric car technology has come since 1977, although at the same time it’s also kind of remarkable that it’s taken that long for electric vehicles to begin going mainstream. But that certainly seems to be where things are going. Certainly any serious climate change solution will require a significant shift away from gasoline to electric vehicles.

Nissan Leaf
Our new 2019 Nissan Leaf can manage about 150 miles on a full charge.

We always figured an electric car would be a great complement to the home solar system–after all, who wouldn’t want to stop spending hundreds or thousands of dollars on gasoline every year and instead “tank up” with energy you generate for free at home? While cutting carbon  emissions at the same time?

The reality, though, is that charging an EV takes more electricity than your typical home system can generate. Our solar array is relatively large for a home system at 6.4 kW but even at solar noon when it’s cranking at capacity it will be close to maxxed out satisfying the demand of a Level 2 EV charger (240V/30A). It’s possible to charge with a Level 1 charger (120V/12A) but that takes much longer and is  less efficient (energy wasted as heat during the charging process).

EV charging
The charging port on the Leaf accepts two different styles of charger plugs–shown here is the Level 2 charger that came with the car.

Since we’re grid-tied, however, that’s not really a problem–we can charge the car fully during the day using all the energy we generate and the grid will supply the balance. It still saves quite a bit of carbon–even if we only charged at night, using strictly grid power, the car would produce only 96g of CO2e (carbon dioxide estimated) per mile versus 381g for a gas-powered vehicle (

EV charger
It wasn’t too difficult or expensive to permanently mount the Level 2 charger that Nissan provided with the car. You’ll need a dedicated 240 volt 40 amp circuit, which I installed myself in about 2 hours using about $50 worth of supplies. Just to be safe I had a licensed electrician look everything over after I finished the installation. This is mounted in an outbuilding that sits at the end of our driveway (a garage would be ideal but we don’t have one), so we just pull the car forward close to the building and attach the charging cable.

The big EV question, of course, is range…just how far will this thing take you before it poops out? Our Leaf has a 40kWh battery which Nissan says will average 150 miles (for $6K more you can get a 62kWh battery rated at 226 miles). We’re still testing and experimenting, but one thing that’s clear is your driving habits have an effect on your range (as do the conditions: wind, terrain, road conditions, etc). For example, the Leaf can actually regenerate power during deceleration–so rather than using your brakes when you pull up to a stop sign, you can switch “gears” and use the car’s momentum to put a little juice back into the battery. It also helps if you don’t drive like a 16-year-old boy trying to impress the girl sitting next to him!

Heating and air conditioning can also reduce your range–unlike a conventional car, the Leaf’s heat is entirely electric, so if you turn on the heated seats and steering wheel with the heating system on high, you’re going to drain the battery faster.

And the driving “experience?” That’s probably not the first criteria for most EV buyers, but the Leaf is no dog. Not exactly like driving a Porsche 911 (athough the chassis-mounted battery gives the car a nice low center of gravity), on the other hand it will get up and go when you ask it to and doesn’t plod up hills like a rented mule. I haven’t pushed it to its limits, but in everyday driving conditions–city, highway, or unpaved roads–it does just fine. You wouldn’t really know you’re driving an electric vehicle from the performance.

It’ll be interesting to see how it does in the wintertime. Cold temperatures reduce battery capacity, and I’m curious to see how it handles in slick road conditions with all-season radials (we may get snow tires if necessary).

It’s great to see electric cars coming into the mainstream–from everything I hear, they are the future and will be a major part of any climate change solution. Here in Maine EVs make up only 1% of vehicles on the road today, but that figure is growing. Rebates certainly help (between rebates offered by Nissan, the State, and the Federal tax credit for EVs, the price on ours dropped from $33K to $18K) but a lot more could be done to encourage people to buy EVs. Expanding the network of charging stations is key. Certainly as EV ranges increase with better battery technology, they will become more and more attractive to car buyers.

I wish Grandpa was around to see these new cars. I’d love to take him for a spin in the new Leaf! He’d be so impressed with how far things have come.

The Case for Consumer-Owned Utilities

Corporate logo

Many Maine electricity consumers struggle with a discouraging combination of poor service and high rates. Maine ranks dead last in the nation in terms of average hours without power annually per customer, excluding major storms, while residential rates are over 23% higher than the national average. By and large we simply pay the monthly bill and sigh. What can we do? For most of us Central Maine Power is the only game in town.

Lately resignation is giving way to anger and consumer action. CMP’s customer service fell to new depths beginning in the fall of 2017, when they bungled their response to a big storm in November that left almost half a million customers without power. That same autumn they also rolled out a new billing system without adequately testing and debugging it beforehand. That Christmas people started getting wildly inflated bills–we’re talking double or triple what they’d normally pay. Other customers stopped receiving any bills at all.

When people called CMP to find out what was going on–including elderly people on fixed incomes who feared losing their heat–CMP customer service representatives assured them that the bills were accurate and the reason for the increase was “abnormally cold weather” or “a faulty appliance.”

Before long thousands of people contacted the state Public Utilities Commission to complain, and a Facebook group called CMP Ratepayers Unite grew to over 7000 members.

CMP denied any problems with their billing system despite abundant evidence to the contrary. Eventually internal emails leaked out showing that, in fact, they’d been aware of issues from the start but management chose to sweep the problems under the rug.

It’s been a year and a half since the billing system fiasco started yet a recent investigative article by the Bangor Daily News indicates that many customers are still struggling with inflated bills–including seniors who’ve reported paying over $500 for one month of electricity rather than face disconnection. The Maine Public Utilities Commission–whose job is to protect consumers from such abuses–has effectively  refused to hold CMP accountable.

All of these circumstances combined have set the table for a consumer rebellion. The company granted a state-protected monopoly on delivering electricity has abused their privileged position so badly and so egregiously disregarded its own customers that a bill is now before the state legislature to have CMP “step aside.” A publicly-owned utility will buy CMP’s transmission infrastructure at fair market value and run it as a quasi-public entity (L.D. 1646).

If this bill passes–and it just might, despite the army of corporate lobbyists hired by CMP to swarm the legislature–Maine’s electric consumers will no longer have to deal with a foreign investor-owned utility prone to predatory behavior, and instead will have their electricity transmitted by a nonprofit publicly-owned utility. According to research done by the bill’s sponsor, legislator Seth Berry, the change would reduce annual transmission costs by 7-9%. More importantly, a consumer-owned utility would provide much-needed transparency and accountability to the system.

If enough Maine consumers push their legislators to back the bill, it just might be enough to counteract the corporate lobbying muscle being flexed by CMP Augusta. Here’s hoping it happens.

When a corporation is permitted to operate without competition in a highly-critical sector of our infrastructure with a guaranteed profit (CMP net was $130 million in 2017), and in return they degrade service and overbill customers, then that corporation has abused the privilege they’ve been entrusted with and must step aside.

First Year – Results

solar power generation by month 2018

It’s now been a full year since we installed solar at the house–time to look at the numbers and see how things went in terms of production and return on investment. While planning back in the summer and fall of 2017, we calculated our estimated production using the PV Watts calculator at the National Renewable Energy Lab. Turns out it was pretty accurate on the whole: 7,705 kWh for the  year, versus actual production of 7,250 kWh.

We used 2,418 kWh of that power ourselves, offsetting power we otherwise would’ve had to buy, and pushed 4,832 kWh onto the grid for other people to use. At the current rate of 15.59 cents per kWh, that saved us $1,139.26 in 2018, a return of 7% of our investment. In short, the system performed very much as expected.

It was interesting to see the variability in power production month to month. May was the biggest month overall, but we had an usually dry and sunny May here. One surprise was that December ended up being a bigger month than November, January, and February, which is surprising given the short days and low sun angle. But we had a lot of sunny days in December, and the cold temperatures help the panels work efficiency.

Here’s to an even better year in 2019!